| 摘要 |
PURPOSE:To control the finishing voltage within a set range by storing the changing width of the system voltage when the number of working phase advance capacitors are adjusted and multiplying the stored voltage changing width by a prescribed coefficient to decide the prescribed value serving as a standard at the present time point for adjustment of the number of phase advance capacitors. CONSTITUTION:When the detected system voltage V1 is different from the target voltage Vref by an extent larger than the prescribed value, an applying comparator 11 outputs a signal to increase the applying frequency of a phase advance capacitor SC. Thus a sampling/holding circuit 17 fetches the voltage V1 and the 1st and 2nd timers 20 and 21 start the time counting actions. The timer 20 is set in a time-up state when the voltage V1 rises due to increase of the applying frequency of the capacitor SC and instructs a sampling/holding circuit 18 to fetch the coefficient voltage V1. A subtractor 22 calculates the output difference between both circuits 17 and 18 and instructs a 3rd sampling/holding circuit 19 to fetch the output difference. Then the subtractors 23 and 24 add and subtract the output difference to and from the voltage Vref for generation of the removing/applying reference voltage. Thus it is possible to secure coincidence between the finishing voltage and the voltage Vref despite the change of the system impedance. |
