Patent ID: 7692395

Claim:
A device for controlling a brushless DC motor including: a first data storage area including a plurality of inputs adapted to be coupled individually to different stator windings corresponding to different motor phases of a brushless DC motor to receive voltage information corresponding to voltages at their associated stator windings; a commutation control signal generator adapted to be coupled to a commutation circuit of a brushless DC motor to provide control signals to the commutation circuit and thereby operate the commutation circuit according to a commutation cycle having a plurality of communication cycle segments symmetrically arranged over a motor electrical rotation of 360 degrees including selected commutation cycle segments during which a given one of the stator windings is not driven; a sampling function operatively associated with the first data storage area, operative during each of the selected commutation cycle segments to sample the voltage information of the given stator winding at first and second predetermined points in the selected segment corresponding to first and second angular locations along the motor electrical rotation; a second data storage area associated with the sampling function for receiving the sampled voltage level information as first and second voltages corresponding respectively to the first and second angular locations; a center point generator associated with the second data storage area, adapted to use the first and second voltages in combination with the first and second angular locations to generate a center point signal indicating an angular center of one of the commutation segments; and a timing function; wherein the commutation control signal generator is associated with the timing function and the center point generator and adapted to use the center point signal to generate the control signals in synchronism with motor speed and position.