| 摘要 |
<p>A torque direction detecting device for an electric motor includes a resolver which provides a pair of a sin theta signal and a cos theta signal with theta changing from 0 degree to 360 degrees in electric angle according to rotation of the brushless motor, a circuit which calculates an electric angle of the brushless motor from the sin theta signal and the cos theta signal, a current sensor for detecting phase current flowing through the phase windings, a circuit which provides a signal if the phase currents is in a prescribed magnitude relation, a circuit which divides a period of the 360 degree-electric angle into 8 timing sections according to magnitude relation between the sin theta signal and the cos theta signal and comparison of the sin theta signal and the cos theta signal with 0, and a circuit which determines a torque direction of the brushless motor if the comparison signal is provided in one of prescribed two timing sections each of which has a specific combination of the magnitude relation and the comparison of the sin theta signal and the cos theta signal.</p> |
