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From: uchuck@uncmed.med.unc.edu
Newsgroups: sci.electronics
Subject: PC Power ON/OFF Scheme
Message-ID: <334@uncmed.med.unc.edu>
Date: 9 Jul 90 21:20:10 GMT
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Reply-To: uchuck@uncmed.med.unc.edu ()
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Organization: UNC-CH School of Medicine
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Gentlemen,
I have devised a scheme using a high current capacity relay and a couple
of small control relays that will allow me to power up or down my PC
system and peripherals simultaneously.  The design includes a power fault
- no power back up feature so that the machine does not try to go through
power up/down sequences that are not purposeful.  In addition, by the use
of a DPDT main relay with the PC and its peripherals on the moving
contacts and the power line on the normally open contacts, I had the idea
of connecting the normally closed contacts together and then to ground in
the hopes of preventing any lightning hits getting to the PC.

Now, I begin to wonder... What is the effect of shorting the power
cord(s) of the PC and associated equipment together and to ground, even
under normal (read operator induced) conditions????  Can anyone think why
this might be a problem??

Chuck Bennett