That was a great demonstration, thanks. I had not seen that before. Really drives home the effect of bad power factor, with the wires needing to carry the (reactive) magnetization current, even if the load (real power) is small.
Thanks - glad you liked the demo! Yes - nothing like single turns to really make things like that stand out. Or for that matter toroid transformers which make it so easy to thread things though the core for a demo. I'm doing to do a future video about magnetizing current and power factor and also saturation and magnetic amps!
Excellent Demo! I suspect you saw this or a similar basic electricity and magnetism demo at the Deutsches Museum in München (Munich, Germany) Their AC and DC very high voltage demos are very exciting, too. The Science Museum in Earls Court (London, UK) removed their impulse generator demo. Also, the mercury-arc rectifier demo that powered the DC motors in the museum's passenger lifts. Pity, as a schoolboy these were the daily demo not to miss. There may be something similar at the Exploratorium, (San Francisco, California, USA) they had a "shorted single-turn secondary" coil filled with aluminium, it melted when energized, and solidified again as it cooled. Great hands-on demos to drive home the theory that comes later in college.
You got it - Deutsches Museum in München was were I saw it as a kid. And I will never forget the HV demo - "lightning" hitting a building, and the person in a Faraday cage. I actually looked on their website the other day and it appears that fabulous demo is shot down for the next few years while they renovate that part of the museum. Sad to hear about the Science Museum in London removing their demos (never been there but others had mentioned it). The San Francisco Exploratorium shorted coil demo sounds great. The museum that have real memorable demos like that are the best and are the one that get remembered. Glad you like this video - yes - a nice connection to the theory for anyone in EE or physics or with that sort of thing in theior future!
@@kanjo-Etienne Well if you mean what happens when a coil on the last toroid is shorted, yes - so that almost sets its magnetic field to zero, so now the copper linking the 2nd last to the last torroid is essentially a short and that works it wat back towards the first toroid. So other than resitive or other losses limiting things, yes.
@@ElectromagneticVideos another idea that came to mind is that you can stack 3 toroids together to have one, though with each still having its independent windings, then wind all three as one core. The central toroid acts as the input while the rest is output I did this back in 2013 with a mentor and had some interesting features
Thank you for making this experiment available, we built the device over the weekend and it works perfectly, with 3 x 5 watt lamps the copper pipe current measurement is 53 amps. It also shows us the relative phase angle between the voltage-in and the current at around 90 degrees out of phase a great demonstration.
Thats great - I'm thrilled to hear that! I would love to see a photo or video of your chain - could you email me one? Email on my about page. Or do a video? How did you bend the copper pipe? I found that the hardest thing to do was bending the pipe and only managed after buying two pipe benders (first one turned out not to be suitable). And even then they are not really made for 180 degree bends. Buy the way - you do know that the individual 120V coils on the cores are isolated so even if you use a gfci to power the chain, you will not be protected from a dangerous shock on those terminals if you put your fingers or anything else across them. For demo purposes it might be safer to run the chain at say 12V or 24V AC and use 12V bulbs ....
Thanks you! And even just a couple of toroid transformers by themselves with some some nice thick wire to thread through them would do. Nothing beats the hole in the toroid for making experiments easy!
Thank you so much! I am planning three more videos on this sort of thing. Two videos from now I will specifically cover transformers and how they work so stay tuned. You right. I do love teaching - years ago I taught university courses on topics like this and had great fun doing it. So making videos is going to be my outlet for doing a bit of teaching again :)
Thats! I am trying to figure out a second video video with the EM chain and that's an interesting idea. It might be interesting to try and see the propagation time from one end to the other and compare with a standard coax or Cat5 transmission line.
@@ElectromagneticVideos your chain is very interesting! You could measure current at each link by creating and adding "magnet wire" winding loops to each link on the chain, and feed each winding loop pair to an oscilloscope channel. The winding loops will measure current induced by magnetism, similar to how your chain works. My hypothesis would be 90 out of phase for each link. Such an interesting contraption. Thank you for sharing it with us
@@LydellAaron I like that - and maybe a bit more of an in-depth look at how wire loops (=loop integrals) work, and its hard (impossible) to directly measure the voltage of "half a loop". Your right about the current being 90 degrees out of phase with the input voltage (assuming no load) but the loops you suggest (assuming I didn't misunderstand your description) will actually show the value of the changing magnetic flux (the Faraday equation in Maxwell's Laws). What you describe would be correct if measuring coil (and hence the system) was essentially shorted as in a current transformer, but that's a different scenario (will be covered in a future video). I do have some clamp on current transformer style current probe's somewhere (=a current transformer) - might be able to use them to show the loop currents on the scope. Thanks for the suggestion!
Can you explain how the right hand rule can be applied to toroids. Also how does ti apply to the horizontal pipe? What formula do you use to find out the needed turns for 120V. ( primary). Can the turns overlap? Both in primary or secondary.? I am a physician, former TV repairman in the 60’s and early 70’s before medical school. Now I am having more time in my hand but still seeing patients . Doing a fast 40 yr catch up & having a hard time catching up… I worked mostly on Yagi antennas as an Extra class amateur radio back then. Also participated on the building of the first amateur radio satellite launched into orbit OSCAR 10. The previous ones were flown in balloons, private airplanes an even using a kite! More details if you are interested. Great lecture on Maxwell’s equations. Had a heck of a time in pre-med physics. My professors came to the conclusion I was missing a reverberating neuron network that must be crucial to actually understand Calculus! I just memorized the formulas and entered th numbers…got A’s and B’s without ever understanding what the purpose was!
So glad you liked it! I sure wish I had the HVAC skills you must have in bending the copper pipe - what job - I have new respect for people in your field. Glad you liked the demo!
@UniversalExpanse Because of the orientation of the magnetic and electric loops and their interactions being at right angles, at first glance it would have little effect other than the iron being less of a conductor. However, due to stray fields, you might get a bit of an interaction. But you got me thinking. Say you somehow made all the cores (both the electric and magnetic) ones identical - electrically conducting and, magnetically permeable like iron, and restive to eddy currents. You might be able to setup two flows of energy - one using the vertical toroids magnetically the other using the horizontal toroids magnetically . So each toroid would be the magnetic path for one flow and the electrical path for the other flow. Much like (circularly) polarized light. That would be a tricky but interesting thing to try, and for a longer chain, see if the their is crossover from say the vertical path the to horizontal.
A few science museums have a version of it. I saw it as a kid in the Deutsches Museum - a fabulous science museum in Munich. I'm certainly hoping that some science teachers may get some inspiration from the demos I am showing. Or for that matter University Profs in EE, Physics or similar fields.
Glad you liked it! But is really more along the lines demoing two of Maxwells classic equations - at least that's what I was hoping! By the way - saw your "Prague library optical illusion" - is that ever cool!
Yes - everywhere in the chain there is no ground connected current path. the purpose of the GFCI/Isolation transformer is to protect my fingers from the two terminals on the left coil where 120V AC is fed into - they are live. I could have covered them with tape, but I also wanted them exposed for other experiments.
@@ElectromagneticVideos Is the GFCI before or after your isolation transformer? Before the transformer, it will trip on a transformer primary failure. After the transformer, and it's unlikely to help (depending on leakage characteristics of the isolation transformer). On the other hand, an AFCI breaker would help protect against incidental differential circuit contacts
@@dl5244 You absolutely right - it will only trip if the isolation transformer were to fail. And there actually is an AFCI breaker in the electrical panel supplying that circuit. I don't think it is likely to trip (from arcing) because I suspect the isolation transformer's limited frequency response will remove much of the higher frequency noise used to detect the arc. The isolation transformer is the main safety device. The reason I mentioned them in passing in the video was to make sure anyone thinking of doing something similar would be reminded to use safety devices. I dont want to set a bad example by being reckless.
@@ElectromagneticVideos one thing that I didn't think you made clear was that an isolation transformer only protects you from touching a single potential net. Even a single finger toughing both terminals of the load bulbs would be shocking.
I have not seen it in a museum, but made something like a miniture version in an electronics lab. Only powered by a signal generator, and loaded with LEDs. We also added capacitors, and observed the effect using a CRO (a real one, not a digital scope).
Incredible! I'm so thrilled someone has finally reproduced and demonstrated this. Originally I had learned of this setup after taking a deep dive on Bill Beaty's Right Angle Circuitry webpage years ago. This was figure 10 on his 15 figure adventure towards mcoils and the proposed electro-electret (the analog of the electromagnet). Bill's articles, esp defining electricity have definitely been a cornerstone for breaking out of conventions and thinking more creatively. If one were to use high-mu materials and form wires, hairpins, or transformer steel laminations to stack a coil, what kind of analog magnetic circuits could we make, and most importantly, would we be able to make a functional electroelectret in the final figure 15? Thanks for the video, really enjoyed the presentation, style, and the thoughtful engagement with your viewers.
So glad you liked it! I first saw a china like this at the Deutsches Museum in Munich when we were visiting Germany when I was a kid years ago. Magnetic circuits are routinely used in the Electrical Engineering to from everything from from motors and transformers to hard drive read and write heads. Unfortunately due to the lack of a magnetic equivalent of an electron (and even if the magnetic monopole particle were ever found, it would not flow like and electron) you cant make magnetic circuits with the same precision and confinement as electrical ones. For magnetic circuits we are always limited to using good magnetic materials as you point out to manage the paths the magnetic fields take. But imagine a universe with not only electrical atoms but also magnetic ones with magnetic equivalents of electrons and protons. You could have magnetic circuits just electrical ones in every way. Of course no idea if you could create a consistent sent of physics constants that would allow such a universe to existing and life to form ....
@@ElectromagneticVideos Yeah its an interesting topic in physics, the magnetic monopole and whether it is a mathematical abstraction or an elementary particle. I do remember reading a paper from Bibhas De, a protege of Hannes Alfven where he provided some proofs on a theoretical Source-Free Magnetic Structure which seemed a bit more reasonable at the time. He had some other interesting propositions including transmaxwellian equations, magnetohydroelectric waves, and essays arguing the case that magnetic field has a co-located mass, and how one would go about building an apparatus to test it. However, I must say I have my doubts that a magnetic monopole or SFMS exist any more than a graviton, or dark matter does. Magnetic fields are the result of charged particles in motion, and can not exist without an electric current or time-varying electric field, much as a shadow cannot exist without something to occlude the light from which the shadow was cast. However, that's not to say that there are hereto undiscovered modes of EM phenomena or suitable transducers from which to detect and convey them. Thanks for response. I appreciated hearing your thoughts over the material constraints and practical considerations.
@@InfinionExperiments The intriguing thing for regarding mag monopolizes for me is Dirac's proof from 100 years ago that if mag monopoles exits, then electric charge must be quantized. Which it seem to be, but the reverse of the result is not true (ie no requirement if charge is quantized, monopoles must exist). I tend to agree with you - unlikely they do exist, but particle physicists still seem to be on the lookout for them and thats what keeps science interesting. Just looked at one of your videos - looks like some of the crazy/dangerous things I did a kid/teenager! I always find sparks and arc discharges experiments so cool. You can expect some comments! One of your videos description says you in BC - I'm in Ottawa but know BC well - my brother lives in BC.
@@ElectromagneticVideos Go team Canada! Thanks for the response. Yeah they are. One of the best sparky setups I put together was one I didn't catch on camera. I reproduced a Tesla Hairpin circuit which used 2 series HV AC tank capacitors with a parallel spark gap. The tank capacitors acted as a high impedance high pass filter, blocking the 60Hz high voltage while transmitting the mirrored current from the tank circuit that discharges through the gap. Large copper conductors connected the doorknob capacitors together. This other side of the capacitors exhibited really perplexing RF-like high frequency transmission line effects. I noted that dragging conductors across the hairpin generated sparking, not unlike what you'd see in a lighter flint. Connecting incandescent bulbs across the hairpin illuminated it brightly even though there was a thick shorted bar a few centimeters away, as the high frequency had potential differences at 1/4 wavelength nodes and antinodes, and finally, when connecting vintage incandescent bulbs that are partially evacuated, the illumination gave off a bright blue as the bulb no longer operated incandescently, and instead ionized and accelerated the rarefied gas that existed near the thin wires. It was the most fascinating high voltage experiment I had ever put together. Some had claimed the high impedance side was safe to touch, but I wasn't quite sure if this circuit was capable of causing tissue heating or possible RF burns. The circuit still today could have applications where 100W bulbs could be illuminated by thin wire, besides generally being a great tool for investigating high frequency phenomenon.
@@InfinionExperiments At the frequencies that got though to bulb filaments, its quite possible that the coiled nature of many filaments acted like an inductor and prevented normal current flow. Cool that the gas ionized and was visible! Your very right about tissue heating a RF burns - better not to test if its damaging to humans. RF isnt a great way to transmit power - too much leakage, hard to confine, and skin depth issues. But if you have plenty of space around a single conductor you can try using a Goubau line which are sometimes (but rarely) used for low loss RF signal transmission.
Thanks! I do try and respond to as you put it "almost every sensible comment". When I don't manage that, its usually the result of TH-cam that doesn't always notify me of new comments particularity when a bunch happen at ones. I do appreciate the time people take to comment, and I have often enjoyed some conversations back and forth.
Well Maxwell's equations are wonderfully symmetric in terms of the link from electric to magnetic fields and vice versa, and the chain demonstrates this nicely. If a magnetic monopole is ever detected, the equations would also be nicely symmetric in terms of magnetic and electric charge as well.
A decade or so ago I experimented with Joule Thief circuits that were popular at the time. I built several and strung them on a few meters of zipwire. Only the first JT was powered, the rest had their power leads shorted. With the zipwire closed in a loop every JT lit up. However the zipwire loop could be twisted up or bundled, it just had to pass through each JT toroid to light its LED. I discovered I could put 10s of toroids on it, each glowing as brightly as the first. Thanks for finally explaining the math, fascinating. 🙂
I had heard about Joule Thief experiments - I dont quite follow your circuit description but great that you got it working so well? Were you near HV power line or just from EM fields in a normal house? I have heard you can hold a fluorescent tube under a HV transmission line and it will glow - have got to try that sometime! I'm so pleased you found the math understandable in that quick explanation. Those two of Maxwell's Equations are so fundamental - and while I didn't mention it in the video because it was already getting too long - with one equation generating an electric field from a changing magnetic field and the other generating a magnetic field from a changing electric field you can image how even without magnetic cores and wires, create an electric field and a magnetic follows, and that will then create another electric field and back and forth slowly spreading out. And those spreading out fields are light, radio waves, x-rays, gamma rays, infra-red, ultra-violet etc. Maxwell predicted the speed of the waves entirely from the measured constants in these equations and people recognized that speed was the same as the measured speed of the then mysterious light. How incredible that light was suddenly explained and understood! More experiments on things like that to come!
@@OriginalMorningStar Very neat - actually it might be intriguing to try a Joule Thief sometime. There is actually of lot of stuff related to micro-power energy harvesting - usually from things like the bumpy motion of your body or a vehicle to power sensors as we become more and more wired. Actually a Tesla coil is something I have never built and and want to make one sometime. I have played around with HV quite a bit (see the Flyback video - one of the first videos I did). What a scary and a bit dangerous in the DIY example in the link is depending on the insulation to protect against the HV, Yeah the current is limited in a neon transformer but I wouldnt trust its limiting very much ....
@@ElectromagneticVideos Microsoft experimented with using lower-voltage modulation to transfer data between devices using the bodyfield. I found a patent filed long after I published my project, but I've never seen a real-world application. Did they try to swipe it? IDK, but I've got Prior Art... ;-)
The fields are not located inside the matter. The fields are outside of the matter. What you are describing is actually called the dielectric field. The electric field is the conjugate field created by the magnetic flux crossing the dielectric flux at right angles. What is going on here is quite a bit more complicated than described as the various coils and tubes are in close enough proximity for induction to occur between them. There is also self induction occurring. Overall good presentation and demonstration.
I'm so glad you liked it! Demos are always way more fun than just book theory - it really brings things to life. I have a few more magnetic demos planned including an all magnetic amplifier, so stay tuned :)
Yes - very similar! Are you an antenna guy? I have never seen an Austin transformer other than in photos. I don't think I would be comfortable on top of an antenna mast so I don't think I will ever actually see one :)
The Austin transformer is near the base of the tower. It is used to couple 60 Hz AC to the lights on the tower, while still isolating the base of the tower from ground at RF so that the antenna can be excited with the standard broadcast signal in the region from 540 KHz to 1700 KHz
For everyone wondering where I first saw a magnetic chain, on of you guessed correctly this afternoon: I saw it at the Deutsches Museum en.wikipedia.org/wiki/Deutsches_Museum , a fantastic science museum in Munich . If you are ever in Munich I highly recommend spending at least a day there! Other commenters thought I saw it in these museums: The Faraday museum in London, The Tesla museum in Serbia and The London Science Museum. Those museums are now on my bucket list - they all sound fabulous too. Just so everyone commenting knows - there is something weird going on with TH-cam comments right now - I get notified of your comment but if I click on it its not there. So my apologies to anyone wondering why I haven't responded to your comment or question. Same thing seems to happen with follow-ups to comments.
I'm so excited to have found this channel. Thank you! I have some binge watching/learning in my near future. I suppose this may be the opposite of your demo in a way (or relative position?), but it reminds me of Sir Lawrence Bragg's demo presented 5 min. into this video: th-cam.com/video/Vwjcn4Vl2iw/w-d-xo.html
@@natesgarage Thank you so much! Another commenter point me to Bragg's lecture as well. Yes almost identical EM chain! I watched the whole thing - wonderful to see such a historically great scientist give such a wonderfully clear lecture. I just subscribed to your channel - your physics demos are great!!!!! From the HV stuff to Faraday's 1st motor. And many demos I had no seen before! Are you a physicist? or an EE?
@@ElectromagneticVideos Thanks Peter! I’m humbled… I’m afraid I squandered my time at university learning finance, but I’m now on the right track; attempting to learn more about the universe. I’m also envious of your workshop - amazing! I like to think that I have a firm understanding of the Bragg’s demo but your slightly different demo has made me rethink my understanding. I thought the entirety of the magnetic field in a toroid was contained within the core of the torus ring (no magnetic field within the donut hole). Yet, a current is induced in the copper tubing. I’m not visualizing any magnetic field lines crossing the lines of current. The demos that contradict my understanding are the good ones - so thanks again!
@@natesgarage It probably more fun when you can experiment and learn the stuff at your leisure than having so many university course on technical topics at once that you dont have enough time to understand them as deeply as you might like at the time. The workshop was the result of recent (ongoing) renovations started just before covid so it was perfect timing in terms of when one might need a project to keep busy. Sometime I will do a video about it - and what I did right an wrong. Unexpectedly the best thing about it is the office style lighting - makes a huge difference. Your comment about Bragg's demo being slightly different. I often find sometimes one way of demoing something triggers my understanding while another may not - or sometimes a combination - there is nothing like two different explanations/demos/lectures etc to help with that. Yeah the bulk of the flux is essentially contained in the toroid core. The copper is around it - but somehow "knows" there is a certain amount of changing flux through the loop, even if virtually no flux "touches" the copper. Its a strange but very fundamental property of the universe - one of the few that is so easily seen. I have never liked the magnetic lines of force thing - and its not something we really use much in thinking about EM theory. I think its often discussed because you can "see the lines" with iron filings and "crossing magnetic lines" is somewhat equivalent to "changing magnetic flux" and maybe more understandable without calculus ... Send me an email if you get a chance - might be fun to collaborate on a video sometime!
