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I figured a little coil for current pickup on
the power line into a comparator, then a relay, but I was hoping for a simpler
solution.
Thanks.
----- Original Message -----
Sent: Saturday, August 30, 2003 5:34
PM
Subject: Re: Current Draw Activated
Switch
I have something like this, but to bring it to the surface
could take hours
and still I don't remember the details.
Why don't you
try and pick up the 15kHz with some microphone OP and filter,
a comparator,
I think this would do the trick without lot's of
problems.
Friedel
At 12:34 30/08/03 -0800, you wrote:
I need to
turn on a couple of small security monitors when a TV is turned on. In
the past, they made a gizmo for the early personal computers that turned on
the monitor, printer, etc. when the computer was turned on by sensing the
current being drawn by the computer. I have not seen them for
years.
It would be trivial to
open the TV and find some voltage in there only present when it is on and
let it activate a relay, but when the TV dies, I would have to go through
the procedure again. A universal device with a plug-in for the TV
would be nicer, and would not require cracking open the TV. I think
modern TVs draw a little line current all the time, so this thing would have
to distinguish between a fraction of an amp, and the higher draw when the TV
is actually on.
Any suggestions
for a simple circuit? Or is there a commercial product that will do
the job?
Thanks in
advance.
Syd H. Levine
AnaLog
Services, Inc.
Phone: 270-276-5671
Telefax:
270-276-5588
E-mail: [EMAIL PROTECTED]
URL: www.logwell.com
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