- Joined
- Sep 29, 2014
- Messages
- 2,102
Just a single speed. 1720 RPM.
I was spinning the shaft by hand clockwise and before it stopped spinning I plugged it in and it spun clockwise.
Spin shaft counter-clockwise and plug in before it stops and it spins that direction with no problem also.
A simplification
A single phase AC source will not create a rotating magnetic field. A single phase induction motor requires a method of causing it to rotate in the desired direction at start up it will then continue to operate in that direction until stopped. Hence the starting coils mentioned above, these are located out of phase and cause the armature to rotate in the biased direction during starting and are then often disconnected.
In a 3 phase AC source the phases are 120° apart and will always result in a rotating magnetic field.
DC will not generate a rotating magnetic field either, this is what the internal or external commutator does, it creates a rotating magnetic field mechanically or electronically.
A stepper motor is basically a permanent magnet DC motor with outside commutation.