| 摘要 |
PURPOSE:To eliminate problem of heating and to reduce the capacity of hold power supply and power consumption by removing pulsating reactive power, to be fed from a hold circuit during OFF interval of a chopper transistor, while employing a DC power supply hold circuit. CONSTITUTION:When a driving signal DRV has Low level, a hold circuit 40 is connected with a hold power supply. When the driving signal DRV goes High, a transistor 52 is turned OFF whereas a chopper transistor 32 is turned ON to feed a driving current I32 quickly to a phase winding 21A. Consequently, a feedback signal (f) increases and when it exceeds a reference voltage in a chopper circuit 31, the transistor 32 is turned OFF. At this time, a current I38 flows through a diode 38 into the phase winding 21A. But a high pulsating current Ih' does not flow into the phase winding 21A from the hold power supply even if a negative voltage appears at point P. |
