"N_Cook" wrote in message ...

On 16/01/2016 18:44, Jeff Liebermann wrote:
On Sat, 16 Jan 2016 10:32:36 +0000, N_Cook wrote:

Is it simple on/off contacts or is change of R monitored for key "action"

http://oi65.tinypic.com/14xdmo3.jpg
The piano keys on a synthesizer might require some form of velocity
sensing which most assuredly is NOT resistive. The buttons in the
above photo are for turning things on/off and are therefore simple
on/off connections.
http://www.dummies.com/how-to/content/key-feel-and-response-of-keyboards.html




I don't know how many contacts are required.
I just tried taking a standard simple 10x10mm footprint click switch
apart , parts just clipped together. Cutting a disc of thin 1mm
silicone rubber, placing over the dome contact and reassembling , the
click noise and abrupt click action disappears, but still functions.
If they can be soldered to the pcb, ignoring the resistive pads, then
only a matter of fudging the right size and height of top protrusion to
glue over the stem of the switches,if necessary .
Well thats my halfpennyworth







Look at the photo, I need to replace the 0-9 data entry keypad on the far
right of the panel, and the four buttons to the left of it.
http://www.vintagesynth.com/sci/stk.php


The customer has said he wants the keyboard for his own use, so doesn't
require it to be restored to original condition, so I am now thinking I
might be able to find a 16 way keypad and wire it directly to the switching
matrix, and pretty much glue it to the top panel.
(He now realises ripping out the old pads because they didn't work properly
was not a good idea. I think he has been using a screwdriver to operate the
pads)

It will need some hacking because from memory, 0 - 7 have a common line, 8 &
9 use part of another, and the other switches I think are kind of random in
the matrix.



Gareth.