Homebrew PCBs

--- 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.