# LS high domes or LED`s with teeth



## danno (Aug 3, 2001)

Yippee!!!!





Since I am the first to respond, I'll try groveling. Gransee, all-knowing and wise source of all things LED, pleeeeeease make these available.


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## RonM (Aug 3, 2001)

What are "high domes" and what makes them different from the other LS LEDs?


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## Badbeams3 (Aug 3, 2001)

Well, they have a higher dome shape (the led itself, the dementions on the outside are the same (optics included model, taller with no optics)...they are also called "Lambertian" (I don`t have a clue)...not flat like the low dome or "batwing"...they have a "typical forward voltage" of 2.95 compared to the low dome batwings at 2.85...so they like .10 volts more to be at their happy max. But still draw the same ma at their max rating (350ma)...so a lot more light for no increase in power use. 

I beleive they still need good heat sinks to run anywhere near max...the red-orange being the brightest of the bunch.

They do not make a white, blue, green high dome...yet.




www.lumileds.com
www.luxeon.com

If Gransee would put these in a Arc...and if you could live with amber or red-orange colors...it would smoke a Surefire E-1 and run twice as long on one 123 batt...dis is good


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## Chris M. (Aug 3, 2001)

_Lambertian_

From what I understand, that refers to the distribution of light output of the bare LED. Not a textbook definition, just out of my fuzzy brain, but Lambertian distribution is even all-round light radiating from a point source, that being- at all angles at an identical distance, its intensity is the same. 
The current LSs are not this way, their "batwing" light output is a little dimmer in the centre on-axis, peaking further off-axis, then dropping off again. Basically like a brighter ring of light round a slightly dimmer centre.

I believe those Lambertian high-dome Luxeons use a slightly more efficient die too- hence the different ratings and greater overall lumen output.

I`d like to see them too if at all possible



. And the newer generation whites as well- that use a triphosphor coating (like compact flourescent lamps) instead of the currently used yellow phosphor- the result, a purer light and better colour rendition. Those, apparently, are avaliable to OEMs (like Arc Flashlight



), or will be very soon. Joe Public will have to wait till early next year to get them directly.


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## **DONOTDELETE** (Aug 3, 2001)

i wonder how much more spotty that would make the light
myself i wouldnt mind finding different degrees of the top optics
if they would stick with ONE style then throw varying optics on that one style
seems thay could keep Design costs down and concentrate on 2 things

making the single design bigger & better and lower in power.

Pumping out quantities of the stuff to pay for it all

sounds like a plan, now where is my diversment of stock options so i can get on the board


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## Badbeams3 (Aug 3, 2001)

Update: From "OEM Guide" pg. 21...the WHITE will be available in the high dome "Lambertian" at the end of 2001.

The current increase in light output from the low dome to high dome is 76%~80%...if the white is in keeping with this it should have an output of...31.68 lumen to 32.4 lumen...compared to the 18 lumen rating we have now...and you can kiss your E-1`s goodbye even if run way under powered...I assume these will work their way into the Arc`s when avalible in 3 or 4 months.

Ken...make that...Bad.


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## Gransee (Aug 3, 2001)

Yes, I have had 3-4 of the lambertian samples here for awhile. Haven't got around to testing them though. When I orginally got the samples, no production was available. Now they have red and amber. The whites will be awhile. Since they are supposed to be drop-in compatible with the batwings I have now, we would like to use the lambertian ambers and red in the LS. Was supposed to be a suprise though. Here's some pics:

Luxeon Star, Amber Color, Lambertian pattern







Amber Lambertian on left, cyan batwing middle, amber batwing with optics right.






The Lambertian draws less current at the same voltage suggesting either a die size difference or efficiency improvement (or both). I won't spec them for the Arc-LS until I can confirm that we can get them in quantity. Still working that angle...


Like Craig, Chris and Brock, the manufacturer's tell us about upcoming products but won't let us say anything until the cat's out of the bag. I will say this, next year LEDs are going to be... Uh. Bright.