7:00 You say that the power input is through a GFCI and an isolation transformer as if it actually means something. You do realize that as soon as you galvanically isolate the current path, the GFCI becomes useless? That means at best the first toroid is protected if you were to accidentally provide an alternative path to source (assuming you have isolation transformer to GFCI to the input of your demonstration)? IE if you were to accidentally touch both sides of any of the other transformers you could provide a path through your body and/or tools that would not be detected by the GFCI, and could potentially be lethal? To be fair you'd have to touch the other end of the coil, not something else that's grounded as I'm sure you didn't ground reference any of the coils. This is a really awesome demonstration otherwise and I'm certain you already know the above, but the way you pass it off as "oh yea its protected and safe" is dangerous to any inexperienced person that could try to replicate this experiment.
Yes - your not the first person to point this out. I was trying to get across that one should have some protection when doing stuff like this, with the isolation transformer or gfci being a possibility. I so happen to have gfci in the wall plug, but prefer the isolation transformer to prevent current flow rather than to stop it once started. And your right - you could get a lethal shock if two parts on other sides of your body (fingers on opposite hands) touch the two 120V terminals on any one of the toriods. A safer setup would be to cover the 120V outputs on each toroid and just use the low voltage ones for sampling voltage and hence flux strength. Glad you liked it otherwise.
The apparent symmetry between electricity and magnetism is a PSEUDO-SYMMETRY. Magnetic fields are actually the relativistic transformation of the electric field. This is seen more clearly in the RELATIVISTIC form of Maxwell's equations. Here, it is obvious that the magnet field is merely an electric field viewed from a relatively moving coordinate system. This is why the search for magnetic monopoles is specious.
Absolutely - but a bit beyond the scope of this video :) Magnetic monopoles - I had the impression that the particle physics types were still on the lookout for them although like you I'm not holding my breath in anticipation...
Thank you Bob! I just looked at your PV DC Arc Fault Detector video - what a great demo of how hard it is to extinguish an DC arc - and how well the DC arc fault detector works!
toroid 2 and 3 are just center cores and the winding dont matters.the light bulb will iluminate at the end only with ferrite or iron centers ,2 and 3, without wires ?it will work much smaller(the center around 15 mm?
Exactly! No need for the windings. I was thinking of removing the transformer windings of toroid 2 and 3 to emphasis exactly that, but I didn't because I didn't want to ruin the transformers in case I needed them for something else and also the light bulbs on the windings are a nice indication of whats going on the those toroids (particularity when shorted).
That was excellent, thank you for taking the time to make the video. I think I need to send this to a colleague who thinks that earth-bonding prevents (potentially hazardous) surface currents close to powerful HF transmitters. lol
Thank you! Funny - I actually do a lot of RF stuff in my day job (right now much higher frequencies although did a lot of HF 15 years ago) - one thing I know is that at RF frequencies, you can always get surprised at where currents and voltages are unless things are entirely enclosed. Highest HF powers I have worked with are a few hundred watts, but have heard for kw installations, a light bulb with a few feet of wire on each terminal can glow in the right location. Wouldn't want to be in areas where there is that amount of energy floating around!
@@BTW... I didn't say that earth-bonding is pointless. I was noting that even "connected" conductors can have a potential difference across them when subject to HF radio electric and magnetic fields. So tell me how a conducting antenna can give you a shock if one end is, necessarily, bonded to earth? And in answer to your second question, I fully subscribe to the 4/3 earth approximation for RF propagation. So I guess you could argue that I subscribe to "the slightly flatter earth" nonsense! lol
Never seen before? It's all over the place, every other corner of the streets has one. You can even change the ratio of the winding inside them to change the output voltage.
Those toroids are heavy. I used one of the same size to experiment with the Romer-Lewin ring, and holding four with your arms stretched must be tendon challenging.
Ha yes! that why I put it down right after the intro! And that was after a few tries at the intro too. I don't have time right now but I will have to watch your videos!
Yes! It would be even better if the copper pipe toroids were suspended in the center of the magnetic torried leavening a large air gap for kilovolt type isolation!
@@ElectromagneticVideos 40mm air gap clearance minimum between bar to bar and/or Earth at 1kV. All HV CTs are epoxy potted to meet isolation Standards. You NEVER EVER want to find HV in a metering or protection/control panel.
Its amazing how good Profs can make a difference. I was so lucky to have absolutely fabulous Profs in the various EM courses (I took all of them) and in Machines which included transformers. To this day I dont much care for Control Theory - hand an awful prof in the one course of that which I took! Glad you liked the video!
Thanks for the video. Here is an idea for video I would love to see: explain how current (measurement) transformer works! Typically a transformer is described in terms of how the ratio of primary and secondary turns change the voltage. And it is implied that this is more or less independent of the load on secondary side. So a transformer changes voltage. But then we find out that there are 'current transformers' that are used to measure current flow. AFAIK they are typically just a straight wire (one turn primary) going through a toroid and a multi turn secondary, And that somehow turns the transformer into a current transformer where the secondary current is proportional to the primary current. Explain that! How the heck does the transformer know what it is supposed to do ;) Ok, I think I know the answer but a video to walk through that might be interesting.
In this video he uses toroid stepdown voltage transformers that are of identical construction as a CT, with a 500:1 ratio. He does state that there are (maybe) 500 turns around the iron core.. and 1 pass through the hole. 500:1... get it? You could call them 2500:5 ratio too if they had a big enough hole. Pass 500A through primary (core) and connected to an appropriate instrument 1A will flow through the instrument at a low voltage. (5A if your pushing 2,500kA) The voltage is irrelevant. Current flow is the intended metering objective. The analogue meter movements are in fact millivolt meters configured as Ammeters directly connected to the CT's. The risk is when CT wiring systems go open circuit in the secondary windings or wiring to an instrument. They can have High Voltage across the terminals that can permanently damage the CT windings. NO fuses are found in any CT wiring systems. A minimum size conductor is specified and maximum cable run applies, because of the low voltage and low current. Specific wiring lugs are used to ensure no loose connection can disconnect, resulting in an open circuit. The wire jerkers soon learn proper CT wiring when they get an Inspection fail.. kinda low hanging fruit for testers. You can almost predict the chance of a fail by looking at the installer. LOL ALL Low Voltage (i.e. Under 1kV) Commercial / Industrial installation revenue metering CT's, provided by the energy retailer, come with secondary terminals shorted out at the CT terminals. ALL customer CT metering wiring into a control panel passes through terminals designed to easily short out the field wiring and disconnect field wiring to the instrument for servicing and calibration. All pissant scale LV Domestic customers have a power meter with the CT's inside the instrument case... so open circuit CT wiring is very unlikely unless tampered with. It gets interesting when dealing with High Voltage CT's, designed for 1.1kV to 600kV systems, but same ratio rule applies. I've only worked with up to 220kV stuff. The isolation between primary and secondary windings is of course a principal design factor with anything rated for High Voltage use... so there is no chance of 220kv appearing in a control panel. Stay safe now.
Glad you liked it! I am planning a couple of transformer videos - one on how a transformer REALLY works and one on current transformers. Its funny - you imply that the operation of current transformers is often misunderstood - and I think you are 100% right on that one. In fact doing some research for this video even showed that voltage transformers are often misunderstood. The current transformer video will most likely be 3 videos from now, and I usually post a video every weekend, so stay tuned!
@@Axel_Andersen Yeah - it really is amazing some of the misunderstandings - you know the one problem with TH-cam videos is the time constraint - too long and people stop watching. So we will have to see how well I do explaining things within a limited time!
That is way cool, I never would have guessed the induced current would be that huge. I suppose to transfer that much energy with only .22 VAC you need a but-load of current. Would you describe this as a chain where you have four 500-turn copper wire low-current high-magnetic links connected by three high-current low-magnetic single-turn copper pipes? What was the current entering the first stage from AC Mains? I suspect it is less than an amp.
Yes - its funny how its so outside of our everyday experience that you just dont expect currents that huge. Thats a fair physical description, but it is worth pointing out that the 500 turn windings in the middle have no effect = behave as if they are not there when not connected to a load so they really arnt part of the chain unless the something like the indicator lights are attached. Refining your description for the middle of the part : a chain of high-current-single-turn-copper-pipe-toroids and high-magnetic-field-single-turn-steel-toroids just to emphasize the symmetry between the electrical and magnetic links in the chain.
I'm of amateur knowledge in this and am trying to understand the part of your demo around 13 minutes in, after you short the coil. I know that a changing electric field causes a changing magnetic field, but, what does changing mean? Is it the speed, the position? Can you elaborate on that please?
By changing I mean the strength of the field is is increasing or decreasing over a period of time. So if the electric field is getting stronger, it creates a magnetic field. Same thing if it is getting weaker (although the field that is created is in the opposite direction). But no field is created if the electric field stays at a constant value. And the effect is symmetric in the sense that just like a changing electric field creates a magnetic field, a changing magnetic field creates an electric field. The changing part can be done as in our example by using a changing (AC) electrical current to create a changing magnetic field in the toroid,. In an electric generator in a power station, a magnet is moved (rotated) in relation to a coil to change the magnetic field in the coil which creates the electricity. Hope that helps!
@@ElectromagneticVideos thanks, it does help, one minor hiccup: what does it mean for the strength of the field to increase? is it more voltage, more electricity, or what exactly? Really appreciate it, knowing those particulars helps so much to grasp what's going on.
@@localverse Think of a regular bar magnet you may have played with as a kid. Some bar magnets can pick up heavier things because their magnetic field is stronger, others can pick up less because their field is weaker. In our case (as with more typical transformers) we create the magnetic field with AC current flowing through a coil wrapped around the toroid core. If the AC current goes from zero to a max value, then back to zero, then to a negative max then back to zero and repeats 50 or 60 times a second depending on where you live (60 for me). The magnetic field is created by the current through the coil and its strength (just like the bar magnet) depends on the amount of current flowing. So when the current is a at max, the magnetic field is at max = like a strong bar magnet. When the current drops as it goes to zero, the magnetic field drops, so the field is now less than it was, like a weaker bar magnet. The ere a more detailed explanation in th-cam.com/video/sc9nqxIfwlA/w-d-xo.html . In December I will do an electromagnet video and a bar magnet video which also may help ....
Pretty cool! Even though the magnetic fields are completely contained within the ferrite toroid, the right hand rule shows that the electric field causes the copper coils to conduct electricity. Did you see it at the Faraday museum in London?
"Even though the magnetic fields are completely contained within the ferrite toroid, the right hand rule shows that the electric field causes the copper coils to conduct electricity." Yeah - is really neat to see that in such an obvious way - usually the "next to each other" nature of inductor and transformer coils and coils makes that hard to see. The funny thing is a number of commenters don't seen to think this demo is real - I guess they must think Maxwell's equations are wrong :) Museum: That's the second museum in London that has been mentioned, but no - right continent though but not in the UK. I'm starting to make a list of museum that have been mentioned and will post it. I'll; bet the Faraday Museum is fascinating to visit!
This is a very nice demo and nice explanation. I do have to take exception to one part of the explanation, however. The voltage you measure across the closed copper pipe loop is not the voltage in that loop but rather is the voltage induced in your measurement loop. The voltage shows up at the meter because it is the high impedance part of the loop. The rest of the loop, being made of copper, is very low impedance so the voltage is not there. The resistance of the copper pipe is so low that even when supporting several amperes of current, the voltage is tiny. The current in the copper pipe loop produces its own magnetic field by Ampere's law, and this field spreads through the space surrounding the pipe. This field opposes the net field of the two toroids through the loop, and is just enough to make the net field (the integral of the magnetic flux, B, over any surface bounded by the loop) essentially zero, by Faraday's law. Faraday's law works in both directions: the shorted turn of copper pipe forces no voltage around that loop which means there is no net changing magnetic flux cutting through a surface bounded by that loop. This doesn't mean that there is no changing magnetic flux, but just that there is as much flux overall in one direction through the loop as there is in the other direction. Some of the magnetic field produced by the high current in the closed copper pipe loop also links through the measurement loop formed by the meter, its leads, and both halves of the copper pipe loop. This field induces the voltage displayed by the meter. You can explore this by making a magnetic field "sniffer" loop of insulated copper wire connected to your meter. Twist the outgoing and returning wires together except at the far end where the wire is formed into a loop. Use the loop to sniff out the flux in and around your setup. If the loop is formed while linking through a toroid, you will see a significant voltage. When the loop is just formed in the air, it is sensing just the magnetic flux in that part of the air. Without the closed copper pipe loop in place around the toroid, you will see only a tiny voltage outside the toroid because the material in the toroid is containing almost all the magnetic flux. With the closed copper pipe loop in place, you will see some voltage when your loop is in the vicinity of the copper pipe, due to the large current in the pipe producing its own field. Another test you can do is to remove the shorted closed loop and form a new closed loop linking your toroid but make the loop out of two leaded resistors of different values, say 1000 and 3000 ohms, with the leads soldered together at the ends. This loop will have only a small current (and thus a small induced magnetic field) due to the high resistance. Then use your voltmeter leads to look at the voltages in the different parts of the loop. You will find that the voltage across the 3000-ohm resistor is just three times that of the 1000-ohm resistor and the voltage along either of the wire leads spanning between resistors is virtually zero. The induced voltage shows up in proportion to the impedance. If instead of the voltmeter, you use an oscilloscope that is triggered by the ac line, you can verify that the instantaneous voltage is in the same direction in both resistors, so that the sum of the voltage around the loop is non-zero, in accordance with Faraday's law. (Some people have argued that the voltage around the loop must be zero in accordance with Kirchoff's law, but this test shows that Kirchoff's law is not applicable in this case due to the changing magnetic flux passing through the loop.) 🙂
Glad you liked it Analog Guy! Its always hard to have a discussion like this in a text only format, so let me try and tell you where I am coming from and where I think we differ (and if I get that wrong my apologies). So I think we agree that the meter reads about 0.2V when attached to the two sides of copper loop. I just did one measurement you suggested: One meter lead though one of the toroids in the chain, other outside the toriod and connected together, effectively a transformer winding with one turn. The result: same voltage 0.2V. And just to prove this is not influenced by the copper pipe loop: same test on an identical transformer not part of the chain and nothing attached: 2v measured. So 0.2V is the one loop voltage of that toroid transformer. Where I believe we differ is you say the copper loop is effectively a short. I respectfully disagree - is not! It is not because it is a one loop transformer winding for the next core which creates its own inductive back emf. Consider if instead we had a 10 loop coil around the first core attached to a 10 loop coil around the second core. That would not be shorted: the first coil would produce about 2V which would be applied to the second coil. That second coil would draw a current to generate a 2V back emf. If we measure the voltage where the two coils are connected, we would see 2V - the voltage from transformer action in the first coil and also the (necessarily) equal voltage from the second coils back emf. Now do the same taking away 1 loop from both coils so now we have 9 loops in each coil. All the reasoning is the same but we now have 1.8V where the coils connect. Repeat and repeat till you are down to coils of one loop - which is exactly what we have. Your right about Kirchoff's law being stymied in loops like this - the fact that the loop itself is a voltage generator along with every component in the loop really does a number on Kirchoff! So what do you think the voltage is if I attach the voltmeter leads to two sides of one of the copper loops, but this time at the points inside the toroids? (ie move 90 degrees along the loop from the measurement position shown in the video)? Answer: 0V. Thanks so much for the comment! I really appreciate it even if I disagree :)
@@ElectromagneticVideos OK. Thank you for your response. I believe we can reach full agreement. I agree it is hard to communicate clearly when using just text. I indeed agree your measurements are just as you state. I agree the voltages you measure as you move down the chain go up and down in proportion to the number of turns, taking into account a very-slight loss as you move along. I agree about the back EMF from the other cores and the voltage being proportional to the number of loops of wire. I think you and I will agree that you have essentially created a cascade of step-down, step-up, ... transformers. Please try the following: With your chain of cores and copper loops energized, first touch the tips of your voltmeter probes together, away from the setup. You will of course see zero volts. Keeping the tips together, touch the tips to one spot on the copper loop at the beginning of the chain. I think you and I will not be surprised to see the voltmeter continues to display zero volts. Now, keeping the tips touching the loop, gradually slide the tips apart along the loop. I expect the voltmeter reading will continue to be very near zero, perhaps increasing slightly due to the loop current acting on the small but finite loop resistance. (I think you and I will agree that if the loop were made of a less-conductive material such as carbon, that you would see a more rapidly increasing voltage.) Keeping the tips in contact with the copper loop, continue sliding the tips apart until you can go no farther due to the blockage by the cores. Continue to slide one of the tips as far into the hole in the core as you can go, keeping contact with the loop. I expect the indicated voltage will still be very low. Make note of the point where the tip touches the loop. Now remove that tip, move it over to approach the loop from the opposite side of the core, and again touch the loop at the exact spot as previously. I expect you will now (magically? but not unexpectedly) see the voltage jump up to your figure of about 0.2 volts! Yet you are probing the same exact spots on the copper loop. Can we agree that absolutely nothing has changed about the copper loop? Yes, I hope so. Can we agree that the only thing that has changed is the configuration of the measurement loop? Yes, I hope so. Now the measurement loop links around the magnetic flux in the core when previously the measurement loop did not link around that flux. Thus, we now see a voltage at the meter. This voltage is induced in the measurement loop. Since the probe wires are also made of copper and the current in those wires is very small, the voltage in those wires is very small, just like we saw for the big copper loop. Virtually all the voltage appears at the meter since that is the high resistance point in the loop. You can approximate the carbon loop by soldering any convenient number of leaded resistors together, forming a loop around the core. Now by probing at different points around the loop (being careful not to form a loop around the core flux with the probes), you will find voltages across each resistor in proportion to the resistance (due to the uniform circulating current, i, times r) and you will find virtually no voltage across each lead wire interconnect because the wire interconnects have virtually no resistance as compared to the resistors. Once again, if you add up all those voltages, they will sum to the voltage produced by connecting a wire from meter terminal to meter terminal while looping the wire through the core. All this is to say that Faraday's law applies. The integral of the electric field around the loop is equal to the negative of the rate of change of the net magnetic flux surrounded by the loop. Since an excellent conductor cannot host an electric field, the voltage shows up in the loop at the points spanned by higher impedance. I think the confusion that arises for many people (including myself) leading to the claim that voltage is induced in the wire is due to the way we model the situation. If we are going to use a transformer in a circuit, we want to know the effect of the transformer on the rest of the circuit without having to concern ourselves with all the construction details, materials, and physics such as Faraday's Law inside the transformer. Thus, we replace the internals of the transformer with a model. In the model we ignore the flux and cut the wires and insert ideal dependent sources. (And if we want a really good model, we also optionally add some ideal inductors and resistors to handle the magnetizing current and voltage drop.) These models lead to the very convenient outcome that we can use Kirchoff's laws to set up loop or nodal equations to solve for all the voltages and currents in the rest of the circuit. With a good model, these calculations predict very close to the same result in the rest of the circuit as the real thing. Thus, we tend to begin to believe those sources are really there. In the same manner, let's consider a transistor model for instance. We know it does not include all the detailed geometry, materials, doping, and quantum effects in the real thing, but our model using common idealized components including dependent sources is a convenient means of being good-enough for circuit analysis and simulation. Rather than saying voltage is induced in the wire, we should say that voltage is induced between the ends of the wire, or between the turns of the wire. Per the Maxwell-Faraday law, there is one sum of the electric field around any closed loop. The field won't add up along the length of the wire because we know that the tangential component of the electric filed is zero adjacent to a good conductor. So the field (and the measured voltage) shows up in the gap between the ends of the wire, or between turns of the wire in the case of a solenoidal winding. So I have to say the copper loop is still shorted when it links two cores. Indeed, the magnetic flux in the second core is in a direction opposing the flux due to the first coil, such as to produce a reverse EMF that largely cancels the EMF of the first coil. The remaining net EMF is much smaller than it would be without the second core, leading to a much smaller circulating current in the copper loop. Any voltage measurement on the copper loop will produce only a tiny voltage, unless the measurement path encircles a core. I hope all this makes sense to you and may help to resolve any apparent differences.
