# What Will The Future Bring?



## Frankiarmz (Apr 23, 2008)

I've only been involved with flashlights for just over one year, my first being a Scorpion. My next flashlight was a AAA Twin Task and soon I was into Olight T-20's. I may be wrong but it seems as though the variety of offerings and technology has exploded in recent months. What do you "Flashoholics" see for the future of LED's, beyond the mid 200 lumen range? Can the technology improve sufficiently beyond what we are currently seeing? Thanks.


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## HKJ (Apr 23, 2008)

The P7 led is the next step for high power flashlights, it can handle 700+ lumens, depending on battery power and cooling. I.e. it needs rechargables or more than two CR123A batteries.

In a few years the flashlights will be better at showing colors and the leds will have improved efficiency, i.e. the 200+ lumens of today will probably be 400+ lumens.


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## MikeSalt (Apr 23, 2008)

LED manufacturers need to take a little step back from the efficiency war and try to broaden the spectrum. Natural white needs some work in the LED domain.


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## BabyDoc (Apr 23, 2008)

MikeSalt said:


> LED manufacturers need to take a little step back from the efficiency war and try to broaden the spectrum. Natural white needs some work in the LED domain.


 
+1!


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## Centropolis (Apr 23, 2008)

I am sure the LED technological advances in the next 5 years will be significant. Just like computer CPUs….they’ll become brighter with less power and longer runtimes. It’ll make my L1, 6PL, G2L, E1B obsolete. The CREE S7 LED in a Fenix L1H will put out 1000 lumens with one AA battery that runs for an hour on max.

Something like that…….


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## kramer5150 (Apr 23, 2008)

More Lumens and less current consumption... Higher efficiency. Imagine getting 200 Lumens from 100mAh current draw, or 100L from 50mAh, WOW that would be a dream come true. I wonder if you would even need a driver board with such low current?, just a direct drive resistor and a NiMH cell.

I really like what Nichia is doing with their LEDs.... more of that will hopefully spread across the industry.

Its too bad Lumileds had the 0100 bin rebel fall-out late last year. I really like the color tint of their LEDs. I think they are still suffering the ill-effects as everyone is now going to Cree.


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## Outdoors Fanatic (Apr 23, 2008)

kramer5150 said:


> More Lumens and less current consumption... Higher efficiency. Imagine getting 200 Lumens from 100mAh current draw, or 100L from 50mAh, WOW that would be a dream come true. I wonder if you would even need a driver board with such low current?, just a direct drive resistor and a NiMH cell.
> 
> I really like what Nichia is doing with their LEDs.... more of that will hopefully spread across the industry.
> 
> Its too bad Lumileds had the 0100 bin rebel fall-out late last year. I really like the color tint of their LEDs. I think they are still suffering the ill-effects as everyone is now going to Cree.


Did Fenix stop manufacturing lights with the Rebel emitter?


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## BabyDoc (Apr 23, 2008)

Outdoors Fanatic said:


> Did Fenix stop manufacturing lights with the Rebel emitter?


Yes, although there are still some available at some of the fenix dealers. (see lighteninghound.com) It is my understanding that the Rebel emitter is currently unavailable from the LED manufacturer who is correcting some quality control issues.


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## russtang (Apr 23, 2008)

Whatever it brings, it sure is fun to be right in the middle of all this 

technological advancement.


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## nerdgineer (Apr 23, 2008)

The Chinese lights will cost about 50% more in 3-4 years due to devaluation of the dollar vs. the RMB (Chinese dollar)...


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## TONY M (Apr 23, 2008)

I am having soooo much fun with what we have now with LED technology. 5 years ago we were nowhere really but we knew that LEDs would be the future when a few things got sorted out and then it did, it happened very quickly aswell.

There could be a very important development in the near future that comes along allowing us to throw away our current crop of high output crees. You never know.

As far as flashlights are considered in my mind LEDs are now king (except for very high output lights).

