Doepfer

I'm curious about how a VCO works.  Specifically, what is the  
mechanism for converting sawtooth to square, or triangle to square?   
And what is the mechanism for PWM?

Monroe

On Jan 7, 2009, at 8:26 PM, Monroe Eskew wrote:

> Specifically, what is the
> mechanism for converting sawtooth to square, or triangle to square?
> And what is the mechanism for PWM?


A circuit called a comparator is used. Basically a comparator is a  
circuit with two inputs, which goes high when the voltage in one of  
its inputs is above the other reference voltage.

As an example, if a wave like a 0-10v triangle or saw is put into one  
input of a comparator and the reference input is set to 5v, the result  
will be a square wave.

To achieve PWM, the reference voltage is also an input, typically  
coming from something like an LFO.

- C

Chris Muir
cbm@well.com	
http://www.xfade.com

> I'm curious about how a VCO works.  Specifically, what is the
> mechanism for converting sawtooth to square, or triangle to square?
> And what is the mechanism for PWM?
>
> Monroe

Look at the A-167 comparator module. With this principle you can create a
rectangle from each other waveform with variable PW.

Best wishes
Dieter Doepfer