Date:         Mon, 22 Feb 2010 10:53:33 -0500
Reply-To:     mordo <helmut.blong@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         mordo <helmut.blong@GMAIL.COM>
Subject:      Re: ISC troubleshooting
Comments: To: John Bange <jbange@gmail.com>
In-Reply-To:  <6da579341002211931n76220b9dwd05d844fe9e8c3e0@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Madness, indeed. I like to imagine some line workers at VDO toiling away,
hand-soldering every pin...

John, what do you reckon all the inputs to the unit are? There's a
fair-sized bundle of wire going to it.

cheers,

On Sun, Feb 21, 2010 at 10:31 PM, John Bange <jbange@gmail.com> wrote:

> >  Someone, I think
> > John Bange, started to map the circuitry but it seems to be a project
> that
> > died. I have taken the defective unit apart and seems almost comical in
> its
> > design and construction - so many resistors, transistors and capacitor!
> > None
> > of them appear damaged to my eye so I'm wondering what has failed.
> >
>
> Yeah, I got about 10% done with that before I realized that That Way Lies
> Madness. It is almost comical in its design. It's a fantastic bit of
> hand-tuned analog circuitry, a throwback to a simpler age. It's almost
> steampunk in its fabulous complexity. I'm not sure why VDO went analog with
> it. Perhaps digital microcontrollers were still just s little bit too
> expensive.
>
> I'm still working on a digital replacement. The controller and interface
> are
> pretty simple--- just a few transistors and resistors with an Atmel chip.
> I've already built a couple test units, and they actually worked. The hard
> part for me is making something that doesn't fall apart. Automotive
> applications just aren't very tolerant of my sloppy soldering style.
>
> --
> John Bange
>



--
mordo
1990 Carat