I've seen the light! (5W Luxeon, that is)

[Steve-at-Springboard]

I\'ve seen the light! (5W Luxeon, that is)

The local Future Electronics rep came by to drop off some 1W Luxeon side-emitter samples and show me his 5W Luxeon flashlight! He was working the LightFair show and got it there. The flashlight is to show off the Luxeon, its not a product for sale. It looked rather like a hand-held broadcast microphone from the sixties. Don't know what it was powered by but, it was enough! Appeared to use the flashlight reflector rather than Luxeon optics. I pulled out my EDC Surefire E2 for comparison. Beam diameter was about 50% larger than E2 and even, not brighter in the center as with the E2. There was some inconsistency in the beam but only in comparison to the E2 beam. About a 9 to the E2 10 in beam quality. Brightness?? About double (as advertised). Could it have been 100 lumens or 110? Yeah, but it could have been 130 also. I used my calibrated Mark I eyeball but I only had the E2 for reference. The rep came a week or so early otherwise I would have brought 4 or 5 other lights for reference, and a couple of big guys to hold him while I ran out the back door with his flashlight. Oh, BTW, the beam color was significantly whiter than the E2 but without any perceptible bluish or other tint. The Luxeons in these lights were probably hand-selected for the demo task, your mileage may vary. Very impressive! Wish I'd had my digital camera and a few hours to compare, photograph, make beam shots, etc.

Hope this helps,

Steve

 

[**DONOTDELETE**]

Re: I\'ve seen the light! (5W Luxeon, that is)

Oh, man, NOW what? Should I buy more lights while waiting, or just wait (while buying more lights)?

Sounds impressive!

 

[Wits' End]

Re: I\'ve seen the light! (5W Luxeon, that is)

You let him leave with it!!??

With optics it would have been, what 4, 6 times brighter than E-2?

I want to be first in line for one of these (or someones) 5W Luxeon lights. PLEASE!

 

[machspass]

Re: I\'ve seen the light! (5W Luxeon, that is)

Holey Moley, Batman! That sounds great! I dunno if I can handle one of those too soon, since I'm still getting over my amazement and fascination with the regular LS. I'm still trying to decide which flashlight I want to retro-fit with it.

 

[Saaby]

Re: I\'ve seen the light! (5W Luxeon, that is)

Ok, question...The Luxeons already run quite...warm. Will these likely run even warmer or will they be about the same as they are designed for 5W? How many volts is that...how many batteries am I going to need to power one of these things?

 

[WaltH]

Re: I\'ve seen the light! (5W Luxeon, that is)

Saaby,
These 5 watters run MUCH warmer than the 1's. I doubt we'll see one in a small package like the ARC-LS. More likely a 3 or 4 C cell setup. You could run it off 2 lithiums 123's but the case would still need to be larger than that to dissipate heat.

 

[Saaby]

Re: I\'ve seen the light! (5W Luxeon, that is)

Alrighy then...sounds like the same thing happening to CPUs, the cores keep getting smaller and smaller and the dies and heatsink/fans people put on them keep getting larger and larger, soon you'll need a separate refrigerated case with an industrial sized (Think underground parking lot) fan for your CPU that's as big as a human hair...

Hopefully some new breakthrough technology is just around the corner that will allow these things to cool down a bit.

 

[Lux Luthor]

Re: I\'ve seen the light! (5W Luxeon, that is)

Steve,

You didn't plummet him to the ground and steal his Luxeon to bring us pictures? How can you be a loyal CPF member if you aren't even willing to spend a few months in prison for aggravated assault?

 

[brightnorm]

Re: I\'ve seen the light! (5W Luxeon, that is)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Steve-at-Springboard:
.....The Luxeons in these lights were probably hand-selected for the demo task, your mileage may vary. Very impressive! <HR></BLOCKQUOTE>

Steve,

Would the 5 watter outrun an efficient 5W incandescent putting out identical lumens from an identical power source?

Brightnorm

 

[Jonathan]

Re: I\'ve seen the light! (5W Luxeon, that is)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by brightnorm:
Steve,

Would the 5 watter outrun an efficient 5W incandescent putting out identical lumens from an identical power source?

