Homebrew PCBs

I decided to try an idea I had for creating custom keypads for my
projects. I have only done a single key, but it worked quite well.

I took a circuit board, a piece of laser transparency and some
aluminum duct tape.  I punched a hole with a hole punch in one piece
of the transparency. The duct tape has adhesive on one side so I stuck
that to a second piece of transperency. I stacked the pieces together
in order of 

transpency with alumunum side down
transparency with hole
circuit board

Since this was a test case I just taped everything down to the board. 
I hooked up my meter to the copper and the aluminum tape. With a
reasonable amount of finger pressure I was able to make contact. I
pushed several times and had no problems with the button opening the
connection when I released. 

So it goes without saying it should be possible to etch a board to
handle multiple pads and connect the aluminum tape to ground, then
have your favorite controller scan the pads for presses. I am sure
some kind of debounce will be need, but that is no different than any
other type of switch.

Clever piece of experimentation.  I wonder what the performance will 
be like after 1K, 10K, 100K presses...

I recall an article in either N&V or CCI where the author created a 
circuit board that held momentary PC mount NO switches and overlayed 
it with some really thick (15-20 mil??) plastic sheeting.  He printed 
a fancy cover and laminated that on top.  custom membrane switches.


--- In Homebrew_PCBs@yahoogroups.com, "javaguy11111" 
<javaguy11111@y...> wrote:
> I decided to try an idea I had for creating custom keypads for my
> projects. I have only done a single key, but it worked quite well.
> 
> I took a circuit board, a piece of laser transparency and some
> aluminum duct tape.  I punched a hole with a hole punch in one piece
> of the transparency. The duct tape has adhesive on one side so I 
stuck
> that to a second piece of transperency. I stacked the pieces 
together
> in order of 
> 
> transpency with alumunum side down
> transparency with hole
> circuit board
> 
> Since this was a test case I just taped everything down to the 
board. 
> I hooked up my meter to the copper and the aluminum tape. With a
> reasonable amount of finger pressure I was able to make contact. I
> pushed several times and had no problems with the button opening the
> connection when I released. 
> 
> So it goes without saying it should be possible to etch a board to
> handle multiple pads and connect the aluminum tape to ground, then
> have your favorite controller scan the pads for presses. I am sure
> some kind of debounce will be need, but that is no different than 
any
> other type of switch.

In a message dated 6/27/2004 7:27:07 PM Central Standard Time, 
phil1960us@... writes:
I am sure some kind of debounce will be need,<<
Phil:  Interesting to read of your efforts, but Aluminum as a 
"contact-material"???  Against raw copper?  Be interesting to continue to read of this 
experiment!


[Non-text portions of this message have been removed]

uh, y'got the wrong guy.  I didn't do that, just responded.

--- In Homebrew_PCBs@yahoogroups.com, JanRwl@A... wrote:
> In a message dated 6/27/2004 7:27:07 PM Central Standard Time, 
> phil1960us@y... writes:
> I am sure some kind of debounce will be need,<<
> Phil:  Interesting to read of your efforts, but Aluminum as a 
> "contact-material"???  Against raw copper?  Be interesting to 
continue to read of this 

> experiment!
> 
> 
> [Non-text portions of this message have been removed]

Aluminum tape was what was available on my workbench when I tried it.
Copper tape would be preferred.

--- In Homebrew_PCBs@yahoogroups.com, JanRwl@A... wrote:
> In a message dated 6/27/2004 7:27:07 PM Central Standard Time, 
> phil1960us@y... writes:
> I am sure some kind of debounce will be need,<<
> Phil:  Interesting to read of your efforts, but Aluminum as a 
> "contact-material"???  Against raw copper?  Be interesting to
continue to read of this 

> experiment!
> 
> 
> [Non-text portions of this message have been removed]

In a message dated 6/28/2004 12:16:16 AM Central Standard Time, 
phil1960us@... writes:
uh, y'got the wrong guy.  I didn't do that, just responded.
OOPS!  Sorry!  As Emily Latella used to say, "NEVERmind!"


[Non-text portions of this message have been removed]