Wow! So that's how it's done! Very similar setup to an experiment I did in 2004, except I used four U-shaped iron cores with a single coil going through the center of all of them, operating at 60 Hz. An aluminum plate would easily levitate, then immediately slide off the edge. I tried putting holes in the aluminum plate to force the eddy currents to occupy restricted paths, but I was never able to achieve stability. I had no idea it could be as simple as what you have done here. Thank you!
I didn't think it was that simple either, until I did some experimenting, initially with tiny flat coils running at 130KHz, levitating aluminum foil disks. What it takes is a pancake coil wound in one direction for the inner half and the other direction for the outer half. Next I made a larger 23KHz version ua-cam.com/video/AHED5xSnnM8/v-deo.html Then I decided that a ring of transformer coils would be similar, as the current in the windings is going in one direction towards the center and in the other direction towards the outside. It would be more efficient to have two larger coils, one on the inside and one on the outside, but transformers come per-wound. So, I think your original version would have worked if you wrapped another coil around the outside of the U cores, in the opposite direction as the inside.
Mathematics is not actually the absolute everyone thinks it to be. In reality, mathematics has numerous flaws which can cause error and misunderstanding. The first and most prominent flaw of mathematics is its reliance upon a linguistic language to convey meaning. There is always a translation issue or a disparity when one language is converted to another. The same thing occurs with mathematics. Just because an equation can provide results which are superficially correct and return repeatable results does not mean that the linguistic language used to describe the processes is correct. The mathematical equation could completely match observation while the explanation of the processes occurring could be entirely incorrect. Most people never even consider such an occurrence and just accept the linguistics that are posited with the mathematics as correct.
@@wesbaumguardner8829 The problems you are describing are not flaws in mathematics itself but rather in how math is used (or misused) in a scientific or engineering application.
@@davekni Actually, no. There is no way to separate this flaw from mathematics itself because pure mathematics is absolutely meaningless and requires a secondary language to make it meaningful.
I'm using the secondary-half of the microwave transformers for this demonstration. All four are wired in parallel, about 1.3A each or about 5A total in this video. It is powered by 240V line. There is a motor-run capacitor in series, forming a series-resonant circuit. The voltage across the transformers is a bit higher, around 300V if I recall correctly. Changing the capacitor size (capacitance) changes the total current. Lower current levitates less, but doesn't overheat as quickly. Higher current is the opposite, a bit higher levitation, but a short run time before overheating. I've ran from 4A to 6A total by changing capacitance.The primary transformer halves should also work, wired in series and running on 120V. I damaged a couple primaries in sawing them in halves, so used secondaries.
@@Stubert619 About 30uF was maximum if I recall correctly. Power was a bit too high there. Coils heated too quickly. I think 40 or 45uF worked out for reasonable tradeoff between levitation and overheating.
@@davekni Thank you so much for the reply. I should probably note I'm 29, familiar with higher voltages and am starting the last 3 remaining semesters of my electrical engineering undergrad program at SDSU at the moment. I figure most real human beings ran into a fit of doubt at some point and mine was in my first 3D integral in my E.M physics class- didn't feel good in the moment. Maybe most people lived shorter spans before seeing a dumb wire move on a battery and magnet but I hadn't- I'm pretty far away from religious but it was like- idk the first bit of intelligent design separated from what had only been on exhausted onto paper up until that point. It lead me to stumble on Professor Eric Lewthwaite's work, and I've been doing my best to study his books in the heat of juggling a heavy STEM load. Maybe there isn't an ocean of money in making subatomic matter persuade their macroscopic counterpart into motion like this, but it is absolutely what stimulates my study. I'm grateful you shared this!
@@Stubert619 Wonderful to see your curiosity and interest in the basic practical physics, such as wires moving in a magnetic field. That understanding will be more important to your success as an engineer than being able to do 3D integrals. Computer simulations do the hard work. Problem is that many engineers don't have the intuitive understanding to correctly interpret simulation results. You will do well.
This is tight! Are all four windings wound in the same direction so that while current passes through the inner half of each solenoid, it pass clockwise, and the outer half of each somewhat combine to form a counterclockwise current.. as though each four were theoretically two separate 1/4s of their respective ring(inner v outer), creating an inward “draft” on a copper flywheel as laithwaite demonstrated keeping the aluminum stable? And is a cooling device in the center?? Quiet brilliant I must say(:
Yes, exactly on the current directions and net effect. No active cooling - this video is about as long as it can run before getting too hot. (The center is just a spacer block and center wire connections.)
I wish I had read all the comments before starting this project. First off, you don't have to saw the transformers in half. When they were initially made, three sets of windings (primary, secondary, and four turns on another secondary for the low voltage heater) were wound around this lamintated E-Core (perhaps wound prior and then slipped over the E-Core). Then, a cap was installed with two welds along the top. If you use a 90 degree angle grinder, just grind off those two welds, and pop the cap off. This exposes the primary (large dia wire, fewer turns) first, then the 3 turn heater windings, and finally (up against the base of this whole thing) the secondary with many turns of smaller wire. I trashed the secondary and 3 turn to use the primary wires. Big mistake. 6 amps when the "E" is capped, and 35 amps when just the primary and open E-Core. Looks like I'll be starting all over again...
@@davekni Hi Dave: Getting there. In series with 120 VAC and 1, 2,3 and 4 MOT's using primary windings: 37,20,15 and 10 amps. Magnetic field (B) is proportional to the core material ur, N (number of windings), I (current). But inversely proportional to the stack height of the windings. You successfully got levitation using the secondaries at 1.3 amps each, 20x the winding count of the primary, and about 1.5x the stack height. I have 20x lower N (bummer), higher current (good) and lower stack height (good). If my calculations serve me correctly, my primary current needed for the same B field would be: (1.3A * 20turns ration * 1.0 ref stack height)/1.5 (ref secondary stack height) = 17 amps. Running off of 240 VAC in series should get me 20 amps per coil. Need to find the aluminum sheets of 1.0 to 1.5mm thickness. I'll play with the series capacitors at a later date. Dave--thanks so much for your responses to all the questions here and below.
Thank you for the compliment! Yes, the coil currents are all in phase - all the top center sections oscillate together - all north poles then all south poles etc. The return flux paths, the outsides of each transformer's laminations, are of course opposite the coil centers, so also all together with each other. The four return-flux poles arranged in the center of my setup are the useful ones. The four around the outside are not helpful. Some day I might try cutting those off to improve efficiency, but I'm not sure I can do that without damaging the coil. To see a more optimum geometry, view my higher-frequency aluminum disk levitation video: ua-cam.com/video/AHED5xSnnM8/v-deo.html
Even my Tesla coil videos involve magnetism. Magnetic fields couple energy from primary to secondary coil. More Tesla coil eventually when my QCW coil is finished. If there's interest, I could post something about poling permanent magnets. Probably plenty already posted by others however.
The plate has a resistance and an inductance and behaves as a low pass filter with a cut off frequency, which is proportional to the resistance over inductance ratio. Below the cut off frequency the plate behaves mostly resistively, the induced EMF and current and opposing magnetic field are leading the coil's field by 90 degrees, producing no net force, only vibration. Above the cutoff frequency, the lowpass filter effect delays the current and opposing magnetic field by 90°, they are now in phase with the coil's magnetic field and creates repulsion. The repulsive effect increases as we get closer to the cut off frequency and remains constant above it. Stacking multiple plates, which is the equivalent of making a plate thicker, reduces the resistance, while the inductance remains constant, lowering the cutoff frequency. Above a certain thickness the cutoff frequency is below mains frequency and the repulsion will not increase. This is a form of induced diamagnetism, where a conductive material exhibits a strong negative susceptibility to alternating magnetic fields. In a superconductor, the resistance is zero, which means the cut off frequency is zero, which explains why superconductors are strongly diamagnetic (susceptibility -1, permeability 0), making able to hover above magnets. (this is independent from the Meissner effect, which is not responsible for levitation)
To make this electrical circuit explanation complete, I think one more detail needs to be explained: When resistance is large (thin plate), the inductor voltage and current are close to 90 degrees separated as you discussed. As resistance drops, phase difference decreases. That alone would make force increase proportionally to cosine of angle. Doubling plate thickness (halving resistance) would produce slightly less than twice the force. The reason for additional force beyond angle is that current in this L+R low pass filter increases as resistance drops. Force is proportional to current times cosine(phase). Both factors increase, making force increase faster than weight.
