"Winston" wrote in message
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jLsj.4753$rh.1058@trnddc02...
Dan wrote:
I know this is off topic, but I know some of you know the answer. I need
to monitor the temperature of a heating element. I need to know
when it is on and when it is off. I don't need to know the
temperature, just that when it is getting hot and when it is not hot.
(...)
http://www.amveco.com/pdf/AC1020_11-01.pdf
http://rocky.digikey.com/WebLib/Amve...15,AC-1020.jpg
This is Digikey TE-1020-ND, a current transformer. Its small and will fit
within a 1" cube.
Disconnect the defrost heater and thread its wire through the hole in the
middle of this part, then reconnect it. Solder a 100 ohm 1/8W resistor
across the output of the transformer. Every amp flowing into your defrost
heater will now be indicated by a voltage of about 0.1V AC at the output
of the transformer, across the resistor.
Connect one of these loggers (US$25.00)to the output of your current
transformer and log the data to your PC.
http://www.dataq.com/products/startkit/di194rs.htm
That's what I would do.
That's what I would do also. Or you could find a toriod choke coil and do
the same. It could even light a LED for direct visual indication.
Tom