Possibly goofy idea...

[Scott Gravenhorst]

Touch switches!  Didn't I read here that a CMOS gate input can
work as a touch switch?  If so, are there biasing requirements?
ESD protection things?  Output conditioning?  Could I make the 
pads by etching a board and coating it with clear lacquer?

"Curtin, Steven D (Steven)" <sdcurtin at lucent.com> wrote:
>Scott,
>
>This is a great idea with a long heritage (although not in M*DI land).  The
>EML 300 series synth had an optional keyboard that was basically a telephone
>touch pad, with an accompanying pot for each of the keys.  Pressing the key
>sent the voltage out to a CV summer, as well as a S/H.  Likewise I think the
>Buchla sequencer and Serge TKB had accompanying knobs for different outputs
>when different touch switches were pressed.  Go for it!
>
>Steve C
>
>-----------------------------------------------------------------
>Steven Curtin  
>Lucent Technologies Microelectronics
>ph: (732)949-4404   fax: (732)949-6711
>http://curtin.emf.org
>sdcurtin at lucent.com
>-----------------------------------------------------------------
>
>
>> ----------
>> From: 	Scott Gravenhorst[SMTP:chordman at flash.net]
>> Reply To: 	chordman at flash.net
>> Sent: 	Tuesday, May 09, 2000 1:45 PM
>> To: 	synth-diy at node12b53.a2000.nl
>> Subject: 	Possibly goofy idea...
>> 
>> I haven't seen this one (but that doesn't mean it doesn't exist)...
>> 
>> One of my favorite things to do with my FatMan is to hold down
>> a key to play a constant pitch and fiddle with the filter cutoff
>> freq knob with rez at max.  One can "select" harmonics.  What I
>> would like to do is to build a very simple device that has 5 to 8
>> micro switches (perhaps a salvaged keyboard).  These switches
>> would conduct to a common point, a DC signal from the wiper of a 
>> pot wired as a voltage divider supplying 0v to max CV.  The CV 
>> seen at the common point is supplied as the filter's cutoff freq 
>> CV.  Each key could be "tuned" by pressing it and adjusting it's 
>> pot.  A sort of human clocked and human programmed analog 
>> sequencer.  I would think I could then "play" these harmonics.  
>> The control voltage output of this could probably be used other 
>> ways as well.
>> 
>> In the real circuit, I'd probably use analogue switches, controlled by
>> the physical switches.
>> 
>> Does this sound useful to anyone else?
>> 
>> -- Scott Gravenhorst
>> -- Linux Rex, Linux Vobiscum  |  RedWebMail by RedStarWare
>> -- FatMan: www.teklab.com/~chordman
>> -- NonFatMan: members.xoom.com/_XMCM/chordman/index.html
>> -- The 21st century does NOT start in the year 2000!!!
>> 
>> 
>> 
>

-- Scott Gravenhorst
-- Linux Rex, Linux Vobiscum  |  RedWebMail by RedStarWare
-- FatMan: www.teklab.com/~chordman
-- NonFatMan: members.xoom.com/_XMCM/chordman/index.html
-- The 21st century does NOT start in the year 2000!!!