@@davekni Thank you for completing my explanation ! (wrote it at 1am on a phone). Interestingly, this levitation effect is also produced in induction motors. However, the torque producing component (or force, for a linear motor) is the out of phase current. As a result, the torque of an induction motor increases with the amount of slip, but not proportionally because it is also proportional to the sine of the phase shift. Above the"cutoff frequency" the induced EMF no longer increases and the phase shift decreased. As a result, induction motors provide less torque at high slip frequencies, because the torque is "converted" into a repulsive force. This property allows us to make a single phase induction motor : the rotor sees an alternating magnetic field which is two rotating magnetic fields turning in opposite directions. Assuming we have some way of momentarily starting the rotor (quadrature winding + capacitor) the rotor will keep turning, as the rotating component with the least amount of slip will generate more torque. In a linear motor, this effect can be used to generate both traction and lift. If the motors are arranged in a way that provides a stable levitation (motors on the side of the aluminium plate) the motor will also provide guidance. Such an arrangement is called a "magnetic river" It has been invented by Eric Lathwaite and proposed for use in maglev trains.
So, this is how the 'aluminum magnet' works! I remember reading about it once in National Geographic. They had covered an article on aluminum in the US.
I'm not familiar with the "aluminum magnet" term, but it is true that aluminum is a magnet only when conducting electricity. In this demonstration, the current in the aluminum is induced by the alternating magnet field below it. Aluminum is a part of some permanent magnet alloys, especially the old AlNiCo (aluminum, nickel, and cobalt added to iron). Small amounts of aluminum are added to NeFeB magnets to improve their high-temperature performance, at the expense of somewhat lower room-temperature magnetization.
I was just watching the levitation halbach array video where they have 4 motors with a halbach on every motor shaft, the field animation they showed I have seen before when I was playing and experimenting with magnets on a crt tv, when a placed a arc ferrite magnet on its side on a crt tv I layed on its back like a table, We need to focus on bowl shaped magnets or what they create..
Another place to find many interesting projects and details and information is the High Voltage Forum: highvoltageforum.net I've documented several of my more recent projects there.
Thinking of cool applications for this. Could you make electro-magnet tiles and tile a floor with it in such a way that the electromagnetic field generated would be flat and smooth enough to ride it with copper skateboard/snowboard decks? I've seen a hoverboard experiment that does the oppposite: An electromagnetic board over a copper surface, but the electromagnetic board is very heavy. Imagine an indoor skiing/snowboarding slope and a flat area for electromagnetic hoverboarding. That would be amazing. You just couldn't bring any electronic devices inside and people with pacemakers shouldn't participate either. :P
Interesting idea! Could be a good project to simulate using FEMM. My guess is that it could be feasible for larger snowboard-sized decks. Probably not for smaller decks, but I'm not sure. Would be expensive and power hungry. The magnetic field would not be flat. Rather a grid of alternating polarities (alternating 180-degree phasing) at a sufficiently fine pitch to average out across the deck. Finer pitch increases power required. Coarser pitch is better, but requires larger decks to average (smooth) out lift force. Copper deck may need some active cooling. Superconducting decks would eliminate most losses, but obviously require much more cooling. Superconducting electromagnets for the tiles would likely be cheaper to operate in spite of cooling requirements, as copper tile coils will waste a lot of electricity.
@@davekni Yesss. You seem to have a far better understanding of electronics and electromagnitism than I do. An active cooling system on the copper snowboard would significantly weigh it down though. But what if you cooled the electromagnet tiled floor instead? The low temperature would improve the conductivity but also cool the layer of air directly above the tiled floor. Your hoverboard would be suspended in that cold layer of air and because you would constantly be moving, the copper hoverboard would probably be sufficiently cooled while in use. Not only could you build a broad, long slope and a flat open skating rink-like area, you could also make a skatepark type of terrain with halfpipes, quarterpipes, banks, ramps, rollins...etc, all of it tiled with actively cooled, superconducting electromagnet tiles. And hoverboarders will be given copper helmets, copper elbow pads, and copper kneepads with cushioning, elastic material on the inside. Hoverboarders falling off of their boards would be magnetically repelled from the floor,effectively acting as a magnetic cushion. Perhaps the surface of the tile could be covered with a thin cushion/elastic mat. Perhaps a composit; Layers of rubber and layers of a firm foam.
@@allonifrah3465 Certainly for an indoor area, cool floor could help cool copper boards above it. Outside there might be enough air flow to prevent much of a cold-air layer. Using a soft insulating layer above a superconducting tile array sounds good too. Of course, the thicker the insulation layer is, the stronger the field required to levitate farther above tiles. Most effective insulation is vacuum (thermos bottles), then aerogel, both of which are not soft. Perhaps helmets and pads should be aluminum for lighter weight. Presumes one doesn't remain fallen for too long so that additional heating is not important.
@@davekni Yeah this is something you'd do indoors, like artificial ski slopes with snow made by machines. And yeah I was thinking of aerogel since only a very thin layer of it insulates insanely well. We wouldn't want to insulate it too well, or else the floor cooling system wouldn't be able to cool down the layer of air right above it. If the aerogel mat had flaps that could open and close, regularly spaced from one another, it could either cool only the electromagnetic tiles or both the tiles and the air directly above the floor. When the flaps are open, it would cause the cooling system to divert part of it's power to cooling the air just above it. These flaps could be simple mechanisms that, when opened, make tiny gaps in the floor. They just need to make an airtight seal in their closed position. A thermostat system that uses equally spaced out thermometers to constantly measure the temperature could open and close those aerogel flaps to ensure that the cold air layer above the floor remains roughly the same. If someone goes down the slope and across the large, flat rink-area, or over any spine or quarterpipe, the aerogel flaps open in a roughly oval ara spanning the space directly below them to about 2 meters in front of them, so the air will be cooled in realtime when and where needed.
@@davekni As for helmets and pads: If Aluminum can induce the same amount of eddy currents and repel magnetic fields with the same force as copper, then hemlets and pads should be made of aluminum. Maybe aluminum pads & helmets with a thin, copper outer layer. You will want that magnetic cushioning effect. The rest would be done by soft cushioning material on the inside of the pads and helmets. Since it'll be could inside that building, people would wear thick, insolated pants, vests and coats, which would also serve as cusioning material in case of a fall.
Thanks for the video! It really peaked my interest into why you chose aluminum to levitate.. So far, I found aluminum to be paramagnetic with a magnetic susceptibility constant of +16.5 x 10-6 cgs. Copper's constant is -5.46x10-6 cgs. Does that mean copper wouldn't levitate because it has a negative constant?
Pyrolytic graphite is the only substance that I'm aware of with low enough susceptibility (at room temperature) to levitate by that principle (diamagnetic, so repels magnetic field gradients). This levitation is by the induced AC current in the aluminum. For that, aluminum is best, because it has the highest electrical conductivity per mass. Copper conductivity is higher, but it is much denser, so aluminum wins.
Ok, I'm starting to get it. Aluminum has a little more than half the conductivity of silver, but 1/3 the specific gravity so aluminum would levitate higher under the same condition. You mentioned in the video that you calculated which amount of plates would cause the highest levitation elevation. Do you know where (hopefully online) I could learn much of this (equations, concepts, etc.) myself? I would like to calculate various heights of levitation based on the material type, it's shape and so on. I would like to understand what would happen when two different types of materials are used at the same time. For example: instead of two aluminum plates, what would happen if a copper and an aluminum plate were levitated (1st with Al on top and, then, Cu on top).
That was a very compelling presentation. It looks like you opened A very interesting door when you showed how adding plates actually raises the distance. I was wondering if you tried other geometries or other sizes of plates to see how that might change the height given the voltages and currents you're using. I Have a suggestion that might be of interest to you if you would like to speak by email.
I experimented with plate/foil size more on my higher-frequency 23kHz unit (and small prototype versions of high-frequency version prior). Did try one larger sheet on this MOT-half version. However, it was a more structural aluminum alloy with somewhat lower electrical conductivity. For this (or any) specific geometry, there is a limited size range that remains stable when levitated. Yes, would enjoy an email conversation: davekni@yahoo.com
the motor running capacitor is that "start capacitor",?(40uf 400) i have or (45uf 400v), it is good? If I open the transformer from the welds of the iron center next to the primary, it means that the iron centers will be 1-1.5cm higher than your device. In this case, it is possible to levitate or you should cut the centers closer to the secondary ?
With weld removal instead of cutting, I'd use the primary windings instead, since they are close to the levitating plate. Unlikely to work using windings away from the plate. So either use primary windings or cut the core down close to secondary height.
Interesting question. I didn't measure current with plates added. For this setup, any current change will be small. Most of the power is consumed in heat (resistive losses) within coil windings.
