Browse Prior Art Database

Remote Floating Switch Sensing With High Insulation

IP.com Disclosure Number: IPCOM000101832D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Martin, J: AUTHOR [+2]

Abstract

This article describes a remote floating switch sensing with high insulation designed to be used in a telecommunication environment, as a modem transmitting over a telephone network.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Remote Floating Switch Sensing With High Insulation

       This article describes a remote floating switch sensing
with high insulation designed to be used in a telecommunication
environment, as a modem transmitting over a telephone network.

      It consists in sensing a remote switch, the wires of which are
routed in the telephone line cable attached to the modem. Therefore,
those wires can be submitted to high voltage and must not propagate
it to the modem.

      For that purpose, an insulation transformer has to be used, and
does not allow the sensing SW ON/OFF, DC information.

      The principle of the operation is based on the detection of
impedance variation when the SW is ON or OFF position. The switch
wires are considered as a transmission line.

      A clock is transmitted over the SW wires 3 through the
insulation transformer 1 (5 KV insulation). The output impedance 2 is
at its nominal value when the SW 4 is OFF. It becomes null, when the
SW 4 is ON.

      The signal magnitude at the transformer 1 primary is dependent
on the load Z 2.

      Thus, the switch position information is available at the
transformer primary and can be latched into one flip-flop in order to
be processed by the modem.