Re: Can a power supply have too much current?

[Don Bruder <dakidd@sonic.net>]

In article <dPOdnZN60-vuGXrYnZ2dnUVZ_rWnnZ2d@comcast.com>,
 "Michael J. Mahon" <mjmahon@aol.com> wrote:

> Mike Spurgeon wrote:
> > Michael J. Mahon wrote:
> > 
> >> And a shorted 500A battery will make a fire *much* faster than a
> >> 200A battery.  ;-)
> > 
> > 
> > If you've never seen the 1.5 volt wet cells the phone company used for 
> > battery backup in the 1970s, they were pretty impressive.
> > 
> > They could melt most wire you think would work...
> 
> I've seen them--actually a whole *room* full of them!
> 
> Nickel-iron cells are very reliable and very low impedance (high
> current capability).  AFAIK, the phone company was the only big
> user of them.

Hospitals used to be another big user of nickel-iron cells. Not so much 
these days, what with easily available, relatively cheap diesel backup 
generators with quick switchover and the capacity to totally replace the 
grid (as far as the hospital is concerned), plus UPS systems that can 
cover the "absolutely critical" stuff during switchover, but you can 
still find a few that have a room filled with bank upon bank upon bank 
of Ni-Fe batteries.

-- 
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