Method and circuit for commutating the voltage supply for a brushless DC motor

摘要

A method and apparatus to commutate the drive voltages of a brushless DC motor. The present invention determines rotor position and velocity by detecting the polarity reversal of the Back-EMF of an undriven leg when compared to a transformed pseudo-reference. In an extra measure of efficiency, the present invention is independent of hardware sensors; it includes a commutation delay timing circuit for optimization of motor operation, and it minimizes the participation of a microprocessor or other microcontroller.