Browse Prior Art Database

Solid State Connecting Arrangement

IP.com Disclosure Number: IPCOM000079695D
Original Publication Date: 1973-Aug-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Glowienka, CB: AUTHOR

Abstract

This circuit provides a means to control the connecting and disconnecting of a device other than a telephone to a telephone extension line, where the device takes its power from the extension line. A means is provided to assure that the correct polarity exists at the device when a connection is made. The extension line voltage may be of either polarity.

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Solid State Connecting Arrangement

This circuit provides a means to control the connecting and disconnecting of a device other than a telephone to a telephone extension line, where the device takes its power from the extension line. A means is provided to assure that the correct polarity exists at the device when a connection is made. The extension line voltage may be of either polarity.

An example of such a device is a data terminal 10, that provides multifrequency tone signals in the voice frequency band in an end-to-end signalling system.

Diodes D1 through D4 form a bridge rectifier, which assures that a fixed polarity is provided for the Q1, R1, Q2 connecting network and the device to be connected.

A positive signal from the multifrequency generator (MFG) control logic turns transistor Q1 ON, which supplies base current to Q2 turning it ON. With Q2 ON, the MFG is connected across the line.

The breakdown voltage rating BV(CEO) of Q1 and Q2 exceed peak ring voltage or the operating line voltage, whichever is greater.

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