It is just resembling electromagnetic transformation, it is magnetic transformation only. All windings are in the same orientation, there is no electric field involved. Besides this, there are heavy losses, because the magnetic coupling is not ideal, this will get warm after some time.
Great demo thanks! I just have one question - when you measure the voltage "across" the secondary pipe @5:49 shouldn't you have to open the pipe connection? You are measuring across a short basically, no? Ok we're dealing with AC here and IxR losses here so maybe this is correct for a "1 turn winding". Thoughts?
Thats a great question! It would be a short if there was no second core that the pipe is going though. Even then it would not be a good short but more like a resistive load because so much power is available at 0.2V that 800A or more will flow though the loop being limited by the (tiny) resistance of the loop of pipe. BUT - what is deceptive - just as the loop is a 1 turn winding around the first core, it is a 1 turn winding around the second core, becoming the primary of the second core at the same time as it is the secondary of the first core. Being the primary of the second core, means the 0.2V generated by the first core is applied to the primary of the second core (applied being used loosely since it is the same wire loop). Now just forget about the first core and consider that the 0.2V is applied (from some unknown source) to one loop though the second core. The AC current that flows increases until the magnetic field it generates creates a voltage equal to exactly the the applied voltage (OK its instantaneous but its easier think as if it increased till equilibrium is met). This sets and limits the current that flows - the magnetizing current - and so its not a short, its an inductive load. So that inductive load nature of the loop though the second core limits the current and so is not a short. If that still isnt clear, trying thinking out it with ten turns around the first core attached to ten turns around the second core. Once that is understand able, take away one turn and the principle is the same. Keep repeating till there is just one turn left and all you have the single loop though both left. Does that help? If not I can try again!
Great video ! thanks . I made a similar object with a big ferriet ring and hi frequency , it was a design of my friend who is teatching me electronics , unfortunately I dropt it and the core broke , but this is a nice occasion to rebuild it , and show it on TH-cam
Thanks! Too bad about dropping the ferrite ring. Sadly they are rally brittle. Would be great if you did rebuild it and made a video - I would love to see that!
Then we would have almost perfect, losses coupling between the cores and the device would behave much more perfectly. An example of perfect behavior would be the if we put a superconducting shorting wire through the most distant core from the power source, the shorting wire forces the the magnetic field in that core to zero as if the core was not there. That means no back voltage from that core to the superconducting copper pipe to the next core. With no back voltage that copper pipe now is a short and the magnetic field in that core is forced to zero. And so on all the way back to the core attached to the power. And with no magnetic field in that core, a huge current flows from the 120V source eventually melting something. In a much better scenario, in normal operation, we would have close to lossless transmission of power other than eddy current and hysteresis heating in the toroids even for larger currents. Right now with plain old copper pipe the resistance starts consuming more and more power as the currents go up limiting power transfer from one end to another to between 50 and 100W or so. The transformers used as the cores are rated at 180W so its much less than one would like. Even copper rod rather than pipe would be better.
I saw a video about magnetic current, if I remember it was something that Ed Leedskalnin did at Coral Castle. It is thought that the chain links transferred magnetism but it didn't have the torroidal transformers like you have here.
I had never heard of him or Coral Castle. From a quick read, sounds like he was on the fringe of science for lack of a better term. Also so interesting reading about people like that. If you do come across the video you mentioned please post the link! Magnetic current - do you mean with magnetic monopoles being the magnetic charge carrier much the way electrons are the charge carrier for electrical current? I was musing about things like that after making the video. Sadly magnetic monopoles are so scarce and if they do exist (or are created in a particle collider) there wont be enough to make an appreciable magnetic current for experiments. Also they are predicted to be way heavier than electrons. I was pondering if one could construct a consistent variant of the standard particle model for some alternate universe where magnetic charge carriers are identical to electrons and you have electric and magnetic antiparticles of each other in true symmetry. Maybe with electric atoms like ours but also magnetic atoms with the magnetic equivalent particles. I guess thats something for the mathematical physicists to tackle! And yes = "1:1 ratio with current being converted to magnetic flux and that flux being converted for the next link and so on and so forth" is the perfect description!
@@ElectromagneticVideos When I say magnetic current I mean as in passin a current though a coil, then a chain link passes through that and then that link goes trought the next and a the next until you have the desired length. Finally the last link goea through a second coil so current can be drawn from it, or I think that's what the narrator was trying to get at anyways.
@@ElectromagneticVideos What I do know is it was part of the perpetual motion holder, the Leedskalnin wheel and lifting heavy objects and transporting current from one place to where ever else in Coral Castle.
Instantly! Or at least to the human eye. If it was unloaded (no light bulbs) there would be a little "ringing" or at least a voltage spike/decay for a few ms as any energy stored in the magnetic fields dissipates as heat in the iron and copper.
It would be nice to know the accumulated delay through all the toroid's. I mean how many stages are needed before the final load starts to decrease the input current rather than increase it ? Thank you for this interesting demonstration.
I'm not quite sure what your are asking - is it how long it takes before the input "knows" that that a load had been connected at the other end and the input current increases? The speed of the effect of the load reaching the input is the speed of light in the medium. In this case its a lot like an electrical transmission line (such a 75 Ohm coax line feeding a TV) where the internal speed of light is often around half that of what it is in air. Here we have lumped elements and relatively high inductance's so its probably somewhat slower. Lets guess a speed of 0.1 x the speed of light (299792458 m / s ) and the length of the chain is 0.5m. So that works out to 17ns. Assuming the AC power is clean enough going in, I should be able to measure that with an oscilloscope. I'm planning a transmission line video - measuring the chain might be an interesting addition to that.
@@ElectromagneticVideos Yes thank you for reply, that is exactly what I was wondering about. The input has to travel thru the chain to reach the load but a secondary signal has to traverse back from the load to the input again, in order to affect the input level. So the delay would be doubled I guess. As you implied probably insignificant at 60Hz. I'd love to see a purely magnetic oscillator built on your chain approach maybe loses are too great?
@@smokyatgroups You have to somehow inject energy to make up for the losses but if you did that you could make an oscillator with a frequency of 1/(round trip time). The other problem is it would be a very high frequency which generally doesnt work well with big things, so a very long chain of small loops might make it possible, and somehow use some non-linear magnetic effect to inject power from an external source.
Also demonstrates why you NEVER bolt to both sides of a metal case through a toroidal transformer, as it would create a shorted turn. That isn't a shorted turn, as it forms the secondary of one transformer and the primary of the other
It's scary that you allowed the 3rd and 4th bus bar copper coils to touch. 😳 I have a serious uneasiness of bus bars/open conductors, as a datacenter I used to work at vaporized a 3ft section of a 1Mw bus bar (yes, 1 megawatt) and there was a green, red and black stain on the ceiling above where the bar was.
Its actually not an issue in this case: maximum 0.2 volts potential so less than a one cell battery, and low enough that the natural resistivity of the copper limits the current to about 800A (=max 160W) so no vaporization here. And no issues with them touching - each loop is a self contained circuit so no current path if if they touch. A 1MW bus bar - wow - I have never seen one of those - I dont work in high power stuff. I can imagine it must have been like when you see videos of pole transformers explode.
@@ElectromagneticVideos basically. I don't work with high power stuff either, I'm a systems (Linux) engineer. I do know that we had a 1 week outage on part of our datacenter floor, and that one of my coworkers near the bus bar in question when it popped apparently soiled himself a little bit. Great Channel BTW, subscribed.
@@ElectromagneticVideos I've worked in the Generation/Transmission sector. 1MW bus is kinda small. A single 4" x 1/4" Copper bar will do that easy. Last job in that field was modifying Cat diesel Gen control panels and the relatively short 3 phase Bus, really just connection flags rated at 1MW each... 3 units went to a new hospital building locally. 2 in Emergency Service with 1 standby. The largest DB I made used 3x 5" x 3/8" per each 3 phase - main bus feeding bus ties and several outgoing 2,400A @ 415V circuit breakers. There was multiple stacks of 250A Combination Fuse Switch units too. It was all 60kA fault rated. Parallel bars require spacing between bars equal to bar thickness. There is a significant amount of design consideration for the strength of bar mounting to resist any fault forces as well as meeting the required mechanical strength at the CB bar connections so that the CB's can achieve their true Fault current rating. I can say it is impressive to see the resulting metal spray applied in microseconds to brick walls after a very serious high current fault occurs that melts 3x 1 metre lengths of smaller single 3" x 1/4" main busbars. Up close you see lots of interesting colours and textures from the curious hybrid alloy of Copper/Steel/Tin fused onto a brick/concrete substrate. The explosion tore off 2 heavy fire doors to the main switchboard room... but not a single wire reo glass louvre window pane was damaged. The fault was huge because the factory was located next door to the Major city sub-station... being the origin of the LV short cable run to the fault. A huge huge prospective fault current presented, despite the correctly rated 800A fuses. Grid engineers estimated the fault was in the100kA range. That night most of East Coast of Australia suffered hours of blackout due to that one faulty main DB. 95% of the major and minor subs went into a cascade protection fault scenario. If a 350MW base load power station was connected to The Grid it was dumped... each one that dropped triggered another to drop. Same thing happened to suburban HV distribution sub stations. Even backwater country towns went down. That night the Grid came within microseconds of loosing synchronisation between all Power Stations. It took hours to get it all back online. Can't blame a DIY idiot for that... the mingy stingy building owner... perhaps.
As someone below pointed out (so I'm not claiming to steal their idea) you could use small ferrite toroids and small copper loops if you ran it at higher frequencies and have it really look like a chain. The higher frequencies make it possible to transfer more energy with smaller magnetic cores which is what happens inside switching power supplies in all our electronics today.
Hmm, interesting, I argue that everyone has seen an electromagnetic chain, we just don't think of it as one, The power distribution system itself. power plant to substation, substation to substation, to distribution transformers, to our very home.
I was just going to comment this. GSU transformers, substations, pole pigs, old school wall warts&MOT’s are all this, just with different impedances and multiple smaller transformers in parallel. And then there’s motors and generators which are the same except the bulk of the power is in the motion of one winding instead of the wattage in it…
@@deltab9768 Good point about motors - particularly induction motors - really neat the way the rotor currents are induced from the stator by transformer action.
I never thought of that, but that's absolutely true. we tend to take the convenience of electricity for granted, but without many of the famous inventors and scientists who lived in the 1700s and 1800s, namely Michael Faraday, Greg Ohm, Nicola Tesla and Thomas Edison, to name a few, we would still be lighting our homes with kerosene and whale oil. Quality of life as we know today, would not exist
Found the following version about five years ago, film from 1965... th-cam.com/video/Vwjcn4Vl2iw/w-d-xo.html Rats, I thought *I* invented it first! But Lawrence Bragg was already using those for his lecture demonstrations forty years before me. I came up with the idea myself in 1989 as a physics exhibit for science museum. An AC transmission line with no circuit, just EM waves alone. Showing people that "Electricity" is not currents or electrons, because the energy-flow in circuits is electromagnetic. The utility companies are selling us some e-fields and some b-fields, at right angles. Radio waves, but at 60Hz. Then finally was able to build one in 1991, from some iron C-cores I found in a surplus store, plus some thick aluminum rings! No coils on the chain, just purely lam-cores and rings. My driver was a 300 watt soldering iron, with a loop of #10 solid copper wire in place of the soldering tip, to put out about 800amps. At the output end of the chain, I had about ten turns of hookup wire, driving a small 3V bulb. I did put up a crude drawing on my website, in 1999, figure 10 in "Right Angle Circuitry"
Sure it's powered through a gfci, but any of the 120 volt windings after the first and even the first one if you say it's on an isolation transformer, could kill you. A GFCI doesn't actually make this any safer. Now because it's all run through an isolation transformer, you could hold on to any one wire and stand barefoot on the floor and it shouldn't get you killed theoretically. Overall though excellent video and I plan on sharing it with people. Keep up the good work.
So glad you liked it - the main purpose of the GFCI/isolation transformer is to protect me if I touch the input terminals. And yes - all the GFCI would do is help if the isolation transformer failed (unlikely). The GFCI is in the wall plug - I mentioned both simply to remind anyone doing this to be careful and protect themselves. Also to your point if you touch both the 120V terminals on any of the transformers you will get a full strength , dangerous 120V shock. The toroid transformers I used also have a 30V winding, and for safety and perhaps for someone doing a classroom demo, the better idea would be to use 30V lamps and power everything from a 30V AC source.
@@ElectromagneticVideos the video really was very good, my comment was just so that someone doesn't misunderstand and think that they couldn't get a full voltage shock anywhere down the line without the GFI getting tripped. What you showed about the magnetizing current makes sense, I had never really thought about that before. It's pretty cool to see how it piles up.
@@chadhiggins8397 Its always good to point out how to make things safe or safer - and I appreciate that! While making a video you don't always remember or think to point out everything or give the best explanation. If you liked the magnetizing current bit you might like the next video which I'm editing right now - hopefully published later this evening or tomorrow morning.
It actually was the Deutsches Museum in Munich. But a few others had also guessed the Faraday Museum in London which I didn't know about. So that's definitely now on my list of places to see next time I am in Europe! Thanks for guessing!
Please explain how it is that you are able to touch the copper loops without a shock. Also, how is it that you were able to measure voltage on a single single copper loop? Also, how is it that the copper loops can touch each other inside the iron toroid without causing a short? This demonstration makes me feel less informed, not more informed. It’s very enjoyable. But I don’t understand how you have so many praising comments and no dumbfounded ones. ☮️❤🌈
The thick copper loops are 1 turn windings around the toroidal magnetic cores. Because its only one turn, the voltage generated across the one turn is low - just over 0.2V (the input coil where 120V is attached has 500 turns with the same voltage per turn). So with only 0.2V across one of those loops, thats less voltage than a typical AAA battery and no chance for a shock. How was I able to measure the voltage of a single loop? The voltmeter and its leads becomes part of the loop so even if I connect it to the half way part of a loop, it completes the loop. In this or another video I even just loop the voltmeter leads though the hole in the core to see the 0.2V. How can the copper loops touch with no short? Well each is an isolated circuit - electrons always have to flow back to where they started - so if the loop is touched at some single point there is no way back for them so no current flows from one loop to another. I'm glad you liked it but sorry you found it somewhat unsatisfying in terms of explaining things. I'm always faced with the dilemma of a widely varied audience online - how much explanation to include? The one thing I can suggest is look though the comments - many aspects of it have been discussed and may shed some light on how the EM chain works.
@@ElectromagneticVideos to be clear, nothing derogatory was intended. I never lose sight of the fact that content creators or me nothing. I just wanted to voice the minority opinion that I presume others are embarrassed to admit. As an autistic, I always look back on my statements and wish I had toned them differently. But I have also learned that mortals want me to limit my words. It's a tough balance. Thanks for the reply! I'm really enjoying going over your back catalog. ☮️❤️🌈
@@RichardBronosky I hope I didn't seem to imply I thought your comment was derogatory - if I did apologize. My last paragraph was just to let you know where I am coming from in terms of finding a balance of explaining too much or too little. I thrilled you liked it well enough to look at other videos I have posted and if you have questions I am always happy to try and answer at least as well as one can do typing text and without pen and pencil to draw things.
Well general principle shown here is the interaction of electricity and magnetism which is used in generators, motors, transformers etc. But more specifically a transformer made out of loops that are help so they don't touch are used in radio transmitter towers as one kind commenter pointed out - take a look here: en.wikipedia.org/wiki/Austin_transformer
Interesting contraption! But your explanation left me in the dark. What's the overall power loss and power factor? Do the toroids have multiple copper windings (other than the one with 500 loops)? There's two pairs of connectors on each, so maybe? If the windings of the two middle toroids are left open circuit, do they affect anything? Would it be like having a ferrite torus with 1 loop as primary and 1 loop as secondary and nothing else? So a 1:1 transformer?
Yeah - unfortunately to keep videos like this to a length that people will watch there always is a compromise between how much detail and how long it can be. Let me try and answer your questions: The overall power loss when unloaded (no light bulbs) was measured to be about 7 watts. The bulk of that would be core loss - heating in the toroids from eddy currents and hysteresis - more more on that in a future video. The restive loss in the copper pipe loops is minimal due to the low currents in them relative to their resistance. Each toroid is actually a transformer with 4 windings: two 525 turn windings (120V) and two 130 turn windings (30V) intended by the manufacturer to allow 120V/240V in and 30V/60V out depending if they are in series or parallel. I added the two pairs of connectors each, one for 120V (the two 525 turn windings in parallel) and one for 30V (the 130 turn windings in parallel). If they are left open (no load) they have no effect (no current flowing though them) and its equivalent to simply a magnetic toroid. I was debating whether I should remove the windings from the center cores to make that point obvious, but decided to leave them because we can use them to show whats going on in each core with the little light bulbs. Your absolutely right - the center is just 1 loop 1:1 transformers. Hope that answered your questions!
@@ElectromagneticVideos Thanks! Yeah, that clarified a lot. I have a decent understanding of transformers as electrical components, but this was quite puzzling because it's so different!
I would like to see the conditions change as line frequency changes from say 25 hz to 60 Hz and then maybe double to 120. I think somewhere around 400 Hz it wouldn’t work that well with iron. Could you try to use a ferrite core torrids instead and then experiment with high frequency. I would really like to know
I think the main issue with changing frequency would first be the thickness of the core lamination vs eddy current loop sizes. I really like your idea of ferrite toroids - you could make a chain of ones maybe and inch in diameter or less, and similarly sized copper loops. And it could be driven with a switching power supply circuit. Maybe sometime in the future!
Scaled down, that could make a nice LED watch band. I'm going to guess you saw it at the London Science Museum. If you didn't, go there and look for it anyway - the place is a scientific wonderland :)
That an interesting idea - unfortunately I think it would have so much power loss that a watch battery wouldn't last long. London Science Museum - I hadn't heard of it - but based on your description is now on my bucket list! I did see it in a European science museum that your description would fit.
