Hi Susan and all, >At 07:49 AM 7/5/2005 +1000, Ron wrote: >>The strobe lighting effect can make a rotating and dangerous >>machine look like its stationary. The newer high efficiency >>flouro's don't suffer from this problem because they can be cycling >>at up to 25k, as opposed to the older styles which run at the 50 or >>60 hz of the power grid supply. At 11:31 PM -0700 4/7/05, Susan Kline wrote: >Hello, Ron. I recently replaced some fluorescent fixtures built into >my kitchen ceiling, containing six fluorescent tubes. They were >humming, and some were a different hue from >the others. I replaced them with the electronic type. Are these the >ones which cycle to 25k? Yes they are. >I found that the hum disappeared completely, the light was pleasant >and white like daylight, They have a much higher luminosity per watt than the mains frequency types, primarily due the much longer on-duty cycle. The older types spend a lot longer off as the voltage swings through zero. > but on some TV stations I got little white interference lines when >the lights were on. The higher frequency gear is more prone to producing RF which interferes with signal reception. If the lighting was housed in a metal housing with a glass lens containing lead, that would greatly reduce the RF emissions. Most laptops also tend to upset TVs if they are nearby. My wife's iBook sits quite near the small TV in our back room. When the computer is awake the reception is pretty ordinary. >I'm keeping the old ballasts and tubes in the garage till the >disposal company has a hazardous waste day, because I heard they >have mercury and other bad stuff in them. Indeed, the early type ballasts are quite dangerous since they contain PCBs. Any ballast which is giving off black soot around the fitting should be changed immediately. When we came to this workshop in 1976 all of the ballasts were of the older PCB filled designs. Over the years we've gradually changed the entire workshop to new ballasts which are dangerous-chemical free. > >They're very nice on dark rainy winter mornings. You turn on the >light, and it looks like >a skylight on a bright sunny day. They are very nice. And for those folks who are prone to contracting retinal-migraines when exposed to strobe lighting, the newer high frequency types don't cause the same problems. Ron O. -- OVERS PIANOS - SYDNEY Grand piano manufacturers ________________________ Web: http://www.overspianos.com.au Email: mailto:ron@overspianos.com.au ________________________
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