[sdiy] generating an s-shaped curve

[Paul Perry]

Ah, not the function I was thinking of..

But, here's a trick for generating a symmetric non-linear function: put the 
non-linear element inside a diode ring. And then use that structure in a 
feedback loop.
A little trick from the old analog computing days ;-D

paul perry Melboune Australia

----- Original Message ----- 
From: "Harry Bissell" > OK i'm tring to make a circuit that expands an 
envelope. I figured out a solution using a diode
> breakpoint generator. The curve is the opposite of the tri/sine converter, 
> larger values get progressively
> larger, smaller ones get larger in a negative direction