[sdiy] VCO sine and triangle waveshapers?

Tim Parkhurst tim.parkhurst at gmail.com
Sun May 22 23:19:46 CEST 2011

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

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