[sdiy] What is a quadrature oscillator good for?

[Magnus Danielson]

From: Grant Richter <grichter at asapnet.net>
Subject: [sdiy] What is a quadrature oscillator good for?
Date: Mon, 08 Sep 2003 09:51:49 -0500

> I have been doing a lot of digging in the local public library for odd-ball
> waveshaper ideas.
> 
> I found an interesting simple waveshaper to generate a quadrature signal
> from a triangle oscillator core. It's from an old Electronics magazine
> article (70s). I will put it up when I get a chance.

Please see my little schematic corners where I let you see usefull stuff from the notebook:
http://home.swipnet.se/cfmd/synths/schematics/

Please check out the Bergfotron of Jörgen Bergfors for its use... (enhanced to handle real life
battles).

> Aside from frequency shifters and qudraphonic panning, is there anything
> else a quadrature oscillator is good for?
> 
> I am prototyping a linear through-zero quadrature LFO to use with the
> Joystick Axis Generator (reverses panning direction with negative voltage),
> I am curious if there are any other non-proprietary applications people
> would share?
> 
> Also, are there other quadrature LFO designs out there? So I can properly
> credit references.

Check out the Bergfotron!
Then also check out the "LFO" (really Z80 assembler) in the OB-8, which had 0, 90, 180 or 270
degrees difference between the voice-boards.

The thing is, when you have a quadrature LFO controlling PWM.... ;O)
Just try it, OK?

Cheers,
Magnus