Electronic advice Off Topic I know but yous guys is smart
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.
It is the defrost coil on my freezer. I have had more than one defrost
controller fail. One failed at Christmas and one at Thanksgiving. I
would like to monitor the temperature of the coil using my PC over
time so I can see that the temperature has increased and then
decreased over some time, probably 24 hrs.
When the defrost controller fails, the freezer freezes up over a 2
week period. If I can find a way to verify that the heating element is
heating or not, I can tell if I'm headed for trouble.
This is a 5-year-old Maytag. Expensive, so throwing it out isn't an
option. I just want to see a freeze-up coming. I have a spare
controller. I just need to know when the existing one failed.
I would like to monitor this with a PC input device that can handle an
input of some kind. Like an RTD or even a 120VAC pulse. The controller
switches the element to ground so I'm not sure how to pickup the 120
pulse.
I know you smart guys can come up with something I can use to see that
this dam thing is heating and defrosting the freezer coil.
Thanks Guys,
An initial thought would be a DVM with thermocouple input and RS232
output. These are available relatively cheaply these days. You might
find one with monitoring software or you may have to knock up a simple
app to pick up the data.
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