That's the entire reason I built this demonstration - to see if that effect of more plates levitating higher was real. Calculated that result theoretically first, but had a hard time believing I'd calculated correctly. I tried to make a simple explanation at the end of the video. Induced current in upper plates creates a magnetic field that attracts lower plates. Another way to view the reason (the one I first calculated) is that the phase of induced current in the plates shifts to better align with phase of MOT winding current when more plates are added. In-phase current creates more average repulsive current. An infinitely thin aluminum sheet would have current 90 degrees ahead (leading phase) of winding current so generate no average levitation force. With infinitely conducting sheets (very thick or superconducting), plate current is in phase with coil current so levitation force is maximum.
@davekni Thanks for the updated explanation. The phenomenon definitely seems counter-intuitive. With all the plate masses being the same, I would think the addition of each plate would surely decrease the height. Up to a point, the added plates seem to be concentrating or, as noted, more efficiently using the induced fields. You have definitely given me more to contemplate on. Excellent work 👏 👍🏽
@@rod3134 Yes, decreased height is what I'd initially expected before thinking about phase in more detail. My 23kHz unit does decrease height for any practical thicknesses. That's because at high frequency even thin foil is effectively "infinite" thickness. Phase is already aligned. (Actually I should say 180 degrees rather than aligned. Plate current is in opposite direction as winding current.)
@@davekni Wow!!! A possible explanation in addition to yours just occurred to me. The analogy of the levitating Styrofoam balls in an enclosed sonic field system. Objects that are too big or too numerous will collapse the frequency node object capture capacity. Your sheet stacks are matching the frequency node central area until there is a max saturation within the effective frequency range. It's probably not that the height is increasing, it's probably more-or-less that as more sheets are added, the sheets frequency energy capacities and capture causes a relocation of the node height. I know this may seem like a very loose thought, but this is really making explore some of my previous research,. Great discourse!!!
@@rod3134 I doubt there is any significant analogy to sonic levitation. With too many plates, upper plates see less magnetic field. Current from lower plates reduces field farther up.
Thanks!👍 First time I saw that configuration. All 4 of those are simply plugged straight into mains? (No extra sequential phasing applied to make that happen?)
No extra phasing. But I do have a motor run capacitor in series with the entire set (between coils and mains) to boost voltage. 240Vac was not quite enough. Series capacitor (series resonant circuit) was the simplest way to boost voltage. Easier than grabbing my 50lb isolating transformers to boost voltage further.
@@OMNI_INFINITY Transformer halves are inductors. Inductor in series with capacitor forms a series-resonant circuit. If capacitor was in parallel with inductor, that would be a parallel-resonant circuit. Series-resonant circuits create higher voltage across capacitor and across inductor than the input voltage.
@@davekni Thanks! I am still learning about resonant electronics circuit design and principles. I get that the cap and inductor should have the same energy storage capability, although still figuring out if the reason a specific AC frequency is resonant in a resonant circuit is because that is the frequency where at the peak of each half of the cycle the energy stored reaches that max rated capacity for the inductor and cap.
@@OMNI_INFINITY Perhaps easier to understand a mechanical analog. Hang a weight from a string or thread. It will swing back and forth at a specific frequency. Energy trades back and forth from motion (at bottom of swing) to gravitational potential energy at the tops of the swing where motion stops. Then notice that you can get the weight swinging many cm by moving the top back and forth only 1cm in time to motion. That is like series resonance.
Yes, eddy current consumes electrical power and generates heat. That is undesirable inside transformers. It is desirable for induction cooking and other induction heating. Also useful for some other applications. Levitation is more of a science demonstration than anything useful.
@@iitaspirant1083 Not sure I'm understanding your question. I did not use a battery for this demonstration. If someone did use a battery, magnetic flux would step up as battery is connected, then remain constant until battery is disconnected or drained. Aluminum plate would experience a brief push upward as flux rises, then no magnetic force after that. Would not levitate.
The fourth transformer could be 750W. is it good for levitation with the others? That is, if the iron center is the same size for the 750w ones, the secondary is the same as for the 700w ones? There is no paper with the power it is. the secondary winding it seems almost as big as the 700w ones, maybe a little bit bigger (2mm maybe) in the unknown one. The unknown one is from another company, maybe that's why it's a little different. What do you say?
Probably fine. Just mount so top surfaces of the haves are all in a plane. 2mm wider isn't likely to matter. 2mm higher than other transformers would be a problem, but easy to fix. Just shim the other three up by 2mm to match (add 2mm shims under other three). I had to add some thin shims to compensate for my imperfect cutting.
Did you connect the iron centers together and the secondary terminal together or did you disconnect the secondary from the iron center? What capacitor do you have in series with the secondaryes in parallel (capacity and voltage)?And wht is the dimension of aluminium plates?
I don't recall if I disconnected secondaries from iron. I don't think so. Not necessary as long as all four windings are the same direction (clockwise or counterclockwise) and electrical connections are parallel as I did. I think cap value is listed somewhere in description or comments. Around 45uF if I'm recalling correctly. 30uF was too close to resonance so made current too high with 240Vac input. You can change capacitor value and/or adjust input voltage to get sufficient current to levitate without overheating windings too fast. Aluminum sheets are 200mm x 200mm x 1mm, pure aluminum for highest conductivity. Some 1000 series alloys may have sufficient conductivity. Others may be too low to work without higher current.
In general it would work better at 500Hz, especially with thin aluminum plates. A single 1mm plate would lift quite well. However, transformer-half steel laminations might heat up too fast, since their thickness was designed for 60Hz. Not sure how bad an issue that would be.
I found 4 other identical transformers that are 800w. Are they good for levitating the aluminum plate? How many watts are your transformers if my transformers are not good with 800w?Are the 800w ones better than the 700w ones or are they the same, using the secondaries in this project?
I don't know the wattage of the transformers I used. Perhaps 1kW. If yours are slight smaller, just place them as close as they fit and use a slightly smaller aluminum plate. Should work fine.
Varnish will add a bit of weight, so decrease height a little. For a single plate, no effect at all on induced current. For a stack of plates, varnish between plates would make a tiny difference in current path. Most current is circulating parallel to plates. Any vertical current pattern would be disrupted by varnish (insulation), but vertical portion is a tiny current to start with.
No. Aluminum conductivity is uniform throughout disk and magnetic field is axially symmetric. There are other demos with rotating disks over permanent magnet arrays (or visa versa with rotating magnet arrays) . For those the magnetic field is alternating polarity around the disk, not uniform.
I've tried a middle void in small-scale experiments (~30mm diameter) before building my 23kHz round version. The void ruins stability if of significant size.
Are your transformers taken from microwave ovens that operate at 220-240v not 120v? I have four (700W) transformers at 220v. Will the aluminum plate levitate with these?Please give me the answers.
The transformers I used had 120V primaries. I used the secondary halves for this project. Secondary windings are the same whether 220V or 120V primary. So, yes, your transformers will work. Primaries would work as well. I used secondaries because I damaged one primary during cutting.
My round 23kHz version is close to limit of levitation height for that geometry. If it is ran at lower height (lower power or heavier levitating disk), it gets more stable too.
Definitely not on this setup. It would be possible with a large industrial induction heater unit with a properly wound water-cooled copper coil. The aluminum would get hot, and perhaps eventually melt.
The aluminum plates are 1mm each. Adding more plates past 3 doesn't increase height much, but not worse either. 5 plates is perhaps 1mm higher than 3 if at all. Yes, adding a fan would allow it to run longer and/or increase power. I didn't include any active cooling because someone would claim that the air was lifting the plates.
My related levitation video:ua-cam.com/video/AHED5xSnnM8h/v-deo.htmlas a lengthy description in my reply to David Riding 6 days ago. Please read that first. If you have further questions, please email me at davekni@yahoo.com
Of course, there’s more material being added. Wouldn’t more of anything usually add more of whatever power or effects it is, ie horsepower, volts, and anything similar?
Yes. What I'd initially thought was that a second plate would double the magnetic force. It would also double the weight (downward force of gravity). The point of this demonstration is that two plates increase the magnetic repulsion by more than twice.
There are many small commercial levitation devices sold for desktop display etc. But they work on a different principal. Permanent magnet within levitated object and actively controlled electromagnets within base. I'm not aware of any commercial eddy current levitation devices.
In general, cuts decrease levitation as they hinder the necessary circular current flow. A hole in the center might help a bit by lowering weight slightly. But that hurts stability. Cuts are fun in aluminum foil on my higher frequency levitation demo. (There's a link in the description to my other levitation demo.) It shows the cut starting at 3:20. Current is forced to concentrate at the cut end, enough to heat the aluminum red and melt it locally.
The floating Aluminum plate vibrates, giving off anti-gravitons from underneath it, which can then be collected and amplified by heavy elements like 115.
