Patent ID: 6943523

Claim:
A control system for a brushless motor or stepping motor comprising a rotor mounted on a shaft and a stator having a plurality of phase windings powered electrically in a predetermined electrical cycle to cause the rotor to advance, said system comprising: an indicator device for indicating the mechanical position of the rotor and placed on the shaft thereof; an optical detector device for measuring the mechanical position of the rotor from the indicator device, and co-operating therewith to form an incremental coder device for the mechanical position of the rotor; and a motor control assembly comprising processor means for processing signals encoding the mechanical position of the rotor connected to regulator means for regulating the power supply to the plurality of stator windings; wherein the indicator device for indicating the mechanical position of the rotor comprises at least a first series of indications arranged in a pattern of periodicity that corresponds to a period of an electrical cycle of the motor so as to provide an indication on the phase of the electrical cycle of the stator based on movement of the rotor, and the incremental coder device delivers a synchronizing signal to the processor means, the processing means synchronizing the start of an electrical cycle on the mechanical position of the rotor for all electrical cycles.