audio to trigger

[Stewart Pye]

At 12:00 10/12/98 +1100, Paul Perry wrote:

>You could use a simple diode&cap&resistor rectifier/integrator, then run
this to
>a comparator with hysteresis. Parts count shd be pretty low, esp if you are
>making
>a bunch for a machine with sep outs.

Thanks for all the responses. I don't want to appear biased towards fellow
Australians but this could be the answer I was looking for. I don't think
the envelope follower on its own would work well enough. I know that for
some devices the audio will trigger it okay.           ( including the HC2
hand clapper)  But some, eg: my tama DS 200 seems to need a sharp, short
pulse to get a decent sound.
This is why I like Pauls idea, but I have a great way to enhance it. Use
the output of the histeresis comparator to switch a 4066 that is passing
the rectifier/integrator signal to allow velocity sensitive (or accent
sensitive) pulses. 
Thanks for all the replys. I now have some experimenting to do but am sure
something really great will eventuate, thanks to you guys. 

Regards,

Stewart Pye
>
>Also, if you go 555, you can have a 'refractory' period (it triggers, but
then 
>cant trigger again for a fixed period). Using a comparator to trigger a
>fixed period 
>555 you cd probably run off the raw audio & have very few parts.

I'm sure the 555 will come in handy somewhere with this project