Types of Stepper Motor:
The permanent magnet stepper motor use a permanent magnet (PM) as rotor, which operate on the attraction or repulsion to the stator electromagnets. The most important features of this motors are:
+ high torque
- Relatively big step angle
Variable reluctance (VR) stepper motors have a rotor consisting of soft iron. This type of stepper motor operate based on the principle that minimum reluctance occurs with minimum gap. So the rotor endpoints are attracted toward the stator magnet poles.
+ Small price
+ Smaller step angles like the PM-stepper motor has are possible
The hybrid stepper motor uses a permanent magnet with two serrated soft iron rings as rotor at its poles.
+ small step angles are possible
+ maximum torque with a small package size
... Soon coming more