1 Watt Luxeons Versus Multiple LEDS

A friend of mine asked me to recommend to him a good, relatively inexpensive Luxeon flashlight. When I asked him what he envisioned using the light for, he replied general purpose, around the house use. Not tactical, EDC, etc. He also wanted a light that runs on common AA's, not more expensive lithiums.

I've heard good things about the Streamlight Jr. Luxeon, so I told him to check that out. I also thought of the Streamlight 4AA, which of course is not a Luxeon flashlight, but has 7 regular LEDS instead.

Which got me to thinking: what are the advantages and disadvantages of a single Luxeon LED versus multiple Nichia LEDS? Which is more efficient in terms of run time? Which is generally better in terms of light output given the same voltage and runtime? Which is more likely to be off color? I would think life expectancy in terms of hours would be comparable, as would ruggedness (both easily besting incandescents). Cost seems comparable for both types as long as the light puts out less than 50 lumens to me.

What do you guys think?

Bruise

Re: 1 Watt Luxeons Vesus Multiple LEDS

sounds like UK4AA for run time.... 12 hours regulated.
and price.. 20.00 not the brightest light since it is underdriven but sturdy and water resistant.
most 5mm LED lights wont be regulated and run time will vary by drive current/battery configuration plus circuitry or resistor values involved. Typically 5mm LED lights will be less white than a lux even if you get one with a tint to it, and run longer with the same amount of cells with tapering light output. beam patterns will be a shorter softer flood with multiple LEDs verses some throw and a hot spot with a luxeon. A luxeon should give you more run time/lumen and voltage isn't the name of the game, it is drive current. Higher voltages have to be regulated or dissapated down to Vf or drive forward voltage which is close to the same for both the luxeon 1watt and the 5mm.

Re: 1 Watt Luxeons Vesus Multiple LEDS

Here's one reason to go Luxeon over multiple LEDs - throw. It'll be a LOT easier to focus the light from one side-emitting Luxeon than from the ten or more 5mms that you'd typically need to pull off even the level of illumination a LuxI will give you.

The main reason you'd go with multiple 5mms is for flood and battery life, since they're not going to be as bright and require as much current to run as the same Luxeon. They're also cheaper, part for part... but that means you give up brightness and throw - the Luxeon'll do more with the same amount of power than the equivalent number of 5mm LEDs required to achieve a similar level of illumination.

With the same voltage, you're going to get better illumination from the Luxeon, and probably better color in most cases so long as the Luxeon is a high-dome (Lambertian).

Re: 1 Watt Luxeons Vesus Multiple LEDS

UK4AAeLED = $20, shipped?
Where can I get this offer from?

Re: 1 Watt Luxeons Vesus Multiple LEDS

the 20.00 doesn't include shipping and you can get it from brightguy.com or premieronlineproducts.com I haven't ordered from either place but I have heard brightguy is ok and know nobody that has ordered from premier but they look legit.
you will have to check on shipping costs

Re: 1 Watt Luxeons Vesus Multiple LEDS

Tell him to help support small business by purchasing an Elektrolumens XM-3 :^)

Re: 1 Watt Luxeons Vesus Multiple LEDS

I used to worry about buying a Luxeon flashlight compared to a flashlight with multiple LEDs because I had the fear that if one LED goes bad in the 5mm flashlight, the light will still work. If one LED goes bad in the Luxeon flashlight, the whole thing goes kaput. Now, the fear isn't as pronounced as knowledge is power and I more believe now that once the Luxeon is heatsinked properly, it will alwayse be better than 5mm LEDs. (unless of course brightness or space is not a priority.Sometimes cheap and easy is better.)
>5mm LEDs are much cheaper than Luxeons.
>You are more likely to be dissapointed by an off coloured Luxeon than by a particularly blue 5mmLED since they are more highly regarded.
> LuxIII LEDs are more expensive than plain ole Luxeons however, they have less colour variations and of course, can handle more power.

Re: 1 Watt Luxeons Vesus Multiple LEDS

I have some multiple LED lights set aside for long-runtime emergency use but I've gotten tired of the blueness of 5mm LEDs. I mainly get Luxeon III lights now because I just enjoy getting that bright white light.

To me the ideal solution is a LuxIII light with a two-level switch so you can have longer run time if needed. The new Streamlight 2L Task Light has this feature but doesn't use AA batteries.

Re: 1 Watt Luxeons Vesus Multiple LEDS

There's one great advantage with 5mm LEDs: they already have their proper photon managment system installed: the epoxy dome. THis means that you can have much smaller lights that do just as well in close quartes as a Luxeon light albeit less beautiful (ringy and blue).
For everything else the Luxeon rulez /ubbthreads/images/graemlins/buttrock.gif !
bernhard

Hi.

I've posted sugetions to such questions. Therefore my appologies for redundancy.

First of all I too do like the SL Jr. and even unscrewing the colminator lens makes it into an impresive short range flood. I'm making another cap to slip over (a MOD) for such
an option.

