[sdiy] Searching for a VC Clock schematic ......

[Rykhaard D.A.M.I.A.N.]

On 12/25/05, harrybissell <harrybissell at prodigy.net> wrote:
>
> I don't know how high your clock needs to go, or what frequency range.
> 4046 might go to the mid MHz range.


Well - I'm going to be setting up 2 x CD4024s as 7 bit dividers for clock
dividing, as well as providing bits for boolean logic functions.
(Making sure of my math) My maximum frequency that I would need from an
oscillator, to have my 13th bit running at 120bpm would be just over 1mhz.
(That seems to be an unreasonably / mostly unusable at the last bit.  128khz
would still give me 120bpm at the 4th or 5th last bit.)
Sooo ...... I'm looking at no more than 256khz roughly as a maximum speed
needed. :)

>From there you could use a 4024 (or 4040, or many others) to generate
> binary clocks.


Aye. :)

The 4046 has a couple of advantages, it uses a VCO that alternates the
> polarity of the timing cap... dielectric absorption would be 'averaged
> out' allowing a smaller and cheaper cap.  You can set (easily) a minimum
> and maximum range.  You get (for free) an x-or gate that could be a ring
> modulator ?


Mmm.  For the digital ring mod.  That could be a  handy effect to have. :)
Setting the min. and max. ranges ...... that could be handy as well. :)

Disadvantage... its not good enough for a pitch VCO.  Even with an expo
> converter...you can't get the accuracy.


I've been trying to figure, how accurate it could be, for doubling the clock
speed.  Could it be a small enough % for accuracy there?

H^) harry


I'm going to grab a couple this week, and see what I can find, as well as
seeing about prototyping my idea.  Hopefully - later today. :)

Here's to hoping you had a wonderful Xmas day. :) :)  Thank you for your
tips, sir. :D

--
Take care,
Warmth and Peace,
Ryk

http://deathlehem.bravehost.com/damian.html - D.A.M.I.A.N.;s webpage - Dec
2105 update
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