Tony Duell wrote:
>
> >
> > > Although, as I am sure you know, these 'water dimmers' were used (in my
> > > lifetime, just) for full-sized theatre lights, running directly off the
> > > mains. Topping them up when live was dangerous. As was finding the darn
> > > things nearly boiling during a play.
> >
> > What reasons for using water dimmers and how big they're like?
>
> Well, there were no power semiconductors (or any semiconductors), large
> thyratorns/ignitrons were darn expensive, and they were simpler and
> easier to maintain than metalic resistors, I guess.
>
> The size depended on the power rating, but a couple of feet tall and
> about 4 inches in diameter will give an idea.
I would guess this was a 1890's invention. The only other light source
at the time was electric arc for the stage, a big light source that uses
a lot power. The only real new light source (LED's don't count) is
sulfur globe ( and a few other trace elements ) that CONVERTS microwaves
into visible light.
--
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html
Received on Tue Jun 11 2002 - 20:49:23 BST