| 摘要 |
PURPOSE:To suppress supersaturation of output transistor groups and to minimize power consumption, by setting a constant in charging an integrating circuit to integrate the operating voltage across a collector and an emitter of output thyristor groups larger than a constant in discharging the integrating circuit. CONSTITUTION:Collector current flows to a collector of a detecting transistor 14 in accordance with the voltage across the collector and emitter of output transistor groups 6a-6c to feed stator coils 10a-10c. An integrating capacitor 23 is charged through a charging resistance 21 or discharged through a discharging resistance 22 in accordance with the collector current of the detecting transistor 14. A comparator 25 controls the output voltage of a voltage conversion circuit 9 in accordance with the comparison result between the voltage across the integrating capacitor 23 and the triangular wave. Here, the charging resistance 21 is set so larger than the discharging resistance 22 that the response to the sudden change of load is expedited. |
