On 2014-05-18, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:

When it arrived I found that P =
E * I was too complicated for them, it was physically sized for 0.1V
at 80A.

Heh! A lot of the old RTL and DTL mainframe computers had prodigious
low-voltage supplies, rated in the hundreds of amps, and with multiple
tens of Farads of filtering. I scrapped an SEL-840 from The Cape that had
two four-foot-long 5/8" x 2" solid copper bus-bars for the logic supply
rails in each of the six chassis cabinets.

Invariably in those old computers, you'll find at least one spot on one
bar where someone has accidentally gotten a wrench or driver across the
bar to ground. THAT must be exciting!

Not as exciting as some other things.

A friend once worked for AT&T Long Lines, and on the next floor
up or down was the main exchange (which, as always, was powered by a
bank of really big lead-acid cells, and *trickle* charged at something
like 300A). Two banks of the cells, one on charge while the other
handles the load of the exchange. Most common voltage is 48V, but there
were higher and lower ones as well.

Anyway -- a new employee was given the job of opening each of a
number of *big* knife switches ganged together, greasing the contact
surfaces, and re-closing them.

Well ... he was not a hefty type at all, and was having
difficulty opening some of them, so he got a big pry-bar and started
using it on the insulating crossbar to pry the switch open.

Well ... one let go rather suddenly, and he fell back. The bar
touched one of the high-current blades at one end, and the other the
metal doors of the relay rack row behind him.

It cut through the sheet metal like a soldiering iron through
butter. He spent some time in the hospital from the burns, and then
when he got back was never trusted with anything more dangerous than a
broom -- until he quit.

So -- yes it *can* get more exiting. :-)

Enjoy,
DoN.

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