Temperature Sensor Circuit

So, I'm designing a cooling system for a project I'm working on, and I'm a little stuck.

This is a phase change system, and I don't want to deal with trying to seal up my circuits to ward off condensation, so here is what I need to build, in psuedo-code:

Temp1 = Ambient Sensor
Temp2 = Component Sensor

IF Temp2 > Temp1 {
Key Relay On
}
ELSE IF Temp2 < Temp1 {
Key Relay Off
}

I would like to build this in a way where I can use a pot to adjust the relay on/off limits, so I can keep the temps just above dew point, to ensure that no condensation occurs.

I've been brainstorming a bit, thinking about possibly using two regulators feeding two thermistors and a comparator and transistor to turn the relay on and off, but I'm not quite sure if that will do what I want, and it would be hard to make it adjustable.

If there is a easier or better way, even without the temp ranges being adjustible, well, that's why I'm here.

hi,
The tempr measurement and threshold detection is fairly easy to do.

Are you saying that you are manually going to set the 'dewpoint' tempr.?

Not exactly. I'd like to just compare ambient temp to component temp and turn the compressor in the cooling system on and off accordingly (off if component temp is lower than ambient, on if it's higher.)

The adjustment isn't really needed, I just thought it might be helpful for extremely humid or dry days.

tip120 said:

ELSE IF Temp2 < Temp1 { Key Relay Off }

Click to expand...

Will you use water injection to achieve that?

Look at this thread