[sdiy] PWM, Vactrols & Opto-Isolators

[Dustin Withers]

Hello All,

I think this maybe my first post here. I guess I should introduce
myself a bit? I've been in and out of Synth DIY for the past 10 years
and have also purchased some modular equipment (specifically Modcan
A). My system is about 1/2 Modcan and about 1/2 things I've built. I
keep a semi regular blog @ http://www.fadeddata.com . Lately I've been
getting into hobby CNC and I've been engraving my own PCB's. I'm going
to begin engraving aluminum panels soon as well.

Most of the things I'm up to are pretty boring compared to the rest of
what some of you are doing :)

Anyhow, enough of that!

I'm curious about what the differences are between Opto-Isolators and
Vactrols. I think they are the same thing, right?

Also I'm interested in converting PWM to a voltage. I know this can be
done with a low pass rc circuit. I remembered that you could also
control the brightness of an LED with PWM. Couldn't a
Vactrol/Optoisolator be used to convert PWM to a voltage? What are the
pros/cons vs the RC circuit?

Thanks for your time,
-dustin