[sdiy] Need some advices... cd4049 touch switches

Dan Snazelle subjectivity at hotmail.com
Fri Jan 24 20:20:10 CET 2014


elektor had TONS of articles on touch switches


ill scan one when i get back from NAMM

Sent from my iPhone

> On Jan 24, 2014, at 11:18 AM, "Tom Bugs" <admin at bugbrand.co.uk> wrote:
> 
> Not sure about that particular ..
> (I remember looking at the Chatterbox years ago before I understood very much - I figured later that probably the opamps should be powered with a bipolar supply - that wasn't clear when I originally read it..)
> Anyways,,,
> Paia have some ideas:
> http://www.paia.com/ProdArticles/touchsw.html -- a bit more complex
> http://www.paia.com/ProdArticles/dual-ribbon-howto.htm -- this actually has a pair of simple touch-switches in the design
> Maybe helpful, I hope
> 
>> On 24/01/2014 18:15, Jean Bender wrote:
>> Hello !
>> 
>> I'm turning around some schematics, and i found this one :
>> http://yusynth.net/archives/WirelessWorld/Chatterbox-1976.pdf
>> 
>> I'm not interested yet by the formant filters, but.. the touch
>> sensitives switches ( shown on P6, on the whole schema). I don't
>> really figure how they work. I've tried to breadboard one with my
>> cd4049UBE, but it doesn't seem to do anything.
>> 
>> I'm powering my breadboard with a 13,3v supply. With the bias built as
>> shown in the schematic, i can get around 6v at the CD4049 inverter
>> input, when i'm touching the points, it's going down, but i don't have
>> nothing at the output. Still at 0, touching points or not.
>> 
>> Could somebody explain me how it should work ? I mean, i think i get
>> the idea, but i can't see where i'm wrong. Maybe my component ?
>> 
>> Anyway, if you have ressources about body controls and way to build
>> touch switches, i'm really interested..
>> Thanks !
>> 
>> Jean
> 
> -- 
> BugBrand LTD
> UK company No. 07199808
> VAT No. GB 988 2629 57
> 1 Ninetree Hill
> BRISTOL BS1 3SB
> United Kingdom
> www.bugbrand.co.uk
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



More information about the Synth-diy mailing list