@@ElectromagneticVideos Yes, you'd probably have to tote around a big car battery to power a watch strap. A tour of the London museums is quite an experience - beware getting hypnotised looking at the giant cloud chamber :)
@@strayling1 As a kid we visited the British Museum - I always planned to go back sometime. Giant cloud chamber - wow - definitely something I would want to see!
This is one other very interessant video to understand how transformer works... In this copper pipe alot magnetic fields. Has damage (risc hurt) touch of pipe? (to blood or hands cells)
Glad you thought it was interesting! No real risk from the fields - generally magnetic fileds are pretty harmless. There is some thought that long term exposure to AC magnetic fields from a nearby power line may have a health effect but I dont know if there are any definitive proving or disproving that. I wouldnt sleep next a magnetic chain every night for 10 years, but a few minutes or hours - no porblem.
Yup. Although some RV ones have low power load sense circuits to keep the inverter on standby when no load is on. Of course that does not work will with the always on AC power adapters for so much of our electronics these days.
I always wondered why the primary side of a transformer isn't just a dead short. I still have trouble "getting" that intuitively, but I guess the current and voltage being 90 degrees apart kind of explains it. Is that because a transformer is basically an inductor? And does it have to be designed for a specific frequency?
Yes - if the secondary is unloaded (and therefor has no effect) it is just an inductor. When the secondary is attached to a load and current is drawn, that current produces a field that reduces the field in the core. That in turn means more current has to flow in the primary to bring the magnetic flux back up to the original level to generate the 120V equal to input voltage. I'm planning a "how does a transformer really work" video probably two videos from now (I do about 1 a week) where I will go into that in more detail. And yes - they are designed for optimal operation at a particular frequency and power level. As a general rule, the higher the frequency the small the transformer can be. So for a typical AC wall adapter switching power supply, the frequency the electronics create is usually between 50kHz and 500kHz so the transformer can be tiny compared to the 60Hz equivalent. Its thanks to transistors and ICs being so cheap that we can do this. Saw your eclipse bands video - how interesting - I totally missed that during the eclipse - I'll have to look next time!
@@ElectromagneticVideos Awesome, thanks for the detailed reply! And yeah, I saw Destin from SmarterEveryDay do a call out for people to capture those shadow bands during the eclipse, so I was on the lookout for it. I was fortunate to live pretty close to the line of totality. A lot of other people had the same idea. The traffic around Nashville that day was insane.
The primary is a dead short - just put your ohm meter on it and see. The ohm meter measure 0 Hz (DC). The transformer here was driven at 60 Hz. At 60 Hz the primary of the transformer has an impedance which is primarily inductive and can be easily calculated (Xp=2*pi*F*Lp). F is the frequency part you are talking about and makes it so the transformer is not a short at 60 Hz. If the input AC source has a DC component on it - this can saturate the transformer and / or short the source depending in the DC resistance of the primary. Faraday did not define a transformer vs inductor - IEEE says that a transformer is a device that transfers energy - an inductor stores energy. In power conversion, there are devices that look schematically like a transformer but are in fact inductors per the IEEE definition….
@@BTW... Sorry dude - Inductors store energy by DEFINITION! Look it up - look up "buck converter" - you will see the inductor stores energy when the switch is on - and supplies energy when the switch is off.
Nope - this is the first time I have seen this and I have been playing around with amateur radio for 50 years. Is there a practical use for such a setup? KB8AH
Not directly other than for demoing electromagnetism, but for a toroid style core and winding, here is something you would appreciate as a ham: en.wikipedia.org/wiki/Austin_transformer
They are but at a max voltage of 0.2V so not much chance of a shock from them. And since they form a closed circuit with no connection to ground, there would be no (however small) current through me to ground from them.
Seen this before, and this principal is commonly used in the electrical industry for current metering and heating applications. ie. Current Transformers and Induction furnace coils. You have a 500:1 ratio CT's... plus the unused secondary winding that are left open circuit there! Bearing heaters work the same way. You clamp meter works the same way. This is why when installing toroid transformers in an instrument case you NEVER allow the mounting bolts to form a short circuit (closed loop) via the metal case. Yeah... seen idiots do that before too. It works in both AC and DC supply modes. Up for another fun experiment with this setup? Try disconnecting all lamps and then put two fingers across the primary or secondary terminals of subsequent transformers while the 1st transformer is connected to mains supply. LOL Spoiler: The potential difference there will be a lot more than the original 120V... in fact sometimes so high a voltage that the insulation in transformer winding can breakdown and ruin the transformer. This is why CT's that are not connected to an instrument (ammeter or Power meter) are ALWAYS shorted out to prevent burning out through excess voltage. It does them no harm. It can be very time consuming and expensive replacing CT's in many installations, especially when 2,500A copper busbar passes through the toroid. LOL... I guess you didn't realise how hazardous that setup was? Frankly, I was expecting a misery yelp when you were handing them energised so close to those open circuit terminals. Sorry, kinda disappointed it didn't bite. So, here is another circuit configuration you may get a chance to play with... if you have exposure to power industry. Imagine this common scenario - 250A 3 phase AC supply cables connected to a load (perhaps motor or heater) enter or exit a power distribution/control cabinet. The cables are single core... not multi-core, so each cable must pass through an individual hole in a metal plate (gland plate) through their own unique hole.. so, that's 3 phases and an Earth ... maybe a Neutral too = 4 to 5 cables and their holes. Each hole for an active or neutral is forming a closed loop circuit around each conductor. Doesn't matter what metal used in gland plate... steel, Al or Brass. What do you think happens if a cut isn't made between those holes, which in essence opens the closed loops.. the same as passing all through a single hole under full 250A loading? What do you think happens if it was 2,500A to 3,000A busbars running through a switchboard with similar closed loop metal rings around each bar? Few electricians realise what will happen and no hobby wannabes would have a clue.
Nice explanation about current transformers! But this is not actually operating as a current transformer. It is simply a 500:1 transformer going in, each middle transformer (toroid) is a 1:1 transformer , and the transformer at the end is 1:500. And of course the 500 turn coils on the middle transformers become 1:500 transformers producing the original 120V. So bottom line - the middle 500 turn coils on the middle toroids do produce and 120V - more than enough for a shocking experience which is why I was careful not to touch them.
Fantastic! I am learning, I want to build devices as a hobby. While TH-cam is a great resource, there is a ton of misleading or outright false info out there. I have many questions and cannot tell very well who to trust when it comes to this kind of thing. I have yet to build, because I want to understand FIRST what I'm doing. I have questions! LOL! What would happen if you placed a rectifier on the first coil? Why is it the AMPS that increase and not the Voltage or Watts? What happens if you wrap a permanent magnet ring with copper wire and apply power? Any direction would be most welcome; I can tell from reading all the comments that you know what you are up to. Thanks for this video, along with any others i haven't seen yet lol, I'm very much looking forward to them.
TH-cam is a great resource but you are so right about some stuff being misleading. Oddly, some people have even accused me of faking this video! No idea what they think might be faked but it might be because so much other stuff is fake. Worse there is some downright dangerous things occasionally send in the electrical or science areas. If you put a rectifer in series with coil feeding the power in, it would mean the coild gets DC (actually pulsating DC) and really only its resistance (really low) would limit current going in. so a low of smoke and fire - could make a youtube video that goes viral :) For why is the voltage essentially constant, and current changing, look at some of my other video about transformers and similar things and that should answer a lot of your questions. Hope you enjoy them!
I think at the most you might get some eddy currents in the copper generating a bit of heat, but to make that even noticeable they would probably need to be spinning really fast ....
Cool demo! Hmmm, so what happens when you create a 4th copper loop, going from the last inductor back through to the first to make a ring chain? I realize the voltage potentials in your current loops are insignificant, but still, it makes me shudder to see someone touch a wire moving that much amperage with bare hands. The ElectroBOOM channel has nothing on you!
If you had it the right way so the potentials were about equal, it would be equivalent to feeding power into the chain from both ends and make drawing power in the middle a bit more efficient. If you had the coil in the opposite orientation, it would be an effective short with the current (and power) limited by the resistance of the copper and after a while insulation on the 500 turn copper windings would be melt and we would get into ElectroBOOM type territory. Although his experiments are a bit more spectacular!
There is no point to a GFCI if you're also going through an isolation transformer, or vice-versa. It's a good idea to have one or the other, but having both doesn't give you any extra protection. Also, you really should turn off the power before connecting or disconnecting things from terminals which are running at mains voltages. An isolation transformer or GFCI still won't protect you from accidentally bridging across the terminals, which can still produce a nasty shock.
I guess it does look like silver paper - its plastic wrap the transformer manufacturer used to protect the windings they put on the original toroid. Your absolutely right though - if it was silve paper it would have made for a much more exciting video!
Very cool. You're going to have too much viewer feedback soon. From one of the electrical terminals at the far end of the chain: Would they each measure about 60V to ground? (it may depend on where the copper pipe rests in the toroid, so maybe 40V and 80V to ground) If you grounded one of them (if that's safe, or thru a lightbulb), would the other terminal be about 120V to ground? I expect the GFCI at the wall outlet will not trip. A GFCI placed at the far end of the chain should trip with one terminal grounded and a fault from the opposite terminal. [edit: a GFCI is supposed to account for a leakage current, but not sure how that works if neutral and gnd are electrically the same]
Thanks! Your right about the terminal to ground voltage varying depending on the location of the copper pipe or anything else that touches it. Would be very hard to predict because of the very high insulation resistance and for that matter, it would almost almost be impossible to measure because any current getting though the insulation is probably in the micro-amp range. I might even guess a significant portion of any such current might also be from capacitive coupling between the winding and the core. And yes - if you grounded one or the other of the end terminals, the other would be 120V to ground and with a good connection to ground, be as dangerous as 120V out of a normal wall socket. And the GFCI on the wall would not trip because it is not in the current path. A GFCI at the end: The GFCI works by tripping if the currents on line and neutral wires are not equal and opposite. If they are not equal and opposite, there must the current flowing somewhere else so the device trips because that shouldn't be happening. So if we add a GFCI to the end and ground one of the wires between the GFCI and the transformer coil, there is now a ground path possible for shock type currents. The GFCI should trip if someone were to touch the wire on "the safe side of the GFCI" that is 120V to ground since the shock current diverts some of the away from the GFCI and the two wires going though it are no longer equal and opposite. You hit on a few neat things that have real applications: 1) GFCIs are sometimes used when retrofitting old houses that do not have ground wires at each outlet. In that case the GFCI ground is not attached to anything and like in the situation above, it protects by noticing the difference in currents on its two wires and shutting off power. 2) The 120V output end of the chain is isolated as you described. There are transformers that are build with an isolated output for testing and other safety applications because without the connection to ground, there are less paths for a current to accidentally go though people. I did a video about that here: th-cam.com/video/olq9wdeNS4c/w-d-xo.html
@@ElectromagneticVideos In Scenario 1... here, such a residence would be disconnected from mains supply until it complied with current Standards wiring rules. No two ways around it. No electrician would touch the place until it was agreed the work be done in accordance to such rules, in fact, we are obliged to disconnect rather than risk their Licence to work in the industry be suspended. No self respecting tradesman would work on the place... because as the last person to work there they would be blamed for not disconnecting when someone gets killed. Oh yeah... we don't allow unlicensed DIY idiots to work on Mains wiring systems in homes, unlike the USA and UK. Good luck with that recipe for disaster. Senario 2. Touch between the two transformer output terminals, or circuitry after and get the belt of a lifetime. Isolation Tx have a very specific limited use, because all appliances in use in a home should have an Earth/ground available if it is needed... eg. if they are not Double insulated construction. Anything with a resistive heating element built into a metal hotplate or pan require such an Earth/Ground. Also, there are sound reasons for Neutral Earth bonding that far exceed and perceived 'additional means' of accidental electrocution. One other matter noted there.... you can find a lot more than your 120V AC across the terminals of that Tx in an open circuit situation... both sets of windings. The copper pipe used has a very thin wall section... low Cross Sectional Area that would hardly carry 40A at below 75 C... or 105 C, for extended periods of time. If it was cable with a CSA of 25-35 sq mm and so, a safe current rating of 80-100A there would be no problem shorting out the winding terminals (BOTH) for safety. They will NOT burn out from overcurrent or heating effects. Do the math... All Tx after the one energised by 120V AC are CT's with a ratio of 500:1 Pass 500 A through the core and get 1A current flow into a high impedance voltmeter load. Open circuit they can suffer HV insulation resistance breakdown that renders them useless as a VT or CT... and provide a significant shock to those playing with 'em.
@1:28 electrically connected? That torroid looks insulated to me. If it wasn't and you were holding it in your hand you'd be holding onto mains voltage with your hands. The copper is insulated from the transformers. There might be some eddy current in the copper, but there's no electrical connection.
OK, this might be for people have no idea what any of this stuff is, but as a power electronic engineer, let this for a while and then look at it with a thermal camera. That light bulb has almost nothing to do with the power consumption of that chain of stuff. You might get to that point sometime in the video but its frustrating to be made to sit through grade school level introductory electronics.
God's. What are the vars on that? The powerfactor on that has to be massively thin I would love to see if you added capacitors on your single copper pipe winding. And see if you could drop that unused power use.
And the power factor gets worse as the chain gets longer but is actually quite low: the unloaded current in the copper pipe 1 turn winding at the last link of the chain is 5A at 0.2V so 5A x 0.2V = 1VA so each core adds 1 VA to the system. So at the input end the amount is about four times 1VA equaling 4VA from the 120V input. The transformers I used are rated at 180VA so if the system was fully loaded with a 180W load the power factor would be pretty good!
@@BTW... I actually experienced that once as a kid - was in the garden and my leg hit a hidden live wire under a metal windmill tower which I was holding onto with my hands at the time (no better ground than that) - was completely paralyzed but conscious. If my mom hadn't noticed something was wrong and and pulled me away I wouldn't be here. And that was in a 240V country - really amazing that I survived.
If you power the first 500 turn toroid coil by itself, with no copper ring, how many amps? how many amps with only a copper ring? how many amps with the second toroid added, but shorted? ("lots" right?)
At 4:23 the 1 turn magnetization current is measured to be 5A. Since the 120V coil is 500 turns, if we powered it with 120V (and no 1 loop copper), we would expect 5A/500 = 10mA. Powering the 500 turn 120v coil with 120V and a copper rings with no second core. Thats a dead short - so huge current limited by the resitance in the primary and secondary. Same as your final example " second toroid added, but shorted" = "lots" So the really interesting thing is putting a second core though a shorted coil ends up "unshorting" it.
@@Iowa599 YES!!!!! Exactly! You could think of it as the transformer acting in reverse: the shorted side is 0 volts, so that gets transformed to the primary and regardless of the step up or down ratio, any ratio times 0 is so. So V across the primary = 0 = a short.
That was a great demonstration, thanks. I had not seen that before. Really drives home the effect of bad power factor, with the wires needing to carry the (reactive) magnetization current, even if the load (real power) is small.
Thanks - glad you liked the demo! Yes - nothing like single turns to really make things like that stand out. Or for that matter toroid transformers which make it so easy to thread things though the core for a demo. I'm doing to do a future video about magnetizing current and power factor and also saturation and magnetic amps!
@@ElectromagneticVideos It also demonstrates nicely how the magnetic field is perpendicular to the electric field.
@@paulmichaelfreedman8334 Yes!!!!!! An I plan to use it again to show that when a do a video on EM waves.
Power factor and coupling. Both decrease efficiency of the circuit.
@@spvillano Oh yes! Definitly not the ideal way to efficiently transmit power :)
Excellent Demo! I suspect you saw this or a similar basic electricity and magnetism demo at the Deutsches Museum in München (Munich, Germany) Their AC and DC very high voltage demos are very exciting, too. The Science Museum in Earls Court (London, UK) removed their impulse generator demo. Also, the mercury-arc rectifier demo that powered the DC motors in the museum's passenger lifts. Pity, as a schoolboy these were the daily demo not to miss.
There may be something similar at the Exploratorium, (San Francisco, California, USA) they had a "shorted single-turn secondary" coil filled with aluminium, it melted when energized, and solidified again as it cooled.
Great hands-on demos to drive home the theory that comes later in college.
You got it - Deutsches Museum in München was were I saw it as a kid. And I will never forget the HV demo - "lightning" hitting a building, and the person in a Faraday cage. I actually looked on their website the other day and it appears that fabulous demo is shot down for the next few years while they renovate that part of the museum.
Sad to hear about the Science Museum in London removing their demos (never been there but others had mentioned it). The San Francisco Exploratorium shorted coil demo sounds great. The museum that have real memorable demos like that are the best and are the one that get remembered.
Glad you like this video - yes - a nice connection to the theory for anyone in EE or physics or with that sort of thing in theior future!
You are an excellent teacher. Thank you for creating this channel and content 👍
That you so much! I really appreciate that!!!!!
@@ElectromagneticVideos when you load the last toroidal, do you still have lenz law affecting the input?
@@kanjo-Etienne Well if you mean what happens when a coil on the last toroid is shorted, yes - so that almost sets its magnetic field to zero, so now the copper linking the 2nd last to the last torroid is essentially a short and that works it wat back towards the first toroid. So other than resitive or other losses limiting things, yes.
@@ElectromagneticVideos thanks
@@ElectromagneticVideos another idea that came to mind is that you can stack 3 toroids together to have one, though with each still having its independent windings, then wind all three as one core. The central toroid acts as the input while the rest is output I did this back in 2013 with a mentor and had some interesting features
Thank you for making this experiment available, we built the device over the weekend and it works perfectly, with 3 x 5 watt lamps the copper pipe current measurement is 53 amps. It also shows us the relative phase angle between the voltage-in and the current at around 90 degrees out of phase a great demonstration.
Thats great - I'm thrilled to hear that! I would love to see a photo or video of your chain - could you email me one? Email on my about page. Or do a video? How did you bend the copper pipe? I found that the hardest thing to do was bending the pipe and only managed after buying two pipe benders (first one turned out not to be suitable). And even then they are not really made for 180 degree bends. Buy the way - you do know that the individual 120V coils on the cores are isolated so even if you use a gfci to power the chain, you will not be protected from a dangerous shock on those terminals if you put your fingers or anything else across them. For demo purposes it might be safer to run the chain at say 12V or 24V AC and use 12V bulbs ....
I have made a permant magnet monopole
@@andrewmcqierry4542 Please invite me to attend the ceremony when you receive your Nobel Prize :)
In high school, we had selectable tap AC bench power supplies from 2 volts up to 12 volt. Something like that would work well for a demo like this.
Great video and detailed explanations - this setup should be standard kit for teaching electro-magnetics!
Thanks you! And even just a couple of toroid transformers by themselves with some some nice thick wire to thread through them would do. Nothing beats the hole in the toroid for making experiments easy!
Excellent job. I wish you would have went into turns ratios deeper.
Clearly you have the heart of a teacher.
Well done.
Thank you so much! I am planning three more videos on this sort of thing. Two videos from now I will specifically cover transformers and how they work so stay tuned.
