"Shawn" shawn_75ATcomcastDOTnet wrote:


"DoN. Nichols" wrote in message
...
In article ,
Sunworshipper wrote:


Now -- one possibility (but *very* unlikely) would be that you
are seeing the sum of light powered by two different power grids which
are not precisely at the same frequency, so the brightness of the sum
will vary, if the lights actually vary in intensity fast enough to track
the power line.

I don't know how much truth there is to it, but when I was in the Navy I was
taught that adjacent light fixtures were intentionally wired to different
phases. This was to prevent pump / turbine shafts from appearing as if they
were not moving. Was I being fed a load of BS or is there some merit to
this?

Shawn

There is a little merit to it. It is for fluor and discharge type
light though. Two different phases, it will still look stopped, but
you well "see" two different views of the shaft at the same time. Same
thing you get from a stroboscope at a submultiple of shaft speed.


jk