A kind of electrical motor which instead of continuously turning when voltage is applied, has distinct steps. To make it turn, its coils have to be energised in sequence.



A stepper motor usually has either four or six wires. The four wire variety is called a bipolar stepper motor. Those with six wires are called unipolar stepper motors.


Phase 0


Phase 1


Phase 2


Phase 3


Phase 4

Unipolar stepper motors have a structure as depicted above. There are four coils wound around two sets of armatures. The coils wound around the same armature (mostly) share a common wire.