Date   : Tue, 11 Aug 2009 21:10:31 +0100
From   : jumbos.bazzar@... (Mark Haysman)
Subject: Tales of woe and stupidity

Ok....here's one from me.

Many moons ago, I worked as a technician in an R&D lab for power supplies, 
big industrial switch mode untis. I would assemble the prototypes that the 
engineers designed, and put them thru their paces, most often to destruction 
by overheating, overloading them etc.

So I have this one I'd assembled, 48V, 20A Switch mode...not the biggest we 
did, but still hefty. I'd assembled it all up, connected the resistor array 
load, turned it on and there was a pause whilst the hum in the isolation 
transformer on the bench built up....about 3 seconds later, an almighty 
BANG, and the room filled with yellow smoke, the fire alarm went off, and we 
all had to evacuate.

Yes, I'd fitted the large Mains Rectifier caps backwards. Boss was not 
impressed, about as impressed as the clenaers who had to clean the yellow 
paste off the ceiling and the paper debris that came out of the caps that 
was spread all around the lab. Still makes me laugh to think about it, and a 
good reminder to me to always check the polarity!

Mark.