No matter how its done, with whatever level of fakery, magnetic levitation just looks cool. We don’t know about you, but merely walking past the tackiest gadget shop, the displays of levitating and rotating objects always catches our eye. Superconductors aside, these devices are pretty much all operating in the same way; an object with a permanent rare-earth magnet is held in a stable position between a pair of electromagnets one above and one below, with some control electronics to adjust the field strength and close the loop.
But, there may be another way, albeit a rather special case, where a magnet can not only be levitated, but locked in place using a rotating magnetic field. The video shows a demonstration of how the mass of a magnet can be used to phase lock it against a rotating field. In essence, the magnet will want to rotate to align with the rotating magnetic field, but its mass will mean there is a time delay for the force to act and rotation to occur, which will lag the rotating magnetic field, and if it is phased just so, the rotation will be cancelled and the magnet will be locked in a stable position. Essentially the inertia of the magnet can be leveraged to counteract magnet’s tendency to rapidly rotate to find a stable position in the field.
Whilst the idea is not new, Turkish experimenter [Hamdi Ucar] has been working on this subject for some time (checkout his YouTube channel for a LOT of content on it), even going as far as to publish a very detailed academic paper on the subject. With our explanation here we’re trying to simplify the subject for the sake of brevity, but since the paper has a lot of gory details for the physicists among you, if you can handle the maths, you can come to your own conclusions.
Thanks [keith] for the tip!
Thought provoking, great timing for this post, Thanks for bringing this to our attention :-)
Fwiw. Been working on a lesser known aspect of electro-magnetism in relation to torque & hysteresis, far too early to report though ‘intriguing’ ;-)
Cheers
Wow Half Life gravity gun :D
> these devices are pretty much all operating in the same way; an object with a permanent rare-earth magnet is held in a stable position between a pair of electromagnets one above and one below, with some control electronics to adjust the field strength and close the loop.
True for those specific devices but what about Levitron? No electronics at all, only permanent magnets and a spinning top.
I’d guess [Hamdi Ucar] device works by the same principle as a Levitron but “in the opposite direction”.
Why isnt there more discussion on the magnetic locking that happens with rotating magnetic fields. And I’m not talking the spinning top over magnets but the opposite the rotating magnets that will hold a stationary magnet others I wish I could remember his name but he’s out of Japan I believe and he’s using rotating drums of magnets to stabilize a ball in mid air and I know what this phenomenon is useful for. Anti-gravity in space flight and split second propulsion like we observe in whatever it is that we’re calling UFOs that always dictionary and then shoot off in the direction of breakneck speed‘s. It’s done by and I know this so if anyone has any ideas otherwise please I’m happy to discuss but it’s done by taking a super massive magnetic metal and you surround it with completely with rotating magnetic drums or discs or some some form like that so that you create a rotating magnetic field that keeps the high density core stable and it’s just the adjustment of rotation rotational speed of the you know however many discs you have surrounding it you know in them I would guess in the in the hundreds of disks rotating the surrounding so you just a few it on one side and the remaining discs that are staying stable keep the central core locked while applying thrust from the change of rotation in the other side that cause-and-effect I know that I don’t even know how I know it works but that’s the way it works when I first thought is the sky doing this experiments with just a couple discs in a little ball it came flooding into my head that’s the way that speed and that precision of movement is achieved and maybe someone here will understand what the hell I’m talking about and we can actually do something with it and I get it makes perfect sense in my head but I don’t have the mathematics to prove it so if there was somebody that knows did the study I’m talking about and and could help verify that I really believe that that’s that’s the thing that will do it or maybe I’m just crazy I don’t know but it seems like a lot of things when they pop in my head like that turned out to be true cell please if anyone can shed some light on this I would appreciate it
So this thing of magnetic locking through spinning magnets is the same in both instances its just doing it through the reverse of the spinning magnet from stationary to floating. They both have the same outcome, levitation. Now as I was explaining in my reply below. If you take the form featured here and put say 100 Dremel magnet spinners in a sphere around a high density magnetic ball you should be able to produce thrust by adjusting the rotational speed of some of the magnets at the same time as keeping the primary locking magnets held firmly in place.
Now replace the spinning magnetic with a static electromagnet that has a rotating magnetic field and you’ve got solid state magnetic levitation without the need for a superconductor, not to mention, you can then drive the rotation much faster.
*spinning magnet.
Came here to say the same thing. A properly driven near field antenna (or phased array) should do the trick, and could even work on a conductive but not magnetic object through induction. The biggest problem I can see is the inductance of the electromagnet. You need several amperes of current oscillating in the several kHz range (audio frequency), I imagine it would create quite a buzz.
If the geometry of the coil was carefully chosen it might be possible to use a much higher frequency. Instead of simply driving the entire coil and having multiphase windings, in theory it should be possible to energize sections of a coil and then move the nodes of the standing wave. But still,granted, no doubt you’d need to feed it with plenty of current. Although perhaps a bifilar design might improve the response by negating a good portion of the self capacitance.
Umm… isn’t that what those electromagnetic levitation devices do?
No, I think they use a control loop with position sensing to stabilize unstable configurations. This, on the other hand, is inherently stable in a range of frequencies/rotational speeds.
I beleive i saw video showing experiment with simple wire coil layed on top of copper plate. By running mains AC voltage through it (limited by variac) it was caused to levitate. But it was not extremely stable due to obvious reasons.
https://www.youtube.com/watch?v=BuWflDnAO9s
Thank you for mentioning my work. The “time delay” stated above causing the floating magnet to sync to the opposite phase therefore creating the repulsion force is not merely a time delay due to the inertia. This is a characteristics of the driven harmonic motion inherited from harmonic motion, say the simple pendulum. Because of this, the effect don’t require a specific frequency, for example a frequency matching this “time delay”. Instead it works in any frequency about a certain frequency which can be identified as the resonance frequency. This mechanism is called “phase lag” and it is the working principle of reflex subwoofers (http://youtube.com/watch?v=v6K759IHXk8) .
In this video the air going in and out from the passive speaker or from the hole in the same phase of the driven speaker where one can expect the opposite if the frequency is above 40Hz which is the resonance or characteristics frequency of this subwoofer therefore it gives strong bass volume above this frequency.
Thank you for mentioning my work. The “time delay” stated above causing the floating magnet to sync to the opposite phase therefore creating the repulsion force is not merely a time delay due to the inertia. This is a characteristics of the driven harmonic motion inherited from harmonic motion, say the simple pendulum. Because of this, the effect don’t require a specific frequency, for example a frequency matching this “time delay”. Instead it works in any frequency about a certain frequency which can be identified as the resonance frequency. This mechanism is called “phase lag” and it is the working principle of reflex subwoofers (http://youtube.com/watch?v=v6K759IHXk8) .
In this video the air going in and out from the passive speaker or from the hole in the same phase of the driven speaker where one can expect the opposite if the frequency is above 40Hz which is the resonance or characteristics frequency of this subwoofer therefore it gives strong bass volume above this frequency.
Just to mention why that thing you tried as kids (balancing one magnet on top of another) didn’t work, no matter how many magnets you had.
https://en.wikipedia.org/wiki/Earnshaw%27s_theorem
I just ordered some cube magnets. Can’t wait to try it. I may also be building a high-speed dynamic balancer.