You should give superconducting magnets a try. You won't have to worry about heat or any power loss, just need a good source of liquid nitrogen. Would love to see your detailed analysis of one!
I think even that "ordinary" electro magnet (without the need to build one out of exotic superconducting materials) would probably be able to get as strong as the neodymium magnets without generating too much heat, if cooled down by liquid nitrogen. Copper never really get super conducting, but it lower it's resistance really much (about 8,8 times compared to 25°C) at liquid nitrogen temperatures.
Even just submerging these commercial electromagnets in liquid nitrogen would allow you to significantly over-power them without them heating up and loosing efficiency
Thank you very much! I was under an unusual time pressure for this video since I basically got carried away with the number of experiments testing an electromagnet for the first time. Truly exciting and enlightening for me. But I always aim for quality over quantity ;) Much more to come!
@@brainiac75 I can resonate with quality over quantity: something I've tried taking to heart on my own channel. Can't wait to see more, keep it up good sir!
Overclocking an electromagnet and colling it with an AIO. Are we now at LTT? 😆 Biggest gains on that magnet would come from cooling it down with LN2. Would be a great vid, temperature vs magnetic strength vs power draw. With that tesla meter of yours, it would be very interesting to see that curve!
Laboratory LN2 has largely been replaced by Peltier pump. With a Peltier we do not need to go down to -196° but merely remove the heat the power in the magnet is dissipating. The electrical resistance will always produce heat and the magnetic field will add to the impedance because it counters the potential voltage (delta V). The electro-magnet needs to dissipate heat at the same rate it creates it to remain at equilibrium. Unit of heat is Joule, rate of heat is J/s = Watts. We need a Peltier pump that cools equal to the heating. Another power supply and a suitable Peltier.
A lot of times when stuff is advertised as "12V" they actually mean something more like 14V because that is the kind of voltage it would actually see in an automotive application and most 12V applications are automotive. Could explain some of the wattage discrepency.
Most are not automotive at all not even close and 14.4v-14.6v is more accurate in automotive when using a alternator with no load and that can drop fast depending on load and alternator etc
@@primus711 13.8v is considered "standard" alternator voltage, the way 120/240v is standard in the house. Yes it can vary up and down a bit but that is a good average to use for ratings. There is however much usage of 12v outside of automotive applications. In those applications they really do mean TWELVE volts! Things like massive servers have a PS that outputs about 12.2v @ 100+ amps, voltage always adjusting to meet demand and stay at 12v. 12v is also heavily used for all kinds of control circuits - I think one of the uses of these magnets is to lock doors remotely, such a system would likely use a 12v power supply. If it was made in china, I don't care what it is or how much it cost, the specs are not reality.
The magnetic strength doubling with a 4 fold increase of wattage is logical. The field strength is linear with the current, and the current is linear with the voltage. Since P=I*U and I and U both increase linearly with the field strength, the power (wattage) increases quadraticly (or the magnetic field with the root of the power). To combat the heating issue, set your power supply to "unlimited" voltage, and limit the current, then the field strength will stay constant (even though it still heats up a lot)
I'm an engineer that designs linear motors with permanent magnets. Your testing of the open air magnetic field does not represent the lifting power of the electromagnet. If you put the electromagnet against a flat piece of steel with a gauss meter in between, you would measure a much higher field. Note that the steel plate should be thick to get the highest measurements (10 mm thick is probably enough). With the electromagnet in the open air (no steel plate), the magnetomotive force must be distributed across the air gap between the center circular pole and the outside ring pole. If you put those poles against against a flat steel plate (steel has high permeability), the air gap is much smaller, and you will end up with a much larger field (probably around or over 10000 Gauss, approaching the saturation point of the steel pole in the center). When you use the neodymium magnet against a steel plate, it's large magnetomotive force is mostly spent creating a magnetic field across its own (low permeability) interior -- its own material acts much like an air gap. It's magnetomotive force is so high, however, that it can create high forces. I would suggest that you perform a lifting test with the two magnets, and see how much weight you can lift with each one. Hang your magnet from a strong support with the poles facing down on the electromagnet (it looks like the electromagnet may have threaded holes for this purpose). Stick a thick (1 cm or more), flat piece of steel to the bottom of the magnet. Add weight to the steel until it falls off. That will give you a much better idea of the lifting capability. Repeat with the Neodymium magnet (You will likely have to use a clamp to hang the Neodymium magnet, or you can just stick it to the bottom of a thick steel beam or plate). The electromagnet will have high attractive forces with a small gaps, but the force will fall off quickly with increasing gaps. The Neodymium magnet's forces will fall off more slowly with increasing gap. When performing the same test with a thin sheet of steel, the sheet of steel will saturate (it has high permeability for only about the first 20000 gauss, and then saturates), and you will get much lower attractive forces. Good luck!
One of the measures of a good quality holding magnet is how smooth and flat it's surface is. The better quality ones are ground better. The same applies to the steel plate, so a machined/ground one is WAY better than a rusty cold rolled steel bar.
How crucial would the remaining air gap be? Because you could even go a step further and use something like heat sink grease to eliminate the air. The only drawback is if you even look at the stuff it gets everywhere.
The electromagnet has the advantage of metal cup to close (concentrate) the magnetic circuit. If you gave the neo magnet a similar cup it would increase its holding force, further increasing its advantage. A lot of fridge magnets do this so they can use cheaper ceramic magnets that wouldn't hold without the cup. flexible sheet magnets do something similar by alternating polarity in stripes. You should also look at switchable permanent magnets as they have feature parity with electromagnets.
Yep, didn't have time for it for this video, but I will try to source a 50x30 mm neo magnet (preferable grade N52) and a potted 50x30 mm neo magnet. Would make for a much better one to one comparison. No doubt that the neo magnets will still win though. Thanks for watching!
I have some pretty thin 30mm neo magnets that are in steel cups, and it does make a huge difference. The manufacturer didn't have to bother with gluing them, it's almost impossible to get them out.
Electromagnets are interesting in their own right, though happy to hear that passive neodymium magnets beat them out in some cases! Great video as always.
Your electromagnets brought some memories. When I first got to deal with the math of electromagnets, I decided to try some optimization of my own. To my frustration, the math "converged" always to the lowest number of wire turns, using heavier and heavier gauge wires. In fact, my end result was that a single turn of wire that filled the whole available volume always produced the highest magnetic flux with least resistive heat. Of course, the flux density is determined by the air gap, as long as the core does not saturate. Your probing showed well below my usual assumption of 1.2 T (tesla = 10 000 gauss) to 1.5 T field density saturation for ordinary magnetic core materials. So you would be able to push beyond the neodymium field density with a single turn winding and maybe 0.1 V / 200 A supply without excessive heating, if you can provide such a supply. (0.1 V x 100 A = just 10 W).
@@NEW-WATER-ATTRIBUTES-2023 I am not at all sure what exact help you would expect. I just have one idea that may be easier to implement than, say some superconducting suggestion. It is to make your coil of copper tube, such as the one used in air conditioner heat exchangers. You could find that kind in most any big hardware store. Then you would need to insulate the tube, with for example heat shrink tubing before winding it to a coil. An alternative would be some insulating spacers mounted between coil turns after winding, I assume you would already have insulation around the iron core. With appropriate fitting(s) and a pump, or just tap water, you could reduce the temperature rise to negligible level, meaning you could use much more current. This kind of arrangement is used in flameless - Eddy current - annealing heaters. In them, they don't need insulation, because they have the coil stiff, just air core magnet, maybe 2 or 3 inches inside diameter, 3 to 6 inches long. I assume you would want DC use, and a more compact structure, with a U- or maybe E- shaped iron core. However, keep in mind that any iron core eventually saturates, and after that any increase in magnetizing current causes only field increase at the same rate that results in open air. All that means, initially the iron core effect is good and strong, but after saturation level, FURTHER INCREASE tapers off. I hope this at least gives you some idea what to consider, or try next. As to the source of current, somebody already suggested using car batteries. Just pick some with a high cranking current rating (like 600 amperes or more). The cranking current rating is for relatively short times, so you still might need two or more in parallel, if you want more than about 10 or 20 seconds duration. And of course, the cables from the batteries to your coil must be thick and short. I would suggest 0 or 00 size welding cables. 0000 size could handle over 600 A long term, but I don't think any practical batteries would. Finally, you would need a really big switch to turn your current on and off!
