Capacitor charging device for a flash

摘要

A capacitor charging device for a flash, finishes charging the flash capacitor in a gradual manner. It has a flash capacitor, a voltage transforming circuit, a voltage mode pulse width modulation (PWM) control circuit and a charging control circuit. The charging control circuit has a time control capacitor to make the pulse width of the pulse voltage output from the voltage mode PWM control circuit increase gradually. The voltage transforming circuit is driven to provide a gradually increasing induced current to the flash capacitor to reduce the damage of the external circuit, flash capacitor and rechargeable battery.