| 摘要 |
PURPOSE:To enhance the interchangeability and universality of the strobe device by incorporating a polarity inversion circuit for light emission stop signal or amplifier circuit for the same and applying the light emission stop signal from the camera to the auto strobe device in an optimum state. CONSTITUTION:When the reflected light from the subject by light emission of a discharge tube L becomes an optimum value, the light emission stop signal of negative polarity from the photometric control circuit Ex of the camera is applied to the base of a transistor TR via terminals t03, T03 and resistance R7 to turn ON the TR. As a result a thyristor SCR4 goes ON as its cathode becomes potential of -B lower than the gate potential, then the charged charge of a capacitor C8 discharges through SCR4, diode D2 and resistance R11, and therefore a pulse of positive polarity is produced across the resistor R11. This becomes the light emission stop signal of positive polarity and reverse biases the SCR1 through the light emistion stop terminal t3 of the auto strobe device and therefore the discharge tube L immediately stops the light emission. Thereby, the interchangeability and universality of the strobe device are enhanced. |
