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Path: utzoo!linus!philabs!cmcl2!seismo!brl-tgr!gwyn
From: gwyn@brl-tgr.ARPA (Doug Gwyn )
Newsgroups: net.physics
Subject: Re: Magnetic Levitation
Message-ID: <567@brl-tgr.ARPA>
Date: Fri, 9-Aug-85 04:44:37 EDT
Article-I.D.: brl-tgr.567
Posted: Fri Aug  9 04:44:37 1985
Date-Received: Mon, 12-Aug-85 01:23:47 EDT
References: <249@weitek.UUCP>
Organization: Ballistic Research Lab
Lines: 23

I don't know how the eddy current magnet you saw was constructed,
but one can be made as follows:

	---------------------------------------
	---------------------------------------
	ooooooooooooooooooooooooooooooooooooooo
	ooooooooooooooooooooooooooooooooooooooo
	---------------------------------------
	---------------------------------------
	---------------------------------------
	ooooooooooooooooooooooooooooooooooooooo
	ooooooooooooooooooooooooooooooooooooooo
	---------------------------------------
	---------------------------------------

(This is a cross-section of a cylindrical magnet with its axis of
symmetry running horizontally.  "o" is the copper wire and "-" is
soft iron.)

A magnet like this (actual size, using 10-pitch printout) will
easily lift a quarter when powered off a hefty AC supply.  This
is the result of the induced eddy current in the quarter being
opposite the main field of the magnet.