| 摘要 |
PURPOSE: To prevent the drop of a battery voltage while shortening the charging time. CONSTITUTION: A switch element such as FET 12 or 14 is provided on the primary coil side circuit C1 of a booster transformer 10, and a secondary current is induced in the secondary coil side circuit C2 by its ON/OFF to charge a main capacitor 20. When a battery voltage Vp is low, a CPU 26 sets the ON- time of the switch element shorter than in the case of a high battery voltage Vp, whereby the sudden drop of the battery voltage Vp is prevented. When the charging voltage Vc of the main capacitor 20 is high even with a low battery voltage Vp, the ON-time of the switching element is set longer than in the case of a low charging voltage Vc to shorten the charging time. |
