Patent ID: 6891343

Claim:
A method for commutating an electronically commutated multiphase electric motor having a rotor rotatable about a motor axis and a stator assembly configured with stator windings defining phases, comprising the steps of: (a) providing a sensible system rotatable in correspondence with the rotation of said rotor and having phase commutating information defining sensible transitions at the commencement of each of said phases as they occur in commutational succession; (b) providing a single sensor operatively associated with said sensible system, having a sensor output altering between sensor states in response to said sensible system transitions; (c) identifying a starting phase for energizing said stator windings to cause said rotor to rotate about said motor axis in a given direction; (d) commencing the operation of said motor by energizing those said stator windings establishing an aligning phase occurring prior to said identified starting phase in said commutational succession to an extent effective to cause said rotor to rotate toward a magnetically stable position exhibiting substantially zero torque; (e) then de-energizing said stator windings representing said aligning phase and energizing said stator windings representing said starting phase; and (f) energizing only those said stator windings representing a next phase in said commutational succession in response to said sensor output.