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# Magnetic Levitation (without electromagnet above, or spinning top)? Answered

Hey, so I was watching some of these videos about magnetic levitation, and I notices that some levitating globes don't have an electromagnet above the globe. Nor is the globe spinning very fast. This is one of the devices that I have seen, and I would like to know how it works so that I can build it....and maybe make an instructable along the way. Also, SimerLab has the levitation down pretty well. Anyone have any ideas?
Thanks!
Sam
P.S. Found another good website here that has one taken apart (it was a Levitron AG). And this website has a kinda breakdown on how one might work, but it definitly isn't specific enought o build one.

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## Discussions

The holding magnetic field is produced by 4 electro magnets in the base unit - this field is circular in shape and hollow like a bowl in the centre so the fixed magnet tends to fall towards the centre.

I am guessing but I would think that the fixed magnetic field is sensed in the base unit and the power of the electromagnets is altered to keep the fixed magnet in the centre.

As for building - I would look at using some light sensors to check the position of the hovering magnet and control the magnetic field. For specific details you may well be on your own.

If the floaty part is above the base then for magnetic levitation you need two magnets. One in the base and one in the floating object. Floating globes usually have another set of magnets above to stabilise the floating object. The video link you sent seems to stabilise the floating object using multiple electromagnets in the base but I can't say anything for certain without taking it apart.
If the base is above the floating object you could get away with one magnet in the base and a ferric metal in the floating object but you would need to very exactly balance weight versus magnetic pull.

In any situation the forces are similar. Similar poles repel (forcing the object away from the base), odd poles attract (pulling the object towards the base) and gravity (pulling the object down). With electromagnets you can even control when they are active and the direction of the poles. Combine the above in any number of ways to get a levitating globe.

I hope that helps