Bi-pulse convertor (ON-topic)

[Torbjörn Hörnfeldt]

Hi!
Why don't you ask Ian Fritz? He just may have had something to do with it? :-) Actually, it is in the EN Preferred Circuits Collection and was first presented in EN#72. I think it has also been presented in Elektor(?)

Torbjörn

----- Original Message ----- 
From: "KA4HJH" <ka4hjh at gte.net>
To: <synth-diy at node12b53.a2000.nl>
Sent: Thursday, December 28, 2000 10:19 AM
Subject: Bi-pulse convertor (ON-topic)


> Here's a little project for everybody (and I keep thinking I already saw
> this in ElectroNotes or somewhere but...). This evening I got to fool
> around with the software synth Reaktor and I really like the harmonic sweep
> you get with the "bi-pulse" oscillator. This is basically a pulse wave
> where the positive and negative halves are generated separately and work in
> opposition. The top varies from 50% to 1% while the bottom varies from 50%
> to 99%, and vice versa.
> 
> The waveforms (converting from a ramp) look something like this:
> 
> 0% CV
> 
> ----------              +5
>           |
>           |
>           |              G
>           |
>           |
>            ----------   -5
> 
> 50% CV
> 
> -----                   +5
>      |
>      |
>       ---------          G
>                |
>                |
>                 -----   -5
> 
> 75% CV
> 
> ---                     +5
>    |
>    |
>     -------------        G
>                  |
>                  |
>                   ---   -5
> 
> Sounds like PWM but distinctly different. Should also work with a triangle
> input. Obviously this is a simple quantization problem, which has been
> discussed before. Anyone have a schematic?
> 
> 
> -- 
> Terry Bowman, KA4HJH
> "The Mac Doctor"