Patent ID: 7265505

Claim:
A motor control apparatus for controlling a synchronous motor having a stator core with a plurality of respectively separate stator windings formed thereon, with each said stator winding comprising a plurality of phase windings and each said stator winding being capable of effecting rotation of a rotor of said motor when supplied with drive current, said motor control apparatus being selectively operable in a normal-torque drive mode and a low-torque drive mode; wherein said motor control apparatus comprises means for selectively supplying drive current to successively alternating sub-sets of said plurality of stator windings in a predetermined pattern which periodically alternates between a condition in which said drive current is supplied to phase windings of each of said sub-sets and a condition in which said drive current is supplied to phase windings of only a part of said sub-sets, during operation in said low-torque mode.