Universal Temperature Controller

I got one of these cheap “REX C100” temperature controllers from Amazon a while back. So I figured I’ll make it usable by building a desk temperature controller with it.

Modifying the Controller

By default when you buy cheap temperature controllers like this it’s essentially Russian roulette on whether you get one with a SSR driver or a relay output. I happened to get one with a SSR driver, but need a relay for this. Fortunately it’s the same PCB as the relay version and the latter uses a fairly standard footprint. So I just looked through my box with 12V relays and found one that fits.

Putting it together

Basically I just installed the controller in a box and added connectors for all the outputs and inputs of the controller. The thermocouple/RTD input and the alarm contact are connected to a screw terminal. The output relay switches the IEC 60320 C13 socket. I’m aiming to control at least 1kW (~5A at 230V) with this at most, if I ever need to drive more I’ll build a small box with a 230V contactor that then gets switches by this.

Overview Back connectors