Whoa! The feedback from everyone on this build is tremendous. The outpouring of love, mutual excitement, and kindness i'm seeing from people in the comments section is so empowering for me to see, and i'm honored that each and every one of you took time out of your day to enjoy my video. I just really love Plasma. Thank you to Skillshare for sponsoring this video, and good luck Mehdi, Drake, and Joe (lol).
Assuming scaling up means more difficulties with potting- When doing very large motors & generators, we lay a strip of tissue like paper, or thin cloth dipped in resin between groups of windings, & between separate sections of the same winding, maybe every 300-1K turns (depends alot on the wire gauge) & for or high amperage we use fiberglass strips dipped in resin. This aids in 3 ways, 1) If a section fries it is almost always contained to 2 adjacent windings, either layered above/below or directly next to the armature of wire. 2) It allows snipping the lead wires to the coils & testing which coils were "kissing". 3) Offending coils can often be replaced with minor work compared to a brand new build. My recommendations: At the very least, make the coils independent- so you can print them off in modules that you can just snap together after potting, solder adjacent wires & where the solder bead would be cover it with silicone covered fiberglass tube (often used in high temp/high amperage electronics), or a good D-clip connector, so if a coil goes up you can literally just swap it out for another one without destroying the entire build. Also I suggest using slower curing resin- & use a cooking / gram scale to measure as close to exact amounts (if it's 2 or 3 part) epoxy/resin & stir extra well, so you don't end up with pockets of uncured resin. Gravity does terrible at trying to pull viscous liquids by itself. Vacuuming out the air from the resin prior to poring will help alot. Pour it, pull a vacuum a second time, let the air back in for a few minutes, & repeat, until you no longer see bubbles. If you have a chamber capable of pressurizing as well that's much better & much faster (like how a pressure cooker cooks faster). If our having issues with transistors/components blowing, always rate for at least 1/3rd more than you need, ideally, go for double-4x for something that you should never need to replace, except a fuse; always use a fuse- preferably a "fast blow"" in conjunction with a lower rated thermofuse- like what are used in circuit protectors that can either be manually reset or will reset themselves when they cool down. During testing we used transistors mounted to a heatsink not unlike yours, but the leads just plug into metal receptacles on the board, to avoid re soldering them every time they blow. Using diodes to prevent backfeeding & having good channel/module isolation is a must. A capacitor shunted to a small ceramic resistor is a good way to safely deplete sudden voltage spikes also. You'll save a ton in additive costs of cooking components by adding $1.50 worth of safety measures.
you're going to nerd snipe me and try to get me to make a transformer with a higher voltage step up ratio eh? are resonant devices like tesla coils allowed? :p also at 16:50 i could feel the pain as that kind of thing has happened to me so many times. i was already nervous from you extending the electrode distance for that very reason lol
Was about to comment the same thing, a couple resonant transformer with 0 resistance (impossible) mathematically hits infinity voltage, the problem I had with those are the transistors, they tend to explode for some mystical reason 😅
@@JeffGeerling My favourite Raspberry Pi creator replying to my favourite 3D printing creator who himself is reply to my favourite HV electronics creator?? 😮😅❤
Electroncis guy here, you will get lots of benefit placing decoupling capacitors as close to the FET and supply as possible (not the electrolytic one used in the video, ceramic will be better). Not all capacitors are the same, you need a low impedance with a value tuned to the circuit. also on your driving circuit, during the low state, a flyback diode will save your transistors from shorting from the high reverse voltage created during the field collapse
Thank you! Indeed there is...it would mean driving the frequency above our audible range. Which is easy to do with the driver. But...the transformer would need to be built entirely differently. One with less turns and a higher resonant frequency.
@@PlasmaChannel so cool! I’m assuming a higher frequency would need more power for the same voltage increase but I have no idea if that’s the case because electricity is magic to me.
nearly 70 years ago,I worked in a facility that built high voltage power transformers,did not allow bare fingers to touch the enamelled wire,fingers have acid ,body fats,you name it.the windings were heated under vacuum,to drive out moisture, after a certain time under vacuum and heat , a special varnish was admitted to the vacuum tank,and the wings were impregnated with varnish.The windings were then place in their respective steel tanks and sealed,vacuum was again applied to the enclosed windings in their tanks,dry nitrogen was then admitted to the enclosed tanks at a positive pressure of 2lb's per square inch,ready for transport.At arrival at he the substation the transformers were fitted out with bushings[insulators].when finished the transformers were then placed under high vacuum,2mm,comes to mind.When this was achieved,pumping stopped ,the vacuum had to be held for 2 hours,with only minor loss of vacuum .Oil filling commenced,under vacuum.And that was 70 years ago,shows the extent that the manufacturers and construction crew had to go to to contain HV. reliability.Frogot to mention that the trnsformer oil was also tested,had to withstand 50kv at a 1mm gap.
You touched on one point that deserves a little more attention, purging with dry nitrogen. When trapped air is ionized by high frequency/high voltage, it is converted into ozone, monoatomic oxygen and oxides of nitrogen. All of these gases are powerful oxidizers and will attack anything they come into contact with, especially organic materials, which will leave conductive carbon residues exactly where you don't want them. Substituting N2 for air greatly reduces this problem. For even better dielectric performance, purge with sulfur hexafluoride gas (SF6). SF6 has an incredibly high breakdown voltage and is used in megavolt rated circuit breakers and switchgear.
Solid state transformer (10kV to 375V DC for data center) engineer here. When we pot transformers, we use high pressure. Vacuum degassing is cool, it is not thorough. We use a combination of heated ultrasonic (pre-vacuum and post-vacuum) degassing, vacuum soaking, and high pressure curing to minimize air pockets. The problem with using only vacuum is that pressure can only get to zero, no less, so the maximum force can be excerpted on tiny (low surface area) bubbles is limited and that force can be well below the force trapping it inside. When cured, not only there is a gas pocket, it is also low pressure, making it even easier to breakdown. By applying ultrasound, we shake things up, and the heat lowers its viscosity so the trapping force is lowered. Finally, we apply high pressure to make sure the remaining bubbles are packed tight and their breakdown voltage is increased. You don't need a very high pressure, 0.5~1MPa is enough (commonly used for cast resin art projects, you need some training though as a bucket holding 1MPa is undoubtedly dangerous). We also do partial discharge testing (hi-pot for instance) with fast breakdown counting equipment to grasp an idea of how many air bubbles are there, early PD count is strikingly effective at predicting insulation reliability and lifetime in the long run.
I have had excellent results using a vacuum oven with a potting material made from beeswax and rosin, previously melted together and cooked at higher temperatures than required to simply melt it. Once all bubbling has ceased, I keep the oven hot but let the pressure come back up to atmospheric, slowly, and then let everything cool overnight before opening the oven. Once such potting job has lasted for fifteen years and hundreds of hours of operation. I believe one term for the kind of high-potential test equipment you are describing is the "Holiday Detector" - yes?
@@zinckensteel Wax is an amazing high voltage and high vacuum material, commonly used in accelerators and other science apparatus. One valuable nature is that it flow very well above certain temperature, way better than epoxy monomers, but the resulting pot is not as hard and mechanically stable than pure epoxy, so they don't see may uses outside scientific applications where maintenance is expected. The PD detector I mentioned is not exactly a holiday detector but works similarly. Holiday detector uses a brush to examine the surface, while a PD detector tests between two electrical connections, usually between the windings or a winding to the shielding or the core. More like a hi-pot tester, but with pulse counting capability.
Just know, I really want to like this comment, but I don't want to ruin the perfect amount of likes lol thank you for this info, I'm personally working on a new concept for cores to hopefully reduce (ideally remove) eddy currents all together [hopefully this is not already done and im unaware]. I love reading and learning trade secrets on how to do certain processes for the best outcome. Thank you for sharing this info
@@zinckensteel I guess that the 19th century scientists/engineers used exactly what you describe. Is expoxy better? I don't know. Regarding old methods/materials, the pre-war TVs here in England usually stepped up the 50Hz mains (lethal!) to 5 kV or so but break-downs were not unknown. Many years ago, one of the DIY mags over here descibed an EHT divider probe with a stipulation that candle-wax was not a suitable insulator. Any comments, please? Best regards!
A good way to avoid air pockets is to pump out and after the bubbles stop, let the air back in and even pressurize the pot as much as the chamber will allow. This will force the compound into all the voids and any remaining air bubbles will be a fraction of the size they would be at atmospheric pressure. I learned this from some friends who resin clear cast for a living.
Could also take advantage of the airgaps between the three winding sets. Add some horizontal drain holes that go from the winding chamber to the empty chamber next to it. Then, when you vacuum/pressure pot it, the resin will be able to fill in from below as well. Since you're resin-potting it anyway, the holes won't matter because they'll be filled with the resin.
Having gone through the pain of designing and building classic induction coils driven by trembler contacts, classic insulating materials, vulcanite, paxolene (resin bonded paper ), mica, densified wood etc.. Cores made of bundled iron wires, florist wire. The one thing that was the most frustrating was using epoxies for insulation. Once set, they cannot be disassembled. Oil is the choice material for high voltage transmission transformers. It's messy and needs leak proof containers and glands to take conductors. But for convenience and superb insulation, I found that ultra refined bees wax the best all round solid insulator. It degases well under vacuum, is far more fluid than epoxy, back to solid at room temperature. But the best thing is......, you can melt it out after a whoopsie and recover most of the components for reuse.
I love your videos for so many reasons 1. Well researched 2. Easy to follow 3. Interesting 4. Escape from the madness of all the wars in the world 5. Hope that humanity will use your experiments to build startrek
So long as there are at least 2 people alive, someone is going to want someone else d3ad. If the country at war isn't your own, and you have no other ties to it, it's best to just ignore what's happening, otherwise it will just weigh on your mind unnecessarily. Keep your mind on things you yourself CAN control, and don't get put down by the things you can't.
@@Handles_AreStupid Yeah, I need to take your advice in this area. I am SO incredibly sick of political shit going on. It just saps my creative and other energy's in other areas of my life. Time to go on a NEWS FREE DIET.
Finally - someone else with ‘Shitty Flyback Transformer’ squeals all over the place. As that played I hear some dissonance and then either my head or his transformer came together for a second.
@@azurefog for me the transformer amplified the ringing for a short while, I don't normally notice it since I have a fan running at all times to create white noise I recommend it, it helps so much
@@goatboy150 I'm not sure exactly what you don't understand, but I'll try to clarify as much as possible Tinnitus is a ringing in ones ear that can either be constant or it can come and go, it can be caused by head trauma, hearing damage, or even build up of ear wax "shitty flyback transformer squeals" is just a way of describing tinnitus Dissonance is the lack of harmony among musical notes
Some people in the comments already mentioned core air gapping - when you're driving the primary using pulses (and not a nice, clean sine wave), you're basically creating a flyback converter. With a sine wave, you'd be using your magnetic monstrosity as a linear transformer - input voltage is a sine, primary current is a sine, core magnetic flux density is a sine, voltage induced on the secondary (output) winding is a sine, all is good. If you do that, you want to close the core (bring the two halves as close as possible). With a flyback converter, at every start of an input pulse, you force a voltage on the primary winding, as with every inductor, the current increases linearly, but very soon, you reach a point where the core saturates and the input current shoots up. You're no longer storing any more energy in the core, you're just heating the primary winding. When you're driving it like that, you might want to consider adding an air gap to the core - a small shim of paper or mica between the two halves that keeps the two halves at a known distance from each other when you clamp them together. Yes, the coupling between primary and secondary decreases, but saturation comes much later and you can dump more energy into the whole system with every pulse. You could add a small shunt resistor to the primary to observe primary voltage *and* current during operation (on your two channel oscilloscope) or just strip some insulation from the primary a couple of centimeters from the negative connection point to the driver and use resistance of that piece of wire as a shunt - it will drift with temperature but that's alright when you just care about shape of the input current - a qualitative measurement, not a quantitative one. I would definitely watch a follow-up that properly explores what exactly happens when you change the duty cycle, frequency and input voltage of the driver. Of course with high voltage transformers there's much more going on that meets the eye, resonances and such (as you beautifully demonstrated at 15:10). It's great to see you learned a lot with this project, it'd be even better to watch you try to explore this thing in even more depth. The more you know about what exactly goes on in your system, the easier it is to predict what will happen when you change it. Cheers!
