Altair-what do I do first

From: Peter C. Wallace <pcw_at_mesanet.com>
Date: Wed Sep 25 16:30:01 2002

On Wed, 25 Sep 2002, Patrick Rigney wrote:

> > Better still, if you are testing the cards one at a time with an external
> > supply, tack on a 5V (set to 5.5 or so) crowbar on the output side of the
> > local 5V regulator -- no cut traces, only tacking on 2 wires
> > temporarily...
> >
> > Peter Wallace
>
> Peter, yeah, this seems like an easy approach. Question: could a simple
> 6.2V Zener be installed reverse-biased from the 5V regulator output to
> ground? Seems like you'd want inline fuses between the unregulated supply
> and the backplace as well for this kind of test...
>
> Patrick
>
>

        You would have to have a monster zener to be safe, probably 50 W or
so. Those arent that common. A crowbar circuit stolen from another supply or a
home made one would be better than a zener.

        Instead of a crowbar (that usually use SCRs), You could also use a
5.6v or so shunt regulator made with a big (20A) power transistor and a 5V
10W zener...

Peter Wallace
Received on Wed Sep 25 2002 - 16:30:01 BST