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At 14:58 4/5/01 -0500, Mark Kossover wrote:
Howdy-
A couple of weeks ago, I attended the NSTA convention in St. Louis.
/snip/
Another interesting effect is that the solar cell can be brought near a
monitor. The monitor's flashing creates a distinctive buzz on the speaker.
Different refresh rates create different pitch hums.
Marc Kossover
mkossover@newman.k12.la.us
Mark's set up reminds me of a flicker photometer I set up when
I had a bee in the bonnet about flicker from fluorescent lights
provoking eye strain or headaches. People who sell these
lights are not specially forthcoming about their flicker contribution.
I notice that some fittings using electronic power supplies are
reputed to flicker at a much higher and less bothersome rate.
Though I haven't checked them out, the folded fluorescent tubes
on incandescent style screw bases may be in this category.
brian whatcott <inet@intellisys.net> Altus OK
Eureka!