Last major update 7/21/98. Last minor update 8/25/98.
General Notes and Disclaimers
News on Hewlett Packard's best LEDs - TESTED 17-23 lumens/watt!
Red LEDs - 20 lumens/watt by Hewlett Packard. (update 7/20/98)
Orange LEDs - 14 lumens/watt by Toshiba, 19-21 by Hewlett Packard.
Yellow and "amber" LEDs - 11 lumens/watt by Toshiba and AND,
13 by Hewlett Packard.
Yellow-Green LEDs - 3-4 lumens/watt by Toshiba and AND.
Green LEDs - 13-plus lumens/watt by Nichia and Toyoda Gosei.
Blue-Green LEDs - 8-9 lumens/watt by Nichia.
Blue LEDs - 4-plus lumens/watt by Nichia and Toyoda Gosei.
White LEDs - 6-8 lumens/watt by Nichia.
General info on Nichia LEDs.
Important Notes on Nichia/Gallium-Nitride LEDs!
"Micro Lights" Keyring LED flashlights.
Notes on Where To Get Bright LEDs
You might want to check out some Hewlett Packard high performance LEDs.
I recently found links I used to mention to not work, so here is one that does:
You may get bad results typing the very extensive URL into your web browser.
I recommend you follow this link and use your web browser's bookmark function.
Here are two others:
http://www.hp.com/HP-COMP/led_lamps/index.html HP LED Lamps Technical Data
http://www.hp.com/HP-COMP/led_lamps/ HP LED Lamps Home Page
General Notes and Disclaimers:
I don't know everything, and I only mention LED brands and models I know of.
Luminous efficacies were largely determined by one or more of several
methods, mostly almost laughably crude. I give NO warranty as to accuracy.
I have at times slightly changed my estimates for some models. Your
mileage may vary.
Unless otherwise noted, luminous efficacy is stated for a 25 degree Celsius
(77 degree F.) ambient with a current of 20 milliamps. Red, orange,
yellow, and yellow-green models mentioned here generally have maximum
efficiency at currents around 20-25 milliamps. Efficiency of these is less at
low currents of a few milliamps or less. The decrease is not as bad with
GaAlAsP and "T.S." AlGaAs and Hewlett Packard's most efficient InGaAsP red
ones as it is with most other InGaAsP (orangish red through yellow-green)
so red LEDs may be better for currents near or under 2 milliamps than
orange and yellow and yellow-green ones.
Nichia models with part numbers beginning with NS have efficiency that
increases with decreasing current, although the increase may reverse as
current decreases below about a milliamp or two. Same for any similar
models by other companies such as Toyoda Gosei.
Please beware that performance of many LED models at currents below a
few tenths of a milliamp may be unreliable.
There may be significant tolerance in light output. Your mileage may vary.
Some of these LEDs radiate light of slightly different colors in different directions. This is most apparant with Nichia white models and narrow-beam yellow models, as well as the most efficient yellow-green models.
Please note that the lumen per watt figures in this document are lumens of light produced per watt of electricity delivered to the LED. Many LED manufacturers state much higher figures indicating the lumens per watt of radiated light. The difference will usually be by a factor of at least 5-6, more for non-red models, usually 20 or more for yellow, green, and blue models.
Beam brightness and width figures below are mostly ones claimed by manufacturers/distributors and I have NOT confirmed most of these.
News on Hewlett Packard's best LEDs - TESTED!
UPDATE 7/21/98 - TESTED - no extrapolations nor speculations!
The overall luminous efficacy of slightly orangish red and red-orange
Hewlett Packard models using their "InGaAsP II" semiconductor material is
in the 17-23 lumen per watt range. More specific information has been
moved (on 7/26/98) to sections below based on color.
Hewlett Packard's candela and beam specifications indicate that "amber" (orangish yellow) models are slightly more efficient than red and orange models, but the few samples in my hands are more efficient in red-orange and slightly orangish red than amber.
Newark Electronics and most other Hewlett Packard distributors do not stock at
least some of these most amazing Hewlett Packard LEDs as of last time I
checked (7/12/98). Special orders could require a substantial minimum
order, like 500 pieces, and also lead times of a couple months!
