Variable ramp again

[harry bissell]

I think this is Don Tillman's circuit (by Harry Bissell)

Here is what (I think) Don proposed.  See the .gif files.  I'm having
trouble making it work right with voltage control... I get variation in
the overall amplitude as the symmetry is varied... but with this
implementation I don't. Any ideas why...

PS. I'm with Don regarding not trying this with integrators...
PSS. The little spike can be rolled off like JH did in his Korg clone
circuit... Part of it is because I'm starting with a 99.9% sawtooth.

:^) Harry

Don Tillman wrote:

>    From: "Grant Richter" <grichter at execpc.com>
>    Date: Wed, 4 Aug 1999 12:31:25 -0500
>
>    Lets use the classic integrator (3080), hysteric comparator
>    circuit. You have two linear current sources. Two solid state
>    switches switch the two current sources into pin 5 of the 3080.
>    Now you have independent control of the positive and negative going
>    ramp times.
>
> No, you have independent control of the positive and negative going
> ramp *rates*.  Viva la difference.
>
>   -- Don
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