Higher frequency would allow more materials to levitate (lower-conductivity metals, but must still have some conductivity). It also allows higher levitation. Here's my higher-frequency video: ua-cam.com/video/AHED5xSnnM8/v-deo.html
@@manipulativer Yes, lower-conductivity materials would heat more when levitating. For high-conductivity materials like these aluminum sheets, a bit higher frequency would reduce heating for a given levitation height. As frequency goes up further, to the point where the skin-depth is less than the plate thickness, heating goes up again.
@@davekni Ive read that herzian waves are not realy transversal but longitudinal. And if EM waves are longitudinal pressures and depressures of the aether it makes sense that there is a frequency that is higher and that heats less. Is there a "cascade" effect on certain frequencies where the plate vibrates? I am quoting Nikola Tesla on longitudinal waves and he even went to talk to Hertz in person to give him the bad news. (or so i remember)
@@manipulativer The frequency here, or even the higher frequency in my other video, is much too low for any significant EM waves. The wave length is orders-of-magnitude longer than the dimensions of the magnets and aluminum. This is all near-field.
Am aluminum plate will lift over a single transformer, but then fall off to one side or the other. The ring is needed for positional-stability. Three would be enough.
@@andrewkhchan There are iron cores within the coils. Iron would not lift, but rather stick to the base. Copper would lift, but not quite as well as aluminum. Copper conducts electricity better, but is heavier.
Yes, I did try rotating a plate 45 degrees. There is enough vibration that it moves back to more aligned over time. Even thought the plates are not insulated, the contact is so light that conductivity between plates is low compared to within a plate. It would make only a tiny difference if the plates were in solid electrical contact.
I'm using secondary halves wired in parallel. Primary halves in series should work as well. Yes, one outlet, feeding a 120V to 240V transformer, then through a capacitor to paralleled secondary halves.
@@stg3orgeguy26 I damaged one of the primary halves when cutting, so don't have enough to test. From a theoretical viewpoint, I'm not sure, probably close to the same. Primary windings are usually a bit smaller, so could handle a bit less power without overheating too quickly. On the other hand, since primary winding is shorter, more of the wire is closer to the aluminum plate, so more effective. I'd hoped to test both. Don't plan to make the effort to find another same-model transformer and cut it.
Here's the biggest and highest eddy-current levitation I've seen: ua-cam.com/video/txmKr69jGBk/v-deo.html Mine could be significantly better, but I wouldn't say "much" higher. The improvements could be: 1) Higher frequency, ie. 900Hz as in above link. 2) More optimum coil and iron geometry - more like my 23KHz levitation video - two concentric circle windings with iron between. 3) Copper rather than aluminum wire. Microwave oven transformers such as mine use aluminum wire. These would require much more custom work, so I showed what could be done with available parts.
haha I saw ^ that video a long time ago . I was wondering why you cut the transformer in half? i'd think it would be stronger if they were not cut in half? also if I have four of them & cut them I can make two identical levitation things like the one in this video? I wish I could post photos on youtube to show what i'm asking.
@@Casperdj777, When not cut in half, the iron laminations form a complete magnetic path around the coils, so little field extends beyond the transformer. That's desired for normal transformer use - for both efficiency and avoiding fields coupling into neighboring circuitry. Yes, you could make two units, if your mechanical skills are better than mine. I actually cut 5 transformers to get 4 identical halves. Some halves I damaged by crooked cuts that cut into the winding on one side or the other. If I'm not addressing the correct question, please feel free to send email with pictures: davekni@yahoo.com
if I have two hooked up do you think it will support 3.84 pounds? do these get hot like the microwave version if so can I add a mini fan to keep it cool and leave it turned on?
@@Casperdj777, Are you wanting to support 3.84 pounds besides the weight of the aluminum? That would probably be a bit much for even a double-setup. If you want to levitate 3.84 pounds of aluminum, that is probably possible, especially if it is a relatively pure aluminum (1xxx series alloy). Of course, more is possible with a more optimum coil and iron design than microwave oven transformers.
I'm using the secondary-half of the microwave transformers for this demonstration. All four are wired in parallel, about 1.3A each or about 5A total in this video. It is powered by 240V line. There is a motor-run capacitor in series, forming a series-resonant circuit. The voltage across the transformers is a bit higher, around 300V if I recall correctly. Changing the capacitor size (capacitance) changes the total current. Lower current levitates less, but doesn't overheat as quickly. Higher current is the opposite, a bit higher levitation, but a short run time before overheating. I've ran from 4A to 6A total by changing capacitance.The primary transformer halves should also work, wired in series and running on 120V. I damaged a couple primaries in sawing them in halves, so used secondaries.
The same magnetic force that is lifting the plates is pushing down on the transformers. The magnetic force is separating the two. There is no net force to levitate the system. There are videos of the opposite setup, a coil levitating over aluminum plates. Of course, the coil has wires attached to provide power, so it isn't completely isolated levitation as with my floating aluminum plates.
davekni if u increase the force, then its possible can be lifted with transformer and disc, why not? try to install in them iddle magnet, it will push the aluminum plate in some dirrections
It's a basic law of physics, often stated as "every action has an equal and opposite reaction". Any upward (levitating) force has an equal magnitude downward force on something. Airplanes push down on the air. My levitator pushes down on the transformer halves, with just as much force as is pushing up on the aluminum. If I were to put the transformers on a scale, they would weigh more when levitating the aluminum plates than when nothing is above them, exactly as much more as the weight of the plates.
Yes, it's a force in the opposite direction from gravity. It's a magnetic force. It gets stronger as the stack of aluminum plates gets more electrically conductive, which does correlate with the stack getting heavier too.
Smaller works, but frequency needs to be higher. This is already small for 60Hz line frequency. My initial small experiment coils were 40mm diameter and ran at 100kHz. (I'm not familiar with coil shapes of a coffee grinder motor. Shape may not be appropriate.)
Very cool!
Bruh moment
Hey
fancy seeing you here
Wow! So that's how it's done! Very similar setup to an experiment I did in 2004, except I used four U-shaped iron cores with a single coil going through the center of all of them, operating at 60 Hz. An aluminum plate would easily levitate, then immediately slide off the edge. I tried putting holes in the aluminum plate to force the eddy currents to occupy restricted paths, but I was never able to achieve stability. I had no idea it could be as simple as what you have done here. Thank you!
I didn't think it was that simple either, until I did some experimenting, initially with tiny flat coils running at 130KHz, levitating aluminum foil disks. What it takes is a pancake coil wound in one direction for the inner half and the other direction for the outer half. Next I made a larger 23KHz version ua-cam.com/video/AHED5xSnnM8/v-deo.html Then I decided that a ring of transformer coils would be similar, as the current in the windings is going in one direction towards the center and in the other direction towards the outside. It would be more efficient to have two larger coils, one on the inside and one on the outside, but transformers come per-wound. So, I think your original version would have worked if you wrapped another coil around the outside of the U cores, in the opposite direction as the inside.
Me thinking I'm smart when I know how to calculate three equtions with three unknowns, but his guy swiped the smile of my face
3 equations and 3 variables is more than most people are successful with. Enjoy your abilities. There are people well smarter than I am too.
@@davekni Not many.
Mathematics is not actually the absolute everyone thinks it to be. In reality, mathematics has numerous flaws which can cause error and misunderstanding. The first and most prominent flaw of mathematics is its reliance upon a linguistic language to convey meaning. There is always a translation issue or a disparity when one language is converted to another. The same thing occurs with mathematics. Just because an equation can provide results which are superficially correct and return repeatable results does not mean that the linguistic language used to describe the processes is correct. The mathematical equation could completely match observation while the explanation of the processes occurring could be entirely incorrect. Most people never even consider such an occurrence and just accept the linguistics that are posited with the mathematics as correct.
@@wesbaumguardner8829 The problems you are describing are not flaws in mathematics itself but rather in how math is used (or misused) in a scientific or engineering application.
@@davekni Actually, no. There is no way to separate this flaw from mathematics itself because pure mathematics is absolutely meaningless and requires a secondary language to make it meaningful.
I'm using the secondary-half of the microwave transformers for this demonstration. All four are wired in parallel, about 1.3A each or about 5A total in this video. It is powered by 240V line. There is a motor-run capacitor in series, forming a series-resonant circuit. The voltage across the transformers is a bit higher, around 300V if I recall correctly. Changing the capacitor size (capacitance) changes the total current. Lower current levitates less, but doesn't overheat as quickly. Higher current is the opposite, a bit higher levitation, but a short run time before overheating. I've ran from 4A to 6A total by changing capacitance.The primary transformer halves should also work, wired in series and running on 120V. I damaged a couple primaries in sawing them in halves, so used secondaries.
what capacitance value did you find best for max power transfer?
