From: John De Armond
Subject: Re: LED light results -- short
Date: Thu, 30 Mar 2006 00:14:39 -0500
On Wed, 29 Mar 2006 19:50:04 -0800, "Sorobon" <Sorobon@AOL.com> wrote:
>I know this will cause some disagreement.
>I have replaced more than half the lighting in my trailer with LED's. A
>little more than a year ago, I read reports on this group, of failures of
>the replacement LED clusters -- 24 LED's per bulb in my case. I have used
>these lights for 9 months now, over the course of 2 winters. I have had no
>failures and have converted some of my friends to their use. The new --
>second generation white LED's have a less blue light and are closer to
>normal indoor lighting. One light, I left on all summer while I was on
>shore power at home, it still works fine. The LED's are not as "pleasing"
>as regular lights. Most of the incondesant fixtures in my trailer had 2 --
>1141 bulbs I replaced 1 bulb with 6 LED's in each fixture.
>If you are boondocking LED's are the way to go, if you staying in RV parks
>don't waste your money on LED's.
Actually, LEDs are a poor way to go for boondocking. They're only a
little more efficient than incandescents.
The way to go for low power is with fluorescents. Especially the
compact fluorescents because the rare earth tri-phosphors they use are
more efficient than the old halo-phosphates that most conventional
fluorescent lamps still use.
I have a nifty little 7 watt 12 volt-operated, bayonet-base CF that
was sent to me for review (by an importer that went out of business,
unfortunately) It outputs many times more light than 7 watts' worth
of LEDs. And it's a much more pleasing light, having a spectrum
similar to incandescents.
Even more efficient than CFLs are the CCFLs (Cold cathode
fluorescents.) They achieve better efficiency by virtue of using cold
electrodes with no filaments to heat. Here are some examples:
5 whole watts:
These work just fine when operated from a cheap inverter.
If you troll around some of the B2B sites for chinese manufacturers
you'll see that these CCFLs are on the next wave of ChiCom invasion.
Expect to see CCFLs as cheap as CFLs within a couple of years.
From: John De Armond
Subject: RV lighting
Date: Sun, 30 Apr 2006 22:02:54 -0400
I got this inquiry in my private mailbox. I thought the answer might
be of enough general interest to post a copy of my answer here.
On Sun, 30 Apr 2006 05:31:02 -0700, someone wrote:
>You have published various bits of very useful info about cold cathode
>lighting in the past on RORT. I (and I bet many others who dry camp) am
>very interested in low power consumption good quality lighting. I would
>love to see a more detailed posting on your web site (with a RORT
>pointer when it is there.)
You're most welcome. I have a whole bunch of stuff to post to my
website once I get some round tuits. I expect to have lots of those
while sitting on my butt in my truck passing the DOT quiet hours :-)
>I would *like* to see something on ready built stuff or complete
>directions for fixtures, ballasts, bulbs and covers (if needed.) Like
>many I am reasonably handy and can do my own wiring (and basic handy-man
>repairs,) but don't have any cold cathode or significant circuitry
Designing cold cathode driver electronics to avoid electrode darkening
and mercury migration (causes one end of the tube to go dark) is
non-trivial so I highly recommend using commercially available stuff.
I certainly do.
There are basically two types of "cold cathode lighting". One is the
traditional neon style, made to order by neon craftsmen. The other
type is the high intensity, defined life, small tube diameter stuff as
is used in scanners, copiers, computer case lighting and increasingly,
The difference in the two major types is in the electrode design. Neon
electrodes are designed to keep the current density below the level
where metallic sputtering occurs. Sputtering occurs when energetic
ions impact the electrode with enough energy to knock off atoms of
metal or emission coating Sputtering degrades the electrode and buries
noble gas atoms under the coating as it plates out as dark areas on
The small tube defined life CCFL uses a much smaller electrode and
much higher current density, typically a pin protruding through the
glass seal. The diameter pin is nearly that of the tube. The tight
fit between the cathode and glass tube somewhat limits ionic velocity
that causes sputtering but the end of the pin still sputters so the
tube has a defined life, typically 18,00-25,000 hours. That's a
lifetime for intermittent use but not all that long for 24/7 operation
that many neon sign tubes operate.
