I recently built a circuit using a 555 timer which made a complete
cycle every 12 minutes. It was a the standard astable circuit with a
1k pull-up resistor, and a 1 meg for the other resistor. Capacitor was
470uf, so by lowering this value to about half, it would probably be
about right for the SK's. To make the on time short, I used this circuit:
http://www.cgs.synth.net/modules/cgs24_gatetotrigger.html

James

--- In CasioSK@yahoogroups.com, "gmeredith1" <gmeredith1@...> wrote:
>
> I found a circuit to do exactly what I wanted here:
>
> http://www3.telus.net/chemelec/Projects/Timer/Timer.htm
>
>
> Here is an example circuit of the above:
>
> http://www3.telus.net/chemelec/Projects/Timer/Timer-1.jpg
>
>
> I'll let you know how it goes ;)
>
> Cheers, Graham
>
>
>
> --- In CasioSK@yahoogroups.com, "gmeredith1" <gmeredith1@> wrote:
> >
> > That's the sort of circuit I had in mind when I was toying with the
> > idea. Does anyone know what value components you need to use with a
> > 555 to get it to pulse once every 5 mins, but with a short "on" time?
> >
> > Cheers, Graham
> >
> > --- In CasioSK@yahoogroups.com, "Mark Rauch" <billbigrig@> wrote:
> > >
> > > Howdy,
> > >
> > > Couldn't a guy put a 555 timer in there and have it trigger a non-
> > > sound event every 3 or 4 minutes to keep things powered up? It
> could
> > > be switched off when APO is desired.
> > > Rig
> > >
> >
>