US Patent 9130493 Control of a brushless motor

A method of controlling a brushless motor that includes rectifying an alternating voltage to provide a rectified voltage, exciting a winding of the motor with the rectified voltage for a conduction period over each electrical half-cycle of the motor, and updating the conduction period in response to a zero-crossing in the alternating voltage. Additionally, a control system that implements the method, and a motor system that incorporates the control system.