[sdiy] trigger to optocoupler is button?

[Pat Kammerer]

Hi,

Many sound trigger buttons on toys just short an IC pin to the positive
supply voltage.  In this case, your only worry with triggering from a synth
is that the trigger is often a higher voltage than the supply of the toy.
When I have a toy that is supplied with equal voltage of the synths positive
rail, then I've found that the trigger can be delivered directs to the IC
pin side of the switch and it triggers fine.  Some toys with lower supply
voltages will still take the trigger and use it without damage.  Otherwise
you should be able to use a low value series resistor with a zener diode
shunt regulator on the toys trigger input, to clip the trigger at the right
voltage.  The zener could be rated at a bit higher than the toys supply
voltage.

Theres no reason in my opinion to use a bunch of extra parts for switching,
unless you have to, which would mean a toy that does not trigger in this
way.  Some use diode matrixes to know which button is being depressed.
To: <synth-diy at dropmix.xs4all.nl>
Sent: Friday, January 20, 2006 12:30 PM
Subject: [sdiy] trigger to optocoupler is button?


> Hi there,
>
> I would like to trigger some buttons on certain musical toys I have, using
> the triggers of my modular.
>
> Can I use an optocoupler for that?
>
> If so what type?
>
> If not..............any other suggestions are very welcome.
>
> Thanks...
>
> Greetings,
>
> Jean
>
>
>