[sdiy] Outside Synth DIY topics but could be of some interest..

Jean-Pierre Desrochers jpdesroc at oricom.ca
Wed Dec 22 20:47:46 CET 2021

Hi all,

Here is an idea (outside DIY synth) I had sometime ago..
I hope this could be of some interest for you  guys..

Tired of throwing away lots of 'end of their life' batteries
when they reached 70% or less of their original values
and you could not use them for other stuff ?
Well I accumulated a lot of AA type batteries over the years
and kept them in case of.. Happy I did so..
Here is a small project I made to re-use them and even more,
use them as a variable voltage supply..

In this project, over time, I can spot the 'going almost dead' batteries
using the small voltmeter and comparing successive rotary switch voltages
then following the battery's chain number and remove/replace it
with another 'used' battery.

In my case this small box will be used to supply small battery operated
while repairing or testing them.
This thing can supply up to 24 x 1.5vdc = 36vdc (with brand new batteries)
but this is not the primary goal of it.
Here, with used batteries installed I could reach up to 29vdc
which is not bad with 'about to be thrown away' batteries !

Merry Christmas to you all !

Jean-Pierre Desrochers


> -----Message d'origine-----
> De : rburnett at richieburnett.co.uk <rburnett at richieburnett.co.uk>
> Envoyé : 13 décembre 2021 08:02
> À : Jean-Pierre Desrochers <jpdesroc at oricom.ca>
> Cc : Synth-diy at synth-diy.org
> Objet : [Polluriel détecté] Re: [sdiy] My good old VGA oscilloscope
plugged to
> my modular..
> Importance : Faible
> Very pretty!  The perfect use for that old 4:3 analogue VGA monitor that
> everyone still has in the cupboard gathering dust.
> -Richie,
> On 2021-12-12 21:35, Jean-Pierre Desrochers wrote:
> > Here is a short video of my 2015 open source VGA Oscilloscope project.
> > It's made out of a small Microchip PIC micro with the help of some
> > analog comparators circuitry.
> > This box produces a vertical line that follows the incoming stereo
> > audio signal connected to it.
> > It then drives an external VGA display.
> > A choice of 7 different colors can be applied to the vertical line.
> > It just needs an old 4:3 VGA screen with a 800x600 resolution.
> >
> > https://www.youtube.com/watch?v=VKMjb3CpOCE&t=135s
> >
> > Enjoy !
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