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 ½ 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!)
Larry