@@Stubert619 About 30uF was maximum if I recall correctly. Power was a bit too high there. Coils heated too quickly. I think 40 or 45uF worked out for reasonable tradeoff between levitation and overheating.
@@davekni Thank you so much for the reply. I should probably note I'm 29, familiar with higher voltages and am starting the last 3 remaining semesters of my electrical engineering undergrad program at SDSU at the moment. I figure most real human beings ran into a fit of doubt at some point and mine was in my first 3D integral in my E.M physics class- didn't feel good in the moment. Maybe most people lived shorter spans before seeing a dumb wire move on a battery and magnet but I hadn't- I'm pretty far away from religious but it was like- idk the first bit of intelligent design separated from what had only been on exhausted onto paper up until that point. It lead me to stumble on Professor Eric Lewthwaite's work, and I've been doing my best to study his books in the heat of juggling a heavy STEM load. Maybe there isn't an ocean of money in making subatomic matter persuade their macroscopic counterpart into motion like this, but it is absolutely what stimulates my study. I'm grateful you shared this!
@@Stubert619 Wonderful to see your curiosity and interest in the basic practical physics, such as wires moving in a magnetic field. That understanding will be more important to your success as an engineer than being able to do 3D integrals. Computer simulations do the hard work. Problem is that many engineers don't have the intuitive understanding to correctly interpret simulation results. You will do well.
“Motor-run capacitor”?
This is tight! Are all four windings wound in the same direction so that while current passes through the inner half of each solenoid, it pass clockwise, and the outer half of each somewhat combine to form a counterclockwise current.. as though each four were theoretically two separate 1/4s of their respective ring(inner v outer), creating an inward “draft” on a copper flywheel as laithwaite demonstrated keeping the aluminum stable? And is a cooling device in the center?? Quiet brilliant I must say(:
Yes, exactly on the current directions and net effect. No active cooling - this video is about as long as it can run before getting too hot. (The center is just a spacer block and center wire connections.)
I realize this was 5 years ago, but what a nice use for Microwave oven transformers.
Safer than what such transformers are often used for, such as Lichtenberg figure burning. Thank you.
I wish I had read all the comments before starting this project. First off, you don't have to saw the transformers in half. When they were initially made, three sets of windings (primary, secondary, and four turns on another secondary for the low voltage heater) were wound around this lamintated E-Core (perhaps wound prior and then slipped over the E-Core). Then, a cap was installed with two welds along the top. If you use a 90 degree angle grinder, just grind off those two welds, and pop the cap off. This exposes the primary (large dia wire, fewer turns) first, then the 3 turn heater windings, and finally (up against the base of this whole thing) the secondary with many turns of smaller wire. I trashed the secondary and 3 turn to use the primary wires. Big mistake. 6 amps when the "E" is capped, and 35 amps when just the primary and open E-Core. Looks like I'll be starting all over again...
Primaries should work if wired in series instead of parallel. I'll say more in answering your email shortly.
@@davekni Hi Dave: Getting there. In series with 120 VAC and 1, 2,3 and 4 MOT's using primary windings: 37,20,15 and 10 amps. Magnetic field (B) is proportional to the core material ur, N (number of windings), I (current). But inversely proportional to the stack height of the windings. You successfully got levitation using the secondaries at 1.3 amps each, 20x the winding count of the primary, and about 1.5x the stack height. I have 20x lower N (bummer), higher current (good) and lower stack height (good). If my calculations serve me correctly, my primary current needed for the same B field would be: (1.3A * 20turns ration * 1.0 ref stack height)/1.5 (ref secondary stack height) = 17 amps. Running off of 240 VAC in series should get me 20 amps per coil. Need to find the aluminum sheets of 1.0 to 1.5mm thickness. I'll play with the series capacitors at a later date. Dave--thanks so much for your responses to all the questions here and below.
you, sir, have just earned yourself a subscriber. that is insanely cool. are they all wired so that the current thru each coil are in phase?
Thank you for the compliment! Yes, the coil currents are all in phase - all the top center sections oscillate together - all north poles then all south poles etc. The return flux paths, the outsides of each transformer's laminations, are of course opposite the coil centers, so also all together with each other. The four return-flux poles arranged in the center of my setup are the useful ones. The four around the outside are not helpful. Some day I might try cutting those off to improve efficiency, but I'm not sure I can do that without damaging the coil. To see a more optimum geometry, view my higher-frequency aluminum disk levitation video:
ua-cam.com/video/AHED5xSnnM8/v-deo.html
nice, n eed more magnetic experiments. dont get enough of these on here.
Even my Tesla coil videos involve magnetism. Magnetic fields couple energy from primary to secondary coil. More Tesla coil eventually when my QCW coil is finished.
If there's interest, I could post something about poling permanent magnets. Probably plenty already posted by others however.
Wauw!!! That works unexpectly good! Supernice!
Very nice demonstration!
The plate has a resistance and an inductance and behaves as a low pass filter with a cut off frequency, which is proportional to the resistance over inductance ratio.
Below the cut off frequency the plate behaves mostly resistively, the induced EMF and current and opposing magnetic field are leading the coil's field by 90 degrees, producing no net force, only vibration.
Above the cutoff frequency, the lowpass filter effect delays the current and opposing magnetic field by 90°, they are now in phase with the coil's magnetic field and creates repulsion.
The repulsive effect increases as we get closer to the cut off frequency and remains constant above it.
Stacking multiple plates, which is the equivalent of making a plate thicker, reduces the resistance, while the inductance remains constant, lowering the cutoff frequency. Above a certain thickness the cutoff frequency is below mains frequency and the repulsion will not increase.
This is a form of induced diamagnetism, where a conductive material exhibits a strong negative susceptibility to alternating magnetic fields.
In a superconductor, the resistance is zero, which means the cut off frequency is zero, which explains why superconductors are strongly diamagnetic (susceptibility -1, permeability 0), making able to hover above magnets. (this is independent from the Meissner effect, which is not responsible for levitation)
That is a great explanation! Simpler, at least for those with electronics background, than the ways I've explained it.
To make this electrical circuit explanation complete, I think one more detail needs to be explained: When resistance is large (thin plate), the inductor voltage and current are close to 90 degrees separated as you discussed. As resistance drops, phase difference decreases. That alone would make force increase proportionally to cosine of angle. Doubling plate thickness (halving resistance) would produce slightly less than twice the force.
The reason for additional force beyond angle is that current in this L+R low pass filter increases as resistance drops. Force is proportional to current times cosine(phase). Both factors increase, making force increase faster than weight.
@@davekni Thank you for completing my explanation ! (wrote it at 1am on a phone). Interestingly, this levitation effect is also produced in induction motors. However, the torque producing component (or force, for a linear motor) is the out of phase current. As a result, the torque of an induction motor increases with the amount of slip, but not proportionally because it is also proportional to the sine of the phase shift. Above the"cutoff frequency" the induced EMF no longer increases and the phase shift decreased. As a result, induction motors provide less torque at high slip frequencies, because the torque is "converted" into a repulsive force.
This property allows us to make a single phase induction motor : the rotor sees an alternating magnetic field which is two rotating magnetic fields turning in opposite directions. Assuming we have some way of momentarily starting the rotor (quadrature winding + capacitor) the rotor will keep turning, as the rotating component with the least amount of slip will generate more torque.
In a linear motor, this effect can be used to generate both traction and lift. If the motors are arranged in a way that provides a stable levitation (motors on the side of the aluminium plate) the motor will also provide guidance. Such an arrangement is called a "magnetic river" It has been invented by Eric Lathwaite and proposed for use in maglev trains.
So, this is how the 'aluminum magnet' works! I remember reading about it once in National Geographic. They had covered an article on aluminum in the US.
I'm not familiar with the "aluminum magnet" term, but it is true that aluminum is a magnet only when conducting electricity. In this demonstration, the current in the aluminum is induced by the alternating magnet field below it.
Aluminum is a part of some permanent magnet alloys, especially the old AlNiCo (aluminum, nickel, and cobalt added to iron). Small amounts of aluminum are added to NeFeB magnets to improve their high-temperature performance, at the expense of somewhat lower room-temperature magnetization.
I was just watching the levitation halbach array video where they have 4 motors with a halbach on every motor shaft, the field animation they showed I have seen before when I was playing and experimenting with magnets on a crt tv, when a placed a arc ferrite magnet on its side on a crt tv I layed on its back like a table, We need to focus on bowl shaped magnets or what they create..
Thank you for this video you have no idea how much you’ve helped my studies with this video your video’s are very appreciated
You are quite welcome! My key goal is to stimulate interest in physical sciences.
