A method for determining a rotor position in a DC motor having a plurality of windings, including a rotor winding and a plurality of stator windings begins with producing a changing current flow in a pulsed winding to induce a response signal in other windings of the motor. The pulsed winding may be...http://www.google.co.uk/patents/US7072778?utm_source=gb-gplus-sharePatent US7072778 - Method and system for determining a rotor position in a wound field DC motor
