simple way to add harmonics to a fundamental signal

[Rene Schmitz]

At 08:13 25.05.99 +0200, Martin Czech wrote:

>2x, 4x frequency may be obtained by full wave rectifying (proper dc offset
>after each stage).  Input a tri wave, or sine. The result will still
>have some fundamental left, but in a mix with the fundamental, this is ok.
>
>3x is harder to obtain. You could try to feed a sine into a Tchebycheff
>polynome function.  3x would require a 3rd-order polynome.
>
>The question is how to get the x**3, x**2 functions needed.
>Multipliers are expensive, that's why I thought about a nonlinear diode
network.

What about LM1496-type ringmodulators, I've a neat schematic for a
dc-coupled ringmodulator at my website, two of these properly cascaded will
give you x^2 and x^3 at the simultaneously. The LM1496 is pretty cheap, and
you'll need many diodes 
to have similar precision.

Try http://titan.cs.uni-bonn.de/~schmitz/ringmod.gif

Bye
 René

             ,   : (uzs159 at uni-bonn.de)
|") [" |\ | ["   : (http://www.uni-bonn.de/~uzs159)
|"\ [_ | \| [_   : (http://members.xoom.com/Rene_Schmitz)