LED - The Future Evolution?

[Henk_Lu]

Hi!

My first posting...

So, I got me a Surefire U2 and an L4 for my wife a few days ago. Until then, I've only had the LedLenser V2 Triplex (2004), nice to find the way to the toilet at night (but that's all)! The (original) LED modules for the Maglites are nice, the size and weight also (for bodybuilders)...

The beams of the Surefires are terrific for their size, but I think, you already know that. The L4 convinced me, so I decided to get one for myself too. The dealer only had his demonstration model left, I got it at a good price, so I bought it. Well, arriving at home I was more than disappointed, to cut it short, it was the "old" L4, with 65 Lumen. Compared to the "new" one, the light is greenish and lacks of power of course. No problem though, the dealer takes it back and orders me a new one (which I'll get for x-mas, by chance...)

Today I've been researching the whole LED-technology for flashlights and noticed that the output was about 30 Lumen in 2002 while it is now over 120 Lumen, still comparing the size of an L4. So, now I wonder of course how technology will evolve in future...

Will we see 500 Lumen with 5 hours running time for an L4 in 5 years, or have we reached a critical level by now, so that 200 Lumen with 3 hours running time seem more probable?

What do the specialists say:thinking: ???

Greets,

Henk_Lu

 

[Manzerick]

with multi-cores and such anyting is possible!!!


I hope we get to a point where 500 lumens out the front is a reality with a heavy run time but... dimming and other devices (like the U2) would be needed as blazing light all the time may not serve all needs


I can't wait for an updated U2.

 

[Zenster]

I'm new here at CPF as well because I needed a flashlight so I thought I'd do some investigating and see what's been going on in the field.

I was quite shocked to see that 250 Lumen, 3 hour runtime flashlights are now pretty common. The way technology is going, I wouldn't be surprised if LED technology follows computer technology where advances are doubled every few months.
I wouldn't at all be surprised to see a 1000 Lumen LED, variable power light be available within 2 years or so.

Not having had anything "respecteable" in a flashlight since my Magcharger bit the dust, I've already ordered the A9S, will be ordering the MRV-SE when it comes out of backorder, and a Christmas gift to myself is going to be the AE PL24/6-S kit.

I'd like to get a Duree DBS but I don't have nor want PayPal and that's the only way they'll take the order.

There's a lot of interesting stuff going on in the flashlight bidness'.

 

[EVOeight]

Personally, I think 200 lumens is plenty for an EDC flashlight. I want to see strides made in miniaturization, and in run times.

 

[Henk_Lu]

That's exactly why I bought the U2 - The dimming possibility. A lot of power is always good to have, but in reserve. Walking on a path in the moonlight I hardly need any more light, but heading through a forest seeking for tiny little reflectors, a straight and powerfull beam is very helpfull.

Though my U2 is brandnew, I would put its successor on my wishlist, 200 Lumen with steepless dimming! :thumbsup:

Greets,

Henk_Lu

 

[Stereodude]

White LEDs (blue with Yellow phosphor) are limited to about 350lm/watt. No advances are going to fix that because at that point the die is basically 100% efficient and the remaining losses are in the phosphor.

So, roughly speaking we're about 1/3rd of the way there.

 

[EVOeight]

But if we really could have 100% efficient LED's, flashlights would get smaller because there would be no need for any heat sinking all. All photons, no heat.

 

[Zenster]

White LEDs (blue with Yellow phosphor) are limited to about 350lm/watt. No advances are going to fix that because at that point the die is basically 100% efficient and the remaining losses are in the phosphor.

So, roughly speaking we're about 1/3rd of the way there.

Sure, but use your imagination. Think about a multiple emitter in a single LED, sort of a multiple parallel thingy.

What may seem like a dead end to one technology is usually a starting point for another in time.
I can also imagine some real creativity being used to refine reflectors, experimenting with different surfaces, and maybe even interlaced facets that increase luminescance but without adding artifacts.

Remember that just 10 years ago, LED's were just "indicator lights" on electrical panels, and weren't even that easy to see. Then, the first LED flashlights were just gimmicks serving as simply "proof of concept".