Excellent advice! I couldn't have said it any better. Also I would like to mention this. The driver issue from multiple MOSFETs was almost certainly not a load balancing issue but instead a gate drive issue. A 555 timers output is not suitable for sourcing and sinking that much current. A gate driver circuit likely would have solved the issue.
@@johnconrad5487how so? They can be broken down in half and quarter waves and you can play around with negative voltage pulse resonance when you get everything tuned up right
Having an air gap in the core will also increase the resonant frequency. This is not only good for our hearing, but also for the efficiency of the circuit. Most MOSFETS and ferrites are very happy around 100kHz to 300kHz. But making such a massive coil with a high resonant frequency is a tall order! The windings must be neatly wound in a layer, and every layer must have its own insulating layer with a low dielectric constant. You need a lot of patience to do this by hand, lol.
Great work loved every minute of this! I am a professional mold maker and i can see one hurdle for you. Degassing (using a vacuum chamber) will not work the way you need it to here, you would benefit from degassing prior to pouring but once it is in the form it is doing more harm than good. As strange as it would seem you really need a pressure chamber for your intended use (i would sill degass first!) a pressure chamber will make sure your mold is filled, preventing gaps and any air that is trapped will be compressed into microscopic pinpricks that will not be conductive enough to be perceptible. orientation and vents will also be critical, you can add those into your model very easily and they will also be good witness marks that the mold is evenly filled. Looking forward to your next project!
For 3 transistor approach , try reducing the duty cycle by 1/3 and put the 3 pwm signals out of phase by 120 degrees, that way you can reduce the avg power on each transistor, and they all get their turn
Nicely done, it looks fantastic. Just one tip from someone who worked with research HV installations big and small for many years - never, ever lean over or point a digit close to an HV source. I suspect the resistance of your secondary was quite large and the frequency high enough that you would probably have been ok, but you don't want to find out the hard way (strictly it'll be your friend/partner finding out). Rule of thumb: a 5 joule pulse across your heart will generally kill you, that system as a whole involved far more energy than you want potentially passing through you. In my early career I ended up in hospital after an accidental discharge while I was reaching over for a tool (much like you did). It was a spark gap trigger based around an auto transformer. The stored energy in my system was far smaller than the continuous supply you were feeding that transformer.
Challenging Styro to that could result in him blowing off a piece of the moon and destroying man kind. The guy trains moths for gods sake. He’s a super villain.
I feel ya... One of the, then, two remaining Blockbuster stores was near my cabin in Alaska, and for many years was a common stop for us. Alas, it finally closed its doors like 6yrs or so ago. I think the final one did so ~3yrs back. RIP Blockbuster Video 🎞️ 😞🫗 Thanks for all the childhood memories, renting movies and video games!
A lot of towns still have them, just not affiliated with any big chains. Here in the PNW there's quite a few, from recyclers who will sell components on the side to surplus vendors to b2b companies supplying the big boys who might take a private order from a polite hobbyist...
Looks like you learned some of the same lessons about mosfets that I learned when building my coilgun. One tip on the vacuum potting as somebody who's done it before: Reverse the pressure once most of the air bubbles are out. It'll help force the epoxy into any voids that were left by the bubbles vacating. You can also try rapidly cooling the vacuum chamber with liquid nitrogen or even an alcohol+dry ice slurry (the poor mans liquid nitrogen) to help get the pressure down quick before the epoxy hardens. Not sure how well that'll work in a home setup, but we had a vacuum chamber at work designed to work that way.
Hey this is cool! I'm an electrical engineer in the eVTOL industry with a phd in Power electronics. It's awesome how you built the step up converter with the research you did, really impressive. A few improvements id suggest. You can really shrink down on the size of the transformer, and get rid of the annoying whining, by raising the switching frequency and going with a resonant converter design. Around 1MHz and the magnetizing inductance can be very small. Operating at resonance increases the gain like crazy so they can be multistaged too. And the FETs burned probably due to switching loss and or gate charge stress at high frequency. Silicon carbide or GaN switches probably fare better here. Also not entirely aware of the topology but higher voltages will stress the Vds rating, especially in flyback where drain to source stress is really high. Multilevel topologies, flying capacitor, or switched capacitor topologies off the top of my head can help with the component stresses at high voltages. Anyway this was awesome, will be following for more updates ⚡️
For Heavens Sake! The poor guy is enjoying his hobby. He hardly knows how to drive the FET and you guys are making all kinds of complicated suggestions.
You make it look so easy lol It's too easy to watch this video and say "Hey, I could have built that, no problem!" However, that's ignoring the massive research and experimentation you did to get it to this stage. That's the beauty of educational videos like yours (Thanks and double thanks!) If trying to build a homemade two-stroke engine from scratch when you know nothing about that, simply watch somebody who has already gone through the design failures and finally found the one that works and viola!, just build it the same as they did, make your own small modifications, and you're golden! Being a designer myself (3D CAD), I'm very aware of the difference between plagiarizing (bad) and proper attribution (good). If I built this transformer, I'd never fail to inform my amazed and impressed friends that "Yeah, there's this guy named Jay with a channel called 'Plasma Channel', it's a copy of his design." 👍😄
Absolutely love how your channel has progressed. Your content was always hella interesting but your earlier videos definitely had a more tryhard professional vibe (not necessarily bad, just less enjoyable and engaging to myself), but now you seem so comfortable just sharing your special interest through these projects. Plus it's great to see you interacting with the greater yt maker community at large too
I love that you put the mosfets in screw terminals. That's how I know you have had the same experience with them as me, that is to say, you know it's far easier to cook them than it is to solder them...
Very serious impressive results, I did make an air core Tesla coil using a small 9 volt battery which gave a 2" arcs using relays in 1988, the thing that made it impressive was not the arcs but when it was sitting in the dark for 2 months, a creeper plant went 3 ft around to the window into a small crack and 6 ft towards the coil and wrapped itself around it with about a dozen windings of the plants tendril vine. I inadvertently tuned it the the plants frequency as the leaves were thriving in the dark, this had spurned me on the study the nature of plants and living resonances.
Man, i'm so honored you think so. Thank you so much. Comments like this put a smile on my face and encourage me to keep pushing further with builds / videos.
@@PlasmaChannel Are you sure the mosfet issue wasn't due to the lack of a gate driver circuit? A 555 can only source and sink so much current. Once you exceed that current level a gate driver stage is needed.
While vacuum is helpful in removing the bubbles, I have found that curing the epoxy under pressure gives the best results. The reason for this is that the bubbles shrink and air has a higher breakdown strength at higher pressure. The best procedure would be to degas using vacuum and then pressure for the duration of the curing, so that the remaining bubbles are at high pressure. FDM 3D printed pieces are super unreliable under electric fields, so nice thinking using resin printing
* * At 20 minutes, the guy tells how "a coronal discharge eats away the insulators" That is, the electrons in the 65,000V voltage in the state are direct beta velocity flying radioactive beta radiation erosion
Your videos are great! I work with 65.5kV with our H- Ion Source for the Spallation Neutron Source at Oak Ridge National Laboratory! we get to have fun blowing up all kinds of equipment when our system arcs over. Even "Ruggedized" equipment meets great challenges when you combine 80kW of RF and multiple high voltage systems into one environment!
You should extend that Challenge to Alpha Phoenix. That dude does some great science, and I believe could crush it given some of the speed measurements I seen him do with the speed of electrons means his abilities to get proper resonance on a system should be spot on. I noticed a huge difference just switching to low impedance flat caps(instead of saltwater caps) on a tabletop tesla coil that if you can feed resonance circuits really sharp waveforms (TEA Laser setups with nanosecond pulse widths) its output abilities skyrocket. It's also neat to hear the spark gap change from a snap... to a ting like someone flicking a crystal wineglass. Thats how I can now tell if a circuit is low enough impedance to trigger lasing in such setups.
You would be surprised.. Standard Hot Glue can hold off 125KV at 1/4" thickness (8mm disk to flat ground plate). I ran a bunch of tests when I worked at a National Lab.
I had an auto ignition coil in my childhood that produced more than an inch of spark from an antique 12 V toy train transformer. In perfect weather, maybe I got 1.5 inches. I never stuck my finger into it, but I did stick the end of a cheap plastic ballpoint pen into it. That pen turned out not to actually be a good insulator. It launched me six inches into the air. My shop was a rebuilt chickencoop and I was sitting in a lawn chair. When I landed, as I sat there almost paralyzed by a taser, I observed that if it had stopped my heart, it had also restarted my heart. No worse for wear. Memo to self: Do not assume common objects regarded as non-conductive are truly non-conductive. I also spent a lot of time pushing the plasma around with strips of paper, until the paper caught fire. It never got old. My device used a magnetic interrupter that opened physical contacts at maybe 50 Hz. It buzzed. This was the late seventies. I can only recall that it buzzed. At first, the interrupter arced so badly I got almost no final spark at all from the secondary. One day I wired some unknown mil-spec surplus capacitor across it to damp the arcing and suddenly IT'S ALIVE! The spark off my secondary was glorious.
When you pointed at the arc, it reminded me of when our maintenance foreman pointed and said, I see where the short is at the same time hollering because the tip of his thumb disappeared as the art jumped across to thumb
The fact that you don’t have millions of subscribers is mind boggling to me. Your production quality and the tech you’re building are pushing serious boundaries! Loving your videos, keep it up!! 👏
I have been following all the videos since I discovered this channel over a year ago, and as someone who is not in the field, I find the videos super intuitive and easy to understand, even though the topic is extremely complex. Congratulations on the videos!
That really is an attractive transformer. I went to trade school for electrical linework, and though things didn't work out that way exactly, the education was invaluable. Also, I appreciate being able to see windings, insulation, etc. Most of what I learned about transformers was on a textbook page and everybody in electrical work knows that diagrams and formulas don't always help. Nice work! Thank you.
Some tips regarding the Driver: I know the perf board is therapeutic but it is also a nightmare for hf currents. PCB`s are really chap nowadays and KiCAD is free. A missing Ground Plane might be the Reason why the Squar Wave looks so erratic. As I didnt see anny, put some thermal compound under the Fets! Either Past or a Thermal Pad. Keep in Mind that the Backplate of the TO247 Cases you use are conncted to the Drain so the Sink might be under whatever Voltage you are using. Also, for switching use, paralelling Fets normally Works rather fine., or at least in your application it should. It Could be that the Drive signal wasnt equal for all three due to the perv Board. The roundnded edges of your Square Wave indicate that the circuit driving the Mosfet cant handle the gate capacity, which also increases losses as the Fet goes through more of its linear region. A gate driver would be recommended here. Otherwise, massive Transformer!
I think he uses the output of a NE555 directly for gate driving. The NE555 can only source 200mA maximum and power mosfets generally require quite a bit more than that to drive it at any interesting frequency. I think this was also probably the reason for failure of the paralleling mosfets. At low enough frequencies the lower current can probably drive (one of) the mosfets mostly past the saturation region and into the linear region fast enough to avoid major thermal issues, but at higher frequency, only one mosfets gate capacitance gets enough charge to conduct but gets stuck in the saturation region and completely overheats maybe
@@gielb2001 Ive used a MAX232... it can turn the 555 output to a +/_ driving waveform with its own internal supply generator (using two external caps). since RS232 signals are differential and swing positive an negative... they work great for power MOSFET/IGBT drivers... plus you dont have to deal with high side and low side drivers that need a seperate power supply. the other issue is that the way he set up the 555 he is not varying a clean 50/50 waveform...but rather just changing the off time. transformers prefer clean 50/50 sinusoids for the most efficient coupling.