Hamilton Hallmark (USA phone # 800-829-0146) is better at having these,
but told me the minimum order is 500 pieces (This may be only for
new/great items that are difficult to keep in stock.)
Red LEDs - 20 lumens/watt by Hewlett Packard. (update 7/20/98)
The HLMP-DD16 is an amazing, very slightly orangish red LED lamp with an
overall luminous efficacy ranging from 19 to 23 lumens per watt according
to my tests. The conversion efficiency is the best I have seen of any
bright LEDs - varying from 13 to 16 percent.
This is a 5 mm. (T1-3/4) lamp. Rated brightness is 3.6 candela and the
nominal beam diameter is 15 degrees. Peak wavelength is 639 nM and the
dominant wavelength is 630 nM according to the datasheet, mostly a nM or
maybe two longer in the few I have. The dominant wavelength (color-matching
wavelength) is about that of a He-Ne laser and very slightly more orange
than that of the more pure red GaAlAsP and "T.S. AlGaAs" LEDs.
Related Hewlett Packard models:
HLMP-DD18 (with lead standoffs), HLMP-DD25 and HLMP-DD27 (2.1 candela, 23-24 degree beam, without/with standoffs), HLMP-DD31 and HLMP-DD33 (1.4 candela, 30 degree beam, without and with standoffs)
Other bright red models, noted mainly for being more easily available to experimenters and hobbyists:
Hewlett Packard HLMP-8103, 9 lumens/watt, 5 mm., 3 candela, 7 degree beam,
peak wavelength 650-654 nM, dominant wavelength 640-644 nM.
H.P. HLMP-C116, 9 lumens/watt, 5 mm., 2 candela, 14 degree beam.
H.P. HLMP-C124, 9 lumens/watt, 5 mm., 24 degree beam.
Radio Shack 276-203, 8-maybe 8.5 lumens/watt, slightly oval basically 5
mm. diameter, .4 candela, pointed-oval beam 70 by 30 degrees.
NEW Radio Shack LED - 276-309, 8.5-maybe 9 lumens/watt, 5 mm., 40 degree
beam, 800 mcd.
NEW Radio Shack LED - 276-307, 8-maybe 8.5 lumens/watt, 5 mm., 7
degree beam, 3,000 mcd, $1.99.
Radio Shack's 276-086A 8 lumens/watt, 10 mm. jumbo lamp size, 5 candela,
4 degree beam, peak wavelength 665 nM, dominant wavelength 648-650 nM deep
red, conversion efficiency 12-13%
Radio Shack 276-086 (without the A) 6-8 lumens/watt.
Radio Shack 276-087 (without the A) varies widely 3.5-8.5 lumens/watt.
Radio Shack 276-087A 6-7 lumens/watt.
Radio Shack 276-309. (approx. 6.5-8 lumens/watt)
Chicago Miniature CMD53SRC/E, approx. 8-8.5 lumens/watt.
Chicago Miniature CMD53SRD/G, approx. 8.5-9 lumens/watt. I was dissapointed by these, having paid over US$6 apiece to get them from Newark Electronics in early October 1997. Claimed characteristics are 1,000 mcd at 20 mA with a 60 degree beam angle. I have found the beam angle of the ones I have to be somewhat less. However, these are a truly premium high efficiency, high brightness diffused red LED lamp with good consistency from one piece to another.
AND's AND180HRP 8-8.5 lumens per watt. The peak wavelength is supposedly 644 nm. The dominant wavelength is approx. 632 nM. These LEDs are available from Newark Electronics, catalog number 92F2646, US$ 1.72.
The Toshiba TLRH190P has a similar, maybe identical chip and probably has similar color and efficiency. This is a larger 10 mm. LED with a claimed brightness of 15 candela and is available from Hosfelt Electronics with a catalog number of 25-399 and a price of US$ 3.49 according to their 97-E supplemental catalog.
Others with luminous efficacy around 8 lumens/watt or less:
Panasonic LN261CAL(UR)/Digi-Key P408ND
Toshiba TLRA191P, as sold by Hosfelt Electronics with cat. No. 25-246.
