PURPOSE: To reduce wiring by providing a receiving means which superposes a channel selecting address signal onto a low-power AC power supply line to report that a channel corresponding to its own address is called.
CONSTITUTION: A carrier wave controlling unit 12 is provided for the low-power AC power supply line and communication lines 11. A power supply part 25 rectifies the AC of said power supply line. A zero crossing pulse is generated and is outputted to a logic control part 22 for timing of transmission and reception. A coupling circuit 26 has a high frequency oscillating part 27 and a switch circuit 28 and outputs a high frequency between terminals (a) and (b). High frequency components transmitted on these lines 11 are detected and are inputted to the logic control part 22. A selecting address is set by a channel setting part 29, and this set data and data of a received channel selecting address signal are compared with each other in a logic control circuit part 24 and a relay driving circuit part 25 are driven to switch communication lines by a changeover switch 13.
KOJIMA YUTAKA
TOGAWA HIDEO
ISOBE YOUICHI
HISAMATSU NOBUO
| JPS54144109A | 1979-11-10 |
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