@@renaissanceman5847 Thats a pretty neat solution if you dont have a gate driver on hand! Tbh for the price of a MAX232, you could probably get a decent half bridge integrated gate driver IC as the MAX232 has a very limited sinking/sourcing current capability, which will limit switching frequency, it also has like a 200 Ohm output resistance so that will slow switching as well and probably increase switching losses quite a bit. The integrated drivers also often have integrated bootstrap circuits that only require 1 capacitor and can sink source multiple amps in general. The dutycycle thing I fully agree with, seems like a pretty big oversight in his design..
Wow, do you hear that too? My ears start ringing in the highest pitch I can perceive or have ever heard! Every time he turns that thing on, my ears start ringing like crazy. Never experienced!!
2:34 Those development boards are very therapeutic to design and build. I recently made my first constant current variable voltage board, and it worked, I'm quite proud of myself😊
A tip for making these videos more pleasant to watch: I'd recommend putting a low pass filter or notch filter on your audio when you run the arcs to cut out frequencies above 10k+ hz. The high frequency sounds are exceedingly unpleasant to younger folk and may be far worse for those with sensitive hearing.
Or maybe just reducing the loudness of the high frequencies by a large margin. Because it's the reality of working with these circuits, they make high frequency noise... Just like a CRT TV, which is around 16khz I believe.
love the clean electrical work and soldering. Dad taught me to solder when we made my 1st Heath kit back in the early 70's. Clean/neat solder lines were as important to him and how he graded my work. My mother that was teaching me hand sewing, cross stitch, embroidery and the like at the same age. The neatness and beauty of the how the backside of the work was dressed is equally as important as the work itself.
@@AnErrantPhoton We're slowly becoming used to seeing materials in metric, but our daily units are imperial. As someone that studied a fair amount of physics in school, I like metric a lot more, but imperial is fine for day-to-do things, which was basically the point.
This is amazing work! I've tried making a very simple DC to AC circuit and an air core transformer which ended up getting... the same voltage out. I learned a lot from this video and I look forward to seeing what else you can do with this awesome device!
Dude I love your job too! It is indeed a beast. I do have a couple pieces of feedback you might find helpful! 1. When used in switch-mode supplies and driven with a gate voltage well above the threshold voltage, MOSFETs actually are perfectly fine sharing current. The threshold voltage has negative temperature dependence and hogs current if all parallel FETs are supposed to be half way on like in an audio amp, where matching matters; but the Rds,on parameter (on resistance) has positive temperature coefficient, so actually they share fine when they're driven nice and hard. [but, you say, mine blew up so that can't be right!] HOWEVER, what FETs really REALLY don't do well is direct parallel gate connections. This is a super subtle issue that's very difficult to catch with instrumentation or measurement. What tends to happen is that right as the FETs switch (and are in fact half way on) the gate wiring and source/drain wiring's parasitic inductance form a parasitic push-pull RF oscillator of very high frequency with the gate capacitance of two or more parallel fets, and the FETs oscillate, shuttling the current back and forth between them and never turning fully on. Blam, either a gate punch-through due to excessive oscillatory gate voltage or overheating due to switching losses. I think you may have had the former. Just a couple ohms in series with each individual gate (10 is traditional if one is shooting from the hip) will break the oscillator's resonant circuit. If you want to do parallel FETs next time, throw in those gate resistors. It'll help. 1b. Also, helps to form a "kelvin" connection from the gate driver to the source bus wire connecting the sources of the FETs. More or less like a star ground: the important part is to have a separate path going to the sources just from the driver IC, and separate from the switched high current that flows from the input power supply and input filter capacitor. The gate drive IC wants to "ride along" with any bumps and spikes that happens at the FET source, so you really want the negative pin of the gate drive IC to be connected to those sources with a wire that has no significant power current through it (other than the actual gate drive current). Otherwise the wire has voltages spikes along it too and the voltage differences between the FET source pin and driver IC can actually turn the gates back on as the driver tries to turn the FETs off. The positive supply to the gate drive IC needs a separate filter capacitor, and maybe a small number of ohms resistor between the plus pin of the driver IC and the actual power input, again to let the IC bump along with the spiky source voltage and not get tied down to the less important input voltage. Honestly, the best approach is a separate driver per FET each with power supply filtering, but now we're getting pretty complicated, probably not your cup of ... bean juice. 2. You'll notice that flyback designs where energy efficiency is important have the primary winding coaxial/internal with the secondary. Amateur devices omit this for simplicity, and actually when it's a resonant design like a ZVS driver it's no big deal. But doing the primary on the other leg of the core means that there's a large leakage inductance, where stray magnetic field looping only through the primary stores energy that can't be transferred to the secondary quickly enough in a single switch design, and must just be handled (read; usually burned) in the primary circuit. If you can put the primary in the middle of the secondary, yes your insulation is 10x more challenging, but it should be worth it efficiency wise.
3. Ok I said a couple pieces of feedback, but I can't stop talking when I get excited by an excellent video like this. Primary snubbing/capacitor: Wherever the primary, we have to deal with leakage inductance. Where do we put that uncoupled energy? In single switch amateur designs (other than ZVS) the leakage energy is not explicitly handled at all, as a rule. Often it just causes the FET to experience avalanche breakdown every cycle, which is not super awesome for the FET (although many survive it), or else requires the designer to use way too few primary turns to reduce the spike voltage. It also makes the energy transfer to the secondary worse (and hence power consumption higher) If you check how they handle this in commercial CRT television flyback drive circuits, or automotive ignition circuits, the strategy there is to put a capacitor across the power switch. What this does is manifold. Buckle up. First, the cap provides a place for the leakage inductance current spike from the primary to go. The stored leakage energy can only charge that capacitor up so far: correctly designed, it limits the voltage and stops the transistor from avalanching and dissipating that juice as heat. Second, the cap slows down the rate of voltage rise across the primary switch. This is sort of not the most important thing in the world for transistors: transistors are pretty fast. In traditional automotive "points" based ignition it gives the switching contacts time to physically retract from each other before they arc. But even in transistors this is actually super nice. If your gate drive is a little bit laggardly, and the transistor isn't' turning off as fast as you want, the capacitor absorbs some of the current momentarily when the transistor would otherwise be conducting it all at high voltage drop, and so less heating of the transistor. Sweet. Third, the capacitor is a lossless snubbing mechanism. The spike isn't gone, it is shaped into a half sine wave; it rises up to some quite high voltage charging the cap, and then it induces current flow in the primary _back into the power supply_ and actually recycles that spiking energy as the cap discharges. This does mean a couple of things though. It means that you need a good local low voltage power supply capacitor on the driver board, probably more than twice as good as you'd need without this. It also means that the primary winding current doesn't start each switch-on period at zero. The primary actually starts with negative current, and then it ramps back positive, which makes things more complicated to diagnose and make the behavior "weirder". I mean, there's already an interaction with the secondary winding which mean your primary current doesn't start at zero and is load dependent; so this isn't really anything new. But the capacitor definitely makes the primary circuit performance even more dependent on the secondary circuit loading. So if you did this, expect things like the best frequency and duty cycle for open circuit and arcing/loaded being super different. Fourth, another part of this mixed bag is that you REEEAAAALLLY don't want the transistor turning on before the primary has "ringed back down" to zero volts. The half cycle of resonant voltage across the primary capacitor will help efficiency _if_ you let the voltage shoot up and then plummet down to zero before switching on; it actually lets you switch the FET on when the voltage across it is already zero, a condition called zero voltage switching or ZVS. Great for efficiency. But, if you fail to achieve this condition by having too long _or_ too short of a FET off time, then you switch the FET on when there's a super high voltage charged capacitor across it! Not good, perhaps even bye bye FET. Fifth, because you're now explicitly dealing with your primary inductance spike, you can have waaaaaayyyyy more copper in the primary. You can store much more energy in there, and get higher power. This is the thing about these typical home-brew flybacks which really hobbles their performance more than anything, in my mind. You're trying to magnetize that big old core, and you've only given yourself a gram of copper to do it with (or whatever the few turns of wire weigh). And I don't mean to pick on you in particular, this is like a meme or tribal knowledge; everyone does it. But it's not ideal. One needs a certain number of total amp-turns of current to get that core magnetized. If all that current has to squeeze through fewer square millimeters of total primary cross section, that's just heat. And the primary is conducting like most of the time, so this is not a small thing. It's really much easier to get an efficient design with quite a lot more turns, a higher operating voltage, and a lower operating current. Then, with more copper and turns in the primary, you also can get the same inductance with a lower core inductance factor by gapping the core. You'll also notice this if you look at TV flybacks. Those cores are ALWAYS gapped with a small plastic spacer pad. This makes the inductance of the core lower, but if you know your cores you know this means that they can store WAY more energy and transfer more power. The current needed to magnetize the core goes up; the inductance goes down. But the energy goes up as the square of the current, and only down proportional to the inductance: so it goes up more than down. This means more energy transferred each cycle, and more power. I will admit that unless you get an electrical engineer on board to help design this, or you really want to learn some significant EE math, this advice basically isn't useful. The resonant primary capacitor version of the single switch flyback really needs to be _designed_, not tinkered, and part of this design effort would be characterizing impossible to simulate stuff like the actual, measured, constructed properties of the secondary winding. So this is not something anyone can help you with in a TH-cam comment. I am just stoked to share the possibilities! That core looks like it could do 1kW of output with the right driver (just from napkin math using 30mm diameter, 0.4 tesla Bs ferrite, at 10kHz and gapped to 1mm). Think about that! It's a monster. But it could be a demon. Whether you end up finding any of this useful or not, keep doing what you're doing! I always love seeing the next creative thing you come up with!
@@fewwiggle Of course. 1kW is just a rough estimate of the power handling capability of a ferrite core that size in a properly engineered switchmode power supply.
Even better if he'd eq out 10.7 kHz with a notch filter. It quickly becomes annoying, and to my husband at the other end of the room having tinnitus, excruciating...
I was part of Modern Neon, the workshop handbook for neon sign shop practice. I was part of the research into Sprites etc the lights above thunder storms. We work with 18000 volts up to 10000 hertz through silicon indulated spark plug wire. To check the vacuum we carry a little pocket radio transmitter which when touche it on the outside of an evacuated sign tube, produces the shades of light scientists and pilots saw above lightening. Solved by a letter to New Scientist, magazine.
Props for admitting you just had no idea what you were doing, but still plowed ahead. Creating is the process of feeling like an idiot until somehow something cool appears. Works everytime. Unless it doesn't.
Thank you for saying something, there's an elderly gentleman above me sleeping in his apartment. Absolutely hate that youtube doesn't have SOME level of decibel normalization.
im listening on a pair of adam's audio A7V's and lemme tell you, it's gnarly to listen to this video. The HF drivers on these are something else from any other studio monitor I've ever owned.
The funny part was the first time the high pitch happened was when he blew out his component. That part was way louder to me. It was probably too high pitched for him to hear so he didn’t know to warn about it us then.
Prior to retirement I was designing c-ray generators (from control, drivers, transformers etc. To 300kV. Very skeleton advise Majority oil insulated, high voltage section heated to 80C and under vacuum for 3 days to remove all moisture, in the mean time oil circulated through fine filters and showered into vacuum chamber at 80C again to remove moisture and solid bodies which could align up under the high voltage and cause break downs. Some units we filled with SF6 gas at high pressure. Transformer secondaries single tube bobbin. Get rid of the discs separating the windings wasted space. Retain the outmost rings to prevent discharge to the core. Place two turns of thin Kapton tape or other highly insulating film between each layer of the copper windings, copper winding width keep less than the width of the tape. Each subsequent winding width reduce by a couple of millimetres or so and reduce the insulating tape width every few layers so that the endings end up like a trapezoid (pyramid-truncated on the top) whilst the insulation is like a stepped pyramid. You could have grounding strip on the core and the connection to the first layer start of the winding so that the top of the winding is your highest voltage output. Keep an eye on the distance from the top layer to the primary winding. Apologies if I am repeating other comments suggestions.
Except he'll probably use a 200psi injector, and it will just be another "sparkling air cannon". But I hope I'm wrong and he will build a true railgun.
