"Victor Roberts" wrote in message
news
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
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.
Rapid start circuits appear to date from the early 1950s. I have a GE
publication dated 1/56 that describes them and calls them "new", but
which devotes most of the fluorescent section to switch-start circuits. I
remember seeing my first rapid start installation while in college
about 1958 and being fascinated by the smooth starting of a room
full of fixtures without the usual blinking and flickering that
characterized switch-start lamps.
The F90T17 is still a listed lamp in the GE Catalog; however I was surprised
to see the comment that they were used for streetlighting. The light
output is low (about 5000 lumens) for its size. A 40 watt T17 was
promoted for its low surface brightness and touted as one of the few
fluorescent lamps that could be used in bare-tube installations with little
glare.
For streetlighting, (in the US anyway) I thought that either 800 mA or 1500
mA T12 lamps were the only ones commonly used. The 4-foot
1500 mA T12 lamp is rated for about 6200 lumens.
Power Groove lamps are also still listed, but only
in the 8-foot size. I've seen them also used for streetlighting, area
lighting (gas stations) and billboard lighting. The grooved tube increases
the phosphor surface area compared to smooth lamps and also increases the
arc length for a given physical length. If you ever have a chance to
examine a Power Groove lamp, feel the grooves near the center. Two of them
are deeper than the others and they provide the "cold spot" that controls
the amount of mercury in the arc. Power Groove lamps became fairly widely
used in the 1960s (they appeared in 1958, I think) and were primarily
promoted for
high-bay industrial lighting.
I don't know if Gene Lemmers was the inventor. It's certainly likely. Gene
continued working at Nela Park well into his 80s and commented to me
once that he wanted to match the number of his patents to his age before
retiring.
Terry McGowan