Topics

Capacitance Keyboards


john_crane_59
 

Anyone have experience rebuilding foam capacitance keyboards?
I tried rebuilding a Digital Group board, but roughly half of the keys don't work.
I did notice the replacement adhesive foam described in the rebuild article I found was changed by the manufacturer over the years, from grey light foam to a denser slightly thinner white foam.
I'm thinking that extra distance (about 1mm), could be enough to throw the capacitance off spec - so only some of the keys work.

http://www.bytecollector.com/dg_keyboard.htm


Andrew Taylor
 

TexElec sells replacement foam discs for foam & foil keyboards. I haven't tried them personally as both my f&f boards work flawlessly, but I've heard nothing but high praise for them. https://texelec.com/product/foam-capacitive-pads-keytronic/


Jim McClellan
 

Yep - Texelec has excellent capacitive foam pads when they're in stock. I rebuilt a Franklin Ace 1200 keyboard using them and they're excellent.





GO METRIC, AMERICA!
The World Is Waiting...



On Dec 19, 2020, at 6:22 AM, Andrew Taylor <andrewstm244@...> wrote:

TexElec sells replacement foam discs for foam & foil keyboards. I haven't tried them personally as both my f&f boards work flawlessly, but I've heard nothing but high praise for them. https://texelec.com/product/foam-capacitive-pads-keytronic/



john_crane_59
 

Thanks guys, I'll give it a shot.

The grey foam looks exactly like the original!

However I'm worried about:
1) Aluminum pads may oxidize over time.  Not sure if that will be an issue as it's a non-contact keyboard.  The originals used a gold-leaf like material. It's possible that's just over-engineering.  Heck, this whole keyboard is over engineered.  If you dropped it, it could break your foot.
2) I may be altering the capacitance as the PC board pads and corresponding gold leaf original pads look like 4 petaled flowers, not circles. Will have to test.

The keyboard BTW, is a Maxi-Switch, and their logo looks suspiciously like C3PO...