On Sun, 04 Oct 2009 22:11:23 -0500, The Daring Dufas wrote:

The early mercury arc
valve systems have got to be a sight to behold. I can imagine a mad
scientist wearing super thick lensed glasses cackling in the background.

Around 2002 I found a wonderful mid-sized mercury arc recifier
in use still for the tram system at the MOTAT museum in Auckland, NZ - it
might still be operational there. Fascinating to watch it run, and the
brightness change according to load as the trams moved around.

I'm sure there are still some running in other countries, too, but that's
the only one I've seen over the years (although various museums have ones
that aren't hooked up - I don't know how many of those are still
technically OK and could be made to run).

There may still be a few tucked away in buildings with really old DC
elevators, although there can't be many left now that haven't been
updated.

cheers

Jules