| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic flash apparatus which copes with variation of a battery internal resistance depending on exhaustion of a battery or temperature, does not cause an excessive current, and is driven by proper drive pulses. SOLUTION: The electronic flash apparatus comprises a main capacitor, an active type DC/DC converter, and a battery voltage detection circuit which detects a battery voltage under both no load and a load. It also comprises a control circuit as well as a pulse control circuit which determines a pulse width based on the battery state detected by the battery voltage detection circuit just before the DC/DC converter starts to operate which charges the main capacitor. COPYRIGHT: (C)2004,JPO |
