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Power Down Interlock for Personal Computers

IP.com Disclosure Number: IPCOM000110625D
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Klim, P: AUTHOR

Abstract

Disclosed is a circuit including an interlock switch for automatically shutting off electrical power in a personal computer when a system cover is removed, together with a momentary interlock override to be engaged by a service person for troubleshooting.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 87% of the total text.

Power Down Interlock for Personal Computers

       Disclosed is a circuit including an interlock switch for
automatically shutting off electrical power in a personal computer
when a system cover is removed, together with a momentary interlock
override to be engaged by a service person for troubleshooting.

      A personal computer within a system enclosure 10 includes a
circuit 12 extending between a terminal 14, on which AC power is
present, typically from a line cord, and a terminal 16, at which
electrical power enters the system through a power supply.  Terminal
14 is electrically tied to a main power switch 18, which is operated
by a lever 20 to turn power off and on in the system.  Main power
switch 18 is, in turn, wired to an interlock switch 22, which is held
closed by cover 10.

      Opening or removing cover 10 causes interlock switch 22 to
open, so that electrical power is removed from terminal 16, and hence
from the system.  This helps assure that cards and other circuits
which must be installed within cover 10 will be installed with
electrical power off.  Closing or reinstalling cover 10 causes
interlock switch 22 to close, so that operation of the system can
resume.

      It is sometimes desirable for service personnel to operate a
system of this kind with the cover opened or removed.  To make this
possible, a momentary interlock override switch 24 is provided, wired
in a parallel manner across interlock switch 22.

      Interlock ...