You can get "switchable" permanent magnets as well, where you turn something on top to change the positioning of two magnets to cancel eachother out in the off position. (I'm sure you know this, but since you mentioned the ability to turn off as the main advantage I thought I'd add this comment)
Thanks for the reminder! I do need to make a video about the magnetic lifters - and even build my own using permanent magnets to demonstrate how they work. So many videos to make - so little time for it :D
There is a trick with electromagnets , which allows you to reach higher pulling force than any permanent magnet is able on , without overheating of the coil . You need to grind (as fine as possible ) electromagnet’s poles and the metal surface on which you want to lock them . Than use capacitors battery ( you may need ultracapacitors ( also known as supercapacitors or ionistors ) ). Charge the capacitors battery to few times higher voltage than the electromagnet is rated for . Than discharge the capacitors battery via the electromagnet’s coil . The enormous current pulse will create enormous magnetic field . The interesting part is that this field doesn’t disappear or weaken in the magnetic guide after the the coil current is disrupted so there is no any reason for heating and the magnetic guide loop can stay closed infinitely. You can open it by applying the same amount of current but with opposite polarity of the voltage on coil terminals . You can see such experiments in the following video th-cam.com/video/s-5FMFzSPYU/w-d-xo.html unfortunately on Russian language . By the way the strongest magnetic fields are archived by electromagnets !
Magnets happen to be one of my favorite subjects. I believe if the core were taken out and shaved to half its diameter, and then rewound with more windings, you could potentially double the gauss output with the same volume. Can't wait to see you build some of your own! Imagine the ones they use in wrecking yards to lift entire cars, the possibilities are endless. Speaking of turning on and off, I have seen some permanent magnet gadgets that turn on and off the magnetic field by flipping a lever. What's that all about? Great video!
Please don't say "overclock" when you are only changing voltages and currents to values out of spec. The correct term is "overvolt" Having said that, I've enjoyed the video! Let's see what the future brings for that little magnet-on-demand! Cheers
I do upload a video every month (twice a month if you include the one on Patreon), but you may only be notified of my magnet videos if you only watch those? But yes, quality over quantity for my channel :D Thanks for watching!
@@brainiac75 wow that's a great mindset but i feared that you lose subs overtime when you're in the process of making new vids because of how long it takes to make one and yes i do watch some of your videos sometimes but only youtube videos I don't use patreon neither i don't know what patron is.. haha
I love making those little homemade bolt electromagnets in fact, If you give the electromagnet more current it will get hotter. More Voltage = More Strength | More Current = More Heat. I even tried to make an electromagnet oven by giving it around 5v DC 2 amps. this gave the magnets a fair amount of strength. but they got very hot. I was almost able to make toast with my oven! They even have induction cookers that are just a giant electromagnets with lots of current. It's fun to experiment with this kind of stuff! keep it up Brainiac75!!
Just started binge watching this channel a few videos ago. Looking forward to seeing the progression up the liquid-> water -> sub-ambient -> L2N goes, as the colder it run, the better it runs.
I made my own electromagnet recently out of an old microwave transformer. Using a couple old car batteries it got hot fast but it was so strong with that much current, the shovel would instantly stick and not come off until the power was disconnected haha It was fun trying out different ways of powering and messing with different sizes of transformers
Very nice video! Have you heard about the combination permanent- and electro- magnets used for safety critical / lifting applications? This unit includes a permanent magnet with an electromagnetic component. The permanent magnet will produce an external magnetic field under normal non-energized conditions. When the electric coil is turned on, it provides an internal magnetic path, preventing the unit from producing an external magnetic field. No power is required to HOLD the load on the magnet, but power is required to RELEASE the load. These are used for lifting and hoisting, where a power failure with a "pure" electromagnet would result in a dropped load. I think they call it an "electropermanent magnet" assembly.
Great video, When I was younger I used to work for a company that had an electro magnetic lock on the door. During office opening hours the door was propped open and the magnet was at the top of the door frame. For fun we would turn the lock on and put some paperclips on the magnet. Then when someone walked through the door we would turn the magnet off as the paper clips dropped on their head. It was harmless fun as we watched from a distance as the bemused person wondered where the paperclips came from. This would amuse us for hours.
Making a a hybrid of the two would have novel properties, like being able to turn a permanent magnet's field temporarily off, or able to steer its direction. Hybrids are used in load speakers and bidirectional solenoids.
I love how we are both thinking about water cooling the electromagnet. But do watch out for the magnetic impeller inside many all-in-one cooling solutions. It might be better to get a custom water cooling loop.
I'm happy you are finally getting into electromagnets. I really like neodymium magnets. I allways seem to find stray magnets and I have an ever growing collection. I found a stack of 4 2"x3x1/4 on a shopping cart. Those are super strong and were an amazing find.
Funny my first thought with the electromagnet when I saw its performance was - what if it was cooled and you over-volted it? And of course the next thought was - what if you cooled it with LN2? Also I think it would be neat if you could get your hands on a bitter electromagnet or maybe collab with a bitter magnet manufacturer. I think the current record for man made magnetic fields is a bitter magnet rated at 45.5 Tesla (455,000 gauss). Would be super cool to see you experiment with one.
💡Stack an electromagnet and neodymium. (Epoxy a coil around the neodymium magnet.) You can use a pulse to temporarily cancel out the permanent magnet. Iron can also be used to focus the power just like the electromagnet in this video, just make the center part the neodymium magnet. 👍
I’d love to see you take a look At electro permanent magnets. They’ve always fascinated me. Basically a “pulse” of current switches them on and off - during either operation, no electricity is required!
The root relationship is quite simple to explain with basic physics. The magnetic field (B) is directly proportional to the current (A). The relationship between the current and the power (P) is quadratic (P = I² • R). This results in a root relationship between P and B. I would therefore always put the current on the x-axis (set value) and the field on the y-axis (dependent value). What would make the video even better would be a physical underpinning. The electromagnet is a coil. You can strongly influence the properties of this by changing the length, diameter or number of turns. Also, the use of a core of steel or ferrite can influence the strength. You can easily adjust all these properties yourself to make a much stronger magnet. Most importantly, more current, stronger magnet. So if you can get more current through more turns without the magnet heating up too much, then you have a good magnet. Thick wire, many turns, around a ferrite core.
Most people don't realize that it is the field gradient -- NOT the field strength -- that causes magnetic force on iron. (But gradients and intensity both scale with current making it easy to be misled.) Additionally, closing the flux paths by placing iron across the open face will eliminate flux through the coil and greatly increase the field at the poles. As performed, your measurements mean very little; the permanent magnet does NOT have this alternate flux path.
Great video. This gave me inspiration to prepare some electromagnets for use around the shop. My son wanted to make a solenoid engine for a class of his. Running the math to look for more power we found a honey comb array of smaller core and coils had a lot of advantages. We never built it though. His teacher was happy just with the math Thanks again for the video
You might like to read ‘Magnetic Venture” by Audrey Wood. All about Oxford Instruments and the development of big magnets for NMR and later super cooled magnets for MRI scanners.