And you think we're at 100% efficient?

Nah.

 

[Stereodude]

Sure, but use your imagination. Think about a multiple emitter in a single LED, sort of a multiple parallel thingy.

...

And you think we're at 100% efficient?

Nah.

No, I said we're about 1/3rd of the way to the limit. Nothing you mention in your post will get us past the limit, and the limit will never be broken. At some point every electron from the battery gets converted into a photon off the die, and there's no more gains to be made on the LED side. It's simple problem of the conservation of energy. You can't get more light energy off the die than you put into it in the form of electrical energy.

 

[Henk_Lu]

Every technology has its limits. That's why I made the thread. Of course you can put more and more powerfull LEDs together and blow incandescent lights right into the past. Btw, each non-digital technology will suffer that faith sooner or later...

The point of my question was : What is the limit for a palm-sized flashlight (2 cells) ? Perhaps cells will also get better, I think a normal 123A-cell has about 1.400 to 1.600 mAh and we speak of lithium-ion. Is there something new in sight, perhaps miniaturized fuel-cells using hydrogen which they'll get out of ethanol?

For years I was a big fan of the Maglites, best flashlights you could get if money was a matter. Nowadays, they really are behind technology, I am looking forward to new LEDs to power up my nearly 20 years old treasures!

Greets,

Henk_Lu :green:

 

[thiswayup]

Hi!

Today I've been researching the whole LED-technology for flashlights and noticed that the output was about 30 Lumen in 2002 while it is now over 120 Lumen, still comparing the size of an L4.

Actually, you can get 120L out of a light quite a bit smaller than an L4 - one just a bit bigger than an AA cell; say about an inch longer, and a quarter of an inch thicker - about the size to fit in an L4's battery compartment. A Jetbeam MkII or Liteflux LF5 running on 14500's, for example. Perhaps you could go even smaller (and much cheaper - although those lights are hardly expensive) if you don't want multiple light levels and regulation.

 

[Gunner12]

Even the Luveon V in your lights is a little behind. The current LEDs can match it's output with a single die(the Luxeon V has four) and about half the power. And because of the smaller emitting surface, can also have more throw with the same reflector.

the Newer LEDs, Cree XR-E(P4-R2 bin), Seoul P4, and Rebel 100 have at least twice the efficiency of the Luxeon I, III, V and K2. A Cree XR-E Q2 at 350 mA has more output then the Luxeon III at 1000 mA.

I think even this $15 light with a 14500 3.7v Li-ion battery can hit 100 lumen out the front with out too much problem.

There are also many LED drop-ins(and modifications) for the maglite to make them brighter.

:welcome:

 

[k5ride]

 

[SemiMan]

Hey!

Well let's take an engineering look at this over the next 5-10 years:

1) Realistically we may get to say 250 lumens\watt with good color rendering. That is about 75% of theoretical with good color rendering. Maybe we will get higher, but let us call it that.

2) I can realistically dissipate about 5watts in a handheld 2AA flashlight (and perhaps that is pushing it). So my 2AA handheld flashlight is going to top out at about 1,250 lumens in the next say 5 years. That really is not bad at all!

3) Now let's say I can come up with some innovative cooling methods such that I can dissipate 10 watts, then I could in theory do about 2,500 lumens.

4) So now I am pulling out 10 watts. A couple of CR123 can run that flat out for say 30 minutes. Current AA NiMH for not that much less. If I push the size out a bit I go go with bigger Lithiums and get to say 45 minutes.

5) I can run my electronics currently at 90%+ so not going to get much there.

6) Battery technology has not progresses much in the last many years. With the exception of fuel cells, nothing seems to be on the horizon, but realistically if we want long run time, that is where we are going to need to look. I fuel cell can have 5-10x the energy density. That said, the small ones currently do not put out much current, certainly not 5-10 watts continuously.

7) What else could I do? Well it would be nice if I could get a 10watt LED that is even smaller than the current crop of 1mm*1mm LEDS. Imagine if that was 1/2 the size or even smaller. We could have flashlights with incredible through but not just that, adjustable beams. So that is a potential area, but right now we are not there. Maybe an interesting optical configuration to allow the equivalent peformance.


