| 摘要 |
PURPOSE:To prevent a voltage control type switching element from being damaged without requiring a special circuit detecting the bias voltage of the voltage control type switching element. CONSTITUTION:This device is provided with a booster power source circuit 1, a main capacitor C1 charged by the output of the booster power source circuit 1, a flash discharge tube X1 connected in parallel with the main capacitor, a light quantity controlling circuit controlling flash emitting action and having the voltage control type switching element 2 connected in series to the flash discharge tube, a trigger circuit 3 having trigger capacitor to make the flash discharge tube start the flash emitting action, a Zener diode ZD1 by which the bias voltage is impressed on the voltage control type switching element 2, and a light emitting permitting means 4 permitting the light emitting action by the trigger signal based on a Zener current Iz flowing in the Zener diode when the trigger signal TRG from a trigger signal generating means 5 is received. |
