| 摘要 |
<p>A device for activating an electronic slave flash unit for photographic use includes a circuit wherein there is a delay circuit (33a) responsive to a light sensing signal from sensor 25 after a predetermined time delay to activate a flash unit connected at 55. The time delay of the delay circuit is adjustable as required, and the delayed operation of the flash of the slave flash unit eliminates incorrect impulse signals being transmitted to light sensors of other slave flash units which would otherwise prematurely extinguish their flash and give a resultant incorrect lighting effect. The power for the circuit is obtained from a capacitor (33) which is energized by the flash unit. The energy in the capacitor is used to power the delay circuit, and a Zener diode (36), a unijunction transistor (37), variable resistances (45-49) and a capacitor 43 permit accurate variable time delays. <IMAGE></p> |