Peter Gransee


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## The_LED_Museum (Aug 3, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Gransee:
*Like Craig, Chris and Brock, the manufacturer's tell us about upcoming products but won't let us say anything until the cat's out of the bag*<HR></BLOCKQUOTE>

I can almost hear that poor kitty pawing through the 2.0 mil plastic from the Hefty (or Glad) bag it's in. It's making these raspy, gasping, athsmatic noises like it's choking on its own bladder. Please, somebody get out their Tektite Knife-Lite and let the kitty out!!!





I, for one, can't wait to see an LS LED with the new die configuration.
As if I'm not already blown clean out of the water by the LS proto.


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## Badbeams3 (Aug 4, 2001)

According to Future electronics the high domes are avalible now...they want $16, even though thier cataloge says $22...minunmum order is one...ground shipping is $7 (talk about a rip off). I tried to get a hold of Lumileds at their toll free line 1-877-298-9455 to confirm, but no answer.

These are rated much higher than the low domes we are playing with...

red-orange- available in high dome only, 55 lumen...5 less than a SureFire E-2



Makes me feel all warm and cozy inside...like a shot of fine bourbon...where`s my cigar?

red- low dome 25 lumen...high dome 44 lumen

amber- low dome 20 lumen...high dome 36


re-orange high dome (with optics) LXHL-NH94

red high dome (with optics) LXHL-ND94

amber high dome (with optics) LXHL-NL94

All ratings at 2.95 volts at 350ma

Recommendation:...get them...no step-ups, resistors, dancing bears needed, just a 3 volt 123 or 2 AA or 2 (insert favorite batts here)...stop playing with wimpy low domes...keep your sunglasses handy.

Means:...grobbeling, begging, pestering and doing other things to make Gransee miserable unless he makes them available to us is the suggested course of action.

Bad





www.luxeon.com 
www.lumileds.com


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## Badbeams3 (Aug 4, 2001)

The tough choice I must make soon is...should I hold off on getting an Arc LS 4 months untill the high dome whites are out. That would mean losing my chance for a serial numbered one...

What I wish I could do is get a red-orange or amber high dome now and a white high dome later...but my wallet says that won`t happen...

I don`t suppose I could buy a serial numbered body now and let it rest in the Arc company`s store room untill the high dome whites are out?

Bad


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## PeLu (Aug 4, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by badbeam:
*
All ratings at 2.95 volts at 350ma
*<HR></BLOCKQUOTE>

According to my informations the amber ones are rated for 250mA, all the other ones for 350mA. Is that still correct?


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## **DONOTDELETE** (Aug 4, 2001)

could it be? the...silence...of...the...lambertians..????




goodnight evrybody...


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## The_LED_Museum (Aug 4, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by PeLu:
*According to my informations the amber ones are rated for 250mA, all the other ones for 350mA. Is that still correct?*<HR></BLOCKQUOTE>

I had spec sheets on all of these things.
They were all lost in an earthquake.

I have since replaced them all - but they were buried under a flurry of incomings... let me see if I can find them and give you the answer you seek... (searching...)


(searching... 20 minutes later)...
(searching... 40 minutes later)...
(searching... 90 minutes later)...
well that's f***ing crappy... two hours and the $*&#$*@^ documentation has yet to be found...




Dammit, dammit, dammit... I want to snap a 3-wood over my knee and chuck the $*%&# thing in the nearest water hazard... 

I guess I'll have to look for this stuff overnight and then post again in the morning if I find it.


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## danno (Aug 4, 2001)

Is this the data sheet you were looking for? http://www.luxeon.com/LuxeonStarDatasheet.pdf


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## PeLu (Aug 5, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by danno:
*Is this the data sheet you were looking for? *<HR></BLOCKQUOTE>

This one is from May, there are newer datasheets (on paper).
BTW, a person working at Phillips uses the amber one as a main caving light for demanding trips. Getting some 50-60lm/W at 250mA.


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## KenBar (Aug 5, 2001)

I had half a dozen LS to play with. The Amber is the most useful light I have seen in some time. I just finished a proto (



) and I am going to buy a new mounting case today. I am not driving it to the wall either! It is a strange phenomemom. The white is more like a flashlight, but I actually seem to observe more easily with the amber. IMHO
( It goes without saying that you don't want to throw together some cat5 cabling using this color )


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## Badbeams3 (Aug 5, 2001)

Hi Ken, do you have the 20 lumen low dome or the 36 lumen high dome amber? Have you done any run time test on it? Are you useing a resistor? What voltage are you running it at? Do you have one of the 55 lumen red-orange? 