You right. I do love teaching - years ago I taught university courses on topics like this and had great fun doing it. So making videos is going to be my outlet for doing a bit of teaching again :)
Awesome demonstration. It would be interesting to see the current and voltages on some oscilloscopes in order to observe their relative phases.
Thats! I am trying to figure out a second video video with the EM chain and that's an interesting idea. It might be interesting to try and see the propagation time from one end to the other and compare with a standard coax or Cat5 transmission line.
@@ElectromagneticVideos your chain is very interesting! You could measure current at each link by creating and adding "magnet wire" winding loops to each link on the chain, and feed each winding loop pair to an oscilloscope channel. The winding loops will measure current induced by magnetism, similar to how your chain works. My hypothesis would be 90 out of phase for each link. Such an interesting contraption. Thank you for sharing it with us
@@LydellAaron I like that - and maybe a bit more of an in-depth look at how wire loops (=loop integrals) work, and its hard (impossible) to directly measure the voltage of "half a loop".
Your right about the current being 90 degrees out of phase with the input voltage (assuming no load) but the loops you suggest (assuming I didn't misunderstand your description) will actually show the value of the changing magnetic flux (the Faraday equation in Maxwell's Laws). What you describe would be correct if measuring coil (and hence the system) was essentially shorted as in a current transformer, but that's a different scenario (will be covered in a future video). I do have some clamp on current transformer style current probe's somewhere (=a current transformer) - might be able to use them to show the loop currents on the scope.
Thanks for the suggestion!
Can you explain how the right hand rule can be applied to toroids. Also how does ti apply to the horizontal pipe?
What formula do you use to find out the needed turns for 120V. ( primary). Can the turns overlap? Both in primary or secondary.? I am a physician, former TV repairman in the 60’s and early 70’s before medical school. Now I am having more time in my hand but still seeing patients . Doing a fast 40 yr catch up & having a hard time catching up… I worked mostly on Yagi antennas as an Extra class amateur radio back then. Also participated on the building of the first amateur radio satellite launched into orbit OSCAR 10. The previous ones were flown in balloons, private airplanes an even using a kite! More details if you are interested. Great lecture on Maxwell’s equations. Had a heck of a time in pre-med physics. My professors came to the conclusion I was missing a reverberating neuron network that must be crucial to actually understand Calculus! I just memorized the formulas and entered th numbers…got A’s and B’s without ever understanding what the purpose was!
Very cool. I’ve never seen this demonstration before. Very interesting.
So glad you liked it! I sure wish I had the HVAC skills you must have in bending the copper pipe - what job - I have new respect for people in your field. Glad you liked the demo!
@UniversalExpanse Because of the orientation of the magnetic and electric loops and their interactions being at right angles, at first glance it would have little effect other than the iron being less of a conductor. However, due to stray fields, you might get a bit of an interaction.
But you got me thinking. Say you somehow made all the cores (both the electric and magnetic) ones identical - electrically conducting and, magnetically permeable like iron, and restive to eddy currents. You might be able to setup two flows of energy - one using the vertical toroids magnetically the other using the horizontal toroids magnetically . So each toroid would be the magnetic path for one flow and the electrical path for the other flow. Much like (circularly) polarized light. That would be a tricky but interesting thing to try, and for a longer chain, see if the their is crossover from say the vertical path the to horizontal.
@UniversalExpanse Anytime!
I had never seen this demo before...again, this would be great for a high school physics class.
A few science museums have a version of it. I saw it as a kid in the Deutsches Museum - a fabulous science museum in Munich. I'm certainly hoping that some science teachers may get some inspiration from the demos I am showing. Or for that matter University Profs in EE, Physics or similar fields.
This is the most awesome explanation of dielectric losses I've ever seen in my life!
Glad you liked it! But is really more along the lines demoing two of Maxwells classic equations - at least that's what I was hoping!
By the way - saw your "Prague library optical illusion" - is that ever cool!
Errr.... NO.
Great demo! Though the GFCE would not trip since all the current in the first coil all comes back.
Yes - everywhere in the chain there is no ground connected current path. the purpose of the GFCI/Isolation transformer is to protect my fingers from the two terminals on the left coil where 120V AC is fed into - they are live. I could have covered them with tape, but I also wanted them exposed for other experiments.
@@ElectromagneticVideos Is the GFCI before or after your isolation transformer? Before the transformer, it will trip on a transformer primary failure. After the transformer, and it's unlikely to help (depending on leakage characteristics of the isolation transformer).
On the other hand, an AFCI breaker would help protect against incidental differential circuit contacts
@@dl5244 You absolutely right - it will only trip if the isolation transformer were to fail. And there actually is an AFCI breaker in the electrical panel supplying that circuit. I don't think it is likely to trip (from arcing) because I suspect the isolation transformer's limited frequency response will remove much of the higher frequency noise used to detect the arc.
The isolation transformer is the main safety device. The reason I mentioned them in passing in the video was to make sure anyone thinking of doing something similar would be reminded to use safety devices. I dont want to set a bad example by being reckless.
@@ElectromagneticVideos one thing that I didn't think you made clear was that an isolation transformer only protects you from touching a single potential net.
Even a single finger toughing both terminals of the load bulbs would be shocking.
I have not seen it in a museum, but made something like a miniture version in an electronics lab. Only powered by a signal generator, and loaded with LEDs. We also added capacitors, and observed the effect using a CRO (a real one, not a digital scope).
So a higher frequency version with the capacitors to make the chain have a resonant frequency? Intriguing!
Incredible! I'm so thrilled someone has finally reproduced and demonstrated this. Originally I had learned of this setup after taking a deep dive on Bill Beaty's Right Angle Circuitry webpage years ago. This was figure 10 on his 15 figure adventure towards mcoils and the proposed electro-electret (the analog of the electromagnet). Bill's articles, esp defining electricity have definitely been a cornerstone for breaking out of conventions and thinking more creatively.
If one were to use high-mu materials and form wires, hairpins, or transformer steel laminations to stack a coil, what kind of analog magnetic circuits could we make, and most importantly, would we be able to make a functional electroelectret in the final figure 15?
Thanks for the video, really enjoyed the presentation, style, and the thoughtful engagement with your viewers.
So glad you liked it! I first saw a china like this at the Deutsches Museum in Munich when we were visiting Germany when I was a kid years ago.
Magnetic circuits are routinely used in the Electrical Engineering to from everything from from motors and transformers to hard drive read and write heads. Unfortunately due to the lack of a magnetic equivalent of an electron (and even if the magnetic monopole particle were ever found, it would not flow like and electron) you cant make magnetic circuits with the same precision and confinement as electrical ones. For magnetic circuits we are always limited to using good magnetic materials as you point out to manage the paths the magnetic fields take.
But imagine a universe with not only electrical atoms but also magnetic ones with magnetic equivalents of electrons and protons. You could have magnetic circuits just electrical ones in every way. Of course no idea if you could create a consistent sent of physics constants that would allow such a universe to existing and life to form ....
@@ElectromagneticVideos Yeah its an interesting topic in physics, the magnetic monopole and whether it is a mathematical abstraction or an elementary particle. I do remember reading a paper from Bibhas De, a protege of Hannes Alfven where he provided some proofs on a theoretical Source-Free Magnetic Structure which seemed a bit more reasonable at the time. He had some other interesting propositions including transmaxwellian equations, magnetohydroelectric waves, and essays arguing the case that magnetic field has a co-located mass, and how one would go about building an apparatus to test it.
However, I must say I have my doubts that a magnetic monopole or SFMS exist any more than a graviton, or dark matter does. Magnetic fields are the result of charged particles in motion, and can not exist without an electric current or time-varying electric field, much as a shadow cannot exist without something to occlude the light from which the shadow was cast. However, that's not to say that there are hereto undiscovered modes of EM phenomena or suitable transducers from which to detect and convey them.
Thanks for response. I appreciated hearing your thoughts over the material constraints and practical considerations.
@@InfinionExperiments The intriguing thing for regarding mag monopolizes for me is Dirac's proof from 100 years ago that if mag monopoles exits, then electric charge must be quantized. Which it seem to be, but the reverse of the result is not true (ie no requirement if charge is quantized, monopoles must exist).
I tend to agree with you - unlikely they do exist, but particle physicists still seem to be on the lookout for them and thats what keeps science interesting.
Just looked at one of your videos - looks like some of the crazy/dangerous things I did a kid/teenager! I always find sparks and arc discharges experiments so cool. You can expect some comments!
One of your videos description says you in BC - I'm in Ottawa but know BC well - my brother lives in BC.
@@ElectromagneticVideos Go team Canada! Thanks for the response. Yeah they are. One of the best sparky setups I put together was one I didn't catch on camera. I reproduced a Tesla Hairpin circuit which used 2 series HV AC tank capacitors with a parallel spark gap. The tank capacitors acted as a high impedance high pass filter, blocking the 60Hz high voltage while transmitting the mirrored current from the tank circuit that discharges through the gap. Large copper conductors connected the doorknob capacitors together.
This other side of the capacitors exhibited really perplexing RF-like high frequency transmission line effects. I noted that dragging conductors across the hairpin generated sparking, not unlike what you'd see in a lighter flint. Connecting incandescent bulbs across the hairpin illuminated it brightly even though there was a thick shorted bar a few centimeters away, as the high frequency had potential differences at 1/4 wavelength nodes and antinodes, and finally, when connecting vintage incandescent bulbs that are partially evacuated, the illumination gave off a bright blue as the bulb no longer operated incandescently, and instead ionized and accelerated the rarefied gas that existed near the thin wires.
It was the most fascinating high voltage experiment I had ever put together. Some had claimed the high impedance side was safe to touch, but I wasn't quite sure if this circuit was capable of causing tissue heating or possible RF burns. The circuit still today could have applications where 100W bulbs could be illuminated by thin wire, besides generally being a great tool for investigating high frequency phenomenon.
@@InfinionExperiments At the frequencies that got though to bulb filaments, its quite possible that the coiled nature of many filaments acted like an inductor and prevented normal current flow. Cool that the gas ionized and was visible!
Your very right about tissue heating a RF burns - better not to test if its damaging to humans.
RF isnt a great way to transmit power - too much leakage, hard to confine, and skin depth issues. But if you have plenty of space around a single conductor you can try using a Goubau line which are sometimes (but rarely) used for low loss RF signal transmission.
Great video! Very impressed that you responded to almost every sensible comment . Great job!
Thanks! I do try and respond to as you put it "almost every sensible comment". When I don't manage that, its usually the result of TH-cam that doesn't always notify me of new comments particularity when a bunch happen at ones. I do appreciate the time people take to comment, and I have often enjoyed some conversations back and forth.
This is a great visual demonstration! Thanks for sharing! :)
Thanks! Glad you liked it!
Your right I love it when people are Right.😅
Not sure what I was right about, but glad to hear I was :)
that's what I keep telling Everybody Symmetry, is
Geometric, Boogie On.
give it Up !
Well Maxwell's equations are wonderfully symmetric in terms of the link from electric to magnetic fields and vice versa, and the chain demonstrates this nicely. If a magnetic monopole is ever detected, the equations would also be nicely symmetric in terms of magnetic and electric charge as well.
A decade or so ago I experimented with Joule Thief circuits that were popular at the time. I built several and strung them on a few meters of zipwire. Only the first JT was powered, the rest had their power leads shorted. With the zipwire closed in a loop every JT lit up. However the zipwire loop could be twisted up or bundled, it just had to pass through each JT toroid to light its LED. I discovered I could put 10s of toroids on it, each glowing as brightly as the first. Thanks for finally explaining the math, fascinating. 🙂
I had heard about Joule Thief experiments - I dont quite follow your circuit description but great that you got it working so well? Were you near HV power line or just from EM fields in a normal house? I have heard you can hold a fluorescent tube under a HV transmission line and it will glow - have got to try that sometime!
I'm so pleased you found the math understandable in that quick explanation. Those two of Maxwell's Equations are so fundamental - and while I didn't mention it in the video because it was already getting too long - with one equation generating an electric field from a changing magnetic field and the other generating a magnetic field from a changing electric field you can image how even without magnetic cores and wires, create an electric field and a magnetic follows, and that will then create another electric field and back and forth slowly spreading out. And those spreading out fields are light, radio waves, x-rays, gamma rays, infra-red, ultra-violet etc. Maxwell predicted the speed of the waves entirely from the measured constants in these equations and people recognized that speed was the same as the measured speed of the then mysterious light. How incredible that light was suddenly explained and understood! More experiments on things like that to come!
@@OriginalMorningStar Very neat - actually it might be intriguing to try a Joule Thief sometime. There is actually of lot of stuff related to micro-power energy harvesting - usually from things like the bumpy motion of your body or a vehicle to power sensors as we become more and more wired.
Actually a Tesla coil is something I have never built and and want to make one sometime. I have played around with HV quite a bit (see the Flyback video - one of the first videos I did). What a scary and a bit dangerous in the DIY example in the link is depending on the insulation to protect against the HV, Yeah the current is limited in a neon transformer but I wouldnt trust its limiting very much ....
@@ElectromagneticVideos Microsoft experimented with using lower-voltage modulation to transfer data between devices using the bodyfield. I found a patent filed long after I published my project, but I've never seen a real-world application. Did they try to swipe it? IDK, but I've got Prior Art... ;-)
Just found your channel. WHOAAH
I hope that means you like it :)
@@ElectromagneticVideos yes 👍
@@rocktech7144 Excellent :)
I'm late to this party but I'll echo many of the comments here. That was outstanding as a visual!
New subscriber.
Well I'm glad you eventually came to the party and enjoyed it :) Thanks - really appreciate the comment!
The fields are not located inside the matter. The fields are outside of the matter. What you are describing is actually called the dielectric field. The electric field is the conjugate field created by the magnetic flux crossing the dielectric flux at right angles. What is going on here is quite a bit more complicated than described as the various coils and tubes are in close enough proximity for induction to occur between them. There is also self induction occurring. Overall good presentation and demonstration.
That was awesome, thank you so much for taking the time. I don’t understand books well, but practical demos. Thank you!
I'm so glad you liked it! Demos are always way more fun than just book theory - it really brings things to life. I have a few more magnetic demos planned including an all magnetic amplifier, so stay tuned :)
@@ElectromagneticVideos I’ll be sure to check back in soon :D
@@maxtroy I try and do a video every weekend, so unless something comes up, usually Sunday is a good time to look!
One core and one loop of that looks sort of like an Austin transformer. Now I think I understand how they are constructed.
Yes - very similar! Are you an antenna guy? I have never seen an Austin transformer other than in photos. I don't think I would be comfortable on top of an antenna mast so I don't think I will ever actually see one :)
@@ElectromagneticVideos I like photographing infrastructure and I’ve seen them on the bottom of NDB transmitters used in aircraft navigation.
The Austin transformer is near the base of the tower. It is used to couple 60 Hz AC to the lights on the tower, while still isolating the base of the tower from ground at RF so that the antenna can be excited with the standard broadcast signal in the region from 540 KHz to 1700 KHz
For everyone wondering where I first saw a magnetic chain, on of you guessed correctly this afternoon: I saw it at the Deutsches Museum en.wikipedia.org/wiki/Deutsches_Museum , a fantastic science museum in Munich . If you are ever in Munich I highly recommend spending at least a day there!
Other commenters thought I saw it in these museums: The Faraday museum in London, The Tesla museum in Serbia and The London Science Museum. Those museums are now on my bucket list - they all sound fabulous too.
Just so everyone commenting knows - there is something weird going on with TH-cam comments right now - I get notified of your comment but if I click on it its not there. So my apologies to anyone wondering why I haven't responded to your comment or question. Same thing seems to happen with follow-ups to comments.
I'm so excited to have found this channel. Thank you! I have some binge watching/learning in my near future.
I suppose this may be the opposite of your demo in a way (or relative position?), but it reminds me of Sir Lawrence Bragg's demo presented 5 min. into this video: th-cam.com/video/Vwjcn4Vl2iw/w-d-xo.html
@@natesgarage Thank you so much! Another commenter point me to Bragg's lecture as well. Yes almost identical EM chain! I watched the whole thing - wonderful to see such a historically great scientist give such a wonderfully clear lecture.
I just subscribed to your channel - your physics demos are great!!!!! From the HV stuff to Faraday's 1st motor. And many demos I had no seen before! Are you a physicist? or an EE?
Funny you replied but now I cant see the reply. TH-cam is acting odd! Please keep up your videos - I look forward to more!
@@ElectromagneticVideos Thanks Peter! I’m humbled… I’m afraid I squandered my time at university learning finance, but I’m now on the right track; attempting to learn more about the universe. I’m also envious of your workshop - amazing!
I like to think that I have a firm understanding of the Bragg’s demo but your slightly different demo has made me rethink my understanding. I thought the entirety of the magnetic field in a toroid was contained within the core of the torus ring (no magnetic field within the donut hole). Yet, a current is induced in the copper tubing. I’m not visualizing any magnetic field lines crossing the lines of current.
The demos that contradict my understanding are the good ones - so thanks again!
@@natesgarage It probably more fun when you can experiment and learn the stuff at your leisure than having so many university course on technical topics at once that you dont have enough time to understand them as deeply as you might like at the time.
The workshop was the result of recent (ongoing) renovations started just before covid so it was perfect timing in terms of when one might need a project to keep busy. Sometime I will do a video about it - and what I did right an wrong. Unexpectedly the best thing about it is the office style lighting - makes a huge difference.
Your comment about Bragg's demo being slightly different. I often find sometimes one way of demoing something triggers my understanding while another may not - or sometimes a combination - there is nothing like two different explanations/demos/lectures etc to help with that.
Yeah the bulk of the flux is essentially contained in the toroid core. The copper is around it - but somehow "knows" there is a certain amount of changing flux through the loop, even if virtually no flux "touches" the copper. Its a strange but very fundamental property of the universe - one of the few that is so easily seen. I have never liked the magnetic lines of force thing - and its not something we really use much in thinking about EM theory. I think its often discussed because you can "see the lines" with iron filings and "crossing magnetic lines" is somewhat equivalent to "changing magnetic flux" and maybe more understandable without calculus ...
Send me an email if you get a chance - might be fun to collaborate on a video sometime!
Love this channel!
Thank you! I appreciate that!
This was fantastic! Thanks so much for sharing
Glad you liked it! You might find the next video interesting which used the same toroids to make a magnetic amp.
Is it just me or is there something not quite right here?
You've won me over, I'm subscribed now.
Great! I hope you enjoy my future videos!
7:00 You say that the power input is through a GFCI and an isolation transformer as if it actually means something. You do realize that as soon as you galvanically isolate the current path, the GFCI becomes useless? That means at best the first toroid is protected if you were to accidentally provide an alternative path to source (assuming you have isolation transformer to GFCI to the input of your demonstration)? IE if you were to accidentally touch both sides of any of the other transformers you could provide a path through your body and/or tools that would not be detected by the GFCI, and could potentially be lethal? To be fair you'd have to touch the other end of the coil, not something else that's grounded as I'm sure you didn't ground reference any of the coils.
This is a really awesome demonstration otherwise and I'm certain you already know the above, but the way you pass it off as "oh yea its protected and safe" is dangerous to any inexperienced person that could try to replicate this experiment.