Toshiba TLRA180AP, as sold by Hosfelt Electronics with cat. No. 25-249.
Orange LEDs - 14 lumens/watt by Toshiba, 19-21 lumens/watt by
Hewlett Packard.
The most efficient Hewlett Packard orange LEDs I have seen are the
HPWT-PH00. I can't find these in Hewlett Packard's web site, but I got a
few from someone I did a bit of consulting work for. My recent tests on
7/25 and 7/26 1998 indicate an overall luminous efficacy of 21 lumens per
watt at currents from 20 to 25 mA. These appear to be a variation of
Hewlett Packard's "AutoLEDs" and have a roughly 70 degree beam.
As for a model I have and that Hewlett Packard mentions and gives a
datasheet for in their web site? This is the HLMP-DH16. My tests indicate
an overall luminous efficacy ranging from 17.5 to 21 lumens/watt. This
is a 5 mm. lamp with a 4000 mcd 15 degree beam.
Related Hewlett Packard models:
HLMP-DH18, similar except with lead standoffs.
HLMP-DH23 and HLMP-DH25, 2600 mcd 23-24 degree beam, without/with standoffs
HLMP-DH31 and HLMP-DH33, 1700 mcd 30 degree beam, without/with standoffs
The HPWT-DH00 and HPWT-MH00 are red-orange "AutoLEDs" of "acceptably tail-light
color" (my words), very reddish orange. H.P.'s data sheets claim a
typical light output of 3 lumens for 70 mA with a typical voltage drop of
2.5 volts. This is 17.1 lumens per watt! I saw elsewhere in H.P.'s site
a figure of 2.5 lumens - this is still impressive at 14.3 lumens per watt!
The HLMP-DH00 has a nominally 40 degree beam and the HLMP-MH00 has a
nominally 70 degree beam. Overall luminous efficacy is probably maximized
around 20 lumens/watt at lower currents around 20-40 mA.
Toshiba's TLOA190P(WX) is the most efficient LED that I know of that is
easily available to hobbyists and experimenters, along with Nichia's NSPG
series pure green ones. Their overall luminous efficacy is roughly 14 to maybe
15 lumens per watt. These are available from Hosfelt Electronics, catalog no.
25-276, price US$ 3.49 each according to Hosfelt's no. 98-B catalog.
They have a very narrow main beam that is roughly 2.4 degrees square with
a dim spot in the center (my finding). These LEDs are 10 mm. jumbo lamps.
The beam brightness at 20 mA seems to meet the claim of 36 candela.
Almost as efficient is Radio Shack's 276-206. This LED's overall luminous efficacy is roughly 12-13 lumens per watt. It has a somewhat irregular main beam that is roughly a 2.5 by 3.7 degree rectangle with a claimed brightness of 12 candela at 20 mA. It is a large 10 mm. diameter LED lamp.
Other orange models worth mentioning:
Toshiba TLOA156P, 12 lumens/watt, Hosfelt Electronics catalog number
25-280, 5 mm., .8 candela, 45 degree beam, US$ .55 according to Hosfelt's
no. 96-B catalog.
Toshiba TLOA180AP, 10-11 lumens/watt, and supposedly have 3 candela, 18
degree beam, Hosfelt Electronics Cat. # 25-277, US$ .75 according to their
no. 98B catalog.
Please note that the above orange LEDs have a red-orange color, with dominant wavelengths generally around 610 to 617 nm. Some of these sometimes look more red than orange. Some LED lamps in this color class are supposedly red enough to be used for automobile tail lights!
Hewlett Packard has the HLMP-DJ08, which is truly orange. The dominant wavelength is supposedly 605 nm, which is about that of an NE-2H neon lamp, and less red than the color of most other orange LEDs. This model supposedly has a 9.5 candela 6 degree main beam. I am guessing that the overall luminous efficacy is somewhere around 12 to maybe 16 lumens per watt, (update 7/12/98) but I don't know what this figure is. Other H.P. LEDs with this color and efficiency include the HLMP-GH08, HLMP-DH10, and HLMP-GH10.
