Process Automation: Relays and triacs


Andy Brown designed and built this relays and triacs controller board that he could use to automate his homebrewing process:

The heaters, fridge and fans that control the temperature in my brew fridge need to be switched on and off and that’s what this board is designed to achieve.

As you can see from the diagram the main features of the board are:

  • Three relays for basic on/off switching. To solve one of the issues with the STC-1000 controller I will use 16A, name brand relays for maximum reliability.
  • A triac. This will give me the ability to do phase-angle ‘dimming’ control and will be used for proportional heater or fan control.
  • USB connectivity to the host PC via a USB-to-UART IC.

More details at  Firmware source code available on github.

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.