I chose to use a gate and a trigger. The gate going false will
'cancel' a pending delayed trigger. The gate input is normaled to
'true'. I made a dual delay and normal'd the second to the first.
Thus I can cascade them for even longer delays. I also had to decide
if I wanted a subsequent trigger should restart the delay (e.g.
retrigger) or be ignored. Eventually I made this switch selectable
and I do use it both ways.
Details and schematics on
http://modularsynthesis.com/modules/DJB-008/djb008.htmI used a 4538 one shot which worked quite well. To do it over again I
might add a variable pulse width. My delayed trigger is a fixed 5 mS
trigger and there have been times I'd like to have stretched that a
bit. The LED indicator simply shows delay time. It turns on when a
trigger has started the delay and turns off when the delayed trigger
occurs.
Dave
--- In motm@yahoogroups.com, Scott Juskiw <scott@t...> wrote:
> I had planned to build a digital gate delay (the TLN-774), but
that's
> been on the back burner for two years now, I may never get it done.
> So maybe a simple MUUB gate delay would be useful in the meantime.
> There is space on the MUUB boards for adding a 7555 timer chip. I'd
> like to fit two gate delays into 1U of space, so it would have to be
> very simple, just a delay of the rising edge of the gate, not the
> falling edge.
>
> 1. delay time pot and jack
> 2. input gate jack
> 3. output delay jack
> 4. LED
>
> What other features would we need? Maybe a hold time on the delayed
> gate, if that's not too complicated for a MUUB.