---------------------------------------------

One possible advantge is the more efficent high domes should produce the same light output at a lower power level resulting in less HEAT to contend with.

Another advantage is it should be able to run on a lower power step-up (white) resulting in a longer run time with the same or better lumen output. 

Is a step-up even usefull in the amber LS`s given their volt requirments or is it a waste of batt power? Silvirons test seem to indicate a long and bright burn time without one, although he has yet to test an amber.

It seems to me that a small resistor or better heatsink and no resistor would be the way to go with the amber color...the step-up serving only to reduce the initial brightness without improving the total run time (actually shortening the run time). 

Has anyone actually done a comparison test to determine whether this is true or not? 

I am thinking about getting the high dome amber Arc LS now (assuming the Arc company can get and decides to use them) and getting a high dome white Arc later...when their out.

I have a amber spot light that shines up on the ceiling in my living room and it`s nice, easy to see with...warm and lights the room very well...makes my wife look younger... saves money as I don`t need as many viagra pills.

Thanks, Bad


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## KenBar (Aug 5, 2001)

I have high dome.
I had a conversation with a Canadian LumiLed engineer and we swapped some information....mostly one way...from him



. He showed interest, and we had a discussion about the 2621. I'm going with it as well as the SatCure to drive it.
I have not totally decided on the power. I go back and forth. I am taking my daughter on an outing 100 miles to Radio Shack in a few minutes



. I am going to look for heat sinks and project boxes. I really like the Amber LS.
=================
I am running it at 300-310 ma and around 3-3.5 volts. I am using the 2621 as it is pulsed and IF I read the doc correctly, it will allow me to run a little more current through it without damage. I have not run any balls to the wall output tests as I don't want to mess up the amber LS. I will not do that in real life. I suppose if I had some to throw away, I might. I did sacrifice one of the white LSHL's, however. I took off the optics etc. etc. down to the bare board to see if I could get along with the reduced light output. NO WAY. They must use some optical grade plastic or something as it really makes it brighter. That is my biggest problem now ....trying to mount it with that chunk of lens....and a heat sink and not have a boat anchor..LOL


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## KenBar (Aug 5, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by badbeam:
[QB]I took the refector/lens out and was surprised the back of the reflector is clear...no chrome/no white..QB]<HR></BLOCKQUOTE>

In school I worked for an eye surgeon and ran the dispensary. I have forgotten most of what I used to know about lenses. Here is my guess without throwing around words I no longer remember what they mean...angle of incidence etc etc..... The reflector must have had some major thought go into its development. It seems to take ALL stray light and focus/reflect it forward. It also looks to be made of a high grade polycarb. You can pop these things out for peanuts once you do the initial design. This is just an educated guess. I was really sad that I have to use the lens as it it such a space hog...HUGE. I still am trying to figure out a graceful way to mount it.


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## Badbeams3 (Aug 5, 2001)

I must agree the lens really does a great job...but I still wonder if it would be brighter if the barrel area was white or chromed (not the back of the lens, just the inside barrel area) maybe just filling it with white tissue paper? What do you think? Waste of time?


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## Gransee (Aug 5, 2001)

I have to admit, I don't know all that it going on with this lens. When you coat it with a black material (epoxy or sharpy ink) the output is reduced. If you spray the back (keep it out of the interior and off the front) with chrome paint, the output is reduced. It seems strange to me that if the outside of the lens is touched by almost anything, the output is reduced. Going to try clear epoxy next. This is an important step because we want to maximize shock resistance by encasing the lens.

Btw, in the Arc-LS, the ID around the lens is shiny aluminum. Not sure it has any effect though since it has an air gap between it and the lens.

Peter Gransee

Update 8/5/01 11:41PM, I found out what was causing the output to be reduced. It has to do with the index of refraction of the material interfacing with the OD of the lens. The farther it is from the properties of air, the more light is absorbed (making the output reduced).


