Three-speed dual-winding direct current permanent magnet motor method and apparatus

摘要

A direct current motor having a primary armature winding, a secondary armature winding and a switching circuit adapted to selectively energize the primary winding and the secondary winding to achieve three-speed motor operation is disclosed. The system is adapted to achieve a high speed of the motor by energizing only the primary winding, a medium speed of the motor by energizing only the secondary winding, and a low speed of the motor by energizing both the primary winding and the secondary winding. The system also includes a voltage source providing a direct current level voltage with respect to an electric ground and a switching circuit adapted to operate the motor. The switching circuit is coupled to the voltage supply for energizing the primary winding only to achieve a high speed, energizing only the secondary winding to achieve a medium speed, and energizing both the primary winding and the secondary winding in series with each other to achieve a low speed. A method of operating the motor is also disclosed. <IMAGE>