Browse Prior Art Database

Automatic Matching Impedance Remote Loop Circuit

IP.com Disclosure Number: IPCOM000106363D
Original Publication Date: 1993-Oct-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 4 page(s) / 76K

Publishing Venue

IBM

Related People

Albano, A: AUTHOR [+3]

Abstract

The problem is to simulate an alive PBX G.703 interface or terminal G.703 interface while it is temporarily powered-off, for PTT personnel convenience.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 59% of the total text.

Automatic Matching Impedance Remote Loop Circuit

      The problem is to simulate an alive PBX G.703 interface or
terminal G.703 interface while it is temporarily powered-off, for PTT
personnel convenience.

      G.703/ G.704 networks are usually made of PBXs
(private/customer side) and CX (PTT side) which are always powered-on
and where links are always activated.  The CX checks about each 20 mn
that the line is still alive.  The network trend shows-up that
application using stand-alone terminal (ex : PS/2 ) can be used by
customers.  These small equipments can be switched-off at any times.
From PTT point of view, if the link is interrupted it generates an
alarm, and often requires PTT agent investigation

      The following schematics show an implementation that solve this
problem.  When on disappearance of power supply on the product a
remote loop is performed by relay contacts toward the network in
order to simulate for the Network interface an alive interface.

      Fig. 1 is an abstact of a G.703 design interface using a
SIEMENS PEB-2235 G.703 TRANSCEIVER chip set (referenced transceiver)
and a 8 contacts relay labelled RR.

      When the interface is powered-on the relay RR is activated.
Con tacts 1C to 7C are set in such way that the Primary windings of
the transformer T2 (t11 and t12), are placed in series, so that T2
ratio is 1:1.  And, transmit transformer T1 has its windings t11 and
t12 in paral lel, so that T1 ratio is 1:2 (Fig. 2)....