It can be very difficult to make a normal rotating electric motor stop in a precise position. Stepper motors overcome this limitation as they are designed to rotate in a number of precisely defined steps.
The number of steps per revolution are defined by the number of magnetic poles in the motor. For instance, a stepper motor with 360 poles would be able to rotate in precise steps of exactly one degree each. Stepper motors can have many thousands of microsteps, depending on the degree of precision required.
Stepper motors do not use brushes and commutators, as they are usually controlled by a microprocessor electronically switching a set of stationary electromagnets.
Stepper motors are used in automotive for applications such as instrument panel controls and air conditioner controls.
