| 摘要 |
PURPOSE:To carry out charging up to a specific voltage and shorten the charg ing time by one time pressing operation of a stroboscope charging switch. CONSTITUTION:A stroboscope charging switch 6 is turned on once and immediately after that, it is turned off. An oscillation transistor 16 starts oscillation by an oscillation transformer 13 and amplifies current from a primary winding 13a. The oscillation transistor is saturated, feedback current from a secondary winding 13c is gone, and current in primary side lowers. Since bias voltage is applied to the oscillation transistor, the transistor is not turned to be in complete off. Primary side current starts flowing again and oscillation is continued. When secondary side current is rectified and a main capacitor 21 is charged up to the specified voltage, current flows in a Zener diode 30 and an oscillation stopping transistor 40 is turned on and no bias voltage is applied to the oscillation transistor, so that the oscillation transistor is turned completely off and a control transistor is also turned off and the oscillation is interrupted and the charging of the main capacitor 21 is stopped. |
