[sdiy] Temperature Compensated VCO attempt - help?

[Don Tillman]

   > Date: Tue, 04 Feb 2003 08:54:35 +0100 (CET)
   > From: Magnus Danielson <cfmd at swipnet.se>
   >
   > Ah, right. You've spotted exactly where I made a mental note "fix
   > this".  You win a pint of beer next time we're in the same bar!
   > ;O) (Fat chance... but I did enjoy Antonios Nuthouse back in '96)

For the others: Antonio's Nuthouse is an unpretentious little bar
about a mile east of where I live.

   > So Don, does this seem to bark up the right tree now?

I don't think so. 

This is a problem I've spent a lot of time on over the last few years.
I just found it completely fascinating, that a VCO function so easily
implemented in the digital domain is such a complete pain in analog,
and maybe if I could find a way to implement it in analog it would
open the door to other interesting concepts of VCO design.

I don't think you can do it with a triangle core.  There's not enough
state information, with really well defined transitions between the
states, to pull it off.  

Nor with a sawtooth core; there's even less state information.

I believe I have an elegant solution.  And of course it looks nothing
like any other VCO.  But it's on paper, I've never built it.  And I
want to build it and make some measurements before distributing
schematics, because hey, any idiot can scribble stuff on a napkin.
And I'm hopeful I can make some pretty wild claims about it.

With the ridiculous number of things going on in my life (the twins,
the day job, the band, etc.) my synth projects have been neglected.
But I've been sitting on this for too long, and I'm really eager to
prove it works.

Sorry to be so mysterious, but I'll be writing up something soon.

(No Fermat, I can't fit it in the margin!)

  -- Don

-- 
Don Tillman
Palo Alto, California, USA
don at till.com
http://www.till.com