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Path: utzoo!watmath!clyde!burl!ulysses!allegra!alice!jj
From: jj@alice.UUCP
Newsgroups: net.analog
Subject: Re: AC current monitor
Message-ID: <3484@alice.UUCP>
Date: Fri, 22-Mar-85 16:46:19 EST
Article-I.D.: alice.3484
Posted: Fri Mar 22 16:46:19 1985
Date-Received: Sat, 23-Mar-85 04:07:23 EST
References: <5139@fortune.UUCP>
Organization: New Jersey State Farm for the Terminally Bewildered
Lines: 20


It's not necessary to have any connection at all.

You can wrap a few turns on a small core (ferrite) that's been sliced
in half, and then glue it back together around ONE of the conductors
in the wire.  It varies as to what voltage you get, but it's usually
well within what any grunge op-amp can amplify to a big enough
signal to rectify and drive a schmidt trigger.  You want to put a pair of
diodes across the coil, and a fairly large resistor in series
with in (and then take the signal across the diodes).

I really don't have time to draw it out, but the problem is
conventional and fairly easily solved...

JJ
-- 
TEDDY BEARS NEED SECURITY BLANKETS ONCE IN A WHILE!

"... John?  Who'd of thought it! ..."
(allegra,harpo,ulysses)!alice!jj