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We
sent our L.E.D. tree to an expert in the technology, and
asked if he would honor us in writing us a letter which
would better explain to our customers, what L.E.D. is, and
why it is so great.
Here is what he wrote........
November
7, 2004
Dear
LEDtrees,
Thank
you so much for sending the multi colored tree for
evaluation. I have enjoyed measuring and analyzing it while
looking at non-LED trees to compare their electrical current
status. It is so much more than I expected in brightness,
please read my evaluation below.
AUTHOR:
Lawrence A. Horn, PE - BSEE Syracuse University - Electrical
Engineer of 35 years working throughout varied industries.
Major interest in project work focused on energy savings for
industrial cost reduction.
ELECTRICAL
MEASUREMENTS:
Out of curiosity, I measured the power the entire tree uses.
(Mr. Horn was measuring our 4 foot
tall L.E.D. tree.) After it was operating for 3 hours
at full on, I found the following:
Lights
Full ON: 4.5 Watts
Lights ? ON by dimming wave pattern 2.1 Watts
THIS
IS FOR THE ENTIRE TREE! AWESOME! I hope you counted the
LED?s. (160 L.E.D.s) I did not
take time for that, but would guess there are over 100 on
this tree; and I find it quite bright enough.
(There are actually 160 L.E.D. lights on the tree we sent
Mr. Horn.) We have not decorated it yet with the
family heirlooms and keepsakes that always adorn our tree.
When we do I believe the effect of these lights will be
exceptionally pleasing. This will be the first year in many
that I will look forward to helping decorate the tree.
I did a little shopping for, supposed, energy efficient
trees. The smallest miniature single light found in most
stores consumes .4 Watts. That means that 12 of these single
lights exceed the total energy of all the LED lights on one
of your 4? trees. A standard 4? pre-lit artificial Christmas
tree has more than 120 of these miniature lights. This
calculates too more than 10 times the energy consumption!
Although these miniature lights are pretty low on heat
output, they are still much warmer than the LED lights in
your tree.
The next size up miniature light string is a little brighter
and hotter plus they suck up .77 Watts each. After that we
get to the ones I grew up with that are 5 Watt apiece. One
of these bulbs draws more energy than your whole tree!
Also, worth noting, the standard miniature Christmas tree
light string that is common in most retail stores have the
distinct disadvantage that they run off of 120VAC and can
shock you if changing a bulb while plugged in.
BACKGROUND
/ HISTORY OF LED
My
father Dr. Fordyce Hubbard Horn, working with Dr. Robert
Hall at General Electric Research Lab in Schenectady, New
York, was one of the pioneers in researching how to make
single crystal pure elements in the semiconductor portion of
the periodic table. Some of his first work was growing
Czochralski crystals of Germanium; then Silicon; then
Gallium; etc. Their, and others, work was the foundation for
the Semiconductor market we now know as transistors and
integrated circuits. At General Electric in Syracuse, New
York, I was also helping to develop this same market as an
electrical engineer. About the same time, my father?s
research friends continued to try to understand the energy
balance for a simple diode. This was a junction formed by
doping a pure single crystal material with two different
elements. (Doping is a very complex metallurgical process
diffusing various materials into an extremely pure base.)
When electricity was passed through a diode, it produced
heat and conducted electricity nicely. The amount of heat
did not add up to the total energy input to the diode. The
missing energy was finally discovered to be radiation
emitted as light. Once this was theorized, and proven, then
people worked to create junctions that would produce more
light than heat. These guys were comprised of PHD
physicists, scientist and engineer from around the globe
working in this special area of quantum physics. Soon they
found the magic combinations to make diodes produce much
more light than heat. Some of the earliest and cheapest
Light Emitting Diodes (LED?s) were from Gallium doped with
Arsenic (They are called Gallium Arsenide LEDs). The
chemicals used for the manufacturing process of LEDs are
chemically hazardous. Once finished, though, they are stable
and safe. Today, I would guess the red LED?s on your tree
are GaAs (Gallium Arsenide) material. The others colors are
exotic materials used to produce blue and green. An even
mixture of Red, Green and Blue (LED?s) can be used to
produce a white LED. That is why some white LED?s do cost a
lot more. The 3 RGB colors must be intensity balanced. So
far Red has been the least expensive of all of the LED
colors. The correct mixing of RGB can make virtually any
color, but most others are too cost intensive to be
practical. From an energy-input viewpoint, the LED light
efficiency rates way beyond any incandescent lamp. They
operate at very low voltage and at very low current making
them inherently safe in the home because it is unlikely
people will receive a shock from handling the LED?s. They
also are less likely to be a fire hazard when rubbing or
touching a combustible material such some Christmas tree
ornaments because they produce only miniscule heat. Last,
but not least, LED?s outlast any incandescent lamp in most
applications. The last I knew the ratio was greater than 10
to 1. In industry we use them when we must have a light and
count on it. There are even LED replacements for many
popular small bulbs. They are normally an array of tiny
LED?s on a carrier of some sort to produce a similar amount
of light like their counterpart incandescent lamp. LED
replacements appear initially pricey when compared to the
equivalent incandescent lamp. However, when considering the
energy savings and the life of the LED?s themselves, the net
result is almost always a brighter light at lower long-term
cost. In our disposable society, most people do not
appreciate the long-term gain. But, as energy costs
skyrocket, this is bound to change.
Your
fiber Optic Tree
I
had the privilege of helping Corning Incorporated develop
production quantities of commercial glass fiber for the
telecommunications market right after its conception. The
plastic fibers in a home application are similar in nature,
but don?t need to be as technically precise in manufacture.
The concept is to shine a light source LED on the end of a
bundle of many fibers. Each one will ?light pipe? the light
it sees at the source to its other end producing the effect
of a small light. Larger scale versions of this are used in
homes for lighting from the roof into the home during
daylight hours and can save sizable energy over any
electrical light.
I am eager to see how you put together your LED concept
Fiber Optic Christmas Tree and evaluate it if you wish. I
sense this will be a much more challenging project. (We
are sending Larry our new LED powered Fiber Optic Tree on
Thanks Giving weekend for review...stay tuned)
I
had planned many years ago to make a wreath with LED?s (all
red) with Darla?s help. We never got it started. Maybe this
will spur me on. Thank you so much. (We
got those coming too!)
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