Yes - your not the first person to point this out. I was trying to get across that one should have some protection when doing stuff like this, with the isolation transformer or gfci being a possibility. I so happen to have gfci in the wall plug, but prefer the isolation transformer to prevent current flow rather than to stop it once started.
And your right - you could get a lethal shock if two parts on other sides of your body (fingers on opposite hands) touch the two 120V terminals on any one of the toriods. A safer setup would be to cover the 120V outputs on each toroid and just use the low voltage ones for sampling voltage and hence flux strength.
Glad you liked it otherwise.
The apparent symmetry between electricity and magnetism is a PSEUDO-SYMMETRY. Magnetic fields are actually the relativistic transformation of the electric field. This is seen more clearly in the RELATIVISTIC form of Maxwell's equations. Here, it is obvious that the magnet field is merely an electric field viewed from a relatively moving coordinate system. This is why the search for magnetic monopoles is specious.
Absolutely - but a bit beyond the scope of this video :) Magnetic monopoles - I had the impression that the particle physics types were still on the lookout for them although like you I'm not holding my breath in anticipation...
Excellent video ! Probably great for STEM as well !
Thank you Bob! I just looked at your PV DC Arc Fault Detector video - what a great demo of how hard it is to extinguish an DC arc - and how well the DC arc fault detector works!
🤔🤔🤔 such a nice video 😊
Thanks you so much!
toroid 2 and 3 are just center cores and the winding dont matters.the light bulb will iluminate at the end only with ferrite or iron centers ,2 and 3, without wires ?it will work much smaller(the center around 15 mm?
Exactly! No need for the windings. I was thinking of removing the transformer windings of toroid 2 and 3 to emphasis exactly that, but I didn't because I didn't want to ruin the transformers in case I needed them for something else and also the light bulbs on the windings are a nice indication of whats going on the those toroids (particularity when shorted).
That was excellent, thank you for taking the time to make the video.
I think I need to send this to a colleague who thinks that earth-bonding prevents (potentially hazardous) surface currents close to powerful HF transmitters. lol
Thank you! Funny - I actually do a lot of RF stuff in my day job (right now much higher frequencies although did a lot of HF 15 years ago) - one thing I know is that at RF frequencies, you can always get surprised at where currents and voltages are unless things are entirely enclosed. Highest HF powers I have worked with are a few hundred watts, but have heard for kw installations, a light bulb with a few feet of wire on each terminal can glow in the right location. Wouldn't want to be in areas where there is that amount of energy floating around!
@@ElectromagneticVideos Stand under a 550kV aerial feeder line with a fluro tube and be surprised.
You think Earth bonding is pointless?
Do you also subscribe to the flat Earth nonsense too?
@@BTW... I didn't say that earth-bonding is pointless. I was noting that even "connected" conductors can have a potential difference across them when subject to HF radio electric and magnetic fields.
So tell me how a conducting antenna can give you a shock if one end is, necessarily, bonded to earth?
And in answer to your second question, I fully subscribe to the 4/3 earth approximation for RF propagation. So I guess you could argue that I subscribe to "the slightly flatter earth" nonsense! lol
I enjoyed this video. Thank you!
Glad you liked it! I just looked at your channel intro - subscribed - I'm looking forward to some interesting stuff!
This was somewhat interesting, thanks!
Glad you liked it!
Yeah, me too, @@ElectromagneticVideos, thanks!
ahh perfect for my 8 ton Christmas tree setup
Yes! And now that I think about it, if I had used green lights and the red background it would be perfect for Christmas. Hope its a strong tree!
Never seen before? It's all over the place, every other corner of the streets has one.
You can even change the ratio of the winding inside them to change the output voltage.
Those toroids are heavy. I used one of the same size to experiment with the Romer-Lewin ring, and holding four with your arms stretched must be tendon challenging.
Ha yes! that why I put it down right after the intro! And that was after a few tries at the intro too. I don't have time right now but I will have to watch your videos!
Awesome video!
Thanks you so much! I just subscribed to your channel!
@@ElectromagneticVideos Thank you! I definitely subscribed to yours, you are great at teaching and explaining!
@@ThriftyToolShed I really appreciate the teaching and explaining comment. I always find it hard to find the right level for a varied audience!
it's also a phenomenal isolation transformer, triple isolation?
Yes! It would be even better if the copper pipe toroids were suspended in the center of the magnetic torried leavening a large air gap for kilovolt type isolation!
@@ElectromagneticVideos 40mm air gap clearance minimum between bar to bar and/or Earth at 1kV.
All HV CTs are epoxy potted to meet isolation Standards.
You NEVER EVER want to find HV in a metering or protection/control panel.
@@BTW... I have seen videos of wireless connected current transformers for linesmen working on power lines - what a great use for wireless.
Totally awesome ! If my lazy-ass profs at O.D.U. would have done something like this, life would have been easier.
Its amazing how good Profs can make a difference. I was so lucky to have absolutely fabulous Profs in the various EM courses (I took all of them) and in Machines which included transformers. To this day I dont much care for Control Theory - hand an awful prof in the one course of that which I took! Glad you liked the video!
Nice Experiment.
Thanks! Glad you liked it!
Thanks for the video. Here is an idea for video I would love to see: explain how current (measurement) transformer works! Typically a transformer is described in terms of how the ratio of primary and secondary turns change the voltage. And it is implied that this is more or less independent of the load on secondary side. So a transformer changes voltage. But then we find out that there are 'current transformers' that are used to measure current flow. AFAIK they are typically just a straight wire (one turn primary) going through a toroid and a multi turn secondary, And that somehow turns the transformer into a current transformer where the secondary current is proportional to the primary current. Explain that! How the heck does the transformer know what it is supposed to do ;) Ok, I think I know the answer but a video to walk through that might be interesting.
In this video he uses toroid stepdown voltage transformers that are of identical construction as a CT, with a 500:1 ratio. He does state that there are (maybe) 500 turns around the iron core.. and 1 pass through the hole. 500:1... get it?
You could call them 2500:5 ratio too if they had a big enough hole. Pass 500A through primary (core) and connected to an appropriate instrument 1A will flow through the instrument at a low voltage. (5A if your pushing 2,500kA) The voltage is irrelevant. Current flow is the intended metering objective. The analogue meter movements are in fact millivolt meters configured as Ammeters directly connected to the CT's.
The risk is when CT wiring systems go open circuit in the secondary windings or wiring to an instrument. They can have High Voltage across the terminals that can permanently damage the CT windings.
NO fuses are found in any CT wiring systems. A minimum size conductor is specified and maximum cable run applies, because of the low voltage and low current. Specific wiring lugs are used to ensure no loose connection can disconnect, resulting in an open circuit. The wire jerkers soon learn proper CT wiring when they get an Inspection fail.. kinda low hanging fruit for testers. You can almost predict the chance of a fail by looking at the installer. LOL
ALL Low Voltage (i.e. Under 1kV) Commercial / Industrial installation revenue metering CT's, provided by the energy retailer, come with secondary terminals shorted out at the CT terminals. ALL customer CT metering wiring into a control panel passes through terminals designed to easily short out the field wiring and disconnect field wiring to the instrument for servicing and calibration.
All pissant scale LV Domestic customers have a power meter with the CT's inside the instrument case... so open circuit CT wiring is very unlikely unless tampered with.
It gets interesting when dealing with High Voltage CT's, designed for 1.1kV to 600kV systems, but same ratio rule applies. I've only worked with up to 220kV stuff.
The isolation between primary and secondary windings is of course a principal design factor with anything rated for High Voltage use... so there is no chance of 220kv appearing in a control panel.
Stay safe now.
Glad you liked it! I am planning a couple of transformer videos - one on how a transformer REALLY works and one on current transformers. Its funny - you imply that the operation of current transformers is often misunderstood - and I think you are 100% right on that one. In fact doing some research for this video even showed that voltage transformers are often misunderstood. The current transformer video will most likely be 3 videos from now, and I usually post a video every weekend, so stay tuned!
@@ElectromagneticVideos Brilliant, looking forward to it, I think there are a lot misconceptions out there!
@@Axel_Andersen Yeah - it really is amazing some of the misunderstandings - you know the one problem with TH-cam videos is the time constraint - too long and people stop watching. So we will have to see how well I do explaining things within a limited time!
That is way cool, I never would have guessed the induced current would be that huge. I suppose to transfer that much energy with only .22 VAC you need a but-load of current.
Would you describe this as a chain where you have four 500-turn copper wire low-current high-magnetic links connected by three high-current low-magnetic single-turn copper pipes?
What was the current entering the first stage from AC Mains? I suspect it is less than an amp.
Yes - its funny how its so outside of our everyday experience that you just dont expect currents that huge.
Thats a fair physical description, but it is worth pointing out that the 500 turn windings in the middle have no effect = behave as if they are not there when not connected to a load so they really arnt part of the chain unless the something like the indicator lights are attached. Refining your description for the middle of the part : a chain of high-current-single-turn-copper-pipe-toroids and high-magnetic-field-single-turn-steel-toroids just to emphasize the symmetry between the electrical and magnetic links in the chain.
I'm of amateur knowledge in this and am trying to understand the part of your demo around 13 minutes in, after you short the coil. I know that a changing electric field causes a changing magnetic field, but, what does changing mean? Is it the speed, the position? Can you elaborate on that please?
By changing I mean the strength of the field is is increasing or decreasing over a period of time. So if the electric field is getting stronger, it creates a magnetic field. Same thing if it is getting weaker (although the field that is created is in the opposite direction). But no field is created if the electric field stays at a constant value.
And the effect is symmetric in the sense that just like a changing electric field creates a magnetic field, a changing magnetic field creates an electric field.
The changing part can be done as in our example by using a changing (AC) electrical current to create a changing magnetic field in the toroid,. In an electric generator in a power station, a magnet is moved (rotated) in relation to a coil to change the magnetic field in the coil which creates the electricity.
Hope that helps!
@@ElectromagneticVideos thanks, it does help, one minor hiccup: what does it mean for the strength of the field to increase? is it more voltage, more electricity, or what exactly? Really appreciate it, knowing those particulars helps so much to grasp what's going on.
@@localverse Think of a regular bar magnet you may have played with as a kid. Some bar magnets can pick up heavier things because their magnetic field is stronger, others can pick up less because their field is weaker. In our case (as with more typical transformers) we create the magnetic field with AC current flowing through a coil wrapped around the toroid core. If the AC current goes from zero to a max value, then back to zero, then to a negative max then back to zero and repeats 50 or 60 times a second depending on where you live (60 for me). The magnetic field is created by the current through the coil and its strength (just like the bar magnet) depends on the amount of current flowing. So when the current is a at max, the magnetic field is at max = like a strong bar magnet. When the current drops as it goes to zero, the magnetic field drops, so the field is now less than it was, like a weaker bar magnet.
The ere a more detailed explanation in th-cam.com/video/sc9nqxIfwlA/w-d-xo.html . In December I will do an electromagnet video and a bar magnet video which also may help ....
Pretty cool! Even though the magnetic fields are completely contained within the ferrite toroid, the right hand rule shows that the electric field causes the copper coils to conduct electricity. Did you see it at the Faraday museum in London?
"Even though the magnetic fields are completely contained within the ferrite toroid, the right hand rule shows that the electric field causes the copper coils to conduct electricity." Yeah - is really neat to see that in such an obvious way - usually the "next to each other" nature of inductor and transformer coils and coils makes that hard to see. The funny thing is a number of commenters don't seen to think this demo is real - I guess they must think Maxwell's equations are wrong :)
Museum: That's the second museum in London that has been mentioned, but no - right continent though but not in the UK. I'm starting to make a list of museum that have been mentioned and will post it. I'll; bet the Faraday Museum is fascinating to visit!
This is a very nice demo and nice explanation. I do have to take exception to one part of the explanation, however. The voltage you measure across the closed copper pipe loop is not the voltage in that loop but rather is the voltage induced in your measurement loop. The voltage shows up at the meter because it is the high impedance part of the loop. The rest of the loop, being made of copper, is very low impedance so the voltage is not there. The resistance of the copper pipe is so low that even when supporting several amperes of current, the voltage is tiny. The current in the copper pipe loop produces its own magnetic field by Ampere's law, and this field spreads through the space surrounding the pipe. This field opposes the net field of the two toroids through the loop, and is just enough to make the net field (the integral of the magnetic flux, B, over any surface bounded by the loop) essentially zero, by Faraday's law. Faraday's law works in both directions: the shorted turn of copper pipe forces no voltage around that loop which means there is no net changing magnetic flux cutting through a surface bounded by that loop. This doesn't mean that there is no changing magnetic flux, but just that there is as much flux overall in one direction through the loop as there is in the other direction. Some of the magnetic field produced by the high current in the closed copper pipe loop also links through the measurement loop formed by the meter, its leads, and both halves of the copper pipe loop. This field induces the voltage displayed by the meter. You can explore this by making a magnetic field "sniffer" loop of insulated copper wire connected to your meter. Twist the outgoing and returning wires together except at the far end where the wire is formed into a loop. Use the loop to sniff out the flux in and around your setup. If the loop is formed while linking through a toroid, you will see a significant voltage. When the loop is just formed in the air, it is sensing just the magnetic flux in that part of the air. Without the closed copper pipe loop in place around the toroid, you will see only a tiny voltage outside the toroid because the material in the toroid is containing almost all the magnetic flux. With the closed copper pipe loop in place, you will see some voltage when your loop is in the vicinity of the copper pipe, due to the large current in the pipe producing its own field.
Another test you can do is to remove the shorted closed loop and form a new closed loop linking your toroid but make the loop out of two leaded resistors of different values, say 1000 and 3000 ohms, with the leads soldered together at the ends. This loop will have only a small current (and thus a small induced magnetic field) due to the high resistance. Then use your voltmeter leads to look at the voltages in the different parts of the loop. You will find that the voltage across the 3000-ohm resistor is just three times that of the 1000-ohm resistor and the voltage along either of the wire leads spanning between resistors is virtually zero. The induced voltage shows up in proportion to the impedance. If instead of the voltmeter, you use an oscilloscope that is triggered by the ac line, you can verify that the instantaneous voltage is in the same direction in both resistors, so that the sum of the voltage around the loop is non-zero, in accordance with Faraday's law. (Some people have argued that the voltage around the loop must be zero in accordance with Kirchoff's law, but this test shows that Kirchoff's law is not applicable in this case due to the changing magnetic flux passing through the loop.) 🙂
Glad you liked it Analog Guy! Its always hard to have a discussion like this in a text only format, so let me try and tell you where I am coming from and where I think we differ (and if I get that wrong my apologies).
So I think we agree that the meter reads about 0.2V when attached to the two sides of copper loop. I just did one measurement you suggested: One meter lead though one of the toroids in the chain, other outside the toriod and connected together, effectively a transformer winding with one turn. The result: same voltage 0.2V. And just to prove this is not influenced by the copper pipe loop: same test on an identical transformer not part of the chain and nothing attached: 2v measured. So 0.2V is the one loop voltage of that toroid transformer.
Where I believe we differ is you say the copper loop is effectively a short. I respectfully disagree - is not! It is not because it is a one loop transformer winding for the next core which creates its own inductive back emf. Consider if instead we had a 10 loop coil around the first core attached to a 10 loop coil around the second core. That would not be shorted: the first coil would produce about 2V which would be applied to the second coil. That second coil would draw a current to generate a 2V back emf. If we measure the voltage where the two coils are connected, we would see 2V - the voltage from transformer action in the first coil and also the (necessarily) equal voltage from the second coils back emf. Now do the same taking away 1 loop from both coils so now we have 9 loops in each coil. All the reasoning is the same but we now have 1.8V where the coils connect. Repeat and repeat till you are down to coils of one loop - which is exactly what we have.
Your right about Kirchoff's law being stymied in loops like this - the fact that the loop itself is a voltage generator along with every component in the loop really does a number on Kirchoff!
So what do you think the voltage is if I attach the voltmeter leads to two sides of one of the copper loops, but this time at the points inside the toroids? (ie move 90 degrees along the loop from the measurement position shown in the video)? Answer: 0V.
Thanks so much for the comment! I really appreciate it even if I disagree :)
@@ElectromagneticVideos OK. Thank you for your response. I believe we can reach full agreement. I agree it is hard to communicate clearly when using just text. I indeed agree your measurements are just as you state. I agree the voltages you measure as you move down the chain go up and down in proportion to the number of turns, taking into account a very-slight loss as you move along. I agree about the back EMF from the other cores and the voltage being proportional to the number of loops of wire. I think you and I will agree that you have essentially created a cascade of step-down, step-up, ... transformers.
Please try the following: With your chain of cores and copper loops energized, first touch the tips of your voltmeter probes together, away from the setup. You will of course see zero volts. Keeping the tips together, touch the tips to one spot on the copper loop at the beginning of the chain. I think you and I will not be surprised to see the voltmeter continues to display zero volts. Now, keeping the tips touching the loop, gradually slide the tips apart along the loop. I expect the voltmeter reading will continue to be very near zero, perhaps increasing slightly due to the loop current acting on the small but finite loop resistance. (I think you and I will agree that if the loop were made of a less-conductive material such as carbon, that you would see a more rapidly increasing voltage.) Keeping the tips in contact with the copper loop, continue sliding the tips apart until you can go no farther due to the blockage by the cores. Continue to slide one of the tips as far into the hole in the core as you can go, keeping contact with the loop. I expect the indicated voltage will still be very low. Make note of the point where the tip touches the loop. Now remove that tip, move it over to approach the loop from the opposite side of the core, and again touch the loop at the exact spot as previously. I expect you will now (magically? but not unexpectedly) see the voltage jump up to your figure of about 0.2 volts! Yet you are probing the same exact spots on the copper loop. Can we agree that absolutely nothing has changed about the copper loop? Yes, I hope so. Can we agree that the only thing that has changed is the configuration of the measurement loop? Yes, I hope so. Now the measurement loop links around the magnetic flux in the core when previously the measurement loop did not link around that flux. Thus, we now see a voltage at the meter. This voltage is induced in the measurement loop. Since the probe wires are also made of copper and the current in those wires is very small, the voltage in those wires is very small, just like we saw for the big copper loop. Virtually all the voltage appears at the meter since that is the high resistance point in the loop.
You can approximate the carbon loop by soldering any convenient number of leaded resistors together, forming a loop around the core. Now by probing at different points around the loop (being careful not to form a loop around the core flux with the probes), you will find voltages across each resistor in proportion to the resistance (due to the uniform circulating current, i, times r) and you will find virtually no voltage across each lead wire interconnect because the wire interconnects have virtually no resistance as compared to the resistors. Once again, if you add up all those voltages, they will sum to the voltage produced by connecting a wire from meter terminal to meter terminal while looping the wire through the core.
All this is to say that Faraday's law applies. The integral of the electric field around the loop is equal to the negative of the rate of change of the net magnetic flux surrounded by the loop. Since an excellent conductor cannot host an electric field, the voltage shows up in the loop at the points spanned by higher impedance.
