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

[Magnus Danielson]

From: "Rykhaard D.A.M.I.A.N." <rykhaard at gmail.com>
Subject: Re: [sdiy] Searching for a VC Clock schematic ......
Date: Sat, 24 Dec 2005 10:25:08 -0500
Message-ID: <b6b288a70512240725k1c1ea3b0x6ae2fc0ae0f476f6 at mail.gmail.com>

> Had you meant, the CD4046 phase locked loop?  I've chosen not to go with it,
> only because I don't have any. :)  And my 1 supplier here, that stocks CMOS,
> carries it, but they're a fair travelling distance away - for immediacy in
> building. ;)  (I.E. - lazyness in getting to. :O (shy grin))

Well, they are cheap enought and you should have a few of them lying around
like I do, in case you want to do something. Versatile if you care to learn it.
Doesn't solve all the worlds problems, but for certain applications it gives
you pretty good bang for the buck.

> A problem with Vactrols for me, is availability. :(  My 3 local suppliers
> don't stock any, at all. :(  That's kept me away from experimenting with
> Buchla circuits. :(

You can buy a hell of a lot off 4046s for the cost of one vactrol alone.

> >Ray Wilson's musicfromouterspace site has some circuits that use a >40106
> clock. I don't remember if they're VC-able.
> >
> >peng
> 
> Ray's sequencer is what started me ON the CD40106. :) :)  A wonderful ship
> for buffering, in the CMOS end of things. :)  I've picked up 6 of the chips
> in the last 2 weeks, as I'm adopting the idea of it for all of those
> purposes, as well as for sharpening the squarewaves up when in use for
> triggering such. :D

I have a friend which excells in using the 40106 for alot of purposes. Hug your
40106 as you hug your 4046! ;O)

> Now a trouble that I thought of last night, with my using the CA3080 to VC
> the speed of the 40106 clock:
> 
> The output of the 40106 clock, would go through a 100k/220r divider into the
> positive input of the 3080, to control the amount of current that's charging
> the grounded cap, at the input of the 40106.
> My thought last night though - when the output of the 40106 switches Low,
> will the output of the 3080 (with diode, to prevent any Negative voltages
> from coming out) be at Ground, so that the cap can discharge?  As with the
> 40106 output being Low, it's input will be High, with the charge on the
> cap.  It's only other 'exit' is to the Output at Low.  But - the 3080 will
> be in the way, of it's discharging, wont it?

Hey! If you want triangle, you would like your 3080 do both charge and
discharge your capacitor directly, no diode. The only thing differering about
these cases is the state of the 40106, the voltage on the input of the 3080,
the direction of the current on the 3080 output and those the direction of the
voltage over the cap.

So, you have a 40106 inverter, a 3080, two resistors and a capacitor in the
core, that ought to work well enought. Toss in the expo and you are home free!
;O)

> I would go and breadboard it right now - but we're headed out for many
> Christmas Eve visits today and tomorrow and my girlfriend, wouldn't think to
> much of things, if I headed up to my 'lab'. :(  Soooo ...... I can only play
> with the circuit in my mind - hence - asking for help. :)

Well, well, let us help you to a less neurotic christmas experience then! ;O)

> Now - if this is not possible, with the 40106, then I just may come back to
> a standard Integrator / Comparator setup with VC, for doing it simply. :)
> (Actually ....... using 1 of the 40106's for the Comparator section, would
> make that square much sharper, and I'd just have to block any negative
> voltage from the Integrator output ........ more for the brain to fiddle
> with til I can prototype on the breadboard again. :D )

What negative voltage? If you have these hooked to the same supply things
should work well.

> Thank you greatly for your help guys!  I do hope that you have a wonderful
> Xmas Season. :)  (warm smile)

A Merry Christmas to you too!

Warm Analogue Christmas feelings,
Magnus