| 摘要 |
An I.G.B.T. (Insulated Gate Bipolar Transistor) driven electronic flash unit includes a control switch for controlling an off-operation of the I.G.B.T. The control switch has a first terminal for receiving a light-emission stopping command of a very short pulse width, a second terminal supplied with a collector electrode voltage of the I.G.B.T. connected in series with a flash tube, third and fourth terminals respectively connected with gate and emitter electrodes of the I.G.B.T., which short-circuits the third and fourth terminals upon receiving the light-emission stopping command at the first terminal, and maintains the short-circuit operation as long as it receives the collector electrode voltage of the I.G.B.T. at the second terminal. |
