I am looking for a design to build a control for my really old hot tub. Currently I switch it manually monitoring the temp but due to inattention, frequently over heat it, which causes the wife to overheat. I would like to have two modes, a "maintianing" function which would not allow the temp to drop below a certian level, say 65 F, and an "operating" mode which would bring the temp up to about 103 F and hold it there plus or minus a half degree. I would like to be able to change those values as the season requires. Am currently using a cheap inside outside temp monitor with the probe (thermistor) mounted in a wet well in the out line from the heater. I would like to incorporate a temp display in the new design to simplify the set up. Any help or links would be appreciated.
Jeff
Jeff
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