[sdiy] Variable waveform LFO

[Mike]

>.  This helped when I was working on SNIC circuits.
>
> http://home.earthlink.net/~ijfritz/sy_cir10.htm
>
Looking at this, I vaguely remember a circuit for a variable waveform
oscillator from years ago, working on a function generator principle. It
depended upon a switchable current mirror, (I think), in the charging
circuit. This allowed the main waveforms to be varied from a positive decay
sawtooth via a triangle  to a negative decay sawtooth, on one output, and
from about a 5% to a 95% mark-space squarewave on the other. I'm sure it's
around somewhere, but I've not seen it recently. I'm not sure if it was
stable enought for a main VCO, but it made an interesting and useful LFO.

Any suggestions, or is my google-fu not good enough?

||\/||ike