DEVICE FOR THE DETECTION OF AN ANGLE OF ROTATION OF A BRUSHLESS MULTI-PHASE D.C. MOTOR

摘要

The device detects an 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. In operation electric drive signals are applied to the windings in order to drive the rotor. The device includes drive means for applying pulse-shaped electric test signals to the windings while the rotor does not rotate. The device further includes a measurement circuit for detecting flyback pulses generated by the motor in response to the test signals. The device further has a processing unit which processes the durations of the detected flyback pulses in combination in order to determine said angle of rotation. On the basis of the angle of rotation thus determined the motor can be started in such a manner that the rotor is set into rotation in a predetermined direction of rotation.