Brightnorm<HR></BLOCKQUOTE>

Based upon datasheets and reports here, the Luxeon '5 watter' when operated at rated current, will produce about the same amount of light as a properly driven efficient incandescent lamp. But there are lots of details that go into the comparison.

I took a look at data from Luxeon and from Carley lamps in order to make these comparisons.

The first detail is that the LEDs actually show quite a range of performance. While the datasheet gives typical values, it also reports minimum values which are about 25% lower than typical. Additionally, the datasheet reports the light output with the junction at 25C...and it will almost always be warmer than this in operation, which reduces light output.

On the other hand LEDs actually in the field produce better results that the datasheet claims, eg:
PeLu's report on the LS 5W; 130 lumen out with 4.3 watt in!!!

So depending upon which sample of the LS5W you get, you might be quite happy or quite disappointed.

There is also the issue of 'properly driving' the incandescent lamp. Lamp efficiency is tremendously dependant upon voltage, and scales roughly as the square of the voltage. Lamp output is even worse, scaling as voltage to the 3.5 power. This means that if the lamp voltage were to drop by 10%, the lamp efficiency would drop by 19%, and the lamp output would drop by 31%. (Say yuk now!) If you push the voltage up above the ratings, then the efficiency and output actually go up, but the life time goes to hell in a bucket.

To run an incandescent properly takes an electronic voltage regulator, and if you don't have one, then you will not get the rated efficiency.

LEDs efficiency also changes with applied voltage, in a somewhat different fashion. The great thing is that the efficiency goes _up_ as power levels go down. This means that as batteries drain and the power going to the LED decreases, the light output will decrease as well, but you don't get kicked in the *** by dropping efficiency on top of the drop in power.

Finally, incandescent lamps are pushed to rather short life times in order to get reasonable efficiency. The LS is rated at a 100,000 hour life, and at the end of life (if properly operated) the output is expected to drop by some 20%. The Carley lamp that I picked for comparison has a rated life of 20 hours.

So I would say that if properly driven, using the same amount of input power to the electronics, the Luxeon would usually put out more light, and last for a longer time, than a selected incandescent.

I've planning on replacing the 5W halogen headlamp on my bike

But I'm keeping the 15W 'high beam'.

-Jon

 

[brightnorm]

Re: I\'ve seen the light! (5W Luxeon, that is)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Jonathan:
Based upon datasheets and reports here, the Luxeon '5 watter' when operated at rated current, will produce about the same amount of light as a properly driven efficient incandescent lamp. But there are lots of details that go into the comparison.
<HR></BLOCKQUOTE>

Jon,

Thanks for that very informative and comprehensive answer. I think that if we tapped all the knowledge here at CPF we could produce one heck of an information sheet or even a flashlight textbook!

Pelu's 130L/4.3W is hard to believe, really stunning.

Brightnorm

 

[Steve-at-Springboard]

Re: I\'ve seen the light! (5W Luxeon, that is)

To answer some of your questions (that haven't been answered by other CPFers):

The 5W demo flashlight DID have optics but they weren't part of the Luxeon package. The flashlight was specially made to demo the Luxeon and was similar to the one they previewed the 1W Luxeon part. It had a reflector about 1.25" diameter and, I think, a glass lens that may have really been a plano-convex lens to collimate the output. Since they are larger than what will come with the Luxeon w/optics, they may perform better so, no, the Luxeon with optics will probably not be brighter.

The rep showed up several weeks early so I was not prepared with digital camera, other flashlights, restraints, Scopolamine, etc. I have emailed him with several questions.

I did not run it long enough to see how warm it got. It was so bright my mind was telling me "incandescent - save batteries", instead of "they're someone else's batteries". The theoretical maximum efficiency is 683 lumens per watt. Luxeon is hoping to reach 50 lumens per watt soon. We are still wasting over 90% of our battery energy making heat, I/R, electromagnetic and other non-visible light-type stuff. If we could ever get to 50%....the mind boggles!

BTW, even green lasers put out less than 5mW. Any idea how many lumens?? and how much drain on the batteries?? Perhaps the efficency trail leads to laser diodes instead of LEDs!

More later,

Steve