On Mar 3, 12:52*am, "Wild_Bill" wrote:
...
AC PM motors don't exist, as far as I know.
...

See Tim Wescott's reply.

Segways use 3 phase AC motors with an -extremely- strong permanent
magnet rotor. They stick to the sheet metal of lab benches so hard the
bench slides before they pull loose.
http://www.moonbasecafe.com/summativ...2/science.html

jsw