Turning existing circuit board into "digital" version - digital potentiometer

Other
1

Hello all!

I am working on a project that is taking an existing circuit board and turning it into a digital version.

Circuit Goal: The circuit board connects into a light panel and has three control knobs. Each knob controls red, green and blue lights and the dials adjust the value of the RGB lights so the panel changes colors by “mixing” the knobs.

Current problem: Currently, the pots keep breaking off/ knobs are getting pulled off.

  • current potentiometer: standard panel mounted, d-shaped
  • Retention method: Set screw locking knob onto flat edge of d-shaped pot

Solution:

  1. Changing circuit board to fully digitalized
    • Using digital potentiometers on circuit board and rotary encoders with current knobs?
  2. Different, more durable potentiometers?
  3. Another idea?

I am looking into digital potentiometers to make that part of the circuit “contactless” but does anyone have experience with this issue or some suggestions to avoid it?

Thanks!!

2

I’d start with looking for more rugged potentiometers and knobs. A recessed knob with a dimple in it for a fingertip might do what you need it to without being able to be pulled off. Some end stops that prevent the knob from turning farther than the pot can travel would protect the pot as well.

Digital pots will still need an encoder to control them and a rugged encoder can be expensive. Encoders and digital pots will also require more electronics, microcontrollers and code to work, this wouldn’t be a simple matter of wiring the new part in where the old one was.

In any case, nothing will be “contactless,” the user will be touching/spinning something.

3

Maybe replace the pots with pairs of rugged “up” and “down” pushbuttons? And do the fading digitally?

If you want to get carried away, add a display or displays to show the current R, G and B levels?

Best,
Paul

4

Thanks for the input! What would a more rugged pot look like?

5

thanks for the response! hmm thats an interesting idea!

6

If the potentiometers work well for a while but fail after use, I’d also seek better versions of those. There’s stunning variety for such seemingly simple components. I recently had find some for a PA amp gain control and the 270° knob swing was such a pain that I simply gave up trying to find them from a general partshouse and bought a pair from an audio specialist for a king’s ransom ($30! And they’re pretty crummy looking).

It’s hard to guess where to suggest since they’re used so widely but I’d start with electronic gaming suppliers, both video/arcade games and adult slots and video poker, etc. Next might be industrial controls, then maybe more niche-y vendors like point-of-sale suppliers, appliance repair, tradeshow booths, museum kiosks, etc. Consider trying out some knobs at a thrift store or pawn shop or musical instrument shop (Guitar Center) to get ideas or even donors.

7

Very good points. Thanks for the input!