Most Efficient Yellow LEDs - 11 lumens/watt by Toshiba and
AND, 13 lumens/watt by Hewlett Packard.
Hewlett Packard's "amber" HLMP-DL16 has an overall luminous efficacy of
about 13 lumens per watt accodring to my tests. This is a 5 mm. model
with a 4.5 candela 15 degree beam. I was hoping for a lot more, given
the beam width and brightness ratings in the datasheet for these and
the orange and red related models.
Related Hewlett Packard "amber" models:
HLMP-DL18 (same thing with lead standoffs), HLMP-DL25 and HLMP-DL27, 2800
mcd 23 to maybe 24 degree beam (without/with standoffs), HLMP-DL31 and
HLMP-DL33 1700 mcd 30 degree beam (without/with standoffs).
There are amber "autoLEDs", HPWT-DL00 and HPWT-ML00. The data sheet works
out 11 lumens per watt for a typical overall luminous efficacy. The typcal
light output is supposedly 2 lumens at 70 mA and the typical voltage drop
at 70 mA is supposedly 2.6 volts. Overall luminous efficacy is probably
maximized closer to 13 lumens/watt at lower currents of 20 to 40 mA.
One really efficient yellow LED is the one in Micro-Light's original
yellow keyring light - about 11 lumens per watt. The LED has a somewhat
irregular beam that is roughly 8 degrees wide.
Someone has e-mailed me a probable supplier of these, or something with a
sodium-yellow color, a 7 degree beam, and a brightness of 6.5 candela.
Conrad Electronics
P.O. Box 12
NL 7500 AA Enschade
This place is in the Netherlands. Ten of these yellow LEDs were reportedly obtained for the equivalent of US$ 1.90 apiece.
The most efficient yellow LED lamps that I have obtained separately are Toshiba's TLYH180P and the suspiciously similar AND "double bright yellow" AND180HYP. Both have luminous efficacy around 11 lumens/watt, and 8 candela 7-8 degree beams. These are 5 mm. lamps. Newark Electronics sells the AND ones for US$ 1.72 each with a catalog number of 92F2647.
You can get the Toshiba TLYH180P(U2) from Hosfelt Electronics (catalog number 25-337) for US$ 1.25, according to their 98-B catalog.
This one used to be available from All Electronics, Phone: (800)-826-5432 web http://www.allcorp.com but they seem to have run out sometime in February 1998.
Yellow LEDs with bright beam candela ratings:
Hewlett Packard HLMP-DL08 and HLMP-DL10, 9500 mcd 5 mm. lamp size, probably
around 11 lumens/watt.
Toshiba TLYH190P, supposedly 23 candela beam which is about 2.4 degrees
roughly square. Hosfelt Electronics catalog no. 25-342, $3.49 according
to the 98-B catalog. My tests indicate an overall luminous efficacy of
only 6 lumens/watt for the two of these I have.
Radio Shack yellow 5 mm. efficient LED lamps - these are very orangish, dominant wavelength around 594 nM:
Wide angle yellow LED lamp 276-302, approx. 10 lumens/watt. 500 mcd 40
degree beam.
276-301, roughly 6 degree square beam with a dim spot in the center (my
findings), a few thousand mcd, approx. 7 lumens/watt.
Most Efficient Yellow-Green LEDs - 3-4 lumens/watt by Toshiba and AND.
The most efficient yellow-green LED I know of is AND's AND183HGP (double bright
green) and the similar Toshiba TLGA183P. These have a luminous efficacy around
3-4 lumens/watt. The beam is supposedly 3 candela and 8 degrees wide. As
many already know, the brightest green LEDs (other than types using
gallium nitride variants) have a very yellowish shade of green, with
dominant wavelengths generally around 570 to 573 nm.
The AND ones are available from Newark Electronics with a catalog number of 92f2644, and a price of US$ 2.01.
The Toshiba TLGA183P is now available from Hosfelt Electronics, with a catalog number of 25-341 and a price of US$ .99 according to their 98-B catalog.
Most Efficient Green LEDs - 13-plus lumens/watt by Nichia.