The small tube CCFL typically runs at a higher current level than
conventional neon and that combined with the small tube diameter
results in very high surface brightness. The lamp is essentially a
line source which makes it handy for things like scanners and copiers.
Traditional neon is characterized by larger tube diameters, lower
surface intensity (lumens per square inch) very high efficiency and
essentially infinite life.
Yet another difference is that the small tube CCFL has to warm up to
build mercury vapor pressure before it achieves its full light output.
it has this characteristic in common with hot cathode CFLs.
Traditional neon warms little to none at all so the initial intensity
is its normal intensity.
OTOH, traditional neon does not do well in cold weather because the
mercury vapor pressure drops so rapidly and because the tube generates
little heat. A CFL (hot or cold cathode) will generally operate to
far below freezing if the tube is surrounded by still air.
Traditional neon CCFL pretty much has to be made to order by a neon
craftsman. Expect to pay around $30 minimum per tube for simple
straight line units. A little more if the tubing is to be bent to fit
something. A little less if you buy many at a time. A group buy
would great for this. Small diameter CCFL is mass produced and so is
available in either straight units or spirals like CFL twister tubes
but not in custom shapes unless you're a Hewlett-Packard.
Many different "colors" (called color temperature) of white are
available with traditional neon tubing. A very pleasant one is 2700
deg K tubing which duplicates the color temperature of incandescent
lamps. Warm and comforting. 4-8000 deg K is various shades of "cool
white", the higher ones being bluish-white like sunlight. This is
good for doing detailed work and reading but it isn't very relaxing.
"High CRI" (color rendering Index) white is available for where
accurate color comparisons are necessary. Women like high CRI lamps
for applying makeup that is to look good outdoors. The "OTT Light" is
an example of a commercial product. Such phosphors also usually
contain a longwave UV emitter that makes whites pop and text jump off
the pages of coated paper. That "high brilliance" paper that the
office supply companies sell is coated with a blue dye that responds
to this long UV. Under black lighting, that paper is blindingly
Small tube CCFLs are generally available in 2700, about 5000 and 8000
deg K plus primary colors.
CCFL requires a high voltage, low current driver. A 15 mm diameter
tube will typically require 400 volts per electrode plus 400 volts per
linear foot. Drivers are constant-current devices so it's OK to put
fewer feet of tubing than specified on a driver. The voltage per foot
goes up as the tube diameter goes down.
Drivers can be solid state or traditional coil-and-core transformers.
I like C&C for line-operated devices, as they're more rugged, cheaper
and don't generate EMI. They are heavy and slightly less efficient
than solid state devices and tend to buzz when powered from
Solid state drivers can be had for anything from 12 volts DC to about
277 volts AC. For mobile use, I like the Tech-22 drivers
(http://www.tech22.com) These are small, reliable, dimmable and
modulatible (just in case you want your lighting to throb to the music
:-) He makes both 12 and 24vdc and 120vac units.
Coil and core transformers are usually bought through sign supply
companies like Reece Supply, Neon Engineering and Tubelite. I think
Tubelite has an on-line store now. Another supplier, West Coast
Custom Designs (google for the URL) imports Chicom units that aren't
bad. There's a guy in Lubbock, TX that imports ceiling fans from
China, of all things, who also imports some nice and very cheap small
coil and core units.
Small tube CCFLs come either as an assembled unit ready to apply power
to or with a matched driver. Linear tubes are widely available both
as surplus and for geeks who like to light up their computer cases.
I'm pretty sure I posted earlier this year a URL for a company making
small tube CCFL lighting fixtures for RVs and boats. I'm not on-line
at the moment so I can't look it up.