I think the confusion that arises for many people (including myself) leading to the claim that voltage is induced in the wire is due to the way we model the situation. If we are going to use a transformer in a circuit, we want to know the effect of the transformer on the rest of the circuit without having to concern ourselves with all the construction details, materials, and physics such as Faraday's Law inside the transformer. Thus, we replace the internals of the transformer with a model. In the model we ignore the flux and cut the wires and insert ideal dependent sources. (And if we want a really good model, we also optionally add some ideal inductors and resistors to handle the magnetizing current and voltage drop.) These models lead to the very convenient outcome that we can use Kirchoff's laws to set up loop or nodal equations to solve for all the voltages and currents in the rest of the circuit. With a good model, these calculations predict very close to the same result in the rest of the circuit as the real thing. Thus, we tend to begin to believe those sources are really there. In the same manner, let's consider a transistor model for instance. We know it does not include all the detailed geometry, materials, doping, and quantum effects in the real thing, but our model using common idealized components including dependent sources is a convenient means of being good-enough for circuit analysis and simulation.
Rather than saying voltage is induced in the wire, we should say that voltage is induced between the ends of the wire, or between the turns of the wire. Per the Maxwell-Faraday law, there is one sum of the electric field around any closed loop. The field won't add up along the length of the wire because we know that the tangential component of the electric filed is zero adjacent to a good conductor. So the field (and the measured voltage) shows up in the gap between the ends of the wire, or between turns of the wire in the case of a solenoidal winding.
So I have to say the copper loop is still shorted when it links two cores. Indeed, the magnetic flux in the second core is in a direction opposing the flux due to the first coil, such as to produce a reverse EMF that largely cancels the EMF of the first coil. The remaining net EMF is much smaller than it would be without the second core, leading to a much smaller circulating current in the copper loop. Any voltage measurement on the copper loop will produce only a tiny voltage, unless the measurement path encircles a core.
I hope all this makes sense to you and may help to resolve any apparent differences.
It is just resembling electromagnetic transformation, it is magnetic transformation only. All windings are in the same orientation, there is no electric field involved. Besides this, there are heavy losses, because the magnetic coupling is not ideal, this will get warm after some time.
Great demo thanks! I just have one question - when you measure the voltage "across" the secondary pipe @5:49 shouldn't you have to open the pipe connection? You are measuring across a short basically, no? Ok we're dealing with AC here and IxR losses here so maybe this is correct for a "1 turn winding". Thoughts?
Thats a great question! It would be a short if there was no second core that the pipe is going though. Even then it would not be a good short but more like a resistive load because so much power is available at 0.2V that 800A or more will flow though the loop being limited by the (tiny) resistance of the loop of pipe.
BUT - what is deceptive - just as the loop is a 1 turn winding around the first core, it is a 1 turn winding around the second core, becoming the primary of the second core at the same time as it is the secondary of the first core. Being the primary of the second core, means the 0.2V generated by the first core is applied to the primary of the second core (applied being used loosely since it is the same wire loop). Now just forget about the first core and consider that the 0.2V is applied (from some unknown source) to one loop though the second core. The AC current that flows increases until the magnetic field it generates creates a voltage equal to exactly the the applied voltage (OK its instantaneous but its easier think as if it increased till equilibrium is met). This sets and limits the current that flows - the magnetizing current - and so its not a short, its an inductive load. So that inductive load nature of the loop though the second core limits the current and so is not a short.
If that still isnt clear, trying thinking out it with ten turns around the first core attached to ten turns around the second core. Once that is understand able, take away one turn and the principle is the same. Keep repeating till there is just one turn left and all you have the single loop though both left.
Does that help? If not I can try again!
Wow, that's the biggest Post-It in the entire universe.
You saw it here first :)
It’s just a chain of transformers, right? It’s pretty.
Exactly! With the one turn copper windings (pipe) make it hopefully a bit more obvious as to whats going on.
Great video ! thanks . I made a similar object with a big ferriet ring and hi frequency , it was a design of my friend who is teatching me electronics , unfortunately I dropt it and the core broke , but this is a nice occasion to rebuild it , and show it on TH-cam
Thanks! Too bad about dropping the ferrite ring. Sadly they are rally brittle. Would be great if you did rebuild it and made a video - I would love to see that!
thanks I will let you know @@ElectromagneticVideos
@@mirenfred Great!
Thank you. This is fantastic! New subscriber.
Well thanks you Paul! I appreciate that!
Really good. Thanks.
Thank you!
what would happen if the large copper tubing wires were replaced with superconductor materials of the same size?
Then we would have almost perfect, losses coupling between the cores and the device would behave much more perfectly.
An example of perfect behavior would be the if we put a superconducting shorting wire through the most distant core from the power source, the shorting wire forces the the magnetic field in that core to zero as if the core was not there. That means no back voltage from that core to the superconducting copper pipe to the next core. With no back voltage that copper pipe now is a short and the magnetic field in that core is forced to zero. And so on all the way back to the core attached to the power. And with no magnetic field in that core, a huge current flows from the 120V source eventually melting something.
In a much better scenario, in normal operation, we would have close to lossless transmission of power other than eddy current and hysteresis heating in the toroids even for larger currents. Right now with plain old copper pipe the resistance starts consuming more and more power as the currents go up limiting power transfer from one end to another to between 50 and 100W or so. The transformers used as the cores are rated at 180W so its much less than one would like. Even copper rod rather than pipe would be better.
Spooky action at a distance 🤪
Actually sometime when I have more time it would be neat to do some sort of Spooky action at a distance demo!
I saw a video about magnetic current, if I remember it was something that Ed Leedskalnin did at Coral Castle. It is thought that the chain links transferred magnetism but it didn't have the torroidal transformers like you have here.
I assume a 1:1 ratio with current being converted to magnetic flux and that flux being convereted for the next link and so on and so forth.
I had never heard of him or Coral Castle. From a quick read, sounds like he was on the fringe of science for lack of a better term. Also so interesting reading about people like that. If you do come across the video you mentioned please post the link!
Magnetic current - do you mean with magnetic monopoles being the magnetic charge carrier much the way electrons are the charge carrier for electrical current? I was musing about things like that after making the video. Sadly magnetic monopoles are so scarce and if they do exist (or are created in a particle collider) there wont be enough to make an appreciable magnetic current for experiments. Also they are predicted to be way heavier than electrons. I was pondering if one could construct a consistent variant of the standard particle model for some alternate universe where magnetic charge carriers are identical to electrons and you have electric and magnetic antiparticles of each other in true symmetry. Maybe with electric atoms like ours but also magnetic atoms with the magnetic equivalent particles. I guess thats something for the mathematical physicists to tackle!
And yes = "1:1 ratio with current being converted to magnetic flux and that flux being converted for the next link and so on and so forth" is the perfect description!
@@ElectromagneticVideos When I say magnetic current I mean as in passin a current though a coil, then a chain link passes through that and then that link goes trought the next and a the next until you have the desired length. Finally the last link goea through a second coil so current can be drawn from it, or I think that's what the narrator was trying to get at anyways.
@@ElectromagneticVideos
If I do spot the video again I will copy the link.
@@ElectromagneticVideos
What I do know is it was part of the perpetual motion holder, the Leedskalnin wheel and lifting heavy objects and transporting current from one place to where ever else in Coral Castle.
If you unplug it does it turn off instantly or it fades out slowly?
Instantly! Or at least to the human eye. If it was unloaded (no light bulbs) there would be a little "ringing" or at least a voltage spike/decay for a few ms as any energy stored in the magnetic fields dissipates as heat in the iron and copper.
This makes me want to make a giant transformer out of copper tubeing
:) Ijust looked at the videos of you discrete LED low res video displays - really cool!
@@ElectromagneticVideos hey cool , cheers. Just ideas
It would be nice to know the accumulated delay through all the toroid's. I mean how many stages are needed before the final load starts to decrease the input current rather than increase it ? Thank you for this interesting demonstration.
I'm not quite sure what your are asking - is it how long it takes before the input "knows" that that a load had been connected at the other end and the input current increases? The speed of the effect of the load reaching the input is the speed of light in the medium. In this case its a lot like an electrical transmission line (such a 75 Ohm coax line feeding a TV) where the internal speed of light is often around half that of what it is in air. Here we have lumped elements and relatively high inductance's so its probably somewhat slower. Lets guess a speed of 0.1 x the speed of light (299792458 m / s ) and the length of the chain is 0.5m. So that works out to 17ns. Assuming the AC power is clean enough going in, I should be able to measure that with an oscilloscope. I'm planning a transmission line video - measuring the chain might be an interesting addition to that.
@@ElectromagneticVideos Yes thank you for reply, that is exactly what I was wondering about. The input has to travel thru the chain to reach the load but a secondary signal has to traverse back from the load to the input again, in order to affect the input level. So the delay would be doubled I guess. As you implied probably insignificant at 60Hz. I'd love to see a purely magnetic oscillator built on your chain approach maybe loses are too great?
@@smokyatgroups You have to somehow inject energy to make up for the losses but if you did that you could make an oscillator with a frequency of 1/(round trip time). The other problem is it would be a very high frequency which generally doesnt work well with big things, so a very long chain of small loops might make it possible, and somehow use some non-linear magnetic effect to inject power from an external source.
Also demonstrates why you NEVER bolt to both sides of a metal case through a toroidal transformer, as it would create a shorted turn.
That isn't a shorted turn, as it forms the secondary of one transformer and the primary of the other
Yes! I wonder how many times that has happend because someone didnt realize it.
It's scary that you allowed the 3rd and 4th bus bar copper coils to touch. 😳
I have a serious uneasiness of bus bars/open conductors, as a datacenter I used to work at vaporized a 3ft section of a 1Mw bus bar (yes, 1 megawatt) and there was a green, red and black stain on the ceiling above where the bar was.
Its actually not an issue in this case: maximum 0.2 volts potential so less than a one cell battery, and low enough that the natural resistivity of the copper limits the current to about 800A (=max 160W) so no vaporization here. And no issues with them touching - each loop is a self contained circuit so no current path if if they touch.
A 1MW bus bar - wow - I have never seen one of those - I dont work in high power stuff. I can imagine it must have been like when you see videos of pole transformers explode.
@@ElectromagneticVideos basically. I don't work with high power stuff either, I'm a systems (Linux) engineer. I do know that we had a 1 week outage on part of our datacenter floor, and that one of my coworkers near the bus bar in question when it popped apparently soiled himself a little bit.
Great Channel BTW, subscribed.
@@ElectromagneticVideos I've worked in the Generation/Transmission sector. 1MW bus is kinda small. A single 4" x 1/4" Copper bar will do that easy. Last job in that field was modifying Cat diesel Gen control panels and the relatively short 3 phase Bus, really just connection flags rated at 1MW each... 3 units went to a new hospital building locally. 2 in Emergency Service with 1 standby.
The largest DB I made used 3x 5" x 3/8" per each 3 phase - main bus feeding bus ties and several outgoing 2,400A @ 415V circuit breakers. There was multiple stacks of 250A Combination Fuse Switch units too. It was all 60kA fault rated. Parallel bars require spacing between bars equal to bar thickness.
There is a significant amount of design consideration for the strength of bar mounting to resist any fault forces as well as meeting the required mechanical strength at the CB bar connections so that the CB's can achieve their true Fault current rating.
I can say it is impressive to see the resulting metal spray applied in microseconds to brick walls after a very serious high current fault occurs that melts 3x 1 metre lengths of smaller single 3" x 1/4" main busbars. Up close you see lots of interesting colours and textures from the curious hybrid alloy of Copper/Steel/Tin fused onto a brick/concrete substrate.
The explosion tore off 2 heavy fire doors to the main switchboard room... but not a single wire reo glass louvre window pane was damaged.
The fault was huge because the factory was located next door to the Major city sub-station... being the origin of the LV short cable run to the fault. A huge huge prospective fault current presented, despite the correctly rated 800A fuses. Grid engineers estimated the fault was in the100kA range.
That night most of East Coast of Australia suffered hours of blackout due to that one faulty main DB. 95% of the major and minor subs went into a cascade protection fault scenario. If a 350MW base load power station was connected to The Grid it was dumped... each one that dropped triggered another to drop. Same thing happened to suburban HV distribution sub stations. Even backwater country towns went down. That night the Grid came within microseconds of loosing synchronisation between all Power Stations. It took hours to get it all back online.
Can't blame a DIY idiot for that... the mingy stingy building owner... perhaps.
this is cool! can it be done on a smaller scale?.. with less windings etc? i dont understand all the math but itd be fun to try n get one to work
As someone below pointed out (so I'm not claiming to steal their idea) you could use small ferrite toroids and small copper loops if you ran it at higher frequencies and have it really look like a chain. The higher frequencies make it possible to transfer more energy with smaller magnetic cores which is what happens inside switching power supplies in all our electronics today.
Hmm, interesting, I argue that everyone has seen an electromagnetic chain, we just don't think of it as one, The power distribution system itself. power plant to substation, substation to substation, to distribution transformers, to our very home.
Yes - your absolutely right - this one is just made to be a bit more obvious!
Exactly!
I was just going to comment this. GSU transformers, substations, pole pigs, old school wall warts&MOT’s are all this, just with different impedances and multiple smaller transformers in parallel. And then there’s motors and generators which are the same except the bulk of the power is in the motion of one winding instead of the wattage in it…
@@deltab9768 Good point about motors - particularly induction motors - really neat the way the rotor currents are induced from the stator by transformer action.
I never thought of that, but that's absolutely true. we tend to take the convenience of electricity for granted, but without many of the famous inventors and scientists who lived in the 1700s and 1800s, namely Michael Faraday, Greg Ohm, Nicola Tesla and Thomas Edison, to name a few, we would still be lighting our homes with kerosene and whale oil. Quality of life as we know today, would not exist
Found the following version about five years ago, film from 1965... th-cam.com/video/Vwjcn4Vl2iw/w-d-xo.html
Rats, I thought *I* invented it first! But Lawrence Bragg was already using those for his lecture demonstrations forty years before me.
I came up with the idea myself in 1989 as a physics exhibit for science museum. An AC transmission line with no circuit, just EM waves alone. Showing people that "Electricity" is not currents or electrons, because the energy-flow in circuits is electromagnetic. The utility companies are selling us some e-fields and some b-fields, at right angles. Radio waves, but at 60Hz.
Then finally was able to build one in 1991, from some iron C-cores I found in a surplus store, plus some thick aluminum rings! No coils on the chain, just purely lam-cores and rings. My driver was a 300 watt soldering iron, with a loop of #10 solid copper wire in place of the soldering tip, to put out about 800amps. At the output end of the chain, I had about ten turns of hookup wire, driving a small 3V bulb.
I did put up a crude drawing on my website, in 1999, figure 10 in "Right Angle Circuitry"
Sure it's powered through a gfci, but any of the 120 volt windings after the first and even the first one if you say it's on an isolation transformer, could kill you. A GFCI doesn't actually make this any safer. Now because it's all run through an isolation transformer, you could hold on to any one wire and stand barefoot on the floor and it shouldn't get you killed theoretically. Overall though excellent video and I plan on sharing it with people. Keep up the good work.
So glad you liked it - the main purpose of the GFCI/isolation transformer is to protect me if I touch the input terminals. And yes - all the GFCI would do is help if the isolation transformer failed (unlikely). The GFCI is in the wall plug - I mentioned both simply to remind anyone doing this to be careful and protect themselves. Also to your point if you touch both the 120V terminals on any of the transformers you will get a full strength , dangerous 120V shock. The toroid transformers I used also have a 30V winding, and for safety and perhaps for someone doing a classroom demo, the better idea would be to use 30V lamps and power everything from a 30V AC source.
@@ElectromagneticVideos the video really was very good, my comment was just so that someone doesn't misunderstand and think that they couldn't get a full voltage shock anywhere down the line without the GFI getting tripped. What you showed about the magnetizing current makes sense, I had never really thought about that before. It's pretty cool to see how it piles up.
@@chadhiggins8397 Its always good to point out how to make things safe or safer - and I appreciate that! While making a video you don't always remember or think to point out everything or give the best explanation. If you liked the magnetizing current bit you might like the next video which I'm editing right now - hopefully published later this evening or tomorrow morning.
The Faraday Museum in London?
It actually was the Deutsches Museum in Munich. But a few others had also guessed the Faraday Museum in London which I didn't know about. So that's definitely now on my list of places to see next time I am in Europe! Thanks for guessing!
@@ElectromagneticVideos OK.
Please explain how it is that you are able to touch the copper loops without a shock. Also, how is it that you were able to measure voltage on a single single copper loop? Also, how is it that the copper loops can touch each other inside the iron toroid without causing a short? This demonstration makes me feel less informed, not more informed. It’s very enjoyable. But I don’t understand how you have so many praising comments and no dumbfounded ones. ☮️❤🌈
The thick copper loops are 1 turn windings around the toroidal magnetic cores. Because its only one turn, the voltage generated across the one turn is low - just over 0.2V (the input coil where 120V is attached has 500 turns with the same voltage per turn). So with only 0.2V across one of those loops, thats less voltage than a typical AAA battery and no chance for a shock.
How was I able to measure the voltage of a single loop? The voltmeter and its leads becomes part of the loop so even if I connect it to the half way part of a loop, it completes the loop. In this or another video I even just loop the voltmeter leads though the hole in the core to see the 0.2V.
How can the copper loops touch with no short? Well each is an isolated circuit - electrons always have to flow back to where they started - so if the loop is touched at some single point there is no way back for them so no current flows from one loop to another.
I'm glad you liked it but sorry you found it somewhat unsatisfying in terms of explaining things. I'm always faced with the dilemma of a widely varied audience online - how much explanation to include? The one thing I can suggest is look though the comments - many aspects of it have been discussed and may shed some light on how the EM chain works.
@@ElectromagneticVideos to be clear, nothing derogatory was intended. I never lose sight of the fact that content creators or me nothing. I just wanted to voice the minority opinion that I presume others are embarrassed to admit. As an autistic, I always look back on my statements and wish I had toned them differently. But I have also learned that mortals want me to limit my words. It's a tough balance. Thanks for the reply! I'm really enjoying going over your back catalog. ☮️❤️🌈
@@RichardBronosky I hope I didn't seem to imply I thought your comment was derogatory - if I did apologize. My last paragraph was just to let you know where I am coming from in terms of finding a balance of explaining too much or too little.
I thrilled you liked it well enough to look at other videos I have posted and if you have questions I am always happy to try and answer at least as well as one can do typing text and without pen and pencil to draw things.
@@ElectromagneticVideos Your comment was above reproach. You are a man of character. A gem in a desert. I love your attitude. ☮️❤️🌈
@@RichardBronosky Your too kind! And I look forward to your comments in the future!
Interesting, but can I generate power with it to charge up my solar batteries?
Unfortunately its not a perpetual motion machine so you still need sunlight for your solar panels:)
Are there any examples of where this principle would be useful in engineering?
Well general principle shown here is the interaction of electricity and magnetism which is used in generators, motors, transformers etc. But more specifically a transformer made out of loops that are help so they don't touch are used in radio transmitter towers as one kind commenter pointed out - take a look here: en.wikipedia.org/wiki/Austin_transformer
Interesting contraption! But your explanation left me in the dark. What's the overall power loss and power factor? Do the toroids have multiple copper windings (other than the one with 500 loops)? There's two pairs of connectors on each, so maybe? If the windings of the two middle toroids are left open circuit, do they affect anything? Would it be like having a ferrite torus with 1 loop as primary and 1 loop as secondary and nothing else? So a 1:1 transformer?
