| 摘要 |
PURPOSE:To construct a flash control circuit in a small size at a low cost. CONSTITUTION:A series circuitry of zenor diodes 109, 110 is connected between the gate and emitter of an IGBT 3, and a flash start signal TRIG is given directly to the gate of a thyristor 8. The LC resonance frequency determined by the inductance of a coil 108 and the input capacity of the IGBT 3 is made over a certain value necessary for boosting the voltage from the lowest voltage value assumed as a gate drive voltage VGG which can be taken minimally up to the value appropriate to drive the IGBT 3, and is set fixedly. The LC resonance frequency is to monitor the gate drive voltage VGG, and is made over a value necessary for boosting the voltage from the gate drive voltage VGG obtained through monitoring up to the level appropriate to drive the IGBT 3 and is set varyingly. |
