Vaporizing PCB Traces

One assumes someone pulled the First Article protocol out of the file cabinet and made sure Test and QC read it. ...or wrote one before the day was over.

Wow, all that juice had to go (or come from) somewhere.

I'll take a guess at the burn forensics... This was a slow burn. It takes time for smoke vapors (burning FR4 & conformal coating) to condense and accumulate on the pcb. Also, it takes time to form carbon mountains. The pit and crack size in the mountains is proportional to the rate of smoke release. So...not as explosive as my board that blew.

Maybe the ferrite chip turned into a conductive blob.

D from BC British Columbia Canada.

What's wrong with an old-fashioned isolation transformer? If you're particularly strapped for cash, you can use a pair of most any similar transformers connected back-to-back. Or, use a dual-primary transformer, with one of the primaries as a secondary. Paul Mathews

I thought of that too.. I had on hand and wired up 3 50VA identical hammond xformers. These xformers have great isolation with separate windings. Got 210Vpk but dropped down to 100Vpk under load :( Need ~170Vpk. Makes a scary humming sound too..

I still believe I can do testing without a ~200W isolation transformer. It's just a little tricky.

D from BC British Columbia Canada.