Patent ID: 8040095
Filing Date: 2011-10-18
Classification: H02P

Abstract:
1. A method of synchronizing sequential phase switchings in driving stator windings of a multiphase sensorless brushless motor through a sequence of drive configurations of the stator windings, with reconstructed information on a current angular position of a magnetic rotor, the method comprising: sampling on a currently non-conductive stator winding a voltage induced thereon by a resultant magnetic field produced by a drive current forced through currently conductive stator windings that inverts its sign when the magnetic rotor transitions across a plurality of angular positions, at which orthogonality between the resultant magnetic field and a magnetic axis of the non-conductive winding verifies; and comparing the sign of the sampled voltage induced on the currently non-conductive winding with an expected sign upon reaching an angular position of inversion of the sign of the sampled voltage by the magnetic rotor for a current drive configuration, for consequentially switching to a next drive configuration of the sequence upon verifying conformity of the sign of the sampled voltage with the expected sign at the sign inversion.