I often wonder why the Streamlight tt-3AA Luxeon is often over looked.

It uses 3 AA's Has a general battery life of 24+ hours, a 35 lumens beam vs a 30 lumens beam of the JR, 9 inches long
tapered head with recessed button.

I've included a few links for you.

http://zvis.com/flshlit/led/strm3aa.shtml

http://flashlightreviews2.home.att.net/reviews/streamlight_tasklux.htm

http://www.streamlight.com/tasklight_specifications.htm
(bottom of page) /ubbthreads/images/graemlins/smile.gif

P.S> I do beleive that the tt-3aa is much brighter than he posted 35 lumens , more around 40-42 lumens in my opinion.
Probably due to the longer colimnator lens.

Ah, The Luxeon myth. Current generation 5mm LEDs from Nichia (T grade) at ~45lm/W are much more efficient than Luxeon stars . The Nichia Jc grade 1.25W Jupiters are at 40-50lm/W which is also better than Luxeon. Heat sinking is easier with 5mm since the die are spread out and color bins can be had from yellowish to ice blue tint. Mainly the 1W single die parts are just easier to tight focus. Nothing else

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chanik said:
Ah, The Luxeon myth. Current generation 5mm LEDs from Nichia (T grade) at ~45lm/W are much more efficient than Luxeon stars . The Nichia Jc grade 1.25W Jupiters are at 40-50lm/W which is also better than Luxeon. Heat sinking is easier with 5mm since the die are spread out and color bins can be had from yellowish to ice blue tint. Mainly the 1W single die parts are just easier to tight focus. Nothing else

[/ QUOTE ]

At what current level do T-grades get 45-50lm/W? Are t-grade nicias common and easy to obtain? I can run a Q-binned (common) luxeon at 100mA and get 45lm/W.

Heat sinking is not easier - if you want to get the equivalent output of a LuxI, you need 10-15 5mm LEDs - you will still be dealing with the same amount of heat. How about a LuxIII? To get 80 lumens, you need 20-30 5mm LEDs - it's still going to dissipate 2-3W of heat. It's also a wiring nightmare, as you either need to put those all in parallel (each needs its own resistor or you risk large current imbalances) or in series strings, which means higher input voltage, or a boost converter.

5mm LEDs are much worse in the longevity dept. They suffer from epoxy degridation that reduces output to 50% in 10K hours. LuxI and III driven at spec last 50K hours before 70% degridation.

Finally, cost. A LuxI can be obtained for $10-12. An equivalent number of 5mm will cost $10-$15 (for cheap), and $20-30 for Nichias. To replace a LuxIII (cost, $14-$16), would cost $20-$30 in 5mm generics, and $40-$60 in Nichias.

So you have a huge form factor, wiring nightmare, reduced longevity, cost, and difficult optical system. Those are the disadvantages of 5mm LEDs vs. Luxeons.

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evan9162 said:
Heat sinking is not easier - if you want to get the equivalent output of a LuxI, you need 10-15 5mm LEDs - <snip>

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The big error with this is the Luxeon marketting spin "equal to 15-20 5mm LEDs etc.". 45Lm/W at 0.2W is what we've found. If you want to match lumens with the current generation Q bin Luxeon star, you'd need 4 of them. That's all, 4. Q binned 1W star is 30-40lm/W. As for degradation, most flashlight get much less than 100hrs use in their lifetime. A maglight bulb is only rated for 10hrs, for instance. I think I've changed one in my entire life.

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evan9162 said:
Finally, cost. A LuxI can be obtained for $10-12.

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Man, where do you guys buy your LEDs?

I paid $8/ea for LuxIII's about 6 months ago, and I just paid $20/ea for 3 LuxV Portables.

Scott

Mutiple LED in streamlight give a smooth light for walk in the dark around house. But it cann't focus or throw away to something far or behide bush. S5treamlight JR can do that but cann't make a long rumtime as the led 4AA.

[ QUOTE ]
Krit said:
Mutiple LED in streamlight give a smooth light for walk in the dark around house. But it cann't focus or throw away to something far or behide bush. S5treamlight JR can do that but cann't make a long rumtime as the led 4AA.

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That is indeed the main difference with the 1W or 3W single die. The 5W, BTW have such a big die that they too are hard to focus well. That said, any 1W LED can be well focused and Nichia has the edge on Lumileds now. The latest Cree 1W LED at 50-60lm/W seems to have Nichia beat although I haven't tested those yet.

> The 5W, BTW have such a big die that they too are hard to focus well.

The 5W is made out of 4 separate die. The resultant hole in the middle is the problem.

Too bad Fraen doesn't make a small 19mm lens somewhat similar to their larger 30mm medium lens.

Scott

The 1 Watt Luxeons are brighter, cleaner and can be easily
focused. The advantage of Multiple LED Flashlights is that thay are cheaper to purchase, if you lose or damage one
it won't hurt your pocket as much.