Digital Display Microcomputer Thermostat Temperature Controller Switch Temperature Sensor Microcomputer Thermostat for Air Conditioning System DC12V

As a test, I put together a prototype wine cooler. I used an old 12V Coleman picnic cooler. The wall plug power supply is 5 amps. Typical thermoelectric cooler. A Peltier element and a heatsink. A small fan is the only moving part.This cooler is well sealed, and normally cools things down to about 40F, which is too cold for wine.First I hooked the + and - power supply wires to this temperature controller, just to power it up. (The cooler is not yet plugged in.) The display lit up. The top number is the probe's current temperature. The bottom number is the temperature you want things to be. The factory setting is to Cool (rather than to Heat), to a target temperature of 68F. I needed to lower that number to 55F.After reading the poor instructions several times, messing around and pressing buttons, getting familiar with it, the bottom number started flashing. It was ready to be adjusted. I lowered it to 55F, just like you'd adjust the time on a digital clock.Then I plugged in the cooler, fully expecting this controller to smoke and fry.... But the cooler's fan just started spinning. We're in business.I got a digital thermometer and taped its probe to the controller's probe, as a double-check of the function and accuracy. Put the probes into the cooler. It started cooling, and the temperature slowly fell. (The two probes temp readings were within a degree (F) of each other throughout the process.)After about 30 minutes... 55.4.. 55.3.. 55.2... 55.1... 55. And boom... The cooler fan shut off exactly at 55.In a couple minutes the temperature rose to 57F, and the cooler turned on again. I imagine it will keep doing that forever.

My husband's experiment using this device to turn on the fan at a certain temperature was successful. It performs as advertised.

temperature reading 5=7 degrees off actual temperature

Poor quality device only displays LLL and beeps. Unintelligible instructions.

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