The draw of stepper motors lies in their inexpensive and powerful design for positioning loads. In stepper motors an internal rotor with permanent magnets or made of soft metal is electronically controlled by external magnets. When windings are energized, the rotor teeth become attracted, align with the magnetic field, and move in fixed increments. They may change direction, slow, speed up, or even stop because they step from position to position with the energizing and de-energizing of windings.
Although simpler stepper motors have limited positions, more sophisticated ones can proportionally power windings, smoothing rotation and making stops between cog points possible. The value of stepper motors lies mainly in their application for light loads and short moves, though microstepping modes, where the motor is controlled by a computer, make some of the most versatile positioning systems available.
Stepper Motors supplied by MCMA Member Companies