| 摘要 |
PURPOSE:To minimize the influence of a short-circuit accident in the output-side line by connecting the output of a photo coupler to a pulse amplifier circuit, which is operated by a DC constant voltage power source with backup battery, and by connecting a Zener diode between output terminals of the pulse amplifier circuit. CONSTITUTION:Photo coupler 1 is inserted into a long distance transmission line, and a DC pulse signal is inputted. The output of coupler 1 is connected to pulse amplifier circuit 3 operated by DC constant voltage power source 2 with backup battery, and Zener diode Z is connected between output terminals of circuit 3. As a result, coupler 1 is used to insulate electrically input line l1 and output-side line l2 from each other, so that the influence of a short-circuit accident in output-side line l2 can be minimized. |