Another place to find many interesting projects and details and information is the High Voltage Forum:
highvoltageforum.net
I've documented several of my more recent projects there.
Is it made from 4 transformers - all the primary? or 2, with a mix of primary/secondary? Thanks for the video
Yes, 4 transformers. These are all secondaries. (I'd damaged a couple primary windings during cutting, preventing use of all primaries.)
Thinking of cool applications for this.
Could you make electro-magnet tiles and tile a floor with it in such a way that the electromagnetic field generated would be flat and smooth enough to ride it with copper skateboard/snowboard decks?
I've seen a hoverboard experiment that does the oppposite: An electromagnetic board over a copper surface, but the electromagnetic board is very heavy.
Imagine an indoor skiing/snowboarding slope and a flat area for electromagnetic hoverboarding. That would be amazing. You just couldn't bring any electronic devices inside and people with pacemakers shouldn't participate either. :P
Interesting idea! Could be a good project to simulate using FEMM. My guess is that it could be feasible for larger snowboard-sized decks. Probably not for smaller decks, but I'm not sure. Would be expensive and power hungry.
The magnetic field would not be flat. Rather a grid of alternating polarities (alternating 180-degree phasing) at a sufficiently fine pitch to average out across the deck. Finer pitch increases power required. Coarser pitch is better, but requires larger decks to average (smooth) out lift force.
Copper deck may need some active cooling. Superconducting decks would eliminate most losses, but obviously require much more cooling. Superconducting electromagnets for the tiles would likely be cheaper to operate in spite of cooling requirements, as copper tile coils will waste a lot of electricity.
@@davekni Yesss. You seem to have a far better understanding of electronics and electromagnitism than I do.
An active cooling system on the copper snowboard would significantly weigh it down though. But what if you cooled the
electromagnet tiled floor instead? The low temperature would improve the conductivity but also cool the layer of air directly above the tiled floor.
Your hoverboard would be suspended in that cold layer of air and because you would constantly be moving, the copper hoverboard would probably be sufficiently cooled while in use.
Not only could you build a broad, long slope and a flat open skating rink-like area, you could also make a skatepark type of terrain with halfpipes, quarterpipes, banks, ramps, rollins...etc, all of it tiled with actively cooled, superconducting electromagnet tiles.
And hoverboarders will be given copper helmets, copper elbow pads, and copper kneepads with cushioning, elastic material on the inside. Hoverboarders falling off of their boards would be magnetically repelled from the floor,effectively acting as a magnetic cushion. Perhaps the surface of the tile could be covered with a thin cushion/elastic mat. Perhaps a composit; Layers of rubber and layers of a firm foam.
@@allonifrah3465 Certainly for an indoor area, cool floor could help cool copper boards above it. Outside there might be enough air flow to prevent much of a cold-air layer.
Using a soft insulating layer above a superconducting tile array sounds good too. Of course, the thicker the insulation layer is, the stronger the field required to levitate farther above tiles. Most effective insulation is vacuum (thermos bottles), then aerogel, both of which are not soft.
Perhaps helmets and pads should be aluminum for lighter weight. Presumes one doesn't remain fallen for too long so that additional heating is not important.
@@davekni Yeah this is something you'd do indoors, like artificial ski slopes with snow made by machines.
And yeah I was thinking of aerogel since only a very thin layer of it insulates insanely well. We wouldn't want to insulate it too well, or else the floor cooling system wouldn't be able to cool down the layer of air right above it. If the aerogel mat had flaps that could open and close, regularly spaced from one another, it could either cool only the electromagnetic tiles or both the tiles and the air directly above the floor.
When the flaps are open, it would cause the cooling system to divert part of it's power to cooling the air just above it. These flaps could be simple mechanisms that, when opened, make tiny gaps in the floor. They just need to make an airtight seal in their closed position.
A thermostat system that uses equally spaced out thermometers to constantly measure the temperature could open and close those aerogel flaps to ensure that the cold air layer above the floor remains roughly the same.
If someone goes down the slope and across the large, flat rink-area, or over any spine or quarterpipe, the aerogel flaps open in a roughly oval ara spanning the space directly below them to about 2 meters in front of them, so the air will be cooled in realtime when and where needed.
@@davekni As for helmets and pads: If Aluminum can induce the same amount of eddy currents and repel magnetic fields with the same force as copper, then hemlets and pads should be made of aluminum. Maybe aluminum pads & helmets with a thin, copper outer layer.
You will want that magnetic cushioning effect.
The rest would be done by soft cushioning material on the inside of the pads and helmets. Since it'll be could inside that building, people would wear thick, insolated pants, vests and coats, which would also serve as cusioning material in case of a fall.
Simplesmente Sensacional...you have one more subscriber
Thank you for the compliment. It was a fun project.
Cheers to a fun project!
Yes, it was a fun project. I was also happy that it verified what I'd finally concluded from theory. My initial intuition expected a different result.
Очень даже зрелищно. Ну а частоты? Будем менять?
Thanks for the video! It really peaked my interest into why you chose aluminum to levitate.. So far, I found aluminum to be paramagnetic with a magnetic susceptibility constant of +16.5 x 10-6 cgs. Copper's constant is -5.46x10-6 cgs. Does that mean copper wouldn't levitate because it has a negative constant?
Pyrolytic graphite is the only substance that I'm aware of with low enough susceptibility (at room temperature) to levitate by that principle (diamagnetic, so repels magnetic field gradients). This levitation is by the induced AC current in the aluminum. For that, aluminum is best, because it has the highest electrical conductivity per mass. Copper conductivity is higher, but it is much denser, so aluminum wins.
Ok, I'm starting to get it. Aluminum has a little more than half the conductivity of silver, but 1/3 the specific gravity so aluminum would levitate higher under the same condition. You mentioned in the video that you calculated which amount of plates would cause the highest levitation elevation. Do you know where (hopefully online) I could learn much of this (equations, concepts, etc.) myself? I would like to calculate various heights of levitation based on the material type, it's shape and so on. I would like to understand what would happen when two different types of materials are used at the same time. For example: instead of two aluminum plates, what would happen if a copper and an aluminum plate were levitated (1st with Al on top and, then, Cu on top).
That was a very compelling presentation. It looks like you opened A very interesting door when you showed how adding plates actually raises the distance. I was wondering if you tried other geometries or other sizes of plates to see how that might change the height given the voltages and currents you're using. I Have a suggestion that might be of interest to you if you would like to speak by email.
I experimented with plate/foil size more on my higher-frequency 23kHz unit (and small prototype versions of high-frequency version prior). Did try one larger sheet on this MOT-half version. However, it was a more structural aluminum alloy with somewhat lower electrical conductivity.
For this (or any) specific geometry, there is a limited size range that remains stable when levitated.
Yes, would enjoy an email conversation:
davekni@yahoo.com
Excellent. Are you using primary or secondary part of transformer
Secondaries. That's listed in the description. Click on "SHOW MORE" under video descriptions.
the motor running capacitor is that "start capacitor",?(40uf 400) i have or (45uf 400v), it is good? If I open the transformer from the welds of the iron center next to the primary, it means that the iron centers will be 1-1.5cm higher than your device. In this case, it is possible to levitate or you should cut the centers closer to the secondary ?
With weld removal instead of cutting, I'd use the primary windings instead, since they are close to the levitating plate. Unlikely to work using windings away from the plate. So either use primary windings or cut the core down close to secondary height.
I wonder if adding more plates does it draw more current.
Interesting question. I didn't measure current with plates added. For this setup, any current change will be small. Most of the power is consumed in heat (resistive losses) within coil windings.
Nice experiment sr
You are awesome !
Thank you for your compliment! No idea why there was a delay in it showing up.
Great idea
But why does it levitate higher with more plates added???
That's the entire reason I built this demonstration - to see if that effect of more plates levitating higher was real. Calculated that result theoretically first, but had a hard time believing I'd calculated correctly. I tried to make a simple explanation at the end of the video. Induced current in upper plates creates a magnetic field that attracts lower plates. Another way to view the reason (the one I first calculated) is that the phase of induced current in the plates shifts to better align with phase of MOT winding current when more plates are added. In-phase current creates more average repulsive current. An infinitely thin aluminum sheet would have current 90 degrees ahead (leading phase) of winding current so generate no average levitation force. With infinitely conducting sheets (very thick or superconducting), plate current is in phase with coil current so levitation force is maximum.
@davekni Thanks for the updated explanation. The phenomenon definitely seems counter-intuitive. With all the plate masses being the same, I would think the addition of each plate would surely decrease the height. Up to a point, the added plates seem to be concentrating or, as noted, more efficiently using the induced fields. You have definitely given me more to contemplate on. Excellent work 👏 👍🏽
@@rod3134 Yes, decreased height is what I'd initially expected before thinking about phase in more detail. My 23kHz unit does decrease height for any practical thicknesses. That's because at high frequency even thin foil is effectively "infinite" thickness. Phase is already aligned. (Actually I should say 180 degrees rather than aligned. Plate current is in opposite direction as winding current.)
