| 摘要 |
PROBLEM TO BE SOLVED: To prevent step-out due to load fluctuation or the like in a sensorless and brushless motor. SOLUTION: Induction voltage generated in the stator coil of the brushless motor 1 is input to a sensor signal generation circuit 7, and the sensor signal of the brushless motor is output to a PWM circuit 4 controlling the motor through a delay circuit 18, a sensor signal changeover logic circuit 8 and a motor communicating control circuit. A signal lengthening the delay time of a sensor signal in response to the increase of detection current by a current detection circuit 19 for detecting current flowing in the brushless motor is output from a delay time regulation circuit 20 to the delay circuit. Even when the sensor signal has an excessive advance angle due to load increase, the motor can be stably driven because a delay angle is corrected without step-out up to high load. |
