Nowadays it is hard to imagine a kitchen without a blender or a bathroom without a hairdryer. To operate, all these appliances, as well as analog clocks, tools, projectors, supervising cameras, programmers, copy machines, etc., you need a synchronous motor. The main difference between PM stepper motors and synchronous motors is in the way of rotation. Synchronous motors rotate with constant speed. Their basic goal is to transform electric energy into mechanic energy. The most important characteristic, that distincts various synchronous motors, is the stability of rotational speed according to supply voltage. The bigger stability, the better the motor.