Patent ID: 8624543

Claim:
A method of controlling a motor, comprising the steps of: determining a speed of the motor; and engaging a soft chopping routine on a first switch and a second switch of each phase if the motor speed is relatively low, the first switch being driven by a first pulse width modulated (PWM) signal and the second switch being driven by a second PWM signal, the first and second PWM signals being alternatingly configured such that at least one of the first switch and the second switch is closed at any point during the distributed soft chopping routine and both the first switch and the second switch are never simultaneously open, relatively low motor speeds corresponding to motor speeds approximately ranging between zero and a base speed, the base speed being a maximum speed at which the motor is able to output constant torque before torque output begins to decrease proportionally with motor speed; and engaging a single pulse routine on the first switch and the second switch if the motor speed is relatively high, and engaging a hard chopping routine on the first switch and the second switch if the motor speed is nominal, relatively high motor speeds being approximately greater than the base speed and nominal motor speeds approximating the base speed.