The most powerful magnetic fields are generated by compound coils, admittedly using super conductors. If electric vehicle development is not to be limited by the availability of rare earth elements, then motors must use electromagnet field generation, rather than permanent neodymium magnetics.
YES! more electromagnets!! That is pretty cool. I think you should give a microwave transformer a try, easy to get and you can cut out the secondary and put 2 primaries into it for more coils!
Very detailed overview. I challenge you to solve the faraday paradox!!! A faraday homopolar generator with fixed magnets on the rotor, poles will be axially and radially. It produces dc voltage with no back emf
I'd definitely like to see the results of cooling the elecromagnet. Regular computer heatsink, heatsink with fan, submerged in ice water, heatsink with ice water submersion, liquid CPU cooler, or even liquid nitrogen as someone mentioned. Maybe you could use an intermediate medium to work your way down to liquid nitrogen temps instead of doing it all in one step. Hopefully you'll do several of those, but even one cooling method will be neat. Thanks for a great video as always.
You should go all out with experimenting with pushing a electromagnet's ability and using a cooling system. Its just really interesting to be able to play with the settings, adjustments, etc. Im wondering if there could be some insane ways a super powerful one, or a setup system of them could be used if say: hypothetically you ran some off of a modern advanced nuclear energy reactor. Could be small form, thorium reactor, LFTRs... But could definitely power some really fun science experiments that's for sure. And the energy source would be efficient, no emissions, stable, strong. It would be exciting to power a efficient system that runs off of the electrical output from a power source like that.
These magnets don't mind so much being heating up. They are used in metal industry to lift e.g. large metal plates and iron beams. They are usually not activated for more than from a few seconds, to a few minutes at a time. With 4 to 8 of these, just in sizes that are larger, you can lift lift metal plates for e.g. ship construction, that weights several tonnes. I don't remember the pulling power of magnets of this kind, that has a diameter 4 to 5 times the size, but we are talking maybe a tonne per magnet. But you always want to have twice as many magnets as needed. One, several of the magnets can be short circuited/defect, second, their max pulling power decreases radically, just by having dust in the environment.
You should test electromagnet door locks. The ones commercial buildings use to lock their doors. Not a lot of pull force, but holding force is incredible.
Just bolting a regular finned heatsink to the back of the electromagnet would help keep the temps down when overvolting the electromagnet. There is however a risk of burning out the windings if too much current is applied. If you want to push the overvolting experiment further there's no reason you couldn't put the electromagnet in a simple waterbath, at least up to the top lip, since the windings are insulated and potted in resin. That would dissipate the heat quite well.
Good job on the video! It's interesting and educational but I respectfully take issue with your use of the word "overclocking". Electromagnets do not have clocks. Therefore, you cannot overclock them. You can over-power them, but not overclock them. Here is the definition of overclocking: "Overclocking is the action of increasing a component’s clock rate, running it at a higher speed than it was designed to run." It applies only to clocked devices such as microprocessors and some other types of computer chips. Keep up your awesome videos!
It would be interesting to see how high the field strength can go if you can supply a pulsed DC power to the electromagnet. - the 8W magnet is average power, and just as with lasers and LED's - pulsing with a low duty cycle should give a high(er) peak-output power... Playing with Power - Pulsed Power Push/Pull'er (or perhaps not, the iron core has a B-H curve, so it's possibly not reacting fast enough) 2*12V car batteries and a beefy relay (w. rev diode protection) controlled by a variable oscillator might be safer for your power-supply ;ø) Looking forward to future videos on these pucks - btw, where did you buy them (and the Radiocode meter, etc. - links/info would be appreciated)
Interesting. May give it a thought, though back EMF and basically running a DC magnet as an AC magnet may get me in trouble :) But I will try running it on AC in a future video. Just to see what happens with heating, field strength etc. I am a total noob when it comes to electromagnets... The electromagnet was bought from Conrad Electronic.
@@brainiac75 AC is alternating current ;ø) - so the magnet will also be alternating its poles. Magnetic Hysteresis then becomes an issue (problem), as energy is spent turning the magnetic domains inside the iron/magnet. Less emitted field pr unit energy spent. Pulsing the magnet with DC - ought to strengthen it, as the h-field moves up-down without having to rotate. Wikipedia has good illustrations of this. This should (I think - not 100% sure) strengthen the field when powered on, and still remain magnetic when power is off. I could build you an electronic switching device for pulsed DC + tell you a bit more (I'm an electrical engineer + radio 'everything'). I live quite close to your favorite sweets-store, if you're interested :ø) - and I have some time on my hands, electrical components + equipment, and I'm curious what your Lake Shore Teslameter reports. (er også bidt af en magnet og deres mysterier)
Oooh! This is fun! I'm particularly interested in how active cooling could affect it. I've been wanting to try building a little Gauss/coil gun for a while, and have been curious if cooling the coils could improve performance, but haven't been sure how much, if any difference it could make. (been thinking of using a Peltier cooler to get them quite cold)
For this and your N40 magnet, I think the best video would be temperature vs magnetic flux density vs max load, with an overclocked electromagnet with a UPS, and cooled by either liquid nitrogen, liquid oxygen or water that is just above freezing point.
I look forward to more of these! Cooling tests will be fun. You could do some pulse tests as well. If you can manage the power supply requirements you can pulse 10 times or more it's rated current, albiet for only a split second. I'm not sure what you would use it for but it would probably make an interesting video.
I thought for a while how i could compare different magnets strengths with something carried everyday. Soooo i use a standard bic lighter standing up with the magnet flat on the same table. From how far away will the magnet pull over the lighter.
OK, sorry to be critical, but "over-clocking" is when you run microprocessors above their rated base frequency for faster computing but at the risk of reduced processor life from overheating (unless you can manage the extra heat through cooling strategies). What you should be saying is "over-currenting" since you're increasing amps and therefore power dissipation. Amps are what contributes to your MMF (Magnetomotive Force in units of Amp x Turns). As your coil heats up, the wire resistance will also rise, causing your electromagnet to operate less efficiently. Additionally, as your iron core begins to saturate, more and more current will only generate excess heat with no appreciable increase in flux so there's a point where more current proves counterproductive.
Yes, I do need to test (and make my own) magnetic lifters that can be turned 'off' using permanent magnets. Interesting subject and gives the permanent magnets one of the advantages of electromagnets ;) Thanks for watching!
Some permanent magnets can also turn on/off by bend their flux in the same direction or opposite direction.(you need at least 2 of them with electromagnet material to make the magnetic force go in loop when turn opposite direction for turning off.)
This is exactly what I need to do my experiments with a variety of stuff. But especially plant growth and cellular health. I need an affordable electromagnetic device that allows it to be variable and see the actual strength of the magnetic field or it’s frequency.
electromagnets are one of the most important components in particle accelerators such as the Large Hadron Collider or some of the many synchrotronns used to make intense X-ray beams. Most of the normal ie not superconducting magnets use copper tubes as "wires" and pass 100's of Amps through them at low ish voltages. The tubes allow low conductivity water to be passed through the wires to keep the magnets at a stable temperature of around room temperature when operating. These magnets have to be very stable under the current load so the magnets do not move as the guide the path of charged particles. For the synchrotron the maximum field that can be made is about 1.4 Tesla and this is related to the saturation magnetic field induced in the iron core. If you use another alloy called permalloy instead of Iron you can get up to about 2.5 Teslas. Fields beyond this require superconducting wires that at present have to use liquid Helium cooling to operate. If you search for magnets for synchrotrons you will find that some devices use rare earth magnets because they can produce very high magnetic fields in very small spaces which you cannot match with normal electromagnets.
