Homebrew PCBs

On Sun, 03 Jul 2005 19:39:37 +0200, Robert Hedan  
<robert.hedan@...> wrote:

> One thing I will always
> remember in auto mechanics is ALWAYS disconnect the positive terminal at  
> the
> battery (usually red, from all the blood splattering on it I guess).


You know it is better to disconnect negative? If you start with positive  
you can easily short it to ground with the wrench while you undo the nut  
on the clamp. Also, there is often no obstructing rubber thingy on it.  
Open circuit is open circuit so that doesn't change anything.

As for using car batteries for EDM, you still need to limit electrode  
current and switch it on/off. You could probably replace the first part of  
the large supply schematic with them, but i think then you can just as  
well go all the way.

ST