| 摘要 |
PURPOSE:To change an electronic flash circuit with electricity by utilizing a self-timer period by providing an electronic flash charging control circuit which commands the charging of the electronic flash circuit during self-timer circuit operation. CONSTITUTION:When a self-timer switch 8 is closed, an RS flip-flop 1, a binary counter 13, and an OR gate 14 constitute a self-timer circuit and the binary counter 13, an AND gate 16, and a NOR gate 17 constitute the electronic flash charging control circuit. Consequently, the electronic flash charging operation is performed during the self-timer period, so the circuit is precharged during self-timer operation suitable to an electronic flash automatic lighting system. Further, actual self-timer seconds never become longer than set self-timer seconds and its variance is eliminated, so an invariably constant self-timer wait time is obtained.
|
