Shaded-Pole Induction Motor
This is another method to create two phases, with phase differences using pole shading.
The shaded pole has salient poles, each pole split into two sections. A small part of each pole face is wound with a short-circuited copper ring.
When supply is given, the flux under the shaded portion lags behind that of the unshaded portion. Thus a phase difference is created. This causes the creation of a rotating magnetic field.
The shaded pole motor is inexpensive, since it does not consist of an auxiliary winding or other mechanisms. These are low-torque motors, generally used for small fans and blowers.