ELECTROMAGNETIC ALUMINUM LEVITATOR

By Thomas R. Fox

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Photograph by Sam Murphy

POWERS OF INDUCTION

This simple AC-powered coil device uses magnetism to levitate aluminum rings and shoot them into the air — and aluminum isn’t even magnetic!

About 13 years ago I learned of some military research into a satellite- and missile-defense device that would propel projectiles using Lenz’s law, which governs the direction of electrical current induced by a changing magnetic field. I decided to make a little gadget based on the same principle for my kids, to get them interested in science and electronics. The gadget worked — both at levitating and shooting ...

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