In order to push More power thru an Acymetric Capaciter for Lift, you Must Seal the Anode and Cathode, and Pressurize. It’s essentially an Air Capacitor. Air is the Dielectric Barrier. Higher Air pressures allow for More Power to be Pushed. THIS, is what our Favorite Space agency refused to show the Public, of their Experiments! UAP’s ARE REAL, and THIS is how they Work. Plus, try different Gasses. 😉
If you google Ruhmkorff coil. You can find pictures of various versions of a small transformer that was invented in 1836. Some of them produce much longer bushier sparks than the one above. They do operate in general at a lower frequency than the ferrite coils that are in old TVs. Jay's work always looks nice.
For the record, much better transformers can be made by constructing them the way N.Tesla did (with large spacing between turns and a voltage magnification that is unrelated to the number to turns). It could have saved you some time with winding and you would have had a more robust coil, capable of much more intense plasma discharges due to the higher frequency and voltage limits. You can refer to the scale model of the Colorado Springs transformer that Eric Dollard built to get an idea of what I am talking about.
Yeah that noise warning was after he blew out my ears twice. Really should have been at the start of the video. First thing he does is blow out my ears.
@@Subcode Headphones I presume? I'm admittedly watching this on my S23 Ultra at ~90% volume _(with Atmos enabled, which means it's more like 95%),_ but its speakers had (surprisingly) no issue screaming all those noises... I was quite impressed! But yea, if I had my planar dynamic earbuds in, it's plausible I'd be singing a similar tune to yours... 😅 Thankfully my 14.5 and 15.5 year old doggos have hearing loss and they didn't even flinch - the oldest was
That thing is wicked. As for the coil part that failed, it really is a work of art. It deserves to be mounted and displayed…or turned into a cool lamp !
Things like this is what the internet should be for. Expanding our knowledge and pushing its limits. Happily subscribed, looking forward to future content.
I'm 58 and could not hear a thing. I thought he was joking because it was silent. I even turned up my speakers, replayed it, and still nothing. lol It is true that as we age the HF hearing disappears.
@@ybsmike6512 I mean it really depends on the person as to when it happens but it'll happen to most of us eventually. People often are ashamed of hearing loss as well, which makes my job a lot harder sometimes. (I test hearing and sell hearing aids)
Always love seeing your videos , very educative, I'm really blessed only God knows how much I praise him, getting $100k bi weekly and I’m retired now. I’ve got a good cash and can also support my family
Love it guys. Whether you realize it or not you are kind of starting an open source hardware and science movement. Akin to what GNU and Linux did with software years ago.
Not sure why putting those transistors in parallel caused any issues since many car audio amplifiers that use transistors have many of them in parallel to distribute the load.
I'm moving next week, can I borrow those bags? I bet I can fit my entire apartment in those. You need to sleep more, my dude. Imagine... A world where you wake up with energy. You'll process things faster, allowing you to get more things done in less time, negating the need to stay awake far too long and chug bean water to stay alive. If efficency doesn't convince you, I'll appeal to vanity; you look OLD and EXHAUSTED. Sleeping will more will fix that. You're a good-looking dude. Don't ruin it. Plus, you clearly work extremely hard. You deserve a good night's rest. You've definitely earned it at this point.
I am 72 now, but when I was in high school for a science fair project I built a tesla coil that was nearly as tall as I was. The primary was 12 turns of wire energized with a neon lighting transformer that spits out 12,000 volts. The secondary was more than 100,000 turns of wire around a thick-walled cardboard tube (i.e., nothing ferric). I have no idea how many volts it put out, but I could hold a 60w fluorescent light in one hand and have it light up by pointing the other end at the Tesla coil from 6 feet away. I realize after reading the video that you are basically building what I started with. But while that transformer was large and heavy, it was also dated from the 1930's. It was at least 5 times larger in total size than the final device you are making. I am pretty sure the entire neon lighting transformer was just that. a transformer driven entirely from wall current AC.
Also, UAP are NOT made out of Metals. They’re Mostly made out of Sophisticated Ceramics, Glass, and Graphene Infused Ceramics. (This is why they appear Silverish or Grey)
I'm no engineer but I built a Jacob's Ladder, with a Volkswagen coil. I used AC mains input at 120 Volts, through a light dimmer and mylar caps. Stream began at about 1/2 inch. Put out a pretty good plasma stream. But what you made looks frightening and beautiful. Can't imagine spending so much time on that coil only to have it short...ugh!
11:54 - the gaps on your transformer bobbin would be best left as air spaces rather than being resin filled. Because arcs tend to travel along the surface, the resin potting reduces the amount of surface. For those who doubt this, please look at the insulators used on power transmission lines - the shape of the surface on these is nowhere near a straight line.
Pretty cool! Reminds of an experiment I did when I was maybe 14 or 15. I had 6 or 7 step down AC transformers. The main one was a huge transformer that was 120AC in and iirc 24vac out, so 5x, and I had 5 or 6 more that were more typical rations of 10:1 or 12v output. I wired them all up, in reverse.... so they would be stepping up. I recall calculating it as being 500,000x step up. I used straight power from the wall, so 120vac in, so yeah it would be in the millions of volts. I had this all wired up on the floor of my room, which was shag carpet. I spaced the output pair of wires about 1 inch apart. I didn't know exactly what to expect, it was why I was experimenting :) When I plugged it in, the whole house hummed, lights dimmed... lol It created a white arc that looked like old tv static, the spark was a good 1/4 inch wide. Never seen a spark like before or since. I was away from the thing, plugging it into the wall. I only kept it plugged in for maybe a half second. In that time, it made that amazing, weird spark, all of the transformers got so hot that they melted the shag carpet. Once it cooled, I had to pull them out of the carpet. All of them were destroyed. Mom knocked on my door and asked what I was doing, I probably lied. Anyway, you might try making your step up transformer as 3 or 4 separate transformers intended to be wired up in sequence. This way on the earlier stages, you can use higher gauge wire for the output side, lower step up ratio in each, and spread out the heat that is generated. You might be able to get to some insanely high output voltages. Also try sine-wave input vs that jagged waveform you were using.
The reason transistor fails at 3.59 was perhaps caused by moment of disconnection of the potentiometer - the generator was at very low freq for a moment, causing very high current building up in inductance saturating ferrite. One should use bypass resistors across potentiometers limiting behavior in such sistutaion. Also, one can reduce number of turns per kV by ~2 by switching to symmetric push-pull flyback ( using diodes in series with transitor drains) and another factor x4..5 by using permalloy wound core (much higher saturation field), works fine at 10KHz and even higher
MOSFETs are actually pretty happy being paralleled due to their R_on going higher with temperature. It still doesn't prevent big R_on mismatches. Also you need to drive them properly: fast transitions (high current in/out the gate) without going into oscillation (with a gate resistor just big enough to stop oscillations). If you want crazy high currents without the inconvenience of paralleling MOSFETs, just go with one IGBT, they are rated for INSANE amounts of current.
When the input voltage is so low, IGBTs are not the way to go, they have a small saturation voltage. It's better to pick a MOSFET capable of switching high currents. My continuous wave tesla coil delivers 150W @ 500 kHz from a single MDP1922 transistor. Vds = 100V, Id = 97A, Ron = 8.4 mOhm, Td(on) = 14ns, Td(off) = 39ns The input capacitance is 3500pF, but that's no problem for the MOSFET driver, MCP1406. From all the transistors I tried, the MDP1922 was the most efficient at this rather high switching frequency. I tried one IGBT, but it was terrible. :)
4:31 I literally laughed out loud at your description of how the MOSFETs were interacting with each other. You and styropyro just have that mad scientist humor that I absolutely love. The kind of vibe I would expect from Nikola Tesla if Nikola was hitting the ether just a little too hard.
Whoa! The feedback from everyone on this build is tremendous. The outpouring of love, mutual excitement, and kindness i'm seeing from people in the comments section is so empowering for me to see, and i'm honored that each and every one of you took time out of your day to enjoy my video. I just really love Plasma. Thank you to Skillshare for sponsoring this video, and good luck Mehdi, Drake, and Joe (lol).
Ferrite cores often have gap inserts to make field collapse faster. Didnt see any in your build, may want to research and try
Thank you for another awesome video
Mine had half mm gaps, just didn’t show it 😃
Assuming scaling up means more difficulties with potting- When doing very large motors & generators, we lay a strip of tissue like paper, or thin cloth dipped in resin between groups of windings, & between separate sections of the same winding, maybe every 300-1K turns (depends alot on the wire gauge) & for or high amperage we use fiberglass strips dipped in resin. This aids in 3 ways, 1) If a section fries it is almost always contained to 2 adjacent windings, either layered above/below or directly next to the armature of wire. 2) It allows snipping the lead wires to the coils & testing which coils were "kissing". 3) Offending coils can often be replaced with minor work compared to a brand new build.
My recommendations: At the very least, make the coils independent- so you can print them off in modules that you can just snap together after potting, solder adjacent wires & where the solder bead would be cover it with silicone covered fiberglass tube (often used in high temp/high amperage electronics), or a good D-clip connector, so if a coil goes up you can literally just swap it out for another one without destroying the entire build. Also I suggest using slower curing resin- & use a cooking / gram scale to measure as close to exact amounts (if it's 2 or 3 part) epoxy/resin & stir extra well, so you don't end up with pockets of uncured resin. Gravity does terrible at trying to pull viscous liquids by itself. Vacuuming out the air from the resin prior to poring will help alot. Pour it, pull a vacuum a second time, let the air back in for a few minutes, & repeat, until you no longer see bubbles. If you have a chamber capable of pressurizing as well that's much better & much faster (like how a pressure cooker cooks faster). If our having issues with transistors/components blowing, always rate for at least 1/3rd more than you need, ideally, go for double-4x for something that you should never need to replace, except a fuse; always use a fuse- preferably a "fast blow"" in conjunction with a lower rated thermofuse- like what are used in circuit protectors that can either be manually reset or will reset themselves when they cool down. During testing we used transistors mounted to a heatsink not unlike yours, but the leads just plug into metal receptacles on the board, to avoid re soldering them every time they blow. Using diodes to prevent backfeeding & having good channel/module isolation is a must. A capacitor shunted to a small ceramic resistor is a good way to safely deplete sudden voltage spikes also.
You'll save a ton in additive costs of cooking components by adding $1.50 worth of safety measures.
tesla coil jaket with open source desings
you're going to nerd snipe me and try to get me to make a transformer with a higher voltage step up ratio eh? are resonant devices like tesla coils allowed? :p
also at 16:50 i could feel the pain as that kind of thing has happened to me so many times. i was already nervous from you extending the electrode distance for that very reason lol
Was about to comment the same thing, a couple resonant transformer with 0 resistance (impossible) mathematically hits infinity voltage, the problem I had with those are the transistors, they tend to explode for some mystical reason 😅
garloid
Glad youre still alive
@@nullboi365same
Ay you alright?
I’ve learned so much about this working with Jay, and I’m stupid excited for what we get to do with it :)
The era of maker-crossovers-creating-death-machines is upon us.
Very cool!!!
@@JeffGeerling My favourite Raspberry Pi creator replying to my favourite 3D printing creator who himself is reply to my favourite HV electronics creator?? 😮😅❤
Thanks, tall Joel
Some cool Mimaki parts coming to the channel perhaps?
Electroncis guy here, you will get lots of benefit placing decoupling capacitors as close to the FET and supply as possible (not the electrolytic one used in the video, ceramic will be better). Not all capacitors are the same, you need a low impedance with a value tuned to the circuit. also on your driving circuit, during the low state, a flyback diode will save your transistors from shorting from the high reverse voltage created during the field collapse
Is it not cool how cool that sounds?: "...reverse voltage during [the] field collapse..."
everyone here is an Electronic guy haha xd
@@weetjewatikwil1 Ah, yes, I should have known. Everyone here has university level formal education in electronics :)
I’m a mechanical engineer and your channel is the first to make me think about learning more about electrical engineering. Love your projects
Out of curiosity is there a way to “soften” the high pitch noise in the final build?
