Compound Wound Motors

Compound Wound Motors have some of the field coils wired in series to the armature and some in parallel. This configuration allows the compound motor to develop good starting torque and constant operating speed.

CEMF: 

Counter Electromotive Force. 

The voltage produced in the starter motor itself through electromagnetic induction. 

This voltage acts against the supply voltage from the battery. 

Motors must be designed to control the CEMF for optimum operation.