| 摘要 |
PURPOSE:To reduce charging rush current in a flash lamp power source device for photoreceptor exposure or toner fixing by conducting and energizing a controllable switching element while a main capacitor is charged up to a specified voltage. CONSTITUTION:When the voltage of a capaictor 3 is dropped by discharging through resistances 81 thru 83, the voltage drop of the resistance 83 becomes low and therefore a light emitting diode 8 emits light and a controllable switching element 7 conducts, thus charging a main capacitor 3. Hence, the charging voltage of the main capacitor 3 is maintained at a constant voltage as far as an Ac input AC is being applied. When a discharging trigger switch 5 is closed and a flash lamp 4 discharges and emits light, the controllable switching element 7 conducts and the voltage of the main capacitor 3 rises stepwise. When the AC input AC is cut off, the main capacitor 33 and the capacitors 6C1 thru 612 of a voltage doubler circuit 6 discharge to an earth level. Hence, each capacitor lowers automatically to the earth level at the cut off of AC input. |
