On Sat, 12 Mar 2005 22:20:07 GMT, "James Sweet"
wrote:
Actually rapid start is much older than the 1970's, but you are
correct about 40-watt preheat start lamps. The 1981 IES Handbook lists
both 40-watt T12 and 90-watt T17 preheat start lamps. Thanks - I
learned something new today.
Perhaps it was 60's? I'm not sure really, but I do know that preheat start
40W tubes were very common in the 50's and at least partly into the 60's, RS
didn't seem to catch on until the 70's. One possible reason is that RS has
much more trouble starting in cold weather or high humidity and requires a
grounded reflector in close proximity to the lamp.
We need some input from Terry here, but we developed the 34-watt T12
energy saving lamp while I was working at GE Lighting in the
mid-1970's. One problem with the lamp was that due to the lower lamp
voltage the 34-watt lamp placed more voltage stress on the internal
capacitor in rapid start ballasts. When the new 34-watt lamp was
installed in fixtures with old rapid start ballasts, many of the
capacitors, which were near end of life anyway, blew. So these
ballasts must have been almost 20 years old by 1975- which means they
were popular by the mid-1950s. By the mid-1970's the 40-watt rapid
start lamp was nearing the end of its life due to the new 34-watt
rapid start lamp.
The 90W T17 lamps are dinosaurs, I've never actually seen one up close but
they were used in streetlighting some in the 50's. Another neat lamp I'd
love to get my hands on are the GE PowerGroove PG17 series of VHO (1500mA)
lamps that were somewhat common in the 70's. They use a rippled tube that
allows a 9' arc length in an 8' tube and were available in 4' as well.
Well, we had lots of Power Groove lamps at Nela Park along with its
inventor - who I believe was Gene Lemmers - who also co-invented the
rapid start ballast, I believe with John Aicher. Terry, can you help
here? The Power Groove lamp was introduced by GE about 1956 and was a
rapid start lamp, so the basic rapid start system must be older than
that.
--
Vic Roberts
http://www.RobertsResearchInc.com
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