Thank you! Indeed there is...it would mean driving the frequency above our audible range. Which is easy to do with the driver. But...the transformer would need to be built entirely differently. One with less turns and a higher resonant frequency.
@@PlasmaChannel so cool! I’m assuming a higher frequency would need more power for the same voltage increase but I have no idea if that’s the case because electricity is magic to me.
Dig deeper FFS. We're not all just here at your convenience.
nearly 70 years ago,I worked in a facility that built high voltage power transformers,did not allow bare fingers to touch the enamelled wire,fingers have acid ,body fats,you name it.the windings were heated under vacuum,to drive out moisture, after a certain time under vacuum and heat , a special varnish was admitted to the vacuum tank,and the wings were impregnated with varnish.The windings were then place in their respective steel tanks and sealed,vacuum was again applied to the enclosed windings in their tanks,dry nitrogen was then admitted to the enclosed tanks at a positive pressure of 2lb's per square inch,ready for transport.At arrival at he the substation the transformers were fitted out with bushings[insulators].when finished the transformers were then placed under high vacuum,2mm,comes to mind.When this was achieved,pumping stopped ,the vacuum had to be held for 2 hours,with only minor loss of vacuum .Oil filling commenced,under vacuum.And that was 70 years ago,shows the extent that the manufacturers and construction crew had to go to to contain HV. reliability.Frogot to mention that the trnsformer oil was also tested,had to withstand 50kv at a 1mm gap.
Most interesting Ty
70 years?? Either you were working at the age of 10 or youre old asf!
What??? Lol
You touched on one point that deserves a little more attention, purging with dry nitrogen. When trapped air is ionized by high frequency/high voltage, it is converted into ozone, monoatomic oxygen and oxides of nitrogen. All of these gases are powerful oxidizers and will attack anything they come into contact with, especially organic materials, which will leave conductive carbon residues exactly where you don't want them. Substituting N2 for air greatly reduces this problem. For even better dielectric performance, purge with sulfur hexafluoride gas (SF6). SF6 has an incredibly high breakdown voltage and is used in megavolt rated circuit breakers and switchgear.
I'm grateful that you're still here to tell us about that! God bless, old man!
Solid state transformer (10kV to 375V DC for data center) engineer here. When we pot transformers, we use high pressure. Vacuum degassing is cool, it is not thorough. We use a combination of heated ultrasonic (pre-vacuum and post-vacuum) degassing, vacuum soaking, and high pressure curing to minimize air pockets.
The problem with using only vacuum is that pressure can only get to zero, no less, so the maximum force can be excerpted on tiny (low surface area) bubbles is limited and that force can be well below the force trapping it inside. When cured, not only there is a gas pocket, it is also low pressure, making it even easier to breakdown.
By applying ultrasound, we shake things up, and the heat lowers its viscosity so the trapping force is lowered. Finally, we apply high pressure to make sure the remaining bubbles are packed tight and their breakdown voltage is increased. You don't need a very high pressure, 0.5~1MPa is enough (commonly used for cast resin art projects, you need some training though as a bucket holding 1MPa is undoubtedly dangerous).
We also do partial discharge testing (hi-pot for instance) with fast breakdown counting equipment to grasp an idea of how many air bubbles are there, early PD count is strikingly effective at predicting insulation reliability and lifetime in the long run.
I have had excellent results using a vacuum oven with a potting material made from beeswax and rosin, previously melted together and cooked at higher temperatures than required to simply melt it. Once all bubbling has ceased, I keep the oven hot but let the pressure come back up to atmospheric, slowly, and then let everything cool overnight before opening the oven. Once such potting job has lasted for fifteen years and hundreds of hours of operation. I believe one term for the kind of high-potential test equipment you are describing is the "Holiday Detector" - yes?
@@zinckensteel Wax is an amazing high voltage and high vacuum material, commonly used in accelerators and other science apparatus. One valuable nature is that it flow very well above certain temperature, way better than epoxy monomers, but the resulting pot is not as hard and mechanically stable than pure epoxy, so they don't see may uses outside scientific applications where maintenance is expected.
The PD detector I mentioned is not exactly a holiday detector but works similarly. Holiday detector uses a brush to examine the surface, while a PD detector tests between two electrical connections, usually between the windings or a winding to the shielding or the core. More like a hi-pot tester, but with pulse counting capability.
Just know, I really want to like this comment, but I don't want to ruin the perfect amount of likes lol thank you for this info, I'm personally working on a new concept for cores to hopefully reduce (ideally remove) eddy currents all together [hopefully this is not already done and im unaware]. I love reading and learning trade secrets on how to do certain processes for the best outcome. Thank you for sharing this info
@@zinckensteel I guess that the 19th century scientists/engineers used exactly what you describe. Is expoxy better? I don't know.
Regarding old methods/materials, the pre-war TVs here in England usually stepped up the 50Hz mains (lethal!) to 5 kV or so but break-downs were not unknown.
Many years ago, one of the DIY mags over here descibed an EHT divider probe with a stipulation that candle-wax was not a suitable insulator. Any comments, please?
Best regards!
@bskull3232
Is any way to contact you for small bespoke orders?
HEH! YOU CHALLENGE ME YOU PUNY MORTAL?! WHY? I may end up killing myself doing it! 🥲 Fine, I'll put it in my to do list!
Had to double check it was the actual electroboom then 😆
Looking forward to that video
If you printed a transformer like this, putting holes in the disks on the resin print would allow resin to more easily get into the windings
Oh my man....the voltage race is on. If I hear explosions coming from you, all the way down here in Seattle...i'll know you've done it.
a question, wouldn't a marx generator be more cost effective than this?
YES, BATTLE OF THE ELECTRONERDS
A good way to avoid air pockets is to pump out and after the bubbles stop, let the air back in and even pressurize the pot as much as the chamber will allow.
This will force the compound into all the voids and any remaining air bubbles will be a fraction of the size they would be at atmospheric pressure.
I learned this from some friends who resin clear cast for a living.
This makes a lot of sense.
Even better would be to pour the resin in vacuum.
@@andan2293 that is how they do fiberglass boats and such. Setup might be cumbersome for a one-off though.
Could also take advantage of the airgaps between the three winding sets. Add some horizontal drain holes that go from the winding chamber to the empty chamber next to it. Then, when you vacuum/pressure pot it, the resin will be able to fill in from below as well. Since you're resin-potting it anyway, the holes won't matter because they'll be filled with the resin.
Also, use a much thinner resin... Or just use straight polyurethane from the hardware store.
Having gone through the pain of designing and building classic induction coils driven by trembler contacts, classic insulating materials, vulcanite, paxolene (resin bonded paper ), mica, densified wood etc.. Cores made of bundled iron wires, florist wire. The one thing that was the most frustrating was using epoxies for insulation. Once set, they cannot be disassembled. Oil is the choice material for high voltage transmission transformers. It's messy and needs leak proof containers and glands to take conductors. But for convenience and superb insulation, I found that ultra refined bees wax the best all round solid insulator. It degases well under vacuum, is far more fluid than epoxy, back to solid at room temperature. But the best thing is......, you can melt it out after a whoopsie and recover most of the components for reuse.
I love your videos for so many reasons
1. Well researched
2. Easy to follow
3. Interesting
4. Escape from the madness of all the wars in the world
5. Hope that humanity will use your experiments to build startrek
So long as there are at least 2 people alive, someone is going to want someone else d3ad. If the country at war isn't your own, and you have no other ties to it, it's best to just ignore what's happening, otherwise it will just weigh on your mind unnecessarily. Keep your mind on things you yourself CAN control, and don't get put down by the things you can't.
yes
Agreed 💯
Love the optimism, but tech without political reform isn't star trek, it's cyberpunk.
@@Handles_AreStupid Yeah, I need to take your advice in this area. I am SO incredibly sick of political shit going on. It just saps my creative and other energy's in other areas of my life. Time to go on a NEWS FREE DIET.
The ringing didnt stop after the frame changed 5:53 , then I remembered I have tinnitus
Finally - someone else with ‘Shitty Flyback Transformer’ squeals all over the place. As that played I hear some dissonance and then either my head or his transformer came together for a second.
@@azurefog for me the transformer amplified the ringing for a short while, I don't normally notice it since I have a fan running at all times to create white noise
I recommend it, it helps so much
What?
@@goatboy150 I'm not sure exactly what you don't understand, but I'll try to clarify as much as possible
Tinnitus is a ringing in ones ear that can either be constant or it can come and go, it can be caused by head trauma, hearing damage, or even build up of ear wax
"shitty flyback transformer squeals" is just a way of describing tinnitus
Dissonance is the lack of harmony among musical notes
hahaha same
Some people in the comments already mentioned core air gapping - when you're driving the primary using pulses (and not a nice, clean sine wave), you're basically creating a flyback converter. With a sine wave, you'd be using your magnetic monstrosity as a linear transformer - input voltage is a sine, primary current is a sine, core magnetic flux density is a sine, voltage induced on the secondary (output) winding is a sine, all is good. If you do that, you want to close the core (bring the two halves as close as possible). With a flyback converter, at every start of an input pulse, you force a voltage on the primary winding, as with every inductor, the current increases linearly, but very soon, you reach a point where the core saturates and the input current shoots up. You're no longer storing any more energy in the core, you're just heating the primary winding. When you're driving it like that, you might want to consider adding an air gap to the core - a small shim of paper or mica between the two halves that keeps the two halves at a known distance from each other when you clamp them together. Yes, the coupling between primary and secondary decreases, but saturation comes much later and you can dump more energy into the whole system with every pulse.
You could add a small shunt resistor to the primary to observe primary voltage *and* current during operation (on your two channel oscilloscope) or just strip some insulation from the primary a couple of centimeters from the negative connection point to the driver and use resistance of that piece of wire as a shunt - it will drift with temperature but that's alright when you just care about shape of the input current - a qualitative measurement, not a quantitative one. I would definitely watch a follow-up that properly explores what exactly happens when you change the duty cycle, frequency and input voltage of the driver.
Of course with high voltage transformers there's much more going on that meets the eye, resonances and such (as you beautifully demonstrated at 15:10).
It's great to see you learned a lot with this project, it'd be even better to watch you try to explore this thing in even more depth. The more you know about what exactly goes on in your system, the easier it is to predict what will happen when you change it. Cheers!
Excellent advice! I couldn't have said it any better.
Also I would like to mention this. The driver issue from multiple MOSFETs was almost certainly not a load balancing issue but instead a gate drive issue.
A 555 timers output is not suitable for sourcing and sinking that much current. A gate driver circuit likely would have solved the issue.
sine waves? how? where? Sine waves are bad waveforms for this project!!!!
@@johnconrad5487how so? They can be broken down in half and quarter waves and you can play around with negative voltage pulse resonance when you get everything tuned up right
Having an air gap in the core will also increase the resonant frequency.
This is not only good for our hearing, but also for the efficiency of the circuit.
Most MOSFETS and ferrites are very happy around 100kHz to 300kHz.
But making such a massive coil with a high resonant frequency is a tall order!
The windings must be neatly wound in a layer, and every layer must have its own insulating layer with a low dielectric constant.
You need a lot of patience to do this by hand, lol.
Great work loved every minute of this!
I am a professional mold maker and i can see one hurdle for you.
Degassing (using a vacuum chamber) will not work the way you need it to here, you would benefit from degassing prior to pouring but once it is in the form it is doing more harm than good. As strange as it would seem you really need a pressure chamber for your intended use (i would sill degass first!) a pressure chamber will make sure your mold is filled, preventing gaps and any air that is trapped will be compressed into microscopic pinpricks that will not be conductive enough to be perceptible.
orientation and vents will also be critical, you can add those into your model very easily and they will also be good witness marks that the mold is evenly filled.
Looking forward to your next project!
