AUTOMATIC OUTGOING CIRCUIT

摘要

PURPOSE:To attain the connection to a telephone circuit without using any special parts nor identifying the circuit polarity by detecting the answer of the remote side from the variation of output of a current detecting means after a selection signal is transmitted. CONSTITUTION:In an automatic outgoing mode, when it is detected by the output of a current direction detecting means 40 that no current is flowed. The the circuit at the side of a telephone 22 is switched toward a selection signal transmission means 24 in a state where the means 24 is released in terms of DC. While it is confirmed for a prescribed period of time by the output of a current direction detecting means 60 that no polarity is inverted by the output of a call signal means 24 that no call signal arrives. Then a switch means 70 is actuated to close the means 24 in terms of DC, and the output of the means 40 is stored. The means 24 outputs a selection signal. Then the answer of the remote side is detected from the variation of the output of the means 40 after transmission of the selection of signal.