Patent ID: 7045979

Claim:
A method of controlling an electric machine, the electric machine comprising a rotor and a stator, the method comprising: providing an electric machine comprising a first speed circuit comprising a first main winding, an auxiliary winding, and a switch connected in series with the auxiliary winding, and a second speed circuit comprising a second main winding; providing an operational power to one of the first speed circuit and the second speed circuit; detecting which of the first speed circuit and the second speed circuit is receiving the operational power, wherein detecting which of the first speed circuit and the second speed circuit is receiving the operational power comprises at least one of detecting an existence of the operational power, and detecting an absence of the operational power, and wherein detecting an existence of the operational power comprises detecting at least one of a current associated with the operational power, a voltage associated with the operational power, and a frequency associated with the operational power; and controlling the switch to limit current through the auxiliary winding based at least in part on the provision of the operational power to the second speed circuit.