I made electromagnets as a child using a nail as core and copper enameled wire about 22swg (0.7mm). I connected them up to my train set 12 V DC transformer but they did not work very well. After reading a book I saw they put a wrap of writing paper around the core so tried this and it worked very well and much stronger.
Congratulations ! This is one of the bether videos that a have seen ! The question is : If I need 8w of power or 8 joules by second of energy to get 400 N of pull , what kind of energy the permanent magnets need and where it receves this energy from? It is almost sure the neodymium magnets receves a kind of energy from universe , then it is not so absurd to imagine a magnect mouter runing by itselfs . Do a video comparing the capacity of moving wheght corps by eletromagnets and permanent magnets along the space. Please!
What about heating in the electro when holding a load (poles connected with Fe object)? What about advantages of electros vs Neos in generator or motor applications (control vs economy)?
Permanent magnet is like superconductor magnet: flow of field despite being disconnected from the power source, and don't heat up :) All the MRI equipment uses them. Get one of those.
I would love to see you put a cooling system on the electromagnet. Especially because magnets and electricity start behaving differently the colder they get.
Some permanent magnets can be turned on and off. The switch reverses a fraction of the magnet with the rest of the magnet so the external field is cancelled.
If you want to try cooling the electromagnet with a PC AIO cooler, look for something with a pump that's not in the waterblock, I can't imagine it will pump very well if at all with an electromagnet stuck to it.
It seems peculiar that you focus so much on wattage of an electromagnet. The magnetic flux you get is proportional to current times number of turns in the coil (at least until you reach magnetic saturation of the core). If you rebuild the graph at 4:35 with current as the x value, you'd get a pretty much linear plot. So, if you want power efficiency, you need to minimise the coil resistance. Use thicker wire gauge, and/or employ some radical cooling (dry ice or even liquid nitrogen).
connecting a diode anti-parallel to the electromagnet will absorb that flyback surge, (back-EMF) which protects the inside coils from possible flash over, and protects you from a potentially nasty shock! Watch for core saturation, if over-clocking. You will reach a point, where the core reaches its absolute maximum strength, and will not become stronger by continuing to increase current.
The limitation of the electro magnet is the resistance from the copper wires that generates the magnetic field, if you used a superconductor like graphene the theoretical limit is much higher
There is a rare type of magnets, that are switchable on/off like an electromagnet, but dont need power and act like constant magnets. I built one this year and I very like it. Would be nice if you made a video about this
You should check out switchable magnets. I have no idea how they work, only that they use a grid of permanent magnets lined up so that when you turn one part there's little to no magnetic field, and when you turn it back there's a very strong one.
You should try to make halbach array out of neodymium, electro magnets, and super conducting magnets. You can arrange them to concentrate the fields and make them even stronger or make them cancel out to "turn off" neodymium magnets.
Would be interesting to see how using various power supply wave forms affects the strength of the magnet. Is the relationship linear if say pulsed square or sawtooth wave DC is supplied or is there a relative gain or loss in the resultant magnetic field?
@@martinshoosterman Perhaps but other effects might be observed as well, such as linearity of attenuation, affect on input current to magnetic strength at different amplitudes and frequency, or any unexpected effects. It might answer the question you ask.
I work at APC (by Schneider-Electric), and seeing an APC UPS in this setup makes me giddy. Too bad our testing cage is off limits when active, it could have been a fun video.
I'd LOVE to see you home-build a monster electromagnet by obtaining a microwave oven transformer (MOT) and cutting off the top of the core and discarding either the primary or secondary winding, as well as the heater winding and magnetic shunts (if they will weaken the field, I'm not sure). The open-core transformer with only one winding becomes a seriously powerful electromagnet with very little work. If you can obtain 3 or 4 of them, you can power them in parallel from a DC power source and arrange them in an array, potted into a single housing. The resultant electromagnet would be able to hold several people hanging from it. I'd be super curious how the field strength of one of these MOT electromagnets compares on an equal weight and size basis to a high grade neodymium magnet with a similar magnetic field shape. :) I'm not sure about over there in your country, but here in the USA we have old, broken microwaves EVERYWHERE with (usually) good MOTs inside that have not been the point of failure. I know inverter-type microwaves are becoming popular, but they haven't really caught on here in the USA. Worst case scenario, you can buy a new MOT on eBay.
The "overclocking" your trying would be better suited if you had a cooling platform to maintain a constant temperature at the electromagnet. The pc watercoolers are designed for use with surface area, rather pointless on a longer bolt shaped magnet. But fairly effecient the flatter the area contact to help cool it. My suggestion for cheap regular cooling would be a pressured airflow system. The airflow and pressure changes around the magnet from a fan suction properly mounted on the back would be able to counter the heating rate. Make a plastic mount to clip on the electromagnet that provides optimal airflow and pressure based on the space around the magnet for it to suck the air. The smaller the gaps the higher the pressure required but it also increases the heat disapation by allowing more constant use of the surface area's.
You should give superconducting magnets a try. You won't have to worry about heat or any power loss, just need a good source of liquid nitrogen. Would love to see your detailed analysis of one!
How much money would it cost me to generate 2-4 tesla on my desk?
Yo, codeparade! Love your game, and happy to see you here
I think even that "ordinary" electro magnet (without the need to build one out of exotic superconducting materials) would probably be able to get as strong as the neodymium magnets without generating too much heat, if cooled down by liquid nitrogen. Copper never really get super conducting, but it lower it's resistance really much (about 8,8 times compared to 25°C) at liquid nitrogen temperatures.
Even just submerging these commercial electromagnets in liquid nitrogen would allow you to significantly over-power them without them heating up and loosing efficiency
Hi CodeParade! Loving your new game :)
Could we all just take a moment to appreciate the quality put into these videos? Truly amazing, keep it up man!
Thank you very much! I was under an unusual time pressure for this video since I basically got carried away with the number of experiments testing an electromagnet for the first time. Truly exciting and enlightening for me. But I always aim for quality over quantity ;) Much more to come!
@@brainiac75 I can resonate with quality over quantity: something I've tried taking to heart on my own channel. Can't wait to see more, keep it up good sir!
@@brainiac75 I can't wait to see what it can do with a cooling system!
@@brainiac75 hi
@@brainiac75 Can you build electromagnet using different core materials?
The truly strongest form of magnetism is produced by your enthusiasm for magnets. It's what keeps attracting people back to your channel.
100/10 nice
Overclocking an electromagnet and colling it with an AIO. Are we now at LTT? 😆 Biggest gains on that magnet would come from cooling it down with LN2.
Would be a great vid, temperature vs magnetic strength vs power draw. With that tesla meter of yours, it would be very interesting to see that curve!
Wonder what the differences are in cinebench before and after overclocking.
The black stuff on top may crack in liquid nitrogen.
Laboratory LN2 has largely been replaced by Peltier pump. With a Peltier we do not need to go down to -196° but merely remove the heat the power in the magnet is dissipating. The electrical resistance will always produce heat and the magnetic field will add to the impedance because it counters the potential voltage (delta V). The electro-magnet needs to dissipate heat at the same rate it creates it to remain at equilibrium. Unit of heat is Joule, rate of heat is J/s = Watts. We need a Peltier pump that cools equal to the heating. Another power supply and a suitable Peltier.
