PERMANENT MAGNET STEPPER MOTOR
Permanent Magnet Stepper Motor
To explain the operation of a permanent-magnet stepper motor, consider the simple schematic diagram. The stator has two sets of windings (i.e., two phases), placed at 90°.
This arrangement has four salient poles in the stator, each pole being geometrically separated by a 90° angle from the adjacent one.
The rotor is a two-pole permanent magnet. Each phase can take one of the three states 1, 0, and -1, which are defined as follows:
State 1:current in a specified direction
State -1:current in the opposite direction
State 0:no current