Patent ID: 9525371
Filing Date: 2016-12-20
CPC Classification: G01D,H02P

Claim Text:
1. An apparatus for an electric motor having a plurality of windings and a rotor associated therewith, the apparatus comprising: a circuit configured to couple at least two of the plurality of windings between a supply voltage and a reference voltage according to a first current path and to discharge a current stored in the two windings according to a second current path, said circuit configured to force the at least two windings to a short circuit condition in the second current path; a measurement circuit configured to measure a time period of discharge of the current stored in the two windings between a peak value of the current in the first current path and a portion of said peak value reached by the current in the second path; and a rotor position detector configured to detect a rotor position based on the measured time period of discharge of the current in the second path.