Automatic switching-back device for telephone circuit
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United States of America Patent
Stats
-
Jun 28, 1994
Grant Date -
N/A
app pub date -
Dec 31, 1991
filing date -
May 2, 1990
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
The communication carried out by an auxiliary terminal machine (AUX) utilizes audio signal wires picked up out of an 8-circuit and 6-contact switch (SW) or an 8-circuit and 3-contact switch (SW). An automatic switching circuit (SS), connected to the audio signal wires containing alternating current and separated from the audio signal wires with direct current, serves to detect the termination of the auxiliary terminal machine and switch back to the normal phone. The energy-saving exchanger supplying only alternating current is allowed to be connected to the auxiliary terminal machine for performing a communication function and then automatically switches back to the normal phone connection when the auxiliary terminal machine terminates the communication.
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Family
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Cited Art Landscape
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