Monday, May 25, 2009

The Amazing One-Sided Magnets!

I've got two different magnets that have incredibly unusual properties. Both have one very magnetic face and one face that's almost entirely amagnetic. Their magnetic faces also have a rather strong magnetism for such small iron ceramic magnets.

Why? It appears they're Halbach arrays, a special arrangment of magnets that allows the magnetic field to reinforce itself on one side and cancel itself out on the other. They can produce one-sided magnets, cylinders with magnetic fields only on the inside, and other strange stuff.

Applications include fridge magnets that only stick one way, maglevs, 'wiggler' magnets for particle acclerators, brushless motors, magnetic couplers, and more.

Another good site.

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