Remove thermostat from the mix?

[Postal Dude]

The air con unit im making my current Chilled water project out of has a temperature display and a thermostat. The minimum temperature the AC's control circuit allows is 18c. But iv had it reading 7c by sticking probe somewhere cold.

The circuit looks pretty simple. The power goes to a 12v transformer to power the controller board. Then it just links the AC to the fans and compressor when the temps say so.

What i wanna do is keep the power to the 12v transformer so i can keep temp display. But hook up the mains to the fan and compressor directly.

http://img128.imageshack.us/img128/4748/controllerne4.jpg (http://imageshack.us)
http://img128.imageshack.us/img128/4748/controllerne4.9eed91b021.jpg (http://g.imageshack.us/g.php?h=128&i=controllerne4.jpg)

[wdrzal]

When the probe gets to cold approaching usually 5f or 10f higher than the freezing pointof water it may shut down the compressor so the coil does not freeze or it may not. most do not. They are usually mounted in front of the evaporator and with air flow they don't reach those low temps unless either the charge is low and the evaporator ices up or the filter or air flow is restricted and the evaporator ices up and the ice cover the probe.

The probe is really designed to sense the return air temperature (room air temperature)They usually have a range rom 60f to 80 f before it passes the evap. some have a safety logic circuit to shut down the compressor if the evap freezes but like I said previously most do not.

Depending on the type of sensor it may not be accurate out of is designed preset range, 60f to 80 f or there abouts.

[Postal Dude]

Yeah it shuts off compressor at 18c. I want to keep the thermometer hooked up so i can read the display. But not have it shut compressor off. It seems pretty accurate. Goes down to 0c in ice. And upto 36 in my mouth lol.