U.S. Philips Corporation

Catharinus T Galema

Henricus M Van Hout

A device which detects the angle of rotation of a rotor with respect to a stator of a brushless multi-phase d.c. motor. The rotor comprises a permanent magnet and the stator comprises a plurality of electrical windings. Electric drive signals are applied to the windings in order to drive the rotor. The device includes a drive circuit for applying pulse-shaped electric test signals to the windings while the rotor does not rotate. A measurement circuit detects flyback pulses generated by the motor in response to the test signals. A processing unit processes the durations of the detected flyback pulses in combination in order to determine the angle of rotation. On the basis of the angle of rotation thus determined, the motor can be started such that the rotor is set into rotation in a predetermined direction of rotation.

Growing community of inventors

Eindhoven, Netherlands

Catharinus T Galema