| 摘要 |
PURPOSE:To control operation with simple constitution by providing an oscillation maintaining means, holding an oscillation boosting circuit in an operation state, and resetting the operation state during the operation of other photography relative circuits. CONSTITUTION:When a main switch 2 is turned on, a capacitor 11 is charged and a pulse voltage is generated instantaneously across the diode 12. Then a transistor TR 13 is turned on temporarily and turned off immediately. when the TR 13 is turned on, a capacitor 15 begins to be discharged and TRs 24 and 25 and an oscillation TR 18 turn on to start oscillating. Here, the collector current of the TR 18 makes an exciting current flow to auxiliary winding 22 through an oscillation transformer 21. When the winding 22 is saturated, the base current of the TR 24 decreases to turn off the TRs 18, 24, and 25. Then the winding 22 becomes unsaturated, the TRs 18 and 24, and 25 are turned on and this operation is repeated to maintain the oscillation. The signal is outputted during camera photography relative operation to turn on the TR 13, so the oscillation maintaining means is stopped. |