For 3 transistor approach , try reducing the duty cycle by 1/3 and put the 3 pwm signals out of phase by 120 degrees, that way you can reduce the avg power on each transistor, and they all get their turn
Nicely done, it looks fantastic. Just one tip from someone who worked with research HV installations big and small for many years - never, ever lean over or point a digit close to an HV source. I suspect the resistance of your secondary was quite large and the frequency high enough that you would probably have been ok, but you don't want to find out the hard way (strictly it'll be your friend/partner finding out). Rule of thumb: a 5 joule pulse across your heart will generally kill you, that system as a whole involved far more energy than you want potentially passing through you. In my early career I ended up in hospital after an accidental discharge while I was reaching over for a tool (much like you did). It was a spark gap trigger based around an auto transformer. The stored energy in my system was far smaller than the continuous supply you were feeding that transformer.
so if his finger made contact, his body would be drained of all electricity?
HIGH FREQUENCY HEADPHONE WARNINGS:
0:01 - 0:06
3:54 - 3:57
5:43 - 5:52 (This noise warning is actually forwarned)
10:36 - 10:59
14:47 - 15:24
15:47 - 15:57
16:06 - 16:15
18:45 - 19:24
19:31 - 19:39
Challenging Styro to that could result in him blowing off a piece of the moon and destroying man kind. The guy trains moths for gods sake. He’s a super villain.
Every engineer has to face that moment of truth when power is applied for the first time. It never gets easy. But it builds character.
I miss local electronics stores (11:25). I haven't seen one in like 15 years. This is like seeing a Blockbuster to me.
I feel ya...
One of the, then, two remaining Blockbuster stores was near my cabin in Alaska, and for many years was a common stop for us. Alas, it finally closed its doors like 6yrs or so ago. I think the final one did so ~3yrs back.
RIP Blockbuster Video 🎞️
😞🫗
Thanks for all the childhood memories, renting movies and video games!
They exist, they’re just normally hidden and somehow continue to exist. There’s a store called “Altex” in Dallas, and they’re amazing.
Long live radio shack!!!
Saaaaaaaaame. I would kill for a store like that.
A lot of towns still have them, just not affiliated with any big chains. Here in the PNW there's quite a few, from recyclers who will sell components on the side to surplus vendors to b2b companies supplying the big boys who might take a private order from a polite hobbyist...
Looks like you learned some of the same lessons about mosfets that I learned when building my coilgun. One tip on the vacuum potting as somebody who's done it before: Reverse the pressure once most of the air bubbles are out. It'll help force the epoxy into any voids that were left by the bubbles vacating. You can also try rapidly cooling the vacuum chamber with liquid nitrogen or even an alcohol+dry ice slurry (the poor mans liquid nitrogen) to help get the pressure down quick before the epoxy hardens. Not sure how well that'll work in a home setup, but we had a vacuum chamber at work designed to work that way.
Hey this is cool! I'm an electrical engineer in the eVTOL industry with a phd in Power electronics. It's awesome how you built the step up converter with the research you did, really impressive. A few improvements id suggest. You can really shrink down on the size of the transformer, and get rid of the annoying whining, by raising the switching frequency and going with a resonant converter design. Around 1MHz and the magnetizing inductance can be very small. Operating at resonance increases the gain like crazy so they can be multistaged too. And the FETs burned probably due to switching loss and or gate charge stress at high frequency. Silicon carbide or GaN switches probably fare better here. Also not entirely aware of the topology but higher voltages will stress the Vds rating, especially in flyback where drain to source stress is really high. Multilevel topologies, flying capacitor, or switched capacitor topologies off the top of my head can help with the component stresses at high voltages. Anyway this was awesome, will be following for more updates ⚡️
For Heavens Sake! The poor guy is enjoying his hobby. He hardly knows how to drive the FET and you guys are making all kinds of complicated suggestions.
You make it look so easy lol It's too easy to watch this video and say "Hey, I could have built that, no problem!" However, that's ignoring the massive research and experimentation you did to get it to this stage. That's the beauty of educational videos like yours (Thanks and double thanks!) If trying to build a homemade two-stroke engine from scratch when you know nothing about that, simply watch somebody who has already gone through the design failures and finally found the one that works and viola!, just build it the same as they did, make your own small modifications, and you're golden!
Being a designer myself (3D CAD), I'm very aware of the difference between plagiarizing (bad) and proper attribution (good). If I built this transformer, I'd never fail to inform my amazed and impressed friends that "Yeah, there's this guy named Jay with a channel called 'Plasma Channel', it's a copy of his design." 👍😄
Absolutely love how your channel has progressed. Your content was always hella interesting but your earlier videos definitely had a more tryhard professional vibe (not necessarily bad, just less enjoyable and engaging to myself), but now you seem so comfortable just sharing your special interest through these projects. Plus it's great to see you interacting with the greater yt maker community at large too
I love that you put the mosfets in screw terminals. That's how I know you have had the same experience with them as me, that is to say, you know it's far easier to cook them than it is to solder them...
Oh I will never solder mosfets again. no no no no no hahaah
5:42 I thought my speakers were too crappy to produce such high-pitched screeches, but nope, you've proved me wrong about that in a very painful way…
19:38 "This shit seriously never gets old for me..." I love it! Had to do an instant replay to be sure I heard it right.
Cheers and Well Done.
Haha thanks!
Very serious impressive results, I did make an air core Tesla coil using a small 9 volt battery which gave a 2" arcs using relays in 1988, the thing that made it impressive was not the arcs but when it was sitting in the dark for 2 months, a creeper plant went 3 ft around to the window into a small crack and 6 ft towards the coil and wrapped itself around it with about a dozen windings of the plants tendril vine. I inadvertently tuned it the the plants frequency as the leaves were thriving in the dark, this had spurned me on the study the nature of plants and living resonances.
Magnet for eddy currents as a spool tensioner is such a smart and cool move hot damn. Awesome use of magnetic braking effects~
This is probably the most exciting TH-cam channel for me. Love this and can’t wait to see where you will go with the ion thrusters.
agree.
Man, i'm so honored you think so. Thank you so much. Comments like this put a smile on my face and encourage me to keep pushing further with builds / videos.
@@PlasmaChannel I hope so! Cause we love to watch!
@@PlasmaChannel you know what puts a smile on my face? deeeeez nuts
@@PlasmaChannel Are you sure the mosfet issue wasn't due to the lack of a gate driver circuit? A 555 can only source and sink so much current. Once you exceed that current level a gate driver stage is needed.
While vacuum is helpful in removing the bubbles, I have found that curing the epoxy under pressure gives the best results. The reason for this is that the bubbles shrink and air has a higher breakdown strength at higher pressure. The best procedure would be to degas using vacuum and then pressure for the duration of the curing, so that the remaining bubbles are at high pressure.
FDM 3D printed pieces are super unreliable under electric fields, so nice thinking using resin printing
I wonder if adding mica to the resin would increase the dielectric strength.
I don't know anything about plasma (other than what I've learned from watching your videos) still so excited every time you have an upload!
Practically an expert already
* * At 20 minutes, the guy tells how "a coronal discharge eats away the insulators" That is, the electrons in the 65,000V voltage
in the state are direct beta velocity flying radioactive beta radiation erosion
Never heard a guy so pleased with two inches ;-)
Your videos are great! I work with 65.5kV with our H- Ion Source for the Spallation Neutron Source at Oak Ridge National Laboratory! we get to have fun blowing up all kinds of equipment when our system arcs over. Even "Ruggedized" equipment meets great challenges when you combine 80kW of RF and multiple high voltage systems into one environment!
You should extend that Challenge to Alpha Phoenix. That dude does some great science, and I believe could crush it given some of the speed measurements I seen him do with the speed of electrons means his abilities to get proper resonance on a system should be spot on. I noticed a huge difference just switching to low impedance flat caps(instead of saltwater caps) on a tabletop tesla coil that if you can feed resonance circuits really sharp waveforms (TEA Laser setups with nanosecond pulse widths) its output abilities skyrocket. It's also neat to hear the spark gap change from a snap... to a ting like someone flicking a crystal wineglass. Thats how I can now tell if a circuit is low enough impedance to trigger lasing in such setups.
You would be surprised.. Standard Hot Glue can hold off 125KV at 1/4" thickness (8mm disk to flat ground plate). I ran a bunch of tests when I worked at a National Lab.
Pistols for applying powder coat are going up to 100 kv as well.
I had an auto ignition coil in my childhood that produced more than an inch of spark from an antique 12 V toy train transformer. In perfect weather, maybe I got 1.5 inches.
I never stuck my finger into it, but I did stick the end of a cheap plastic ballpoint pen into it.
That pen turned out not to actually be a good insulator. It launched me six inches into the air. My shop was a rebuilt chickencoop and I was sitting in a lawn chair. When I landed, as I sat there almost paralyzed by a taser, I observed that if it had stopped my heart, it had also restarted my heart. No worse for wear.
Memo to self: Do not assume common objects regarded as non-conductive are truly non-conductive.
I also spent a lot of time pushing the plasma around with strips of paper, until the paper caught fire. It never got old.
My device used a magnetic interrupter that opened physical contacts at maybe 50 Hz. It buzzed. This was the late seventies. I can only recall that it buzzed. At first, the interrupter arced so badly I got almost no final spark at all from the secondary. One day I wired some unknown mil-spec surplus capacitor across it to damp the arcing and suddenly IT'S ALIVE! The spark off my secondary was glorious.
When you pointed at the arc, it reminded me of when our maintenance foreman pointed and said, I see where the short is at the same time hollering because the tip of his thumb disappeared as the art jumped across to thumb
The fact that you don’t have millions of subscribers is mind boggling to me. Your production quality and the tech you’re building are pushing serious boundaries! Loving your videos, keep it up!! 👏
agreed!
I have been following all the videos since I discovered this channel over a year ago, and as someone who is not in the field, I find the videos super intuitive and easy to understand, even though the topic is extremely complex. Congratulations on the videos!
OMG!!! That thing is incredible!!! Thank you for sharing this with us.....You need to show us more of the incredible electronics store....lol
I appreciate that you're showing us your mistakes. Not every TH-camr does that.
That really is an attractive transformer. I went to trade school for electrical linework, and though things didn't work out that way exactly, the education was invaluable. Also, I appreciate being able to see windings, insulation, etc. Most of what I learned about transformers was on a textbook page and everybody in electrical work knows that diagrams and formulas don't always help.
Nice work! Thank you.
This entire video needs a “your dog’s ears will bleed if you play this over speaker” warning
Some tips regarding the Driver:
I know the perf board is therapeutic but it is also a nightmare for hf currents. PCB`s are really chap nowadays and KiCAD is free. A missing Ground Plane might be the Reason why the Squar Wave looks so erratic.
As I didnt see anny, put some thermal compound under the Fets! Either Past or a Thermal Pad. Keep in Mind that the Backplate of the TO247 Cases you use are conncted to the Drain so the Sink might be under whatever Voltage you are using. Also, for switching use, paralelling Fets normally Works rather fine., or at least in your application it should. It Could be that the Drive signal wasnt equal for all three due to the perv Board.
The roundnded edges of your Square Wave indicate that the circuit driving the Mosfet cant handle the gate capacity, which also increases losses as the Fet goes through more of its linear region. A gate driver would be recommended here.
Otherwise, massive Transformer!
The bad waveform comes from the fact, that here is nor ground connected at the scope probe.
I think he uses the output of a NE555 directly for gate driving. The NE555 can only source 200mA maximum and power mosfets generally require quite a bit more than that to drive it at any interesting frequency. I think this was also probably the reason for failure of the paralleling mosfets. At low enough frequencies the lower current can probably drive (one of) the mosfets mostly past the saturation region and into the linear region fast enough to avoid major thermal issues, but at higher frequency, only one mosfets gate capacitance gets enough charge to conduct but gets stuck in the saturation region and completely overheats maybe
@@gielb2001 Ive used a MAX232... it can turn the 555 output to a +/_ driving waveform with its own internal supply generator (using two external caps). since RS232 signals are differential and swing positive an negative... they work great for power MOSFET/IGBT drivers... plus you dont have to deal with high side and low side drivers that need a seperate power supply. the other issue is that the way he set up the 555 he is not varying a clean 50/50 waveform...but rather just changing the off time. transformers prefer clean 50/50 sinusoids for the most efficient coupling.
