| 摘要 |
PURPOSE:To fully automatize an existing video broadcast common listening device with a simple work, by superimposing a video signal and an operating current for power supply switching of a video device on one coaxial cable. CONSTITUTION:An existing video broadcast common listening device consists of a video device 1, mixer 9, amplifier 15, distributor 24, coin timer 33, brancher 39 and television 44. To fully automize them, a video signal and an operating current for power supply switching of a video device 1 are superimposed on a coaxial cable 2 connecting each device and at each device, the superimposition is separated as required. Thus, the video device 1 is brought into operation fully automatically by only depositing a coin to the timer 33. The operating current for video device power supply switching is superimposed on the coaxial cable, then no control wire is provided additionally and fully automation is achieved with a simple work. |
