[sdiy] Varying gate lengths (using a 4017 counter) for a simple sequencer?

[harrybissell]

Have you given any thought to adding a clock that produces very narrow pulses...
then imposing these on the capacitors for each stage ?   This is a method that was
used
for syncronizing timers in the days before digital counters...   This would allow
you to get
times that are multiples of the clock... so each stage could be one, two three...
n pulses long.

If you use the clock, the outputs WOULD be rhythmic but still have variable times.
Turn off the
sync pulses, and your original circuit is back...

I like your self-clocked idea. Cool!

H^) harry

fmg wrote:

> Julian,
>
> This is a clockless (autotrigered) 4017 sequencer with individually
> adjustable step-lenghts.
> Not for percussion or rythmic music (but able too). I made it just
> for ocasionally solos.
>
> This is a one year frozen project. I made a functional proto but
> there are still "bugs" in the circuit that won't let it run as I
> draw it. I used LM324 as comparator for convenience then but this
> should be changed. Hope one of these days I found enough time to
> complete it (put it in a box, draw the correct schematics, etc)
>
> Basically each 4017 output charges a capacitor through a pot
> (adjustable time) until a level where the comparator "clocks"
> the 4017 repeating a new cycle with the next step.
> A single 4017 block gives you 8 outputs. Blocks can be reseted,
> do loops, be "shocked" (externally clock forced), or serialized
> (cascade) for longer sequences. I also used the 4017 outputs as
> gates (with FETs - not in the schematics) for individual notes
> fx (vibrato, pitch bend)
>
> Building 8 or 10 blocks that can be connected in parallel
> or serial or forming groups could bring interesting results.
>
> The schemo below is a 2 cascaded blocks (16 steps) seq.
>
> Hope it helps
>
> http://www.geocities.com/eqys_p/eqys_q.pdf
>
> Fabio
> .
>
> Julian wrote:
> >
> > Hi there,
> >
> > I'm messing with a 4017 decade counter, as a simple sequencer.
> >
> > Is there a simple way to take the regularly spaced outputs (gates) from
> > this, and vary the length of them - i.e.. both make them shorter then they
> > actually are, and longer then they actually are?
> >
> > Basically what I'm thinking is a simple sequencer, like the one mentioned in
> > the 'simple sequencer' thread earlier, but with control over the gate times
> > too.
> >
> > Ken stone's project using this chip offers a solution using switches to swap
> > between the gate signal and a set, shorter, pulse, but what id really like
> > is a completely variable time that can also be different for each step,
> > ideally being able to even have overlapping gates (i.e.. longer then one
> > clock cycle) although, i guess this isn't nearly as important as being able
> > to shorten the gate individually for each step.
> >
> > So, any suggestions? (in relativly novice terms please - im still quite near
> > the bottom of the curve ;)
> >
> > Thank you,
> >
> > Julian