Cody's lab has done a video of cooling an electromagnet with LN2. It works great: th-cam.com/video/YledrMyoqgs/w-d-xo.html
A lot of times when stuff is advertised as "12V" they actually mean something more like 14V because that is the kind of voltage it would actually see in an automotive application and most 12V applications are automotive. Could explain some of the wattage discrepency.
Most are not automotive at all not even close and 14.4v-14.6v is more accurate in automotive when using a alternator with no load and that can drop fast depending on load and alternator etc
@@primus711 13.8v is considered "standard" alternator voltage, the way 120/240v is standard in the house. Yes it can vary up and down a bit but that is a good average to use for ratings.
There is however much usage of 12v outside of automotive applications. In those applications they really do mean TWELVE volts! Things like massive servers have a PS that outputs about 12.2v @ 100+ amps, voltage always adjusting to meet demand and stay at 12v. 12v is also heavily used for all kinds of control circuits - I think one of the uses of these magnets is to lock doors remotely, such a system would likely use a 12v power supply.
If it was made in china, I don't care what it is or how much it cost, the specs are not reality.
watts = {(volts)^2 }/ohm
The magnetic strength doubling with a 4 fold increase of wattage is logical. The field strength is linear with the current, and the current is linear with the voltage. Since P=I*U and I and U both increase linearly with the field strength, the power (wattage) increases quadraticly (or the magnetic field with the root of the power). To combat the heating issue, set your power supply to "unlimited" voltage, and limit the current, then the field strength will stay constant (even though it still heats up a lot)
I'm an engineer that designs linear motors with permanent magnets. Your testing of the open air magnetic field does not represent the lifting power of the electromagnet. If you put the electromagnet against a flat piece of steel with a gauss meter in between, you would measure a much higher field. Note that the steel plate should be thick to get the highest measurements (10 mm thick is probably enough). With the electromagnet in the open air (no steel plate), the magnetomotive force must be distributed across the air gap between the center circular pole and the outside ring pole. If you put those poles against against a flat steel plate (steel has high permeability), the air gap is much smaller, and you will end up with a much larger field (probably around or over 10000 Gauss, approaching the saturation point of the steel pole in the center). When you use the neodymium magnet against a steel plate, it's large magnetomotive force is mostly spent creating a magnetic field across its own (low permeability) interior -- its own material acts much like an air gap. It's magnetomotive force is so high, however, that it can create high forces.
I would suggest that you perform a lifting test with the two magnets, and see how much weight you can lift with each one. Hang your magnet from a strong support with the poles facing down on the electromagnet (it looks like the electromagnet may have threaded holes for this purpose). Stick a thick (1 cm or more), flat piece of steel to the bottom of the magnet. Add weight to the steel until it falls off. That will give you a much better idea of the lifting capability. Repeat with the Neodymium magnet (You will likely have to use a clamp to hang the Neodymium magnet, or you can just stick it to the bottom of a thick steel beam or plate).
The electromagnet will have high attractive forces with a small gaps, but the force will fall off quickly with increasing gaps. The Neodymium magnet's forces will fall off more slowly with increasing gap.
When performing the same test with a thin sheet of steel, the sheet of steel will saturate (it has high permeability for only about the first 20000 gauss, and then saturates), and you will get much lower attractive forces.
Good luck!
One of the measures of a good quality holding magnet is how smooth and flat it's surface is. The better quality ones are ground better. The same applies to the steel plate, so a machined/ground one is WAY better than a rusty cold rolled steel bar.
How crucial would the remaining air gap be? Because you could even go a step further and use something like heat sink grease to eliminate the air. The only drawback is if you even look at the stuff it gets everywhere.
@@kennybruce2597 Not the presence of air specifically makes it weaker but the distance between the steel plates, the lack of ferromagnetic material.
That was such a good safety tip. I would have never thought about needing a UPS for your lab bench power supply.
The electromagnet has the advantage of metal cup to close (concentrate) the magnetic circuit. If you gave the neo magnet a similar cup it would increase its holding force, further increasing its advantage. A lot of fridge magnets do this so they can use cheaper ceramic magnets that wouldn't hold without the cup. flexible sheet magnets do something similar by alternating polarity in stripes.
You should also look at switchable permanent magnets as they have feature parity with electromagnets.
Yep, didn't have time for it for this video, but I will try to source a 50x30 mm neo magnet (preferable grade N52) and a potted 50x30 mm neo magnet. Would make for a much better one to one comparison. No doubt that the neo magnets will still win though. Thanks for watching!
@@brainiac75 Could you run some experiments on hybrid magnets? (Electro-Permanent Magnet)
I have some pretty thin 30mm neo magnets that are in steel cups, and it does make a huge difference. The manufacturer didn't have to bother with gluing them, it's almost impossible to get them out.
@@brainiac75Also, electromagnets can be much more compact. An electromagnet can be much stronger for it's size than a neodymium.
Electromagnets are interesting in their own right, though happy to hear that passive neodymium magnets beat them out in some cases! Great video as always.
Your electromagnets brought some memories. When I first got to deal with the math of electromagnets, I decided to try some optimization of my own. To my frustration, the math "converged" always to the lowest number of wire turns, using heavier and heavier gauge wires. In fact, my end result was that a single turn of wire that filled the whole available volume always produced the highest magnetic flux with least resistive heat. Of course, the flux density is determined by the air gap, as long as the core does not saturate. Your probing showed well below my usual assumption of 1.2 T (tesla = 10 000 gauss) to 1.5 T field density saturation for ordinary magnetic core materials. So you would be able to push beyond the neodymium field density with a single turn winding and maybe 0.1 V / 200 A supply without excessive heating, if you can provide such a supply. (0.1 V x 100 A = just 10 W).
My post pH.D E.E. says..... Your right!
Hey there , I need to pick your brain as to me you have my answer somehow I am searching for...what do you say? Can u help me
Can u help me
@@NEW-WATER-ATTRIBUTES-2023 I am not at all sure what exact help you would expect. I just have one idea that may be easier to implement than, say some superconducting suggestion. It is to make your coil of copper tube, such as the one used in air conditioner heat exchangers. You could find that kind in most any big hardware store. Then you would need to insulate the tube, with for example heat shrink tubing before winding it to a coil. An alternative would be some insulating spacers mounted between coil turns after winding, I assume you would already have insulation around the iron core. With appropriate fitting(s) and a pump, or just tap water, you could reduce the temperature rise to negligible level, meaning you could use much more current. This kind of arrangement is used in flameless - Eddy current - annealing heaters. In them, they don't need insulation, because they have the coil stiff, just air core magnet, maybe 2 or 3 inches inside diameter, 3 to 6 inches long. I assume you would want DC use, and a more compact structure, with a U- or maybe E- shaped iron core. However, keep in mind that any iron core eventually saturates, and after that any increase in magnetizing current causes only field increase at the same rate that results in open air. All that means, initially the iron core effect is good and strong, but after saturation level, FURTHER INCREASE tapers off.
I hope this at least gives you some idea what to consider, or try next. As to the source of current, somebody already suggested using car batteries. Just pick some with a high cranking current rating (like 600 amperes or more). The cranking current rating is for relatively short times, so you still might need two or more in parallel, if you want more than about 10 or 20 seconds duration. And of course, the cables from the batteries to your coil must be thick and short. I would suggest 0 or 00 size welding cables. 0000 size could handle over 600 A long term, but I don't think any practical batteries would. Finally, you would need a really big switch to turn your current on and off!