Semiman

 

[tony22r]

Hey!

Well let's take an engineering look at this over the next 5-10 years:

good points.

I think in the near future..

-as emitters approach 100% efficiency
..converting every mA into light with NO heat loss.. that would make heat dissipation moot.

-power density.. batteries with More mAh in the same size or less.


In the far future..

-miniature hydrogen fuel cells
..that can grab hydrogen from water vapor in the air, and convert/store it into electricity.. "free" perpetual power.

-infinitely adjustable reflectors/optics
.."liquid" metal/glass?

 

[yellow]

fuel cells will never make it into small handheld devices
because to fill them one needs a larger pressure tank (at home?)

the wall plug rechargeable battery cant be beat here: all the installation is common and they keep getting better and better (eneloops, Li-Ion cells, ...)

 

[jbrown50]

Super Battery

Or

Our old friend the capacitor.
http://www.sciencentral.com/articles/view.php3?type=article&article_id=218392803

The Past is Future
As our portable devices get more high-tech, the batteries that power them can seem to lag behind. But Joel Schindall and his team at M.I.T. plan to make long charge times and expensive replacements a thing of the past--by improving on technology from the past.

 

[Outdoors Fanatic]

The future of backlit displays, yes.

 

[jtr1962]

1) Realistically we may get to say 250 lumens\watt with good color rendering. That is about 75% of theoretical with good color rendering. Maybe we will get higher, but let us call it that.

2) I can realistically dissipate about 5watts in a handheld 2AA flashlight (and perhaps that is pushing it). So my 2AA handheld flashlight is going to top out at about 1,250 lumens in the next say 5 years. That really is not bad at all!

You forgot about one thing-your hypothetical 75% efficient 250 lm/W LED will only be dissipating 25% of the input power as heat. The rest will come out the front end as light. Therefore, if a 2AA body can realistically dissipate about 5 watts then you can power your LED at 20 watts. That's 5000 lumens.

3) Now let's say I can come up with some innovative cooling methods such that I can dissipate 10 watts, then I could in theory do about 2,500 lumens.

Along those same lines of thought you could get 10,000 lumens here.

6) Battery technology has not progresses much in the last many years. With the exception of fuel cells, nothing seems to be on the horizon, but realistically if we want long run time, that is where we are going to need to look. I fuel cell can have 5-10x the energy density. That said, the small ones currently do not put out much current, certainly not 5-10 watts continuously.

I agree battery technology is really the big limitation here, not the LEDs or cooling. As we approach 100% efficiency waste heat will be less and less of an issue. At 95% efficiency you can power an LED in a 2AA body to perhaps 100 watts, giving over 30,000 lumens. The problem is that the batteries can't keep up for any length of time. I'm sure cells based on the A123 Systems technology can easily put out 20 watts or more in a AA size, but not for very long. At best a 5,000 or 10,000 lumen level would be possible for only a few minutes barring a revolution in battery technology. If we set 1 hour as a good minimum run time, then 5 to 6 watts is about the most power we have available with current batteries. At best that would give us perhaps 2000 lumens with a near 100% efficient LED. This is still not bad. That's about the amount of light that those huge million candlepower spotlights give.

As for future battery technology, my money is on the supercap. I don't believe there's any inherent limit to their capacity. It's simply a matter of squeezing more charge into a given space. We may well have supercaps the size of AAs capable of storing a few hundred watt hours of energy within a few decades.

 

[LED_Thrift]

...Though my U2 is brandnew, I would put its successor on my wishlist, 200 Lumen with steepless dimming! ...

CPF member Milkyspit, who does beautiful flashlight modifications, is very highly regarded here and I've seen a U2 he modded. It was quite a bit brighter than a standard U2.

As far as actual stepless dimming, check out the Peak First Responder. It is about 400 lumens and has stepless dimming. It has nine battery options, and the total output depends on the choice of batteries. The highest output [400 lumens] is with two RCR123s [7.2 volts]