Browse Prior Art Database

Conference Circuit

IP.com Disclosure Number: IPCOM000091590D
Original Publication Date: 1968-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Garcia, J: AUTHOR [+2]

Abstract

This conference unit, especially applicable to electronic Private Branch Exchanges, allows connection of either five extensions or four extensions and one external line. The unit comprises five input terminals 1...5. Each terminal is connected to a junctor which, in turn, is connected to the PBX switching network. Through the junctor and network, terminals 1...4 can be connected to any extension. Terminal 5 can be connected either to any extension or to any external line.

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Conference Circuit

This conference unit, especially applicable to electronic Private Branch Exchanges, allows connection of either five extensions or four extensions and one external line. The unit comprises five input terminals 1...5. Each terminal is connected to a junctor which, in turn, is connected to the PBX switching network. Through the junctor and network, terminals 1...4 can be connected to any extension. Terminal 5 can be connected either to any extension or to any external line.

A Parallel Negative Resistance Repeater is connected at point A connected between point A and point B, the latter corresponding to terminal 5.

In the idle status, the input lines of the conference units are respectively closed on 300 ohm Line Terminators T1... T5. This avoids oscillations due to parallel repeaters. It is the DC current sent by the junctor which switches off the line terminator corresponding to the line that is to be connected. In this manner, the repeater always sees the same impedance, whatever the number of lines connected on it is.

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