Self-commutating, back-EMF sensing, brushless DC motor controller

Claim 1

A circuit for commutating the voltage supply for a polyphase brushless DC motor having a plurality of commutation states and a plurality of windings comprising: a plurality of comparators simultaneously coupled to said motor for detecting back-EMF associated with a plurality of windings of said motor, wherein each of said windings is individually coupled to an associated one of said comparators, said comparators providing separate detection signals for each of said plurality of windings; detection signal qualification means coupled to said comparators for selecting from said detection signals to provide an output signal based on said detection signals and a commutation state signal corresponding to a commutation state of said motor; commutation state generating means coupled to said detection signal qualification means for providing said commutation state signal; and commutation state signal transformation means coupled to said commutation state generating means for transforming said commutation state signal into motor drive signals, said motor drive signals coupled to said motor for advancing said motor to a next commutation state.