Browse Prior Art Database

Junctor for Private Branch Exchange

IP.com Disclosure Number: IPCOM000091285D
Original Publication Date: 1967-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Besseyre, J: AUTHOR [+2]

Abstract

The use of modern telephone sets makes desirable some loss insertion on internal links to compensate for the increased emission level of the set.

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Junctor for Private Branch Exchange

The use of modern telephone sets makes desirable some loss insertion on internal links to compensate for the increased emission level of the set.

This is a junctor circuit for internal communications, which allows such a loss insertion.

In this circuit, transistors T1 and T2 allow, when controlled, to provide respectively the two voice half-paths with crosspoint holding current. Transistors T'1 and T'2 allow, when controlled by a common latch L, direct bias of diodes D1 and D2 so that voice signals can flow between extensions A and B.

Resistors R1 and R2 are in series with the voice path and R3 is in parallel. This arrangement constitutes a circuit equivalent to a T-matching attenuator, thus providing the junctor with the desired insertion loss.

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