[sdiy] VCO sine and triangle waveshapers?

[Tim Parkhurst]

On Sun, May 22, 2011 at 10:30 AM, James Coplin <james at ticalun.net> wrote:
> I'm looking to add sine and triangle outputs to my SEM oscillators as part
> of my rack mounting project.  What are people's favorite waveshaping
> schematics?  I'm assuming I can just take the saw output and run it
> through some shaper section.  Thanks again!
>
> James R. Coplin

Should be fairly simple. For saw to triangle, you use one op amp as a
rectifier, and then a second op amp to offset and amplify (2X) so that
the result is a triangle centered about 0V. For triangle to sine,
there are several solutions. My fave is a Thomas Henry method that
uses a couple of transistors, a couple of trimmers (one for offset,
one for shape), and an op amp.

Tim (tweakin' da trimmers) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings