DIRECT-CURRENT MOTOR CONTROL DEVICE AND METHOD FOR DETECTING STATE OF DIRECT-CURRENT MOTOR

摘要

A current detection unit detects an electric current caused by superimposing a direct current from a direct-current power source on an alternating current from an alternating-current power source and supplied through a brush to a direct-current motor. An extracting unit extracts an alternating-current component of the detected electric current. An angle detection unit detects a rotation angle of the motor according to the extracted alternating-current component. A direction detection unit detects a rotative direction of the motor according to a change pattern of the extracted alternating-current component. A core of the motor has slots each defined between adjacent two of teeth. The slots respectively accommodate phase coils respectively wound around the teeth. Turns of the phase coils are different from each other.