Nichia NSPG models have extraordinary luminous efficacy of typically approx.
13 lumens per watt. I have briefly tested and eyeballed some of the NSPG500S
LEDs. These are supposedly 15 degree 6 candela LEDs. These are not yellowish
like most other green LEDs, but a very slightly whitish pure green, very
close in color to a green neon lamp - VERY slightly less yellowish. Or, the
color can be described as about that of green "neon" tubing or green
fluorescent lamps - maybe very slightly less white. The dominant wavelength
is around 525 nm.
At lower currents, the color gets less white and less blue, and the dominant wavelength increases slightly (530's at a milliamp or two). The luminous efficacy is higher at lower currents of a few milliamps - around 16-17 lumens/watt.
Another maker of similar LEDs is Toyoda Gosei. The luminous efficacy of
their green LEDs is extremely close to that of the Nichia ones.
Most Efficient Blue-Green LEDs - 8-9 lumens/watt by Nichia.
Nichia also offers the NSPE series of bluish green LEDs. These are about
the color of green traffic lights. The dominant wavelength varies, but is
usually near 500 nM, but slightly longer (more green) at low currents. They are
not quite as bright as NSPG series LEDs, but could easily be around 8-9 lumens
per watt, and may get 10 lumens per watt at lower currents of 2 to a few mA.
There are sub-grades of this LED, sorted by color (dominant wavelength).
Most Efficient Blue LEDs - 4-plus lumens/watt by Nichia.
NOTE: Radio Shack's 276-311 blue LEDs are nice and actually close to
"high brightness", but are not nearly as bright as ones mentioned below.
For more info on blue LEDs in general, please check out my
Blue LED Document.
Nichia's NSPB series blue LEDs have a typical luminous efficacy near 4 lumens
per watt and even higher, near 5 to possibly 6 lumens/watt at lower currents
around a couple to a few mA. They look bright and catch your attention.
The color is only slightly whiter and very slightly greener than that of the
blue phosphor of a TV or a computer monitor. The peak wavelength is around
466 nm, the rated halfwidth is 30 nm, and the dominant wavelength is 470 nm.
Another maker of similar LEDs is Toyoda Gosei. The luminous efficacy of
their green LEDs is extremely close to that of the Nichia ones. There are
some minor differences:
1. The Toyoda Gosei blue LEDs are extremely slightly whiter than Nichia ones. At
very low currents near or under a milliamp, they are also slightly more green.
2. The color change with varying current is slightly greater with Toyoda
Gosei LEDs than Nichia ones.
3. Toyoda Gosei blue LEDs are more efficient and more reliably efficient
at extremely low currents than Nichia ones - especially for blue ones! At
a tenth to a few tenths of a milliamp, Toyoda Gosei blue models could
exceed 8 lumens/watt. (Based on small sample size)
A bright blue LED is now available from Micro Electronics, with a web site at http://www.accesscom.com/~micro/blueled2.htm. Please note that part of the increased candela rating (4 candela) may be due to the longer peak wavelength of 470 nm, closer to the human eye's visual response peak of 555 nm than the shorter wavelengths of other bright blue LEDs. A major part of the intense appearance of blue LEDs is due to stimulation of the human eye's blue response, which peaks around 445-450 nm. These LEDs may not appear more intense than other bright blue LEDs to the extent their candela ratings would indicate. Should this LED be a Nichia NSPB series or similar type, then it should not disappoint anyone.
It is to be noted that Hewlett Packard is now making 470 nM blue LEDs. So is Panasonic, and someone told me they are using Toyoda Gosei chips. Expect almost anyone's 470 nM high brightness blue LEDs to give color, efficiency, and performance like that of the Nichia and Toyoda Gosei ones.
Panasonic 470 nM blue LEDs are now available from Digi-Key. I am keeping
all my info specifically about blue LEDs available from Digi-Key in my
Blue LED Page.
Most Efficient White LEDs - 7-8 lumens/watt by Nichia.
