13 Dec
2004
13 Dec
'04
4:57 p.m.
On Mon, 2004-12-13 at 17:25 -0500, William Donzelli wrote:
I think the original question concerned devices that were originally made
to hook up to the DC grid.
I have a feeling that a lot of trams and trolleybuses over here at least
ran on DC, presumably for traction and speed control reasons. Whether
they were candidates for being supplied by a DC grid or whether rotary
converters were always used, I don't know.
> Old elevators. Lots of old elevators.
Patrick> And, lots of not-so-old elevators.
Some machine tools, too.
I remember seeing a large planer -- 12 foot stroke, roughly -- that
used a DC motor for the bed drive. The idea was that you would get
the back & forth motion of the bed by throwing the motor from forward
into reverse or vice versa at each stroke endpoint.