From: Sandy King (sanking@clemson.edu)
Date: 12/11/01-12:30:35 PM Z
Jeff Foster wrote:
>so last night I went down to my shop and hooked up a ground wire to
>all three ballast (via the screw holding them to the wood top) and
>then to the ground on the ac cord. bingo - no delayed start and no
>flicker! very cool solutions. I looked closely at the wiring
>schematic on the ballast label and it does show a little ground
>symbol leading from the case...hmmm.
Congratulations. Wiring schematics can be useful when all else fails!!
>
>thanks to all who supplied insight - now on to printing ( banding
>test - even with the inverse square law for light fall off....)
Interestingly, the inverse square law only applies to point source
lights, not to a bank of fluorescent tubes being used very close to
the exposing plane, essentially functioning as a diffuse light
system. In other words, contrary to expectations, doubling the
distance of the tubes from 2" to 4" from the exposing plane will
*not* result in a 2X increase in exposure time. It will in fact be
far less, perhaps barely enough to even notice.
Sandy King
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