@@renaissanceman5847 Thats a pretty neat solution if you dont have a gate driver on hand! Tbh for the price of a MAX232, you could probably get a decent half bridge integrated gate driver IC as the MAX232 has a very limited sinking/sourcing current capability, which will limit switching frequency, it also has like a 200 Ohm output resistance so that will slow switching as well and probably increase switching losses quite a bit. The integrated drivers also often have integrated bootstrap circuits that only require 1 capacitor and can sink source multiple amps in general. The dutycycle thing I fully agree with, seems like a pretty big oversight in his design..
Nor to the fets without a ground plane.@@anselml2928
Wow, do you hear that too? My ears start ringing in the highest pitch I can perceive or have ever heard! Every time he turns that thing on, my ears start ringing like crazy. Never experienced!!
It's so loud the entire video.
It's almost louder than the talking, but I think he can't hear it himself.
As a High Voltage Lineman I love this. Man too freaking cool
2:34 Those development boards are very therapeutic to design and build. I recently made my first constant current variable voltage board, and it worked, I'm quite proud of myself😊
A tip for making these videos more pleasant to watch: I'd recommend putting a low pass filter or notch filter on your audio when you run the arcs to cut out frequencies above 10k+ hz. The high frequency sounds are exceedingly unpleasant to younger folk and may be far worse for those with sensitive hearing.
I had to watch the entire video with my volume at its lowest setting and I could barely hear him over the high pitched wine. It is so loud!
eeeeeeeeeeeeeeeeeeeeeee
@@greatnate29I think that's called tinnitus you can hear
Or maybe just reducing the loudness of the high frequencies by a large margin. Because it's the reality of working with these circuits, they make high frequency noise... Just like a CRT TV, which is around 16khz I believe.
My words❤
love the clean electrical work and soldering.
Dad taught me to solder when we made my 1st Heath kit back in the early 70's.
Clean/neat solder lines were as important to him and how he graded my work.
My mother that was teaching me hand sewing, cross stitch, embroidery and the like at the same age.
The neatness and beauty of the how the backside of the work was dressed is equally as important as the work itself.
"5,000 feet of wire in half a kilo of resin" Gotta love the mixing of units.
Yeah, I hate when units of length and units of mass are used in the same sentence too.
Us Americans tend to use standard and metric at the same time.
@@AnErrantPhoton We're slowly becoming used to seeing materials in metric, but our daily units are imperial. As someone that studied a fair amount of physics in school, I like metric a lot more, but imperial is fine for day-to-do things, which was basically the point.
@@AnErrantPhoton yes, 9mm handguns and kilos of cocaine are bringing metric to the US.
i just love this. soooo much, i wish this will be a part of psyics that we neeed to take in the future! Thank you for a amazing video!
This is amazing work! I've tried making a very simple DC to AC circuit and an air core transformer which ended up getting... the same voltage out. I learned a lot from this video and I look forward to seeing what else you can do with this awesome device!
Dude I love your job too! It is indeed a beast. I do have a couple pieces of feedback you might find helpful!
1. When used in switch-mode supplies and driven with a gate voltage well above the threshold voltage, MOSFETs actually are perfectly fine sharing current. The threshold voltage has negative temperature dependence and hogs current if all parallel FETs are supposed to be half way on like in an audio amp, where matching matters; but the Rds,on parameter (on resistance) has positive temperature coefficient, so actually they share fine when they're driven nice and hard. [but, you say, mine blew up so that can't be right!]
HOWEVER, what FETs really REALLY don't do well is direct parallel gate connections. This is a super subtle issue that's very difficult to catch with instrumentation or measurement. What tends to happen is that right as the FETs switch (and are in fact half way on) the gate wiring and source/drain wiring's parasitic inductance form a parasitic push-pull RF oscillator of very high frequency with the gate capacitance of two or more parallel fets, and the FETs oscillate, shuttling the current back and forth between them and never turning fully on.
Blam, either a gate punch-through due to excessive oscillatory gate voltage or overheating due to switching losses. I think you may have had the former. Just a couple ohms in series with each individual gate (10 is traditional if one is shooting from the hip) will break the oscillator's resonant circuit. If you want to do parallel FETs next time, throw in those gate resistors. It'll help.
1b. Also, helps to form a "kelvin" connection from the gate driver to the source bus wire connecting the sources of the FETs. More or less like a star ground: the important part is to have a separate path going to the sources just from the driver IC, and separate from the switched high current that flows from the input power supply and input filter capacitor. The gate drive IC wants to "ride along" with any bumps and spikes that happens at the FET source, so you really want the negative pin of the gate drive IC to be connected to those sources with a wire that has no significant power current through it (other than the actual gate drive current). Otherwise the wire has voltages spikes along it too and the voltage differences between the FET source pin and driver IC can actually turn the gates back on as the driver tries to turn the FETs off. The positive supply to the gate drive IC needs a separate filter capacitor, and maybe a small number of ohms resistor between the plus pin of the driver IC and the actual power input, again to let the IC bump along with the spiky source voltage and not get tied down to the less important input voltage. Honestly, the best approach is a separate driver per FET each with power supply filtering, but now we're getting pretty complicated, probably not your cup of ... bean juice.
2. You'll notice that flyback designs where energy efficiency is important have the primary winding coaxial/internal with the secondary. Amateur devices omit this for simplicity, and actually when it's a resonant design like a ZVS driver it's no big deal. But doing the primary on the other leg of the core means that there's a large leakage inductance, where stray magnetic field looping only through the primary stores energy that can't be transferred to the secondary quickly enough in a single switch design, and must just be handled (read; usually burned) in the primary circuit. If you can put the primary in the middle of the secondary, yes your insulation is 10x more challenging, but it should be worth it efficiency wise.
3. Ok I said a couple pieces of feedback, but I can't stop talking when I get excited by an excellent video like this. Primary snubbing/capacitor:
Wherever the primary, we have to deal with leakage inductance. Where do we put that uncoupled energy? In single switch amateur designs (other than ZVS) the leakage energy is not explicitly handled at all, as a rule. Often it just causes the FET to experience avalanche breakdown every cycle, which is not super awesome for the FET (although many survive it), or else requires the designer to use way too few primary turns to reduce the spike voltage. It also makes the energy transfer to the secondary worse (and hence power consumption higher)
If you check how they handle this in commercial CRT television flyback drive circuits, or automotive ignition circuits, the strategy there is to put a capacitor across the power switch. What this does is manifold. Buckle up.
First, the cap provides a place for the leakage inductance current spike from the primary to go. The stored leakage energy can only charge that capacitor up so far: correctly designed, it limits the voltage and stops the transistor from avalanching and dissipating that juice as heat.
Second, the cap slows down the rate of voltage rise across the primary switch. This is sort of not the most important thing in the world for transistors: transistors are pretty fast. In traditional automotive "points" based ignition it gives the switching contacts time to physically retract from each other before they arc. But even in transistors this is actually super nice. If your gate drive is a little bit laggardly, and the transistor isn't' turning off as fast as you want, the capacitor absorbs some of the current momentarily when the transistor would otherwise be conducting it all at high voltage drop, and so less heating of the transistor. Sweet.
Third, the capacitor is a lossless snubbing mechanism. The spike isn't gone, it is shaped into a half sine wave; it rises up to some quite high voltage charging the cap, and then it induces current flow in the primary _back into the power supply_ and actually recycles that spiking energy as the cap discharges. This does mean a couple of things though. It means that you need a good local low voltage power supply capacitor on the driver board, probably more than twice as good as you'd need without this. It also means that the primary winding current doesn't start each switch-on period at zero. The primary actually starts with negative current, and then it ramps back positive, which makes things more complicated to diagnose and make the behavior "weirder". I mean, there's already an interaction with the secondary winding which mean your primary current doesn't start at zero and is load dependent; so this isn't really anything new. But the capacitor definitely makes the primary circuit performance even more dependent on the secondary circuit loading. So if you did this, expect things like the best frequency and duty cycle for open circuit and arcing/loaded being super different.
Fourth, another part of this mixed bag is that you REEEAAAALLLY don't want the transistor turning on before the primary has "ringed back down" to zero volts. The half cycle of resonant voltage across the primary capacitor will help efficiency _if_ you let the voltage shoot up and then plummet down to zero before switching on; it actually lets you switch the FET on when the voltage across it is already zero, a condition called zero voltage switching or ZVS. Great for efficiency. But, if you fail to achieve this condition by having too long _or_ too short of a FET off time, then you switch the FET on when there's a super high voltage charged capacitor across it! Not good, perhaps even bye bye FET.
Fifth, because you're now explicitly dealing with your primary inductance spike, you can have waaaaaayyyyy more copper in the primary. You can store much more energy in there, and get higher power. This is the thing about these typical home-brew flybacks which really hobbles their performance more than anything, in my mind. You're trying to magnetize that big old core, and you've only given yourself a gram of copper to do it with (or whatever the few turns of wire weigh). And I don't mean to pick on you in particular, this is like a meme or tribal knowledge; everyone does it. But it's not ideal. One needs a certain number of total amp-turns of current to get that core magnetized. If all that current has to squeeze through fewer square millimeters of total primary cross section, that's just heat. And the primary is conducting like most of the time, so this is not a small thing. It's really much easier to get an efficient design with quite a lot more turns, a higher operating voltage, and a lower operating current.
Then, with more copper and turns in the primary, you also can get the same inductance with a lower core inductance factor by gapping the core. You'll also notice this if you look at TV flybacks. Those cores are ALWAYS gapped with a small plastic spacer pad. This makes the inductance of the core lower, but if you know your cores you know this means that they can store WAY more energy and transfer more power. The current needed to magnetize the core goes up; the inductance goes down. But the energy goes up as the square of the current, and only down proportional to the inductance: so it goes up more than down. This means more energy transferred each cycle, and more power.
I will admit that unless you get an electrical engineer on board to help design this, or you really want to learn some significant EE math, this advice basically isn't useful. The resonant primary capacitor version of the single switch flyback really needs to be _designed_, not tinkered, and part of this design effort would be characterizing impossible to simulate stuff like the actual, measured, constructed properties of the secondary winding. So this is not something anyone can help you with in a TH-cam comment. I am just stoked to share the possibilities! That core looks like it could do 1kW of output with the right driver (just from napkin math using 30mm diameter, 0.4 tesla Bs ferrite, at 10kHz and gapped to 1mm). Think about that! It's a monster. But it could be a demon.
Whether you end up finding any of this useful or not, keep doing what you're doing! I always love seeing the next creative thing you come up with!
@@InductorMan "it could do 1kW of output" Surely, you have to put in more than 1 kW to get out 1 kW, right?
@@fewwiggle Of course. 1kW is just a rough estimate of the power handling capability of a ferrite core that size in a properly engineered switchmode power supply.
It must be really discouraging to have something like that fail after spending so much building it. The joys of high voltage experimentation!
Thanks for the noise warning.
Even better if he'd eq out 10.7 kHz with a notch filter. It quickly becomes annoying, and to my husband at the other end of the room having tinnitus, excruciating...
My hearing loose could not hear the tone/noise. Cool work you’re doing. Highly interesting!
wait, there was a sound?
I was part of Modern Neon, the workshop handbook for neon sign shop practice. I was part of the research into Sprites etc the lights above thunder storms. We work with 18000 volts up to 10000 hertz through silicon indulated spark plug wire. To check the vacuum we carry a little pocket radio transmitter which when touche it on the outside of an evacuated sign tube, produces the shades of light scientists and pilots saw above lightening. Solved by a letter to New Scientist, magazine.
Props for admitting you just had no idea what you were doing, but still plowed ahead. Creating is the process of feeling like an idiot until somehow something cool appears. Works everytime. Unless it doesn't.
10:47 wrecked my ears watching on a home theater setup
Oh yikes sorry haha!
@@PlasmaChannel Please, can you run it through equalization next time and mute this frequencies, or at least lower the volume? This is torture.😢
yeah, a quick band pass filter would have made that a lot less unpleasant, I had to turn off the sound and go with subs.
