US Patent 7246029 Electric machine with actively controlled switches

A system, for determining a starting position angle of an electric motor, includes a plurality of windings, a circuit, a processor, and at least one voltage sensor. The circuit is configured to create a pulse current field in at least one of the plurality of windings. The sensor is configured to sense a pulse current field response in a corresponding winding of the plurality of windings. The processor is in communication with the voltage sensor and is configured to determine the position angle of the rotor based on the pulse field response.