On Jan 11, 2008, at 8:34 PM, Lawrence de Bivort wrote:
Does the force of a magnet 'run down' as it is used? That is, does
it lose
internal alignment as a result of its countering interaction with
other
magnetic bodies?
Yes, but the energy required to (re-)magnetize even a neodymium
magnet is very small compared to the energies involved in running a
motor even a fairly short term.
The detrimental effects on magnetization of a permanent magnet by
heating or by motion of another magnet or magnets, and thus changing
flux, in a motor can sometimes be mitigated by inserting an
intermediary iron flux conduction path.
Horace Heffner
http://www.mtaonline.net/~hheffner/
