| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit for preventing ADSL communication failure for preventing communication failure caused by a plurality of filter elements connected with the identical line for the purpose of using a plurality of telephone terminals. SOLUTION: The circuit is provided with filter elements F1, F2 for demultiplexing or halting ADSL communication signals, to output the signals to the telephone terminals and bridge rectifiers DB1, DB2 between telephone lines L1, L2. Closing/opening of the outputs of the bridge rectifiers DB1, DB2 are controlled by control circuits 22, 24. The control circuits 22, 24 close the outputs of the bridge rectifiers DB1, DB2, in response to a no-load line voltage, to connect the telephone lines L1, L2 and the filter elements F1, F2 with each other. When one of a plurality of the telephone terminals provided becomes in-use state, a control circuit provided in the other telephone terminal in no-use state opens the bridge rectifier in the other the telephone terminal by means of variation in line voltages L1, L2, thus preventing the communication failure from occurring. COPYRIGHT: (C)2005,JPO&NCIPI
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