摘要 |
<p>A method and apparatus to commutate the drive voltages of a brushless DC motor without sensors. The present invention determines rotor position and velocity by detecting the polarity reversal of the Back-EMF of an undriven leg when compared to the transformed reference. In an extra measure of efficiency, it includes a commutation delay timing circuit for optimization of motor operation, and it minimizes the participation of a microprocessor or other microcontroller.</p> |