On Tue, 12 Apr 2011 15:24:52 -0400, "vaughn"
wrote:


"David Nebenzahl" wrote in message
rs.com...
You're referring to steppers. Most spindle motors aren't steppers, but simple
DC motors (2-wire, no feedback sensors or additional windings). I know; I've
got a box full of 'em that I've removed from old CD and DVD drives. No
pulsating DC, no PWM (which in any case isn't AC anyhow).


Wrong. Spindle motors either have brushes and commutators or else the solid
state equivalent. Otherwise, they can't work. Just like the commutators &
brush system, that electronic "stuff" may be built directly into the motor where
you can't see it, but it's still there.

Correct. David should refrain from any EE lectures. He hasn't got it in him.