| 摘要 |
PURPOSE: A home equipment connection circuit using an exchange and its control method are provided to connect the home equipment or an interphone etc. to PSTN and the other home equipment within an apartment by using an exchange, thereby providing a communication service. CONSTITUTION: A polarity sensing unit(10) senses the polarity of an exchange. A tone/loop sensing unit(20) senses the change of a tone and loop of a home equipment. A relay(30) connects a switch terminal to the exchange or PSTN(Public Switched Transmission Network) by a control signal. A selection control unit(40) controls the relay according to the sensing signal outputted from the polarity sensing unit(10) or the tone/loop sensing unit(20) and then connects the home equipment etc. to the PSTN or exchange.
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