Yeah - unfortunately to keep videos like this to a length that people will watch there always is a compromise between how much detail and how long it can be.
Let me try and answer your questions:
The overall power loss when unloaded (no light bulbs) was measured to be about 7 watts. The bulk of that would be core loss - heating in the toroids from eddy currents and hysteresis - more more on that in a future video. The restive loss in the copper pipe loops is minimal due to the low currents in them relative to their resistance.
Each toroid is actually a transformer with 4 windings: two 525 turn windings (120V) and two 130 turn windings (30V) intended by the manufacturer to allow 120V/240V in and 30V/60V out depending if they are in series or parallel. I added the two pairs of connectors each, one for 120V (the two 525 turn windings in parallel) and one for 30V (the 130 turn windings in parallel). If they are left open (no load) they have no effect (no current flowing though them) and its equivalent to simply a magnetic toroid. I was debating whether I should remove the windings from the center cores to make that point obvious, but decided to leave them because we can use them to show whats going on in each core with the little light bulbs.
Your absolutely right - the center is just 1 loop 1:1 transformers.
Hope that answered your questions!
@@ElectromagneticVideos Thanks! Yeah, that clarified a lot. I have a decent understanding of transformers as electrical components, but this was quite puzzling because it's so different!
@@renxula Great! Glad to help! And yeah - it is different!
I would like to see the conditions change as line frequency changes from say 25 hz to 60 Hz and then maybe double to 120. I think somewhere around 400 Hz it wouldn’t work that well with iron. Could you try to use a ferrite core torrids instead and then experiment with high frequency. I would really like to know
I think the main issue with changing frequency would first be the thickness of the core lamination vs eddy current loop sizes. I really like your idea of ferrite toroids - you could make a chain of ones maybe and inch in diameter or less, and similarly sized copper loops. And it could be driven with a switching power supply circuit. Maybe sometime in the future!
Scaled down, that could make a nice LED watch band.
I'm going to guess you saw it at the London Science Museum. If you didn't, go there and look for it anyway - the place is a scientific wonderland :)
That an interesting idea - unfortunately I think it would have so much power loss that a watch battery wouldn't last long.
London Science Museum - I hadn't heard of it - but based on your description is now on my bucket list! I did see it in a European science museum that your description would fit.
@@ElectromagneticVideos Yes, you'd probably have to tote around a big car battery to power a watch strap.
A tour of the London museums is quite an experience - beware getting hypnotised looking at the giant cloud chamber :)
@@strayling1 As a kid we visited the British Museum - I always planned to go back sometime. Giant cloud chamber - wow - definitely something I would want to see!
This is one other very interessant video to understand how transformer works...
In this copper pipe alot magnetic fields. Has damage (risc hurt) touch of pipe? (to blood or hands cells)
Glad you thought it was interesting! No real risk from the fields - generally magnetic fileds are pretty harmless. There is some thought that long term exposure to AC magnetic fields from a nearby power line may have a health effect but I dont know if there are any definitive proving or disproving that. I wouldnt sleep next a magnetic chain every night for 10 years, but a few minutes or hours - no porblem.
And this is why inverters still draw 2-3 amps from a battery bank with no load.
Yup. Although some RV ones have low power load sense circuits to keep the inverter on standby when no load is on. Of course that does not work will with the always on AC power adapters for so much of our electronics these days.
I always wondered why the primary side of a transformer isn't just a dead short. I still have trouble "getting" that intuitively, but I guess the current and voltage being 90 degrees apart kind of explains it. Is that because a transformer is basically an inductor? And does it have to be designed for a specific frequency?
Yes - if the secondary is unloaded (and therefor has no effect) it is just an inductor. When the secondary is attached to a load and current is drawn, that current produces a field that reduces the field in the core. That in turn means more current has to flow in the primary to bring the magnetic flux back up to the original level to generate the 120V equal to input voltage. I'm planning a "how does a transformer really work" video probably two videos from now (I do about 1 a week) where I will go into that in more detail.
And yes - they are designed for optimal operation at a particular frequency and power level. As a general rule, the higher the frequency the small the transformer can be. So for a typical AC wall adapter switching power supply, the frequency the electronics create is usually between 50kHz and 500kHz so the transformer can be tiny compared to the 60Hz equivalent. Its thanks to transistors and ICs being so cheap that we can do this.
Saw your eclipse bands video - how interesting - I totally missed that during the eclipse - I'll have to look next time!
@@ElectromagneticVideos Awesome, thanks for the detailed reply! And yeah, I saw Destin from SmarterEveryDay do a call out for people to capture those shadow bands during the eclipse, so I was on the lookout for it. I was fortunate to live pretty close to the line of totality. A lot of other people had the same idea. The traffic around Nashville that day was insane.
The primary is a dead short - just put your ohm meter on it and see. The ohm meter measure 0 Hz (DC). The transformer here was driven at 60 Hz. At 60 Hz the primary of the transformer has an impedance which is primarily inductive and can be easily calculated (Xp=2*pi*F*Lp). F is the frequency part you are talking about and makes it so the transformer is not a short at 60 Hz. If the input AC source has a DC component on it - this can saturate the transformer and / or short the source depending in the DC resistance of the primary. Faraday did not define a transformer vs inductor - IEEE says that a transformer is a device that transfers energy - an inductor stores energy. In power conversion, there are devices that look schematically like a transformer but are in fact inductors per the IEEE definition….
@@justinpenn9250 An inductor is a reactive load that 'stores' no energy.
@@BTW... Sorry dude - Inductors store energy by DEFINITION! Look it up - look up "buck converter" - you will see the inductor stores energy when the switch is on - and supplies energy when the switch is off.
10:17 Bang! Bang! Maxwells silver hammer…
I had never heard of that - had to look it up - not the same Maxwell :)
Nope - this is the first time I have seen this and I have been playing around with amateur radio for 50 years. Is there a practical use for such a setup? KB8AH
Not directly other than for demoing electromagnetism, but for a toroid style core and winding, here is something you would appreciate as a ham: en.wikipedia.org/wiki/Austin_transformer
Are the copper tubes carrying live juice? If you ground yourself they would shock you if you touch them?
They are but at a max voltage of 0.2V so not much chance of a shock from them. And since they form a closed circuit with no connection to ground, there would be no (however small) current through me to ground from them.
Seen this before, and this principal is commonly used in the electrical industry for current metering and heating applications. ie. Current Transformers and Induction furnace coils. You have a 500:1 ratio CT's... plus the unused secondary winding that are left open circuit there! Bearing heaters work the same way. You clamp meter works the same way. This is why when installing toroid transformers in an instrument case you NEVER allow the mounting bolts to form a short circuit (closed loop) via the metal case. Yeah... seen idiots do that before too.
It works in both AC and DC supply modes.
Up for another fun experiment with this setup? Try disconnecting all lamps and then put two fingers across the primary or secondary terminals of subsequent transformers while the 1st transformer is connected to mains supply. LOL
Spoiler: The potential difference there will be a lot more than the original 120V... in fact sometimes so high a voltage that the insulation in transformer winding can breakdown and ruin the transformer. This is why CT's that are not connected to an instrument (ammeter or Power meter) are ALWAYS shorted out to prevent burning out through excess voltage. It does them no harm. It can be very time consuming and expensive replacing CT's in many installations, especially when 2,500A copper busbar passes through the toroid.
LOL... I guess you didn't realise how hazardous that setup was? Frankly, I was expecting a misery yelp when you were handing them energised so close to those open circuit terminals. Sorry, kinda disappointed it didn't bite.
So, here is another circuit configuration you may get a chance to play with... if you have exposure to power industry. Imagine this common scenario - 250A 3 phase AC supply cables connected to a load (perhaps motor or heater) enter or exit a power distribution/control cabinet. The cables are single core... not multi-core, so each cable must pass through an individual hole in a metal plate (gland plate) through their own unique hole.. so, that's 3 phases and an Earth ... maybe a Neutral too = 4 to 5 cables and their holes. Each hole for an active or neutral is forming a closed loop circuit around each conductor. Doesn't matter what metal used in gland plate... steel, Al or Brass.
What do you think happens if a cut isn't made between those holes, which in essence opens the closed loops.. the same as passing all through a single hole under full 250A loading? What do you think happens if it was 2,500A to 3,000A busbars running through a switchboard with similar closed loop metal rings around each bar?
Few electricians realise what will happen and no hobby wannabes would have a clue.
Nice explanation about current transformers! But this is not actually operating as a current transformer. It is simply a 500:1 transformer going in, each middle transformer (toroid) is a 1:1 transformer , and the transformer at the end is 1:500. And of course the 500 turn coils on the middle transformers become 1:500 transformers producing the original 120V. So bottom line - the middle 500 turn coils on the middle toroids do produce and 120V - more than enough for a shocking experience which is why I was careful not to touch them.
You have to be careful when attaching the toriod transformer that you do not create a loop with the attachment screw and housing.
Yes!!!!!! Very good point - you could end up with a giant loop current and something melting or burning up!
Fantastic! I am learning, I want to build devices as a hobby. While TH-cam is a great resource, there is a ton of misleading or outright false info out there. I have many questions and cannot tell very well who to trust when it comes to this kind of thing. I have yet to build, because I want to understand FIRST what I'm doing. I have questions! LOL! What would happen if you placed a rectifier on the first coil? Why is it the AMPS that increase and not the Voltage or Watts? What happens if you wrap a permanent magnet ring with copper wire and apply power? Any direction would be most welcome; I can tell from reading all the comments that you know what you are up to. Thanks for this video, along with any others i haven't seen yet lol, I'm very much looking forward to them.
TH-cam is a great resource but you are so right about some stuff being misleading. Oddly, some people have even accused me of faking this video! No idea what they think might be faked but it might be because so much other stuff is fake. Worse there is some downright dangerous things occasionally send in the electrical or science areas.
If you put a rectifer in series with coil feeding the power in, it would mean the coild gets DC (actually pulsating DC) and really only its resistance (really low) would limit current going in. so a low of smoke and fire - could make a youtube video that goes viral :)
For why is the voltage essentially constant, and current changing, look at some of my other video about transformers and similar things and that should answer a lot of your questions. Hope you enjoy them!
Just Brilliant!
Thanks!!!
Friend, What would happen if you contrived to give one or more of the copper rings some SPIN? What id two of them spin in opposite directions?
I think at the most you might get some eddy currents in the copper generating a bit of heat, but to make that even noticeable they would probably need to be spinning really fast ....
Cool demo! Hmmm, so what happens when you create a 4th copper loop, going from the last inductor back through to the first to make a ring chain?
I realize the voltage potentials in your current loops are insignificant, but still, it makes me shudder to see someone touch a wire moving that much amperage with bare hands. The ElectroBOOM channel has nothing on you!
If you had it the right way so the potentials were about equal, it would be equivalent to feeding power into the chain from both ends and make drawing power in the middle a bit more efficient. If you had the coil in the opposite orientation, it would be an effective short with the current (and power) limited by the resistance of the copper and after a while insulation on the 500 turn copper windings would be melt and we would get into ElectroBOOM type territory. Although his experiments are a bit more spectacular!
There is no point to a GFCI if you're also going through an isolation transformer, or vice-versa. It's a good idea to have one or the other, but having both doesn't give you any extra protection.
Also, you really should turn off the power before connecting or disconnecting things from terminals which are running at mains voltages. An isolation transformer or GFCI still won't protect you from accidentally bridging across the terminals, which can still produce a nasty shock.
It's not that a tauroid is a mathematical term for a donut, it is a donut is a tauroid you can eat
So maybe "Dunkin' Toroids"?
Is that silver paper wrapped around each winding? If it is, why does it not act as though a shorted turn?
I guess it does look like silver paper - its plastic wrap the transformer manufacturer used to protect the windings they put on the original toroid. Your absolutely right though - if it was silve paper it would have made for a much more exciting video!
very interesting.
Thanks! I would have expected a more cranky comment :)
Very cool. You're going to have too much viewer feedback soon.
From one of the electrical terminals at the far end of the chain:
Would they each measure about 60V to ground? (it may depend on where the copper pipe rests in the toroid, so maybe 40V and 80V to ground)
If you grounded one of them (if that's safe, or thru a lightbulb), would the other terminal be about 120V to ground?
I expect the GFCI at the wall outlet will not trip. A GFCI placed at the far end of the chain should trip with one terminal grounded and a fault from the opposite terminal. [edit: a GFCI is supposed to account for a leakage current, but not sure how that works if neutral and gnd are electrically the same]
Thanks!
Your right about the terminal to ground voltage varying depending on the location of the copper pipe or anything else that touches it. Would be very hard to predict because of the very high insulation resistance and for that matter, it would almost almost be impossible to measure because any current getting though the insulation is probably in the micro-amp range. I might even guess a significant portion of any such current might also be from capacitive coupling between the winding and the core.
And yes - if you grounded one or the other of the end terminals, the other would be 120V to ground and with a good connection to ground, be as dangerous as 120V out of a normal wall socket.
And the GFCI on the wall would not trip because it is not in the current path.
A GFCI at the end: The GFCI works by tripping if the currents on line and neutral wires are not equal and opposite. If they are not equal and opposite, there must the current flowing somewhere else so the device trips because that shouldn't be happening.
So if we add a GFCI to the end and ground one of the wires between the GFCI and the transformer coil, there is now a ground path possible for shock type currents. The GFCI should trip if someone were to touch the wire on "the safe side of the GFCI" that is 120V to ground since the shock current diverts some of the away from the GFCI and the two wires going though it are no longer equal and opposite.
You hit on a few neat things that have real applications:
1) GFCIs are sometimes used when retrofitting old houses that do not have ground wires at each outlet. In that case the GFCI ground is not attached to anything and like in the situation above, it protects by noticing the difference in currents on its two wires and shutting off power.
2) The 120V output end of the chain is isolated as you described. There are transformers that are build with an isolated output for testing and other safety applications because without the connection to ground, there are less paths for a current to accidentally go though people. I did a video about that here: th-cam.com/video/olq9wdeNS4c/w-d-xo.html
@@ElectromagneticVideos In Scenario 1... here, such a residence would be disconnected from mains supply until it complied with current Standards wiring rules. No two ways around it.
No electrician would touch the place until it was agreed the work be done in accordance to such rules, in fact, we are obliged to disconnect rather than risk their Licence to work in the industry be suspended. No self respecting tradesman would work on the place... because as the last person to work there they would be blamed for not disconnecting when someone gets killed.
Oh yeah... we don't allow unlicensed DIY idiots to work on Mains wiring systems in homes, unlike the USA and UK. Good luck with that recipe for disaster.
Senario 2.
Touch between the two transformer output terminals, or circuitry after and get the belt of a lifetime. Isolation Tx have a very specific limited use, because all appliances in use in a home should have an Earth/ground available if it is needed... eg. if they are not Double insulated construction. Anything with a resistive heating element built into a metal hotplate or pan require such an Earth/Ground.
Also, there are sound reasons for Neutral Earth bonding that far exceed and perceived 'additional means' of accidental electrocution.
One other matter noted there.... you can find a lot more than your 120V AC across the terminals of that Tx in an open circuit situation... both sets of windings.
The copper pipe used has a very thin wall section... low Cross Sectional Area that would hardly carry 40A at below 75 C... or 105 C, for extended periods of time. If it was cable with a CSA of 25-35 sq mm and so, a safe current rating of 80-100A there would be no problem shorting out the winding terminals (BOTH) for safety. They will NOT burn out from overcurrent or heating effects. Do the math... All Tx after the one energised by 120V AC are CT's with a ratio of 500:1 Pass 500 A through the core and get 1A current flow into a high impedance voltmeter load. Open circuit they can suffer HV insulation resistance breakdown that renders them useless as a VT or CT... and provide a significant shock to those playing with 'em.
@@BTW... In the UK unlicensed idiots are not allowed to work and house wiring.
@@Bernie_the_Bolt Very wise policy if enforced.
Very interesting!!
Thanks you - glad you liked it!
@1:28 electrically connected? That torroid looks insulated to me. If it wasn't and you were holding it in your hand you'd be holding onto mains voltage with your hands. The copper is insulated from the transformers. There might be some eddy current in the copper, but there's no electrical connection.
OK, this might be for people have no idea what any of this stuff is, but as a power electronic engineer, let this for a while and then look at it with a thermal camera. That light bulb has almost nothing to do with the power consumption of that chain of stuff.
You might get to that point sometime in the video but its frustrating to be made to sit through grade school level introductory electronics.
You saw it at the Tesla museum in Serbia
Well I guess that's a museum I have to go visit! I did see it there but your on the right continent!
Doesn't an isolation transformer defeat the purpose of a GFCI?
Actually yes - no need for both. I just mentioned them because I have GFCI in the wall plug and wanted to assure people I was taking some precautions.
God's. What are the vars on that?
The powerfactor on that has to be massively thin
I would love to see if you added capacitors on your single copper pipe winding. And see if you could drop that unused power use.
And the power factor gets worse as the chain gets longer but is actually quite low: the unloaded current in the copper pipe 1 turn winding at the last link of the chain is 5A at 0.2V so 5A x 0.2V = 1VA so each core adds 1 VA to the system. So at the input end the amount is about four times 1VA equaling 4VA from the 120V input. The transformers I used are rated at 180VA so if the system was fully loaded with a 180W load the power factor would be pretty good!
Hey. I got an idea. Attach 120V to the other end of the chain and wear it as a necklace for a few minutes? I hear its pretty cool. 😁
I think from the weight alone you would get a stiff neck!
@@ElectromagneticVideos You would go stiff all over if ya got the shock of a lifetime.
@@BTW... I actually experienced that once as a kid - was in the garden and my leg hit a hidden live wire under a metal windmill tower which I was holding onto with my hands at the time (no better ground than that) - was completely paralyzed but conscious. If my mom hadn't noticed something was wrong and and pulled me away I wouldn't be here. And that was in a 240V country - really amazing that I survived.
7:02 what's the point of using a GFCI if it's followed by an isolation transformer? That completely defeats its purpose.
If you power the first 500 turn toroid coil by itself, with no copper ring, how many amps?
how many amps with only a copper ring?
how many amps with the second toroid added, but shorted? ("lots" right?)
At 4:23 the 1 turn magnetization current is measured to be 5A. Since the 120V coil is 500 turns, if we powered it with 120V (and no 1 loop copper), we would expect 5A/500 = 10mA.
Powering the 500 turn 120v coil with 120V and a copper rings with no second core. Thats a dead short - so huge current limited by the resitance in the primary and secondary. Same as your final example " second toroid added, but shorted" = "lots"
So the really interesting thing is putting a second core though a shorted coil ends up "unshorting" it.
@ElectromagneticVideos that's strange! Adding a shorted secondary shorts the primary wirelessly!
@@Iowa599 YES!!!!! Exactly! You could think of it as the transformer acting in reverse: the shorted side is 0 volts, so that gets transformed to the primary and regardless of the step up or down ratio, any ratio times 0 is so. So V across the primary = 0 = a short.