Gte Automatic Electric Incorporated

Gte Communication Systems Corporation

Hugh S Montgomery

Eduard F Boeckmann

Gary Grantland

Larry A Woodworth

Robert D Greaby

A bidirectional amplifier for use in a transmission line, that utilizes a pair of interconnected bridge circuits including isolation transformers and a pair of unidirectional amplifiers. The transmission in each direction uses a single amplifier to amplify the signal for a particular direction of transmission without effecting the other amplifier.

Bidirectional amplifier

In a hold circuit including a silicon controlled rectifier (SCR) normally turned on and connecting the hold circuit to a subscriber line, a first hold release circuit outputs a trigger signal to a transistor turning off the transistor and disconnecting a line seizing network. A second hold release circuit outputs a trigger signal to a second transistor responsive to the line seizing network being disconnected. The second transistor connects a load resistor across the SCR dropping the holding current flowing through the SCR causing it to turn off. The second hold release circuit is also arranged to output its trigger signal to the second transistor responsive to a pre-arranged timing interval.

Electronic hold release circuit

In a hold circuit connectable to a subscriber telephone line, a silicon controlled rectifier is turned on by a user operated momentary pushbutton connecting the positive side of the line to the hold circuit. A comparator circuit sensing the initial value of the loop voltage, turns on a transistor and connects a line seizing network across the subscriber line.

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Huntsville, AL, United States of America

Hugh S Montgomery