@@InssiAjaton pass me an email I send you something ,pls be quick
You can get "switchable" permanent magnets as well, where you turn something on top to change the positioning of two magnets to cancel eachother out in the off position. (I'm sure you know this, but since you mentioned the ability to turn off as the main advantage I thought I'd add this comment)
Thanks for the reminder! I do need to make a video about the magnetic lifters - and even build my own using permanent magnets to demonstrate how they work. So many videos to make - so little time for it :D
@@brainiac75 Well considering your upload cadence, you are doing very well when it comes to views/subs- so no rush.
Like the way a magchuck for a mill works
@@lenselinkberinge yeah, the ones for welders and millers are usually top notch, since they have to be for safety reasons.
@@brainiac75 Make the first, and biggest neodinium switch. I'm sure turning the lever would be hard 😂
There is a trick with electromagnets , which allows you to reach higher pulling force than any permanent magnet is able on , without overheating of the coil .
You need to grind (as fine as possible ) electromagnet’s poles and the metal surface on which you want to lock them . Than use capacitors battery ( you may need ultracapacitors ( also known as supercapacitors or ionistors ) ). Charge the capacitors battery to few times higher voltage than the electromagnet is rated for . Than discharge the capacitors battery via the electromagnet’s coil . The enormous current pulse will create enormous magnetic field . The interesting part is that this field doesn’t disappear or weaken in the magnetic guide after the the coil current is disrupted so there is no any reason for heating and the magnetic guide loop can stay closed infinitely. You can open it by applying the same amount of current but with opposite polarity of the voltage on coil terminals . You can see such experiments in the following video th-cam.com/video/s-5FMFzSPYU/w-d-xo.html unfortunately on Russian language .
By the way the strongest magnetic fields are archived by electromagnets !
Magnets happen to be one of my favorite subjects. I believe if the core were taken out and shaved to half its diameter, and then rewound with more windings, you could potentially double the gauss output with the same volume. Can't wait to see you build some of your own! Imagine the ones they use in wrecking yards to lift entire cars, the possibilities are endless.
Speaking of turning on and off, I have seen some permanent magnet gadgets that turn on and off the magnetic field by flipping a lever. What's that all about? Great video!
In these gadgets there are 2 permanent magnets. If you flip a lever polarity of one of them flips cancelling each other out.
@@geometrydash-krokoo-6503 cool!
Please don't say "overclock" when you are only changing voltages and currents to values out of spec. The correct term is "overvolt"
Having said that, I've enjoyed the video! Let's see what the future brings for that little magnet-on-demand! Cheers
The King of Magnetism is Back!
This guy take months to make a video but it was worth it
I do upload a video every month (twice a month if you include the one on Patreon), but you may only be notified of my magnet videos if you only watch those? But yes, quality over quantity for my channel :D Thanks for watching!
@@brainiac75 wow that's a great mindset but i feared that you lose subs overtime when you're in the process of making new vids because of how long it takes to make one and yes i do watch some of your videos sometimes but only youtube videos I don't use patreon neither i don't know what patron is.. haha
I love making those little homemade bolt electromagnets in fact, If you give the electromagnet more current it will get hotter. More Voltage = More Strength | More Current = More Heat. I even tried to make an electromagnet oven by giving it around 5v DC 2 amps. this gave the magnets a fair amount of strength. but they got very hot. I was almost able to make toast with my oven! They even have induction cookers that are just a giant electromagnets with lots of current. It's fun to experiment with this kind of stuff! keep it up Brainiac75!!
Just started binge watching this channel a few videos ago. Looking forward to seeing the progression up the liquid-> water -> sub-ambient -> L2N goes, as the colder it run, the better it runs.
I made my own electromagnet recently out of an old microwave transformer. Using a couple old car batteries it got hot fast but it was so strong with that much current, the shovel would instantly stick and not come off until the power was disconnected haha
It was fun trying out different ways of powering and messing with different sizes of transformers
I wish I had cared about my firsts as much as this guy. Starting his first electromagnet for the first time with his first power supply. Very cool.
Very nice video!
Have you heard about the combination permanent- and electro- magnets used for safety critical / lifting applications? This unit includes a permanent magnet with an electromagnetic component. The permanent magnet will produce an external magnetic field under normal non-energized conditions. When the electric coil is turned on, it provides an internal magnetic path, preventing the unit from producing an external magnetic field. No power is required to HOLD the load on the magnet, but power is required to RELEASE the load. These are used for lifting and hoisting, where a power failure with a "pure" electromagnet would result in a dropped load. I think they call it an "electropermanent magnet" assembly.
Great video, When I was younger I used to work for a company that had an electro magnetic lock on the door. During office opening hours the door was propped open and the magnet was at the top of the door frame. For fun we would turn the lock on and put some paperclips on the magnet. Then when someone walked through the door we would turn the magnet off as the paper clips dropped on their head. It was harmless fun as we watched from a distance as the bemused person wondered where the paperclips came from. This would amuse us for hours.
Would be nice to see it cooled down with LN2!
Making a a hybrid of the two would have novel properties, like being able to turn a permanent magnet's field temporarily off, or able to steer its direction.
Hybrids are used in load speakers and bidirectional solenoids.
I love how we are both thinking about water cooling the electromagnet.
But do watch out for the magnetic impeller inside many all-in-one cooling solutions. It might be better to get a custom water cooling loop.
Of course the real fun is combining the two types of magnets. That's how you get things like motors, actuators, voice coils, etc.
Will come back for the follow-up video. Well done!
I'm happy you are finally getting into electromagnets. I really like neodymium magnets. I allways seem to find stray magnets and I have an ever growing collection. I found a stack of 4 2"x3x1/4 on a shopping cart. Those are super strong and were an amazing find.
Funny my first thought with the electromagnet when I saw its performance was - what if it was cooled and you over-volted it? And of course the next thought was - what if you cooled it with LN2?
Also I think it would be neat if you could get your hands on a bitter electromagnet or maybe collab with a bitter magnet manufacturer. I think the current record for man made magnetic fields is a bitter magnet rated at 45.5 Tesla (455,000 gauss). Would be super cool to see you experiment with one.
A quality experiment to entertain before bed. Goodnight, Brainiac75.
💡Stack an electromagnet and neodymium. (Epoxy a coil around the neodymium magnet.) You can use a pulse to temporarily cancel out the permanent magnet. Iron can also be used to focus the power just like the electromagnet in this video, just make the center part the neodymium magnet. 👍
I’d love to see you take a look At electro permanent magnets. They’ve always fascinated me. Basically a “pulse” of current switches them on and off - during either operation, no electricity is required!
Superconducting Magnets are fascinating as well as dangerous too
Thanks for the Video
The root relationship is quite simple to explain with basic physics. The magnetic field (B) is directly proportional to the current (A). The relationship between the current and the power (P) is quadratic (P = I² • R). This results in a root relationship between P and B. I would therefore always put the current on the x-axis (set value) and the field on the y-axis (dependent value). What would make the video even better would be a physical underpinning. The electromagnet is a coil. You can strongly influence the properties of this by changing the length, diameter or number of turns. Also, the use of a core of steel or ferrite can influence the strength. You can easily adjust all these properties yourself to make a much stronger magnet. Most importantly, more current, stronger magnet. So if you can get more current through more turns without the magnet heating up too much, then you have a good magnet. Thick wire, many turns, around a ferrite core.
0:37 "Becareful near strong magnets, dont let them near you fingers" next shot is him holding the electro-magnet
Most people don't realize that it is the field gradient -- NOT the field strength -- that causes magnetic force on iron. (But gradients and intensity both scale with current making it easy to be misled.) Additionally, closing the flux paths by placing iron across the open face will eliminate flux through the coil and greatly increase the field at the poles. As performed, your measurements mean very little; the permanent magnet does NOT have this alternate flux path.
