Angular frequency extractor for controlling a brushed DC motor

摘要

An apparatus includes a motor driver configured to drive a motor across a pair of input terminals to the motor and a current sense unit configured to sense the motor's electrical current amplitude. Further, an angular frequency extractor is operatively coupled to the motor driver and the current sense unit and configured to detect discontinuities in the motor's electrical current amplitude. The angular frequency extractor also is configured to determine a time period for one complete revolution of a rotor of the motor and to generate a feedback signal based on the determined period to control an angular frequency of the motor. The feedback signal may be used to adjust how the motor is being driven (e.g., to slow the motor down or speed it up).

主权项

1. An apparatus, comprising:
a motor driver configured to drive a motor across a pair of input terminals of the motor; a current sense unit configured to sense an electrical current amplitude of the motor; and an angular frequency extractor operatively coupled to the motor driver and the current sense unit, the angular frequency extractor configured to: detect discontinuities in the electrical current amplitude of the motor, determine a time period of a rotor of the motor based on the detected discontinuities, and generate a feedback signal based on the determined time period to control an angular frequency of the motor, wherein the discontinuities in the motor's electrical current amplitude are detected by generating a derivative output signal of the sensed electrical current amplitude.