A sensorless-type brushless motor equipped with a rotor having a plurality of magnet poles and a stator having a plurality of multi-phase drive coils to generate a rotational torque with respect to the rotor. The motor is arranged to be controllable by a control circuit arrangement which includes a drive...http://www.google.ca/patents/US5036264?utm_source=gb-gplus-sharePatent US5036264 - Brushless motor with no rotor-position sensor
