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Subject: Re: Automatic ON Switch Citcuit

Date: 05/16/00 at 6:33 PM
Posted by: Doug Neville
E-mail: dsn@earthlink.net
Message Posted:

In Reply to: Re: Automatic ON Switch Citcuit posted by Vorel on 05/16/00 at 1:55 PM:

Thanks for the reply. Actually, after I posted this message I did a search on the Web to see if I could come up with
some ideas for this project. One of the first things I came up with was a datasheet for a 555 timer.

Using the information in the datasheet, I designed a circuit using 2 555 timers and 3 relays (and of course the various
capacitors and resistors required in connection with that type of circuit.) After playing around with it for a while, I got a
working circuit that does exactly what I was trying to accomplish. I used 2 relays to momentarily trigger the first 555 timer,
which creates a 10 second delay. After the 10 second delay, the first 555 timer then triggers the second 555 timer, which
has its output connected to the third relay (which is a simple normally-open reed relay connected to the ON/OFF switch
on the monitor.) Once triggered, the second 555 activates the reed relay for about 1/2 second, thereby closing the ON/OFF
switch circuit for that amount of time and turning on the monitor. This circuit probably could be simpler, but I don't have
much experience in electronics, so this was the simplest thing I could come up with.

Anyway, thanks again for the response. This turned out to be a fun little project...and best of all, one that worked! :)

Thanks again,

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