The resistance split phase motor has two windings in parallel. One of the winding is the main winding. The other is the auxiliary winding. There is a centrifugal switch in series with the auxiliary winding such that the winding is disconnected at around 75% of the synchronous speed.
The auxiliary winding is made of thin wire of a few turns such as that it has low reactance and high resistance. This creates a magnetic field with a displacement of 30 degrees. This produces a torque which is moderate and can be used in motors up to 250 watts.