| 摘要 |
PURPOSE:To realize a titled device which has a large dielectric strength and is hardly affected by surges, by providing the power supply line and signal coupling line in parallel with each other and by transmitting and receiving signals through their mutual induction. CONSTITUTION:A 4-core cable 16 is used and two cores 16a and 16b among the four cores are used as power supply lines. Transmission and reception of signals are performed through the remaining two cores 16c and 16d. That is, two mid- points of a switch 11 are connected to one end of the lines 16c and 16d, respectively, through a band-pass filter 12 and the terminal of the power source side of the lines 16c and 16d are short-circuited. When the cable 16 is provided to have a length of more than a prescribed length under such a condition, signals are transmitted to distribution lines through the mutual induction between the power supply lines 16a and 16b and the signal coupling lines 16c and 16d. Therefore, when a pair of communication devices are connected to a plug socket, communication can be performed. Since no couplers, such as capacitor, etc., are used, this communication device has a large dielectric strength and is hardly affected by surges. |