Great video. This gave me inspiration to prepare some electromagnets for use around the shop.
My son wanted to make a solenoid engine for a class of his. Running the math to look for more power we found a honey comb array of smaller core and coils had a lot of advantages. We never built it though. His teacher was happy just with the math
Thanks again for the video
I sense a monster neodymium versus monster electromagnet battle coming up, maybe like King Kong versus Godzilla??
I love brainiac's content every time
I love this channel so so much. Thank you, Brainiac75!
You might like to read ‘Magnetic Venture” by Audrey Wood. All about Oxford Instruments and the development of big magnets for NMR and later super cooled magnets for MRI scanners.
The most powerful magnetic fields are generated by compound coils, admittedly using super conductors.
If electric vehicle development is not to be limited by the availability of rare earth elements, then motors must use electromagnet field generation, rather than permanent neodymium magnetics.
YES! more electromagnets!! That is pretty cool. I think you should give a microwave transformer a try, easy to get and you can cut out the secondary and put 2 primaries into it for more coils!
Would enjoy electromagnetic stuff!
Ok this is definitely something I never imagined hearing: Watercooling and overclocking your magnet. LOL
Very detailed overview. I challenge you to solve the faraday paradox!!! A faraday homopolar generator with fixed magnets on the rotor, poles will be axially and radially. It produces dc voltage with no back emf
I'd definitely like to see the results of cooling the elecromagnet. Regular computer heatsink, heatsink with fan, submerged in ice water, heatsink with ice water submersion, liquid CPU cooler, or even liquid nitrogen as someone mentioned. Maybe you could use an intermediate medium to work your way down to liquid nitrogen temps instead of doing it all in one step.
Hopefully you'll do several of those, but even one cooling method will be neat. Thanks for a great video as always.
@1:37 - "...with my first lab power supply." I know this wasn't a joke, but considering the stuff you show off, this made me laugh out loud.
You know very well, how the permanent magnets are beeing magnetized 🙂 That is fun!
You should go all out with experimenting with pushing a electromagnet's ability and using a cooling system. Its just really interesting to be able to play with the settings, adjustments, etc. Im wondering if there could be some insane ways a super powerful one, or a setup system of them could be used if say: hypothetically you ran some off of a modern advanced nuclear energy reactor. Could be small form, thorium reactor, LFTRs... But could definitely power some really fun science experiments that's for sure. And the energy source would be efficient, no emissions, stable, strong. It would be exciting to power a efficient system that runs off of the electrical output from a power source like that.
I've had the fortune to be around industrial strength electric magnets from a young age. It's amazing what can be done with them
These magnets don't mind so much being heating up. They are used in metal industry to lift e.g. large metal plates and iron beams. They are usually not activated for more than from a few seconds, to a few minutes at a time.
With 4 to 8 of these, just in sizes that are larger, you can lift lift metal plates for e.g. ship construction, that weights several tonnes.
I don't remember the pulling power of magnets of this kind, that has a diameter 4 to 5 times the size, but we are talking maybe a tonne per magnet.
But you always want to have twice as many magnets as needed. One, several of the magnets can be short circuited/defect, second, their max pulling power decreases radically, just by having dust in the environment.
I'd really like to see you make your own electromagnet, that is as strong as you can possibly (and safely) make it.
Guys in the future our electromagnets will be water-cooled, braniac is making a breakthrough 😂
Seeing you overclock the magnet with an AIO would be awesome, hope you do it!
You should test electromagnet door locks. The ones commercial buildings use to lock their doors. Not a lot of pull force, but holding force is incredible.
Just bolting a regular finned heatsink to the back of the electromagnet would help keep the temps down when overvolting the electromagnet. There is however a risk of burning out the windings if too much current is applied.
If you want to push the overvolting experiment further there's no reason you couldn't put the electromagnet in a simple waterbath, at least up to the top lip, since the windings are insulated and potted in resin. That would dissipate the heat quite well.
AND IT WILL COME
Good job on the video! It's interesting and educational but I respectfully take issue with your use of the word "overclocking". Electromagnets do not have clocks. Therefore, you cannot overclock them. You can over-power them, but not overclock them. Here is the definition of overclocking: "Overclocking is the action of increasing a component’s clock rate, running it at a higher speed than it was designed to run." It applies only to clocked devices such as microprocessors and some other types of computer chips. Keep up your awesome videos!
It would be interesting to see how high the field strength can go if you can supply a pulsed DC power to the electromagnet.
- the 8W magnet is average power, and just as with lasers and LED's - pulsing with a low duty cycle should give a high(er) peak-output power...
Playing with Power - Pulsed Power Push/Pull'er (or perhaps not, the iron core has a B-H curve, so it's possibly not reacting fast enough)
2*12V car batteries and a beefy relay (w. rev diode protection) controlled by a variable oscillator might be safer for your power-supply ;ø)
Looking forward to future videos on these pucks - btw, where did you buy them (and the Radiocode meter, etc. - links/info would be appreciated)
Interesting. May give it a thought, though back EMF and basically running a DC magnet as an AC magnet may get me in trouble :) But I will try running it on AC in a future video. Just to see what happens with heating, field strength etc. I am a total noob when it comes to electromagnets... The electromagnet was bought from Conrad Electronic.
@@brainiac75 AC is alternating current ;ø) - so the magnet will also be alternating its poles. Magnetic Hysteresis then becomes an issue (problem), as energy is spent turning the magnetic domains inside the iron/magnet. Less emitted field pr unit energy spent.
Pulsing the magnet with DC - ought to strengthen it, as the h-field moves up-down without having to rotate. Wikipedia has good illustrations of this. This should (I think - not 100% sure) strengthen the field when powered on, and still remain magnetic when power is off.
I could build you an electronic switching device for pulsed DC + tell you a bit more (I'm an electrical engineer + radio 'everything'). I live quite close to your favorite sweets-store, if you're interested :ø) - and I have some time on my hands, electrical components + equipment, and I'm curious what your Lake Shore Teslameter reports. (er også bidt af en magnet og deres mysterier)
Oooh! This is fun! I'm particularly interested in how active cooling could affect it.
I've been wanting to try building a little Gauss/coil gun for a while, and have been curious if cooling the coils could improve performance, but haven't been sure how much, if any difference it could make. (been thinking of using a Peltier cooler to get them quite cold)
These magnet episodes are what attracted me to the channel, I think I'll stick with it.
For this and your N40 magnet, I think the best video would be temperature vs magnetic flux density vs max load, with an overclocked electromagnet with a UPS, and cooled by either liquid nitrogen, liquid oxygen or water that is just above freezing point.
I look forward to more of these! Cooling tests will be fun. You could do some pulse tests as well. If you can manage the power supply requirements you can pulse 10 times or more it's rated current, albiet for only a split second. I'm not sure what you would use it for but it would probably make an interesting video.
After you try to overclock with a PC AIO cooler you should go all out and overclock with liquid nitrogen.
I thought for a while how i could compare different magnets strengths with something carried everyday. Soooo i use a standard bic lighter standing up with the magnet flat on the same table. From how far away will the magnet pull over the lighter.
Good video for a nice evening.
OK, sorry to be critical, but "over-clocking" is when you run microprocessors above their rated base frequency for faster computing but at the risk of reduced processor life from overheating (unless you can manage the extra heat through cooling strategies). What you should be saying is "over-currenting" since you're increasing amps and therefore power dissipation. Amps are what contributes to your MMF (Magnetomotive Force in units of Amp x Turns). As your coil heats up, the wire resistance will also rise, causing your electromagnet to operate less efficiently. Additionally, as your iron core begins to saturate, more and more current will only generate excess heat with no appreciable increase in flux so there's a point where more current proves counterproductive.
