| 摘要 |
PURPOSE:To operate a community antenna television (CATV) transmission circuit efficiently by providing two switches in a breaking device, breaking current at the time of short circuit accident, and resuming supply of current automatically immediately after removing of the cause of accident. CONSTITUTION:A breaking device 10 for power source current is provided between a coaxial cable 2 and a power supply device 7. The device 10 provided a switch 15 inserted linearly between the cable 2 and the device 7, and a power source current detecting section 16. Further, the device 10 is provided a power source circuit 17 for retrieving connected to the cable 2 through a retrieving current detecting section 18 to allow supplying of retrieving current weaker than allowable current of the cable 2 and an amplifier 3. The device 10 inputs detected current value of the detecting sections 16, 18, and when the detected current value of power source current is greater than allowable current value, opens the switch 15 and closes a switch 19. When retrieving current becomes lower than the allowable current value, the device 10 opens the switch 15 and closes the switch 19. |