LED's that come in any colour temperature specified could be around the corner. That would be an important one I feel.

I think that over the next few years reaching 1000 lumens per watt is a mark to hit. That coupled with batteries far superior to what we have now is a killer combination. Battery technology is also very important too.

What we have right now is great. As we all know very well most unlightened people still believe that a minimag running on duracell alkalines is the holy grail :candle: (and will probably feel that way for some time). A good $20 DX light puts that to shame.

A 500 lumen AAA EDC that can run for 2 or more hours would be insane and there really WOULD be a need for a low mode!


Whatever happens, the future is BRIGHT! :huh:


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## Frankiarmz (Apr 23, 2008)

TONY M said:


> I am having soooo much fun with what we have now with LED technology. 5 years ago we were nowhere really but we knew that LEDs would be the future when a few things got sorted out and then it did, it happened very quickly aswell.
> 
> There could be a very important development in the near future that comes along allowing us to throw away our current crop of high output crees. You never know.
> 
> ...


 
I agree with your post and many of the points made in the previous posts predicting the future of flashlights. I see the recent advancements as amazing and hard to surpass right now and yet it makes sense that the next two or three years will see your predictions easily come true. When I think of my first MiniMag or even my somewhat recent Scorpion and how impressed I was, I get a big grin considering the future. I think batteries will need to advance more than LED's to accomplish some of these goals. No doubt that china will grow stronger in their technological offerings due to our desire for these products and willingness to pay for them. We are living in very changing times.


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## Hooked on Fenix (Apr 23, 2008)

In the future, I hope to see a light about the size of a Fenix P3D that has a working voltage range from .9 to 10 volts. This is so you can use different lego body tubes to adapt it to whatever size or number of batteries you want (1AA, 2AA, 123A, 2 123A, 17670s, or 1 or 2 18650s). It will have a forward clickie switch and an optional switch with strobes and SOS as well. The light will have two selector rings on it. One for variable intensity brightness control and the other for color of light (red, blue, green, amber, U.V., and I.R.). Another setting on the optional switch will be to adjust the tint of the white l.e.d., otherwise it will be neutral white. Basically, you should be able to adjust battery type, brightness, l.e.d. color, tint, and other settings quickly and easily. It will also have to be as bright as a million candlepower spotlight (400-600 lumens) and fit in my pocket. I think this will be possible if we can get to about 200 lumens/watt, get a wider voltage range on drivers, get better color rendition in l.e.d.s, and have a company to make it that isn't afraid of making the only flashlight you should ever need. Knowing how companies are, they'll probably hold something back that you want so you'll buy their next light. 
Also, I predict that l.e.d. companies will stop pushing the limits of lumens/watt and focus on color rendition to break into the house lighting and car headlight markets. I also think we are in for a price increase for flashlights and batteries. China is becoming a growing industrial nation that will start paying better wages sooner or later. When the Chinese can afford to buy the good lights they make, demand will increase along with prices. Material costs will go up too making our hobby more expensive. I hope I'm wrong about this, but it seems we've had it too good in the last few years. Rechargeable batteries have more than quadrupled from early Ni-CD to current NiMH and Li-Ion batteries and l.e.d. efficiency has increased about the same too. Costs of these batteries and l.e.d.s have mostly dropped over the years as well. I know that as soon as l.e.d.s become a viable option to replace fluorescents, fluorescents will be outlawed here in California whether l.e.d.s are cheap or not. There's too much environmentalist control in California and they already outlawed using mercury in electronics. You can't make fluorescent bulbs without mercury. We may eventually see costs come down a lot on l.e.d.s when they become commonplace in household lighting.


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## RGB_LED (Apr 23, 2008)

I would agree that I would like to see better tonal rendition and broader contrast range with new LED emitters... there's some improvement with the Rebel's and even some of the warmer Cree bins but LED's have a long way to go still.

Also, what about batteries... I know this is a segue and this is the 'LED Flashlights' forum and not the 'Batteries' forum but what about advances in batteries as well? 

