Hello, Syd!!!! here is...
----------->A reply from ELAL<---------
On a nice Sunday (31-Aug-2003 to be precise) I got a message like this:
S\> I figured a little coil for current pickup on the power line into a
S\> comparator, then a relay, but I was hoping for a simpler solution.
You're already in the <10 component count region, simpification beyond this is
futile :-/
But... if you insist:
Drop the current transformer idea.
You're measuring mains power, switching mains power en most likely use mains power to
supply the circuit. You'll have to build the entire circuit to mains powered equipment
safety standards, anyway. Who cares if your comparator power rails are floating at
mains voltages, then?
I'd use a 3.3ohm/5W series resistor with two antiparallel diodes (1N400x or 1N540x) in
parallel to measure the current.
It's nice & linear around the swithing threshold (and a low-impedance >100mV signal ->
noise immunity) yet a <1V voltage drop at high currents.
Just my 2 cents
--
-� A fail-safe circuit will destroy others.
-Klipstein's 4th Law of Prototyping and Production�-
--
Author: Ferry Schouten
INET: [EMAIL PROTECTED]
Fat City Network Services -- 858-538-5051 http://www.fatcity.com
San Diego, California -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB CHIPDIR-L
(or the name of mailing list you want to be removed from). You may
also send the HELP command for other information (like subscribing).