Next test some of those magnets with an on/off switch. Made for fixing and lifting stuff.
Yes, I do need to test (and make my own) magnetic lifters that can be turned 'off' using permanent magnets. Interesting subject and gives the permanent magnets one of the advantages of electromagnets ;) Thanks for watching!
Some permanent magnets can also turn on/off by bend their flux in the same direction or opposite direction.(you need at least 2 of them with electromagnet material to make the magnetic force go in loop when turn opposite direction for turning off.)
I bet Brainiac's dream vehicle is one of those magnetic cranes that we see at scrap yards. I can't wait till he'll eventually get one. 😁
This is exactly what I need to do my experiments with a variety of stuff. But especially plant growth and cellular health. I need an affordable electromagnetic device that allows it to be variable and see the actual strength of the magnetic field or it’s frequency.
electromagnets are one of the most important components in particle accelerators such as the Large Hadron Collider or some of the many synchrotronns used to make intense X-ray beams. Most of the normal ie not superconducting magnets use copper tubes as "wires" and pass 100's of Amps through them at low ish voltages. The tubes allow low conductivity water to be passed through the wires to keep the magnets at a stable temperature of around room temperature when operating. These magnets have to be very stable under the current load so the magnets do not move as the guide the path of charged particles. For the synchrotron the maximum field that can be made is about 1.4 Tesla and this is related to the saturation magnetic field induced in the iron core. If you use another alloy called permalloy instead of Iron you can get up to about 2.5 Teslas. Fields beyond this require superconducting wires that at present have to use liquid Helium cooling to operate. If you search for magnets for synchrotrons you will find that some devices use rare earth magnets because they can produce very high magnetic fields in very small spaces which you cannot match with normal electromagnets.
I second the AIO cooling for a future video.
4:39
Yeah, the maggnetic field is proprtinal to current, and power is proprtional to the square of the current.
I made electromagnets as a child using a nail as core and copper enameled wire about 22swg (0.7mm). I connected them up to my train set 12 V DC transformer but they did not work very well. After reading a book I saw they put a wrap of writing paper around the core so tried this and it worked very well and much stronger.
Congratulations ! This is one of the bether videos that a have seen !
The question is : If I need 8w of power or 8 joules by second of energy to get 400 N of pull , what kind of energy the permanent magnets need and where it receves this energy from?
It is almost sure the neodymium magnets receves a kind of energy from universe , then it is not so absurd to imagine a magnect mouter runing by itselfs .
Do a video comparing the capacity of moving wheght corps by eletromagnets and permanent magnets along the space. Please!
Your channel is such a great find
What about heating in the electro when holding a load (poles connected with Fe object)? What about advantages of electros vs Neos in generator or motor applications (control vs economy)?
You just need to buy a larger electromagnet...Ebay has one that is 12-24V (6X2 inch diameter x height) 1200-1500 lb
lift for $350.
Permanent magnet is like superconductor magnet: flow of field despite being disconnected from the power source, and don't heat up :) All the MRI equipment uses them. Get one of those.
I would love to see you put a cooling system on the electromagnet. Especially because magnets and electricity start behaving differently the colder they get.
Some permanent magnets can be turned on and off. The switch reverses a fraction of the magnet with the rest of the magnet so the external field is cancelled.
A cool idea for a project: build a machine that makes a 3d map of the magnetic fields of magnets.
If you want to try cooling the electromagnet with a PC AIO cooler, look for something with a pump that's not in the waterblock, I can't imagine it will pump very well if at all with an electromagnet stuck to it.
Use the Neodymium magnet for lifting, and the electromagnet to disable the magnetic field for releasing the object.
It seems peculiar that you focus so much on wattage of an electromagnet. The magnetic flux you get is proportional to current times number of turns in the coil (at least until you reach magnetic saturation of the core). If you rebuild the graph at 4:35 with current as the x value, you'd get a pretty much linear plot. So, if you want power efficiency, you need to minimise the coil resistance. Use thicker wire gauge, and/or employ some radical cooling (dry ice or even liquid nitrogen).
because amperage is directly related to magnetix flux. how else can your clamp meter measure current accurately? 😉
good comment, cheers!
connecting a diode anti-parallel to the electromagnet will absorb that flyback surge, (back-EMF) which protects the inside coils from possible flash over, and protects you from a potentially nasty shock! Watch for core saturation, if over-clocking. You will reach a point, where the core reaches its absolute maximum strength, and will not become stronger by continuing to increase current.
The limitation of the electro magnet is the resistance from the copper wires that generates the magnetic field, if you used a superconductor like graphene the theoretical limit is much higher
There is a rare type of magnets, that are switchable on/off like an electromagnet, but dont need power and act like constant magnets. I built one this year and I very like it. Would be nice if you made a video about this
You should check out switchable magnets. I have no idea how they work, only that they use a grid of permanent magnets lined up so that when you turn one part there's little to no magnetic field, and when you turn it back there's a very strong one.
if you wrap that wire really nicely and tightly you may optimize the power you can get out of the home-made electromagnet and C battery.
You should try to make halbach array out of neodymium, electro magnets, and super conducting magnets.
You can arrange them to concentrate the fields and make them even stronger or make them cancel out to "turn off" neodymium magnets.
Would be interesting to see how using various power supply wave forms affects the strength of the magnet. Is the relationship linear if say pulsed square or sawtooth wave DC is supplied or is there a relative gain or loss in the resultant magnetic field?
wouldn't you just end up making a speaker at that point.
@@martinshoosterman Perhaps but other effects might be observed as well, such as linearity of attenuation, affect on input current to magnetic strength at different amplitudes and frequency, or any unexpected effects. It might answer the question you ask.
If you could get your hands on different grades of samarium magnets, I'd be a subscriber forever
I'm switching all my magnets to these!
Now I'll need batteries to keep my daughter's pictures on the fridge.
I work at APC (by Schneider-Electric), and seeing an APC UPS in this setup makes me giddy.
Too bad our testing cage is off limits when active, it could have been a fun video.
I'd LOVE to see you home-build a monster electromagnet by obtaining a microwave oven transformer (MOT) and cutting off the top of the core and discarding either the primary or secondary winding, as well as the heater winding and magnetic shunts (if they will weaken the field, I'm not sure). The open-core transformer with only one winding becomes a seriously powerful electromagnet with very little work. If you can obtain 3 or 4 of them, you can power them in parallel from a DC power source and arrange them in an array, potted into a single housing. The resultant electromagnet would be able to hold several people hanging from it. I'd be super curious how the field strength of one of these MOT electromagnets compares on an equal weight and size basis to a high grade neodymium magnet with a similar magnetic field shape. :) I'm not sure about over there in your country, but here in the USA we have old, broken microwaves EVERYWHERE with (usually) good MOTs inside that have not been the point of failure. I know inverter-type microwaves are becoming popular, but they haven't really caught on here in the USA. Worst case scenario, you can buy a new MOT on eBay.
The "overclocking" your trying would be better suited if you had a cooling platform to maintain a constant temperature at the electromagnet. The pc watercoolers are designed for use with surface area, rather pointless on a longer bolt shaped magnet. But fairly effecient the flatter the area contact to help cool it. My suggestion for cheap regular cooling would be a pressured airflow system. The airflow and pressure changes around the magnet from a fan suction properly mounted on the back would be able to counter the heating rate. Make a plastic mount to clip on the electromagnet that provides optimal airflow and pressure based on the space around the magnet for it to suck the air. The smaller the gaps the higher the pressure required but it also increases the heat disapation by allowing more constant use of the surface area's.