I know that Austin Electronics in Atlanta (770-449-8697) has been
selling about 1 ft long small tube CCFLs with the driver, last time I
checked for about $12. He has a website now but I don't know the URL.
The proprietor is Lloyd Carver, a super guy.
Ready-made CCFL lamps are making a traditional ChiCom mass invasion
right now. Only available on the web right now; look for 'em at Camp
Wallyworld next year :-) They look like CFLs but are lower wattage and
have very long lives.
Here are a couple of sources of ready-made screw-in CCFLs:
I have purchased one time from buylighting.com and have been satisfied
with the service. I have not bought from blackenergy.com, though I've
heard that they're OK.
The disadvantage of this kind of CCFL is, of course, that it won't fit
very well in the RV environment, at least not with regular size RVs.
A couple of years ago I replaced the RV type incandescent 12 volt
fixtures in my rig with those ThinLine hot cathode fluorescent
fixtures. I'm now going back and replacing the fluorescent lamps and
ballasts with traditional neon type CCFLs and Tech-22 drivers. (Maybe
I can Sleazebay the ballasts as spare parts :-)
There are several reasons. First, the ThinLine ballast, while a quite
clever design from a cheapness standpoint, is not regulated, nor is it
filtered. That means that the light varies intensity with incoming
voltage. Worse, over- or under-voltage rapidly shortens the
fluorescent tube's life from sputtering. And with no DC filtering, in
those RVs with Magnetek converters that supply unfiltered DC to
lighting circuits, the lamps flicker badly AND sputter the lamps
quickly. Plus, mine give off significant RFI.
The Tech-22 driver is regulated and filtered, is dimmable and
generates no flicker. The RFI level is quite low. His dimming
technique is clever, involving pulse width modulating the full voltage
signal rather than decreasing the voltage drive like traditional neon
dimmers. This means that the brightness can be reduced to almost
nothing without flicker.
I'm putting a U-shaped run of 10mm 2700 deg K (AKA "incandescent"
color) tubing on each side of the dual lamp fixture. One driver will
run both. When you look at my rig from the outside at night, it looks
like it's lit with incandescent lamps. Nice!
On the agenda is miniature cove lighting under the cabinets and around
the ceilings. For the cove, I'm using thin wall PVC tubing split down
the middle and painted to match the interior of my rig. The interior
of the tubing is lined with this stuff:
I'm using the double-sided 100% reflective stuff held in with Scotch
77 aerosol adhesive. The highest powered Tech-22 Driver can drive
maybe 20 ft of 10mm tubing so one driver can run a whole side's worth
of tubing. I'd rather have one driver for each side of the RV rather
than have to run high voltage wiring across the ceiling.
You've probably already seen my outside neon lighting. There I use
6500 deg Kelvin rare earth TriPhophor (more efficient than the old
halophosphate phosphors) tubing encapsulated in thick walled polycarb
tubing. The high color temperature results in details being
resolvable at lower light levels (things like roots and stobs sticking
up to trip you) and makes reading possible at lower light levels. The
polycarb tubing protects the glass tubing and contains the heat so
that the tube can operate at lower temperatures in the winter. I put
a little Xenon gas in these tubes to raise their resistance and
generate a little more heat than plain argon/mercury does. One
Tech-22 driver runs the whole mess.
I made some for my mom's MH that fits nicely under her awning and
reflects off the inner surface of the fabric when the awning is
>Thanks already for your other very helpful electrical and lighting posting.
You're most welcome. This article is of general interest so I'm going
to post a copy without your name attached to RORT.
>And good luck with your switch from restaurateur to trucker.
Thanks again. I like to change careers every 10 years or so. So far
nuclear engineer->software engineer with a detour into magazine
publishing->restaurateur with a detour into neon and now truck driver.
Who knows what comes next? :-) I have a nice little side practice of
power quality and energy audit consulting. If I don't retire
completely, that may be next.