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## Badbeams3 (Aug 5, 2001)

I found the same results with the bumper chrome paint I just tried (on back side of lens). I wonder if the bumper chrome is to gray...did you use a better chrome? I tried putting white tissue paper in the other one for a quick experment and it`s bright...but I`m not sure if brighter as I don`t have a way to do an a~b comparison now




Have you tried a white tissue Gransee? Could we be seeing wave cancelation? If so would painting the inside of the barrel with flat-black be of benifit to reduce unwanted reflections? Your thoughts please.


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## KenBar (Aug 5, 2001)

Well...I am done... Now to mount this little child..




The heat sink makes a big sucking sound to the south. NO PROBLEM with heat. The sides made great mechanical connection, a little paste, a little hitemp epoxy...and done.





As far as the light output...here may be a clue. I was licensed to do contacts, regular lenses, and artificial eyes. People who had real thick eyeglass lenses ( high minus ) were a constant challenge. Almost ANYTHING I did to the outside edge of the lens was observed in the lens as you looked at the person from the front. You could grind the lens with a bevel to make it much thinner, polish it so you could not see it...but the end product was hideous. Anything that touched, scratched etc. the outside edge would mess up the job.

This is a cousin of the reduced output I would think. I would imagine the (refracted, reflected ) light rays are sensitive to any messing around. I lost outputl when I tried to remove that little tit on the edge and file it down some. 

Any physics people out there? You really would need to see the lens to give an opinion probably.??


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## Badbeams3 (Aug 5, 2001)

Hey, looking good can`t wait to see what the finished product looks like...your trip to Radio Shack was a succes then?


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## KenBar (Aug 5, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by badbeam:
*...your trip to Radio Shack was a succes then?*<HR></BLOCKQUOTE>

Any trip 200 miles with a 5 year old and you make it back is a success



!

I still have the lens problem I am wrestling with. Since this heat sink is doing such an incredible job, I am thinking of mounting a pair side by side. I might just be suffering from LED affluenzia.





I wish I knew what the light rays did as they left the lens....how much light output I would lose if I cut the hole 1mm smaller around the light etc etc...

I haven't come up with a graceful way to present the lens...ARrrgh..
I guess Gransee has figured his out by now.
I am glad I am not in his shoes...LOL 

I think I may even go with just one D cell. 
I am kind of watching to see the results of Brock and Telephony gubumamama....
I will base what I do on them.
One D cell sure will blast out the light and run for a long time and not be too big.

Ken


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## Badbeams3 (Aug 6, 2001)

I took the refector/lens out and was surprised the back of the reflector is clear...no chrome/no white...I wonder if this is done for a reason. Has anyone tried putting foil in there to see if it improves...can`t find any here and da wife`s got the car.


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## Badbeams3 (Jan 14, 2002)

Sorry to drag these old posts up from the graveyard but the delay getting the LS Arc centering problems worked out could be to our benifit...the high dome whites, with optics, should be out any time now and are brighter than the low domes. If the Arc company does not already have a bunch of the low domes sitting around waiting to be used, maybe they will use the brighter (twice as bright?) high domes when they get the Arc LS product out in mass...I believe this would be good...brighter better!


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## Badbeams3 (Jan 14, 2002)

Well, I think all the white ones out right now are low domes...perhaps the increase in brightness you see is do to different batches...stock...the high domes should be much brighter. Perhaps someone will call Lumiled after they open at 8:00 this morning and find out if the high dome are still coming out on time...when the high domes will released. They were supposed to be out the end of 2001. Their phone# 1-877-298-9455


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## Badbeams3 (Jan 14, 2002)

Well, I talked to them but no news...only that it`s a little behind and the release should be in the first quarter of this year...hmm bug.


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## php_44 (Jan 14, 2002)

*Batwing .vs. Lambertian*

There is a _significant_ technology improvement between the "batwing" and "lambertian" type of luxeon stars. It's really a quantum leap in efficiency. *Check this out.*

I've done some mining on the Lumileds web site, in particular I've read about 7 MB of technical papers they've stuck in a corner on the site. The papers are from 2000 and 2001. I've also looked at close up pictures of the LEDs and how they are constructed from the ledmuseum and a few flashlight shots - to match the Lumiled papers with what they are selling. Having said that - this is still my best engineering "guess" and I have not talked with Lumileds.


