Where can I find a PID temperature controller that can operate at -40 degrees?

I am building an electric car - I need to find a digital temperature controller that:

- will work in very cold weather inside a car (-40 deg operating temps).

- uses a 12V dc supply

- has pulsed output (to feed an SSR with PWM control of a ceramic heater)

- 1/32 or 1/16 DIN

I have searched long and hard, and found lots of controllers, but most are 0C or -10C - nothing colder... Are all controllers designed for nice warm factories?

Do you think a -10C controller will work at -40C?

My first post - all help appreciated!

 

I don't think you'll find much industrial equipment designed to operate at -40C.

However, since you will be using it to control a ceramic heater what about venting some of that heated air into the control enclosure?

Even if the controller is non-functional at that temperature you could manually turn on the heater at 100% output until the electronics gets warm enough to operate normally.

 

Do you really need PID temperature control, or would simple on/off thermostat type control work?

As for PID controllers, you really need to contact the manufacturers to find out where they got the -10C limit from. It may just be an issue with a reduction of accuracy or the functioning of the LCD display. It may also be that they've just never tested it below -10C and so aren't prepared to warranty what will happen at that temperature.

 

Thanks Bob:

The question is how would I turn on the heat to 100%? Is it merely a question of the LED's not being visible until it warms up (and the heat will still turn on at first)?

I guess they are not expensive and I should just try it out...