@@davekni Wow!!! A possible explanation in addition to yours just occurred to me. The analogy of the levitating Styrofoam balls in an enclosed sonic field system. Objects that are too big or too numerous will collapse the frequency node object capture capacity. Your sheet stacks are matching the frequency node central area until there is a max saturation within the effective frequency range. It's probably not that the height is increasing, it's probably more-or-less that as more sheets are added, the sheets frequency energy capacities and capture causes a relocation of the node height. I know this may seem like a very loose thought, but this is really making explore some of my previous research,. Great discourse!!!
@@rod3134 I doubt there is any significant analogy to sonic levitation. With too many plates, upper plates see less magnetic field. Current from lower plates reduces field farther up.
Thanks!👍 First time I saw that configuration. All 4 of those are simply plugged straight into mains? (No extra sequential phasing applied to make that happen?)
No extra phasing. But I do have a motor run capacitor in series with the entire set (between coils and mains) to boost voltage. 240Vac was not quite enough. Series capacitor (series resonant circuit) was the simplest way to boost voltage. Easier than grabbing my 50lb isolating transformers to boost voltage further.
@@davekni Ah. Can clarify what "motor-run capacitor in series, forming a series-resonant circuit" means?
@@OMNI_INFINITY Transformer halves are inductors. Inductor in series with capacitor forms a series-resonant circuit. If capacitor was in parallel with inductor, that would be a parallel-resonant circuit. Series-resonant circuits create higher voltage across capacitor and across inductor than the input voltage.
@@davekni Thanks! I am still learning about resonant electronics circuit design and principles. I get that the cap and inductor should have the same energy storage capability, although still figuring out if the reason a specific AC frequency is resonant in a resonant circuit is because that is the frequency where at the peak of each half of the cycle the energy stored reaches that max rated capacity for the inductor and cap.
@@OMNI_INFINITY Perhaps easier to understand a mechanical analog. Hang a weight from a string or thread. It will swing back and forth at a specific frequency. Energy trades back and forth from motion (at bottom of swing) to gravitational potential energy at the tops of the swing where motion stops.
Then notice that you can get the weight swinging many cm by moving the top back and forth only 1cm in time to motion. That is like series resonance.
SUPER COOL !!!!
i always thought eddie current just reduces the efficiency of transformers ...but never thought it can be used in electromagnetic induction
Yes, eddy current consumes electrical power and generates heat. That is undesirable inside transformers. It is desirable for induction cooking and other induction heating. Also useful for some other applications. Levitation is more of a science demonstration than anything useful.
@@davekni if u use dc battery then how is the magnetic flux changing tho?
@@iitaspirant1083 Not sure I'm understanding your question. I did not use a battery for this demonstration. If someone did use a battery, magnetic flux would step up as battery is connected, then remain constant until battery is disconnected or drained. Aluminum plate would experience a brief push upward as flux rises, then no magnetic force after that. Would not levitate.
The fourth transformer could be 750W. is it good for levitation with the others? That is, if the iron center is the same size for the 750w ones, the secondary is the same as for the 700w ones? There is no paper with the power it is. the secondary winding it seems almost as big as the 700w ones, maybe a little bit bigger (2mm maybe) in the unknown one. The unknown one is from another company, maybe that's why it's a little different. What do you say?
Probably fine. Just mount so top surfaces of the haves are all in a plane. 2mm wider isn't likely to matter. 2mm higher than other transformers would be a problem, but easy to fix. Just shim the other three up by 2mm to match (add 2mm shims under other three). I had to add some thin shims to compensate for my imperfect cutting.
Did you connect the iron centers together and the secondary terminal together or did you disconnect the secondary from the iron center? What capacitor do you have in series with the secondaryes in parallel (capacity and voltage)?And wht is the dimension of aluminium plates?
I don't recall if I disconnected secondaries from iron. I don't think so. Not necessary as long as all four windings are the same direction (clockwise or counterclockwise) and electrical connections are parallel as I did.
I think cap value is listed somewhere in description or comments. Around 45uF if I'm recalling correctly. 30uF was too close to resonance so made current too high with 240Vac input. You can change capacitor value and/or adjust input voltage to get sufficient current to levitate without overheating windings too fast.
Aluminum sheets are 200mm x 200mm x 1mm, pure aluminum for highest conductivity. Some 1000 series alloys may have sufficient conductivity. Others may be too low to work without higher current.
Awesome!
Amazing!
what happen when use more frequency ? like 500Hz
In general it would work better at 500Hz, especially with thin aluminum plates. A single 1mm plate would lift quite well.
However, transformer-half steel laminations might heat up too fast, since their thickness was designed for 60Hz. Not sure how bad an issue that would be.
what copper plate also levitate ?
@@N.g.Chanal Yes, though not as well. Copper is more conductive, but also heavier. Weight increase is more than conductivity increase.
I found 4 other identical transformers that are 800w. Are they good for levitating the aluminum plate? How many watts are your transformers if my transformers are not good with 800w?Are the 800w ones better than the 700w ones or are they the same, using the secondaries in this project?
I don't know the wattage of the transformers I used. Perhaps 1kW. If yours are slight smaller, just place them as close as they fit and use a slightly smaller aluminum plate. Should work fine.
Nice
Do you have a video of you making this, I'm not experienced in electrical but mess around with magnets alot
No, don't have a construction video. Do have some more information and top-view image I can share by email. Send me a note at davekni@yahoo.com
Sorry mate late response as i did not get a notification
If you apply varnish to the aluminum, will it improve the flux pattern and give more height.
Varnish will add a bit of weight, so decrease height a little. For a single plate, no effect at all on induced current. For a stack of plates, varnish between plates would make a tiny difference in current path. Most current is circulating parallel to plates. Any vertical current pattern would be disrupted by varnish (insulation), but vertical portion is a tiny current to start with.
Be good to see the camera angle lower to see the space. Looks legit tho
Yes, it would have been better if I'd had someone to move the camera for me during the demonstration. I just picked a compromise angle here.
Super Awesome
If this was spun would it raise higher?
No. Aluminum conductivity is uniform throughout disk and magnetic field is axially symmetric. There are other demos with rotating disks over permanent magnet arrays (or visa versa with rotating magnet arrays) . For those the magnetic field is alternating polarity around the disk, not uniform.
Have you tried plates with a void in the middle?
I've tried a middle void in small-scale experiments (~30mm diameter) before building my 23kHz round version. The void ruins stability if of significant size.
Try using an aluminum rim good job Make Make sure you have a good Aluminum span Try using ice mall copper plate and put it in the middle bottom or top
House to build this tutorial please 😊😊😢😢😢
Are your transformers taken from microwave ovens that operate at 220-240v not 120v? I have four (700W) transformers at 220v. Will the aluminum plate levitate with these?Please give me the answers.
The transformers I used had 120V primaries. I used the secondary halves for this project. Secondary windings are the same whether 220V or 120V primary. So, yes, your transformers will work. Primaries would work as well. I used secondaries because I damaged one primary during cutting.
Thats so coolll
Definitely more stable than your round inductor
My round 23kHz version is close to limit of levitation height for that geometry. If it is ran at lower height (lower power or heavier levitating disk), it gets more stable too.
Would a rectangular ingot of AL-6061-T6 roughly 2”x2”x15” and weight of 5lbs hold up?
Definitely not on this setup. It would be possible with a large industrial induction heater unit with a properly wound water-cooled copper coil. The aluminum would get hot, and perhaps eventually melt.
how thick is the aluminium plates? (all three stacked?) is there a way to keep these cool by adding a fan ?
The aluminum plates are 1mm each. Adding more plates past 3 doesn't increase height much, but not worse either. 5 plates is perhaps 1mm higher than 3 if at all.
Yes, adding a fan would allow it to run longer and/or increase power. I didn't include any active cooling because someone would claim that the air was lifting the plates.
nice work
but how can i contact u for similar levitation project am working on
please reply fast
My related levitation video:ua-cam.com/video/AHED5xSnnM8h/v-deo.htmlas a lengthy description in my reply to David Riding 6 days ago. Please read that first. If you have further questions, please email me at davekni@yahoo.com
Of course, there’s more material being added. Wouldn’t more of anything usually add more of whatever power or effects it is, ie horsepower, volts, and anything similar?
Yes. What I'd initially thought was that a second plate would double the magnetic force. It would also double the weight (downward force of gravity). The point of this demonstration is that two plates increase the magnetic repulsion by more than twice.