There will come a point where LED efficiency is maximized and the real bottle-neck may point back to the need to improve the battery. I would like to see an AA battery with improved efficiency with 10,000mAh (ok, maybe 5,000mAh) driving an LED that is capable of 1000 lumens.  Or better still, perhaps eliminating the venting issues and improving the stability of Li-Ion batteries.


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## Frankiarmz (Apr 23, 2008)

RGB_LED said:


> I would agree that I would like to see better tonal rendition and broader contrast range with new LED emitters... there's some improvement with the Rebel's and even some of the warmer Cree bins but LED's have a long way to go still.
> 
> Also, what about batteries... I know this is a segue and this is the 'LED Flashlights' forum and not the 'Batteries' forum but what about advances in batteries as well?
> 
> There will come a point where LED efficiency is maximized and the real bottle-neck may point back to the need to improve the battery. I would like to see an AA battery with improved efficiency with 10,000mAh (ok, maybe 5,000mAh) driving an LED that is capable of 1000 lumens.  Or better still, perhaps eliminating the venting issues and improving the stability of Li-Ion batteries.


 
I think the discussion of batteries is equally important to LED advancement. Why should a AA, 10,000 mAH be out of reach? I'm sure as we discuss the possibilities there are researchers and inventors working with all sorts of materials to make these batteries of the future a reality. Will it depend on something like Nano technology and what will the cost be? I don't want to sound like an isolationist and I hope living conditions improve around the world, but I would imagine that we are the major consumers of these LED products and if prices do increase due to our weakening dollar and rising costs in manufacturing who will buy these products if we don't ? I don't see how we can continue to be consumers for the world's products if we have to keep paying double digit price increases for essentials.:shrug:


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## Jarl (Apr 23, 2008)

I hope for an EDC that will give 1, 10, 100, 350 and 1000 lumens with an adjustable focus from crazy spot to pure flood, and a good CRI and colour temperature.

I also hope for high capacity, stable lithium batteries. I don't like the idea of it exploding, much...


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## copperfox (Apr 23, 2008)

Correct me if I'm wrong, but 1000lm/w is far above the physical limit of converting energy into light. It's kind of like wishing for a gasoline internal combustion engine that makes 600hp per liter --it ain't gonna happen.

I anticipate that LEDs will hit a ceiling of efficiency after a while, but I can't predict when that will be. I would guess it will be around 200lm/w. I look forward to energy storage improvements, perhaps utilizing carbon nanotubes in a safe chemistry. It sure would be nice to have an AA-sized cell with 25Ah capacity!

Unfortunately, one hurdle bleeding-edge flashlights will always face is sufficient heat-sinking. The laws of physics won't change, so we're limited to using silver, copper, gold, and aluminum for our heat-sinks. Perhaps somebody will begin to integrate heat pipes and piezoelectric devices into flashlights to assist with cooling...


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## Sir Lightalot (Apr 23, 2008)

TONY M said:


> I think that over the next few years reaching 1000 lumens per watt is a mark to hit.


Theoretically full spectrum white can only be 242.5 lumens per watt. see all those "finally! 300 lumens per watt" threads


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## Frankiarmz (Apr 23, 2008)

Sir Lightalot said:


> Theoretically full spectrum white can only be 242.5 lumens per watt. see all those "finally! 300 lumens per watt" threads


 
"This means that typical white (or whitish) light sources produce far fewer lumens per watt than the theoretical maximum of 683 lumens per watt. The ratio between the actual number of lumens per watt and the theoretical maximum is expressed as a percentage known as the luminous efficiency. For example, a typical incandescent light bulb has a luminous efficiency of only about 2%."
The above is a quote and while it refers to your theory it makes me wonder if this theory will be proven wrong someday? Who is to say someone will not invent a new material or process with which to accomplish higher outputs of white light per watt? When I was in high school many years ago "Absolute Zero" had not been reached and when I recently researched the subject it was still unattainable, but