Patent ID: 8786231

Claim:
A driving circuit for a single-phase brushless motor, comprising: a driving signal generating circuit configured to generate a driving signal for supplying, to a driving coil of the single-phase brushless motor, a first driving current and a second driving current opposite in direction to the first driving current, in an alternate manner with a de-energized period therebetween during which neither of the first driving current or the second driving current is supplied to the driving coil; an output circuit configured to supply the first or the second driving current to the driving coil in response to the driving signal; and a zero-cross detecting circuit configured to detect a zero cross of an induced voltage, generated across the driving coil, during the de-energized period, the driving signal generating circuit further configured to determine a length of a subsequent energized period, based on a driving cycle from a start of an energized period, during which the output circuit supplies the first or the second driving current to the driving coil, to a time when the zero-cross detecting circuit detects the zero cross, the zero-cross detecting circuit further configured to start detection of the zero cross after a predetermined time period has elapsed from a start of the de-energized period.