| 摘要 |
PURPOSE:To improve a transient response by smoothing the output voltage of a rectifier by an integrated circuit, converting the smoothed output to a digital data, generating a trigger pulse in accordance with the digital data, and controlling the connection angle of a thyristor. CONSTITUTION:A voltage applied to both the ends of an exposing lamp 4 is detected by a feedback transformer 23 and converted into a DC voltage by an integrated circuit 25 consisting of a rectifier 24, a capacitor C2 and a resistor R6 connected to the capacitor C2 in series. Then, the DC voltage is sent to an A/D converter 29 and converted into digital data, which are sent to a microcomputer 31. The microcomputer 31 calculates a difference value between the level of input data and the level of reference data corresponding to the setting of exposure and drives its internal timer function in accordance with a value obtained by dividing the difference value by 2 and H to generate a trigger pulse. The voltage applied to both the ends of the lamp 4 is controlled by controlling the connection angle of the thyristor 22 on the basis of the trigger pulse. |
