摘要 |
A driving circuit for a brushless motor includes a current sensor for detecting alternating phase-current flowing in one of the phase coils, a switching driver for supplying each phase-coil with prescribed alternating phase-current, a reference value setting circuit which provides a reference value which changes in synchronism with the prescribed phase-current to be larger than the same and an abnormality determining circuit which determines abnormality if the current detected by the current sensor is larger than the reference value.
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