Homebrew PCBs

More like reflashed, perhaps?

Donald.
Pun completely intended.
----- "awakephd" <a_wake@...> wrote:

> --- In Homebrew_PCBs@yahoogroups.com, "James" <jamesrsweet@...>
> wrote:
> >
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "awakephd" <a_wake@> wrote:
> > >
> > > I'm not sure what the big deal is about printed-on fuses. I've
> done that many times -- in fact just the other day, when I made a
> bone-headed connection on the 170V PWM motor control board I was
> working on, several traces turned into instant fuses!
> > > 
> > > I'm embarrassed to confess that I forgot that the "ground" on the
> board was NOT at the level of ground in the wall when I attached the
> ground lead from the o-scope. Fortunately the board "fused" rather
> than the o-scope. It destroyed two IC's on the board in the process,
> but that was a small price to pay compared to fixing or replacing the
> scope!
> > > 
> > > And yes ... the board went in the trash and I started over -- much
> more carefully this time! And yes, the new board works perfectly.
> > > 
> > >
> > 
> > 
> > Been there, done that. *ALWAYS* use an isolation transformer when
> testing "hot chassis" equipment. It may save some expensive test gear,
> or yourself! If you don't have one, it can be made in a pinch with a
> pair of back to back power transformers.
> >
> 
> I'm glad I'm not the only one. I had intended to test the board out
> feeding in power to the logic section from an isolated power source
> (and that is what I did after I re-made the board). But I had had to
> set the project aside for several weeks, so I when I finally got back
> to it I was overly eager ... and it was late, and I was tired, and I
> wasn't thinking. But hopefully the lesson is now burned into my brain!
> Errr ... no pun intended. :)