| 摘要 |
1,229,719. Supply systems for strobe flash apparatus. GRAFLEX Inc. 11 Dec., 1969 [6 Jan., 1969], No. 60537/69. Heading H2H. [Also in Divisions G3 and H3] A strobe flash system comprises a push-pull, saturable core, transistor oscillator driven by a battery and operable to charge a storage capacitor through a rectifier. When a certain charge on the capacitor is reached, a switch is actuated to squelch the oscillator by removing bias from its transistors and by shorting a winding of its output transformer. In the circuit shown, storage capacitor 12 is charged through oscillator 10 by battery 11. The transformer 15 of the oscillator produces an approximate square wave output. When a predetermined charge is reached, a neon lamp 25 breaks down and switches on transistors 27, 28 so that a relay 21 is energized. The contact 24 is moved to its normally open position 23 so that forward bias for transistors 13, 14 is removed from resistors 17, 18, and a feedback winding 15c of the transformer 15 is short-circuited. Oscillations thus cease very rapidly and further charging of capacitor 12 is prevented. After discharge of the capacitor, or leakage down to 85-95% of full charge, the lamp 25 will extinguish and reset the relay 21 so that a further charging operation can take place. |
