| 摘要 |
A circuit for determining a direction of rotation of an electric motor, the motor having asymmetry and/or eccentricity in a profile of back electromotive force as a function of angular position of a rotor with respect to a stator, the circuit receiving a signal representing the BEMF, and use the corresponding asymmetry and/or eccentricity in the signal to derive the direction of rotation. The signal representing the back emf can be generated by a control circuit. The control circuit can have a feedback loop regulator to generate a control signal (TL or TR) to control a current drive circuit ( 11,12 ) to control an amplitude of current (i<SUB>w</SUB>) in the windings, the feedback loop regulator being arranged to compare the amplitude of the current (i<SUB>w</SUB>) in the windings with a reference value (i<SUB>set</SUB>), and use the control signal to provide the signal representing the back electromotive force.
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