Nichia NSPW series white LEDs have an NSPB series chip combined with a
phosphor to convert some of the blue light to green through red. I have
personally seen the spectrum with my own diffraction grating and my own
eyes - it is a high-color-rendering-index white. The spectrum runs low in
violet, high in mid-blue, low in cyan, and medium from mid-green through
mid-red, and drops off in the far red. Nichia claims a color rendering
index of 85, which I think is in no way exaggerated.
As for luminous efficacy - Nichia now claims 7.5 lumens per watt. My
experience is that Nichia's NSPW series LEDs meet this claim.
Expect luminous efficacy on the high side - possibly exceeding 8
lumens per watt - at lower currents of a few mA.
As for shade of white? The ones I tested seemed like about 6000 to 6500
Kelvin. The color is slightly different in different directions, since
the chip and the phosphor have slightly different directional characteristics.
One spec sheet gives a typical color temperature of 8000 K with a wide
tolerance, another gives typical chromaticity coordinates correlating to
6750 K. The NSPW510S is supposedly a 45 degree 1.1 candela (typical) LED.
There are color ranking subtypes - a, b, and c.
a refers to colors closer to 10,000 Kelvin (bluish).
b refers to colors closer to 6750 Kelvin ("daylight" slightly bluish).
I believe b should have more luminous efficacy than a.
c refers to colors closer to 5150 Kelvin (roughly pure white).
Subtypes other than b may have lower luminous efficacy but still at least 5 lumens per watt.
More Nichia info I moved to a separate document http://www.misty.com/~don/nichia.html.
This includes some suppliers of white LEDs that appear to use Nichia's technology. Information specific to blue LEDs I have in my Blue LED document.
Important Notes on Nichia/Gallium-Nitride LEDs!
1) Blue, blue-green, bright non-yellowish green, and other Nichia type LEDs
have a voltage drop around 3-4 volts, higher than the 1.6 to 2.4 volts
typical of other colors.
2) Gallium nitride blue LEDs and other Nichia type LEDs are fussy, and do not
like their ratings to be exceeded. Exceeding 5 volts reverse voltage even with
low current is supposedly damaging to them. I suspect that destructive
electrolysis is what goes wrong. Peak forward currents in excess of 100 mA
may also be bad. These LEDs are also supposed to be considered static sensitive.
"Micro Lights" Keyring LED flashlights.
Now, back to those "Photon" "Micro Light" keyring lights available at Hosfelt Electronics - they now come in 7 colors. Catalog numbers are:
red - 25-292 ($10.95)
orange - 25-354 ($14.95)
yellow - 25-291 ($10.95)
green - 25-333 ($14.95)
turquoise - 23-355 ($15.95)
blue - 25-332 ($14.95)
white - 25-331 ($14.95)
Hosfelt Electronics sells some bright Toshiba LEDs and some other interesting LEDs.
Phone: (800)-524-6464, (888)-264-6464, (614)-264-6464
FAX: (800)-524-5414, (614)-264-5414
Web: http://www.hosfelt.com/index2.htm
or http://www.hosfelt.com
Orders shipped to Ohio addresses subject to 6.5 percent sales tax. No minimum order for prepay or credit card orders, shipping is extra. Prepay orders must include $6.50 for shipping, any excess will be refunded. Some items mentioned on this web page may be out of stock or discontinued - check with Hosfelt, not me for stocking status.
Michael W. Sforza's Custom Model Light Service (e-mail spitfire@enter.net) also sells bright LEDs. Stock is limited, selection is limited but growing, and prices seem reasonable. E-mail for prices and inquiries. This business specializes in sales of smaller to medium quantities of LEDs and customized addition of lights to building, railroad, vehicle and other models.
I have info on a few Nichia sales offices in a separate document.
Toyoda Gosei makes bright green and blue LEDs. Their exclusive distributor is:
Mitsui & Co. (U.S.A.), Inc.
New York Headquarters
Electronics Dept.
Phone: (212)-878-4326, FAX (212)-878-4323
Toyoda Gosei LED info is now on the web at
http://www.mitsui.co.jp/TG-LED/index.htm .
Please read my disclaimer.
Written by Don Klipstein (Jr). Last updated slightly on 11/11/97. Some info here dates back at least to 1995.