All the "batwing" devices (red, orange, amber, green, blue, and white) appear to have wire bonds to bring current to the LED. They also have a pattern of conductive material to distrubute the current evenly over the LED die. I think all these devices are first generation to demonstrate high flux LEDs mounted in a traditional fashion to their very innovative package. The wires and conductive grid are all in the way of light escaping the LED and reduce efficiency.

The "labertian" devices are a new animal. It looks like they came up with a neat method of fabricating the LEDs so that they could mount them upside down with all connections to the die made on the bottom (the side you can't see). They also made the bottom a mirror to reflect light back up. The side we can see is now completely free of wires and conductive grids - allowing much more light to escape.

*Using this new type of device they have demonstrated a 150 lumen (!) white LED that consumes 5 watts!!* (for reference a 15W tungsten buld is good for 90 lumen or so). According to Lumiled materials - the white are the least efficient ones - the red/orange/amber are more efficient so the same 5W would give you 200-300 Lumens.

I haven't checked but someone posted part numbers for Lamberitian LS parts in Red->Amber. These are the AlInGaP chemistry. The green/blue/white are InGaN chemistry - those are harder to flip mount I bet.

*These new LEDs are awesome!*


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## Badbeams3 (Jan 14, 2002)

I admit I don`t understand watts well...how many amps would 5 watts be? To get 150 lumen from a Ls...there must be a lot of heat to deal with...


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## The_LED_Museum (Jan 14, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by php_44:
*Batwing .vs. Lambertian

The "labertian" devices are a new animal. It looks like they came up with a neat method of fabricating the LEDs so that they could mount them upside down with all connections to the die made on the bottom (the side you can't see*<HR></BLOCKQUOTE>

The three lambertian Luxeons I've seen all have the star-shaped top ohmic contact on a TIP chip. One of them (a yellow /O with square PCB and flush-front lens) is of known recent manufacture, the other two (a red & a yellow /C with star-shaped PCB) are of suspected recent manufacture.

So this LED you're describing must be something that's still "down the pipe".


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## **DONOTDELETE** (Jan 14, 2002)

well i am happy to see this thread still survives, i still thought that somone would come up with KENBs answer to his question, as from my observations there is quite a hunk of light leaving the edges of the optics, now if that light is redirected back into the optics, it MAY not provide more light to the SPOT in the center, but how about beyond that, what if it puts more light foreward, but just not directed into the spot location?


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## **DONOTDELETE** (Jan 15, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Video Guy:
*there is quite a hunk of light leaving the edges of the optics, now if that light is redirected back into the optics*<HR></BLOCKQUOTE>

The inexpensive LS/O collimator is 90% efficient. Some of the photons escape off the edges, some are reflected back down into the chip and slug, and others are absorbed by the plastic and re-radiated outside the visible spectrum.

To get more than 90%, you may need to use a more exotic medium and/or finer engineering and/or tighter manufacturing---all of which cost more money.

No doubt Luxeon put a little thought into this, and settled on a good efficiency-per-dollar solution.


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## **DONOTDELETE** (Jan 16, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Ken B:
*I admit I don`t understand watts well...how many amps would 5 watts be? To get 150 lumen from a Ls...there must be a lot of heat to deal with...*<HR></BLOCKQUOTE>

Amps is simply watts divided by volts.

The red/amber/orange LS's have a typical forward voltage of 2.95 volts, so that's 1.7 amps.

The white/green/cyan/blue LS's are around 3.4 volts, so that's about 1.5 amps.

And yes, there's a lot of heat to deal with.


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## php_44 (Jan 17, 2002)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by telephony:
*The three lambertian Luxeons I've seen all have the star-shaped top ohmic contact on a TIP chip. One of them (a yellow /O with square PCB and flush-front lens) is of known recent manufacture, the other two (a red & a yellow /C with star-shaped PCB) are of suspected recent manufacture.

So this LED you're describing must be something that's still "down the pipe".*<HR></BLOCKQUOTE>

This is actually good news! The flip chip mounting will be a significant enhancement when it's available in production units. So knowing that the lambertians you have are still using standard mounting, we can look forward to the flip mount as another big leap in light output - hopefully soon.


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