/diy/ - Do It Yourself

>>1508097
>should include simple electronics that don't belong in /ohm/

this meets that definition. My hot plate on the lowest setting, when the kitchen is chilly, will burn my sardines if I don't stand there and tend to them which is hard to do when the party is raging in the other room.

So this circuit maintains the set temperature no matter what the ambient is. That grey blob over at the right is an LM35 temperature sensor coated with JB Weld epoxy, and it gets placed down in the pan with the sardines or whatever. The circuit is a simple LM339 comparator with hysteresis that drives the solid state relay, which is rated at 25 amps and easily handles the hot plate 8 amps. Might need some heat sinkage when summer rolls around, but it doesn't even get warm now. The tiny pot on the board can adjust the temperature from about 120 F up to about 170 F, I think. The range was chosen so I can keep the food warm without actually cooking it.