Thank you for saying something, there's an elderly gentleman above me sleeping in his apartment. Absolutely hate that youtube doesn't have SOME level of decibel normalization.
@@erifeviLare you serious? It was 3 seconds of noise. Deal with it
Jay's doing a rail gun?!?! Hell yeah!!!
Things gomna be awesome and look amazing too!
Be careful headphone users, the high frequencies in this video can be a little loud.
it's HORRIBLE!!!
im listening on a pair of adam's audio A7V's and lemme tell you, it's gnarly to listen to this video. The HF drivers on these are something else from any other studio monitor I've ever owned.
Imagine dogs
The funny part was the first time the high pitch happened was when he blew out his component. That part was way louder to me. It was probably too high pitched for him to hear so he didn’t know to warn about it us then.
It's funny and sad at the same time that we are witnessing another Tom Scott moment.
Man if only you, Photoinduction and Styro could get together and make something really crazy.
Prior to retirement I was designing c-ray generators (from control, drivers, transformers etc. To 300kV.
Very skeleton advise
Majority oil insulated, high voltage section heated to 80C and under vacuum for 3 days to remove all moisture, in the mean time oil circulated through fine filters and showered into vacuum chamber at 80C again to remove moisture and solid bodies which could align up under the high voltage and cause break downs.
Some units we filled with SF6 gas at high pressure.
Transformer secondaries single tube bobbin.
Get rid of the discs separating the windings wasted space. Retain the outmost rings to prevent discharge to the core.
Place two turns of thin Kapton tape or other highly insulating film between each layer of the copper windings, copper winding width keep less than the width of the tape.
Each subsequent winding width reduce by a couple of millimetres or so and reduce the insulating tape width every few layers so that the endings end up like a trapezoid (pyramid-truncated on the top) whilst the insulation is like a stepped pyramid.
You could have grounding strip on the core and the connection to the first layer start of the winding so that the top of the winding is your highest voltage output.
Keep an eye on the distance from the top layer to the primary winding.
Apologies if I am repeating other comments suggestions.
X-ray not c-ray
"You Fell Victim to One of the Classic Blunders"
Ground war in Asia? Never go in against a Sicilian when death is on the line?
My dogs hated this video
Same😂
Arc noise bothers them ?
Try to use audio equalizer in your device and cut off the higher frequencies, I'd say 18k and more. You're too old to hear them anyway :D
@@fares3651 bro, it was operating at 10.7 KHz 😭 cutting 18KHz isn't gonna do a thing here, whoever can't hear this has really damaged hearing
LoL
I'm sorry, A Massive Rail Gun? 20:38
I need one!😂
looking fofr this comment
Indeed.
Except he'll probably use a 200psi injector, and it will just be another "sparkling air cannon".
But I hope I'm wrong and he will build a true railgun.
@@Pyroteknikiddepending on where he lives, that might be illegal 😅
In order to push More power thru an Acymetric Capaciter for Lift, you Must Seal the Anode and Cathode, and Pressurize. It’s essentially an Air Capacitor. Air is the Dielectric Barrier. Higher Air pressures allow for More Power to be Pushed. THIS, is what our Favorite Space agency refused to show the Public, of their Experiments! UAP’s ARE REAL, and THIS is how they Work. Plus, try different Gasses. 😉
If you google Ruhmkorff coil. You can find pictures of various versions of a small transformer that was invented in 1836. Some of them produce much longer bushier sparks than the one above. They do operate in general at a lower frequency than the ferrite coils that are in old TVs. Jay's work always looks nice.
8:15 That issue is a drastic later shift. It is caused by poor adhesion to the print bed. Try using some gluestick
For the record, much better transformers can be made by constructing them the way N.Tesla did (with large spacing between turns and a voltage magnification that is unrelated to the number to turns). It could have saved you some time with winding and you would have had a more robust coil, capable of much more intense plasma discharges due to the higher frequency and voltage limits. You can refer to the scale model of the Colorado Springs transformer that Eric Dollard built to get an idea of what I am talking about.
What you mean by large spacing between turns? You mean you put insulation between each layer of turn ?
*Plasma Channel:* ⚠️NOISE WARNING⚠️
*My Tinnitus:* Aww... Cute sounds you've made! ☺️
Yeah that noise warning was after he blew out my ears twice. Really should have been at the start of the video. First thing he does is blow out my ears.
@@Subcode Headphones I presume?
I'm admittedly watching this on my S23 Ultra at ~90% volume _(with Atmos enabled, which means it's more like 95%),_ but its speakers had (surprisingly) no issue screaming all those noises... I was quite impressed!
But yea, if I had my planar dynamic earbuds in, it's plausible I'd be singing a similar tune to yours... 😅
Thankfully my 14.5 and 15.5 year old doggos have hearing loss and they didn't even flinch - the oldest was
That thing is wicked. As for the coil part that failed, it really is a work of art. It deserves to be mounted and displayed…or turned into a cool lamp !
Things like this is what the internet should be for. Expanding our knowledge and pushing its limits. Happily subscribed, looking forward to future content.
The poster behind you is cool 1:41 where can I get one
Jezus, HEADPHONE WARNING.... i have this video on 25% and you just blew out my ears.
The high pitched noise at 3:54 really hurt jeez
I'm 58 and could not hear a thing. I thought he was joking because it was silent. I even turned up my speakers, replayed it, and still nothing. lol It is true that as we age the HF hearing disappears.
@@ybsmike6512 I mean it really depends on the person as to when it happens but it'll happen to most of us eventually. People often are ashamed of hearing loss as well, which makes my job a lot harder sometimes. (I test hearing and sell hearing aids)
I love that watch!💚 also amazing video btw!
Thanks!
Always love seeing your videos , very educative, I'm really blessed only God knows how much I praise him, getting $100k bi weekly and I’m retired now. I’ve got a good cash and can also support my family
Hello!! how do you make such bi-weekly , sometimes I feel so down of myself because of low finance but I still believe God
This is what Daisy Clara does, she has changed my life.
Wow! I know Daisy Clara, and I have also had success...
Absolutely! I have heard stories of people who started with little or no knowledge but managed to emerge victorious thanks to Daisy Clara.
Please what’s her contact information?
Love it guys. Whether you realize it or not you are kind of starting an open source hardware and science movement. Akin to what GNU and Linux did with software years ago.
Not sure why putting those transistors in parallel caused any issues since many car audio amplifiers that use transistors have many of them in parallel to distribute the load.
Great video colleague👍👍👍
Out of all the noise warnings I've ever received that one was so chill for the squeal that followed. It wasn't even loud it just cut your brain.
I'm moving next week, can I borrow those bags? I bet I can fit my entire apartment in those.
You need to sleep more, my dude. Imagine... A world where you wake up with energy. You'll process things faster, allowing you to get more things done in less time, negating the need to stay awake far too long and chug bean water to stay alive.
If efficency doesn't convince you, I'll appeal to vanity; you look OLD and EXHAUSTED. Sleeping will more will fix that. You're a good-looking dude. Don't ruin it.
Plus, you clearly work extremely hard. You deserve a good night's rest. You've definitely earned it at this point.
I am 72 now, but when I was in high school for a science fair project I built a tesla coil that was nearly as tall as I was. The primary was 12 turns of wire energized with a neon lighting transformer that spits out 12,000 volts. The secondary was more than 100,000 turns of wire around a thick-walled cardboard tube (i.e., nothing ferric). I have no idea how many volts it put out, but I could hold a 60w fluorescent light in one hand and have it light up by pointing the other end at the Tesla coil from 6 feet away.
I realize after reading the video that you are basically building what I started with. But while that transformer was large and heavy, it was also dated from the 1930's. It was at least 5 times larger in total size than the final device you are making. I am pretty sure the entire neon lighting transformer was just that. a transformer driven entirely from wall current AC.
Also, UAP are NOT made out of Metals. They’re Mostly made out of Sophisticated Ceramics, Glass, and Graphene Infused Ceramics. (This is why they appear Silverish or Grey)
This was so much fun to watch ! I learned so much just by watching, thanks.
Your work is amazing! Can't wait to see your nextgen ion drive!!
I'm no engineer but I built a Jacob's Ladder, with a Volkswagen coil. I used AC mains input at 120 Volts, through a light dimmer and mylar caps. Stream began at about 1/2 inch. Put out a pretty good plasma stream. But what you made looks frightening and beautiful. Can't imagine spending so much time on that coil only to have it short...ugh!
11:54 - the gaps on your transformer bobbin would be best left as air spaces rather than being resin filled. Because arcs tend to travel along the surface, the resin potting reduces the amount of surface.
For those who doubt this, please look at the insulators used on power transmission lines - the shape of the surface on these is nowhere near a straight line.
Pretty cool! Reminds of an experiment I did when I was maybe 14 or 15. I had 6 or 7 step down AC transformers. The main one was a huge transformer that was 120AC in and iirc 24vac out, so 5x, and I had 5 or 6 more that were more typical rations of 10:1 or 12v output. I wired them all up, in reverse.... so they would be stepping up. I recall calculating it as being 500,000x step up. I used straight power from the wall, so 120vac in, so yeah it would be in the millions of volts.
I had this all wired up on the floor of my room, which was shag carpet.
I spaced the output pair of wires about 1 inch apart. I didn't know exactly what to expect, it was why I was experimenting :)
When I plugged it in, the whole house hummed, lights dimmed... lol
It created a white arc that looked like old tv static, the spark was a good 1/4 inch wide. Never seen a spark like before or since. I was away from the thing, plugging it into the wall. I only kept it plugged in for maybe a half second.
In that time, it made that amazing, weird spark, all of the transformers got so hot that they melted the shag carpet. Once it cooled, I had to pull them out of the carpet. All of them were destroyed.
Mom knocked on my door and asked what I was doing, I probably lied.
Anyway, you might try making your step up transformer as 3 or 4 separate transformers intended to be wired up in sequence. This way on the earlier stages, you can use higher gauge wire for the output side, lower step up ratio in each, and spread out the heat that is generated. You might be able to get to some insanely high output voltages. Also try sine-wave input vs that jagged waveform you were using.
The reason transistor fails at 3.59 was perhaps caused by moment of disconnection of the potentiometer - the generator was at very low freq for a moment, causing very high current building up in inductance saturating ferrite. One should use bypass resistors across potentiometers limiting behavior in such sistutaion. Also, one can reduce number of turns per kV by ~2 by switching to symmetric push-pull flyback ( using diodes in series with transitor drains) and another factor x4..5 by using permalloy wound core (much higher saturation field), works fine at 10KHz and even higher
MOSFETs are actually pretty happy being paralleled due to their R_on going higher with temperature. It still doesn't prevent big R_on mismatches. Also you need to drive them properly: fast transitions (high current in/out the gate) without going into oscillation (with a gate resistor just big enough to stop oscillations).
If you want crazy high currents without the inconvenience of paralleling MOSFETs, just go with one IGBT, they are rated for INSANE amounts of current.
When the input voltage is so low, IGBTs are not the way to go, they have a small saturation voltage.
It's better to pick a MOSFET capable of switching high currents.
My continuous wave tesla coil delivers 150W @ 500 kHz from a single MDP1922 transistor.
Vds = 100V, Id = 97A, Ron = 8.4 mOhm, Td(on) = 14ns, Td(off) = 39ns
The input capacitance is 3500pF, but that's no problem for the MOSFET driver, MCP1406.
From all the transistors I tried, the MDP1922 was the most efficient at this rather high switching frequency.
I tried one IGBT, but it was terrible. :)
great video, you are one smart cookie and very professional.
love your style of presentation, your enthusiasm is enjoyable
and highly infectious.
thanks for reactivating my tinnitus with the high frequency oscillations :) the silence was killing me
4:31 I literally laughed out loud at your description of how the MOSFETs were interacting with each other. You and styropyro just have that mad scientist humor that I absolutely love.
The kind of vibe I would expect from Nikola Tesla if Nikola was hitting the ether just a little too hard.
I'm all for the costume changes. Science AND Fashion.
Loved the video. You keep it interesting with the commentary, but such a cool topic as well!
Beautiful, stunningly beautiful.