Can u show me link fr a frequency machine, I can buy please
There are many small commercial levitation devices sold for desktop display etc. But they work on a different principal. Permanent magnet within levitated object and actively controlled electromagnets within base. I'm not aware of any commercial eddy current levitation devices.
Mate can you try using one plate but use angle grinder and cut pieces out of it, say 50mm x 10mm strips to create more flux points.
In general, cuts decrease levitation as they hinder the necessary circular current flow. A hole in the center might help a bit by lowering weight slightly. But that hurts stability.
Cuts are fun in aluminum foil on my higher frequency levitation demo. (There's a link in the description to my other levitation demo.) It shows the cut starting at 3:20. Current is forced to concentrate at the cut end, enough to heat the aluminum red and melt it locally.
Ferromagnetic thin shims or any material to level?
Any material. Shims go under transformer halves, so play no roll in magnetic flux path.
I have 4 microwaves . can you show me wiring/ set up
I've updated the description to include more detail. If yet more would be helpful, please ask again with what needs further expansion.
The floating Aluminum plate vibrates, giving off anti-gravitons from underneath it, which can then be collected and amplified by heavy elements like 115.
I wonder if u could step up the frequency much higher: 100khz or even 2mhz etc. I wonder if u could make other materials levitate.
Higher frequency would allow more materials to levitate (lower-conductivity metals, but must still have some conductivity). It also allows higher levitation. Here's my higher-frequency video:
ua-cam.com/video/AHED5xSnnM8/v-deo.html
@@davekni Ye but it wouls also heat a lot more would it not?
@@manipulativer Yes, lower-conductivity materials would heat more when levitating. For high-conductivity materials like these aluminum sheets, a bit higher frequency would reduce heating for a given levitation height. As frequency goes up further, to the point where the skin-depth is less than the plate thickness, heating goes up again.
@@davekni Ive read that herzian waves are not realy transversal but longitudinal.
And if EM waves are longitudinal pressures and depressures of the aether it makes sense that there is a frequency that is higher and that heats less.
Is there a "cascade" effect on certain frequencies where the plate vibrates?
I am quoting Nikola Tesla on longitudinal waves and he even went to talk to Hertz in person to give him the bad news. (or so i remember)
@@manipulativer The frequency here, or even the higher frequency in my other video, is much too low for any significant EM waves. The wave length is orders-of-magnitude longer than the dimensions of the magnets and aluminum. This is all near-field.
Great 👍🏼 video.... can you do that with one transformer??
Am aluminum plate will lift over a single transformer, but then fall off to one side or the other. The ring is needed for positional-stability. Three would be enough.
davekni will using iron core or copper plates work as well?
@@andrewkhchan There are iron cores within the coils. Iron would not lift, but rather stick to the base. Copper would lift, but not quite as well as aluminum. Copper conducts electricity better, but is heavier.
can you put the plates in a star pattern,
also have you tried insulating each plate
Yes, I did try rotating a plate 45 degrees. There is enough vibration that it moves back to more aligned over time.
Even thought the plates are not insulated, the contact is so light that conductivity between plates is low compared to within a plate. It would make only a tiny difference if the plates were in solid electrical contact.
Only if there was such a thing as a magnetic resonance amplifier.....
Are they wired in series and all into one outlet
I'm using secondary halves wired in parallel. Primary halves in series should work as well. Yes, one outlet, feeding a 120V to 240V transformer, then through a capacitor to paralleled secondary halves.
Would using the primary produce stronger electromagnetic or does the secondary
@@stg3orgeguy26 I damaged one of the primary halves when cutting, so don't have enough to test. From a theoretical viewpoint, I'm not sure, probably close to the same. Primary windings are usually a bit smaller, so could handle a bit less power without overheating too quickly. On the other hand, since primary winding is shorter, more of the wire is closer to the aluminum plate, so more effective. I'd hoped to test both. Don't plan to make the effort to find another same-model transformer and cut it.
Why my comment did not show yet?
I said nice experiment sr
You are awesome.
💚
awesome thanks . if you left them on the or a transformer uncut and add more power can you make it levitation much higher & holding more wait?
Here's the biggest and highest eddy-current levitation I've seen:
ua-cam.com/video/txmKr69jGBk/v-deo.html
Mine could be significantly better, but I wouldn't say "much" higher. The improvements could be:
1) Higher frequency, ie. 900Hz as in above link.
2) More optimum coil and iron geometry - more like my 23KHz levitation video - two concentric circle windings with iron between.
3) Copper rather than aluminum wire. Microwave oven transformers such as mine use aluminum wire.
These would require much more custom work, so I showed what could be done with available parts.
haha I saw ^ that video a long time ago . I was wondering why you cut the transformer in half? i'd think it would be stronger if they were not cut in half? also if I have four of them & cut them I can make two identical levitation things like the one in this video? I wish I could post photos on youtube to show what i'm asking.
@@Casperdj777,
When not cut in half, the iron laminations form a complete magnetic path around the coils, so little field extends beyond the transformer. That's desired for normal transformer use - for both efficiency and avoiding fields coupling into neighboring circuitry.
Yes, you could make two units, if your mechanical skills are better than mine. I actually cut 5 transformers to get 4 identical halves. Some halves I damaged by crooked cuts that cut into the winding on one side or the other.
If I'm not addressing the correct question, please feel free to send email with pictures: davekni@yahoo.com
if I have two hooked up do you think it will support 3.84 pounds? do these get hot like the microwave version if so can I add a mini fan to keep it cool and leave it turned on?
@@Casperdj777,
Are you wanting to support 3.84 pounds besides the weight of the aluminum? That would probably be a bit much for even a double-setup. If you want to levitate 3.84 pounds of aluminum, that is probably possible, especially if it is a relatively pure aluminum (1xxx series alloy). Of course, more is possible with a more optimum coil and iron design than microwave oven transformers.
how much amps and volts?
I'm using the secondary-half of the microwave transformers for this
demonstration. All four are wired in parallel, about 1.3A each or about
5A total in this video. It is powered by 240V line. There is a
motor-run capacitor in series, forming a series-resonant circuit. The
voltage across the transformers is a bit higher, around 300V if I recall
correctly. Changing the capacitor size (capacitance) changes the total
current. Lower current levitates less, but doesn't overheat as
quickly. Higher current is the opposite, a bit higher levitation, but a
short run time before overheating. I've ran from 4A to 6A total by
changing capacitance.The primary transformer halves should also work,
wired in series and running on 120V. I damaged a couple primaries in
sawing them in halves, so used secondaries.
davekni thanks, why dont you connect aluminum disc to transofrmers with plastic or wood? i mean whole system can fly.
The same magnetic force that is lifting the plates is pushing down on the transformers. The magnetic force is separating the two. There is no net force to levitate the system. There are videos of the opposite setup, a coil levitating over aluminum plates. Of course, the coil has wires attached to provide power, so it isn't completely isolated levitation as with my floating aluminum plates.
davekni if u increase the force, then its possible can be lifted with transformer and disc, why not? try to install in them iddle magnet, it will push the aluminum plate in some dirrections
It's a basic law of physics, often stated as "every action has an equal and opposite reaction". Any upward (levitating) force has an equal magnitude downward force on something. Airplanes push down on the air. My levitator pushes down on the transformer halves, with just as much force as is pushing up on the aluminum. If I were to put the transformers on a scale, they would weigh more when levitating the aluminum plates than when nothing is above them, exactly as much more as the weight of the plates.
Opposite of gravity..the heavier the more pressure but here its opposite
Yes, it's a force in the opposite direction from gravity. It's a magnetic force. It gets stronger as the stack of aluminum plates gets more electrically conductive, which does correlate with the stack getting heavier too.
@@davekni so it wont work with for example wood right?
@@DarkLord666SK Correct. This is alternating-current magnetic induction. Works only with electrically-conductive materials.
That frequency isn't good to be near..
Why?
@@blackturbine it effects they way oxygen attaches to hemoglobin for one ... ... .
@@Airtube-2hrb oh boy wait until you learn about sun light
@@blackturbine Im a line engineer.
@@Airtube-2hrb I'm a electrical engeneer
И какая на фиг гравитация? Все подчиняется электро магнетизму,это реальная сила,а не пресловутая гравитация!!!!
опыт хороший) обьяснение не верное)
Can we use smaller winding to levitation system e.g coffee grinder moter winding ??
Smaller works, but frequency needs to be higher. This is already small for 60Hz line frequency. My initial small experiment coils were 40mm diameter and ran at 100kHz. (I'm not familiar with coil shapes of a coffee grinder motor. Shape may not be appropriate.)