Call me daffy!

[Bob Zimmer]

At 10:12 AM 11/1/96 PDT, you wrote:
>     >
>     >but does anyone have a circuit that can produce a gate and trigger 
>     >based on pressing an SPST switch?
>     >

Gosh Gene, you are really trying to make me think on this one! (;^)

>     Should be e-z, maybe vary a little depending on the surrounding 
>     electronics. What exactly are the requirements? Gate high at +5 when 
>     button pressed, trigger as a +5 pulse with a width of say ten 
>     milliseconds on the rising edge of the gate... maybe +10 for gate and 
>     trigger levels? Is V+ okay, like +12 or +15? What about drive 
>     capability - is a buffer needed to drive a 1K output impedance?

What I'm hoping for is the standard +5 levels.  The trigger should be in the
neighborhood of a 10-25 ms pulse.  Similar to what would be expected from an
analogue keyboard.  I have seen the keyboard circuits in Electronotes, but
am hoping to find a simpler circuit as it would detect from a switch rather
than a Control Voltage.  The ones that I saw seemed to be overkill for
something like this.  As far as drive capability, again whatever would be
standard for a keyboard interface.

>     Does the gate need to be de-bounced to eliminate switch contact glitches?

I'd expect that it would just to be safe!  The switch has a solid feel, but
that doesn't mean anything.

>     Is the gate delay to be a on a separate delayed gate output?

I was going to have it switch controlled to a single gate output.  Same with
the CV scale output on the quadrature outputs.  I had pulled the delay
circuit from someone's web page (Ric's maybe!).

>     Does that need its own trigger as well?

No.  I wasn't planning on multiple trigger outputs.     

>     What is the gate delay time range?

Should be based on the RC constant.  Around on 0-.25 seconds should be good.

>     I like questions like these, they're like little puzzles to break up 
>     the monotony.:)

Glad to amuse you (;^)  What I'm working on is a controler interface to a
VCF/EG/VCA for some wild resonant/spacial sounds!

Bob

  >=== Bob Zimmer -- Philadelphia PA ===<
  >=== bzimmer at voicenet.com          ===<