HOW WORKS A MOTOR?
The force that that turns the armature comes from the magnetic field of the armature trying to line up with the external magnetic field of the stator. This force is called torque. This torque will cause the armature to turn until its magnetic field is aligned with the external field, but no further. How does the armature continue to spin? One of the magnetic fields must be changed so that the armature has to turn again. The armature will spin so long as there is always a torque acting on it. How this is accomplished is what sets each type of electric motor apart.
