Summary

Here is a little project to accurately control the temperature inside an enclosure. It works by controlling the speed of a high pressure fan with PWM control line (4 wire fan connection). Works great for the fans that come with the Prusa Enclosure.

With the help of AI I hacked a little Arduino script together and it is acutally very accurate in the temperature control.

I don't want to write a full tutorial but maybe it serves as a basis for your own projects. Rough sketch of what is in the box:

Voltage step down converter to power the arduino nano clone with around 12V
Dallas ds18b20 temperature sensor
2 line display with I2C connection
Screw terminals for the connection.
100k Potentiometer to adjust the temperature
push button to toggle between modes (PID control, fan at 100%, off)

The Box uses 24V from the fan.

I also built a version for the Prusa Box and included the Fusion 360 file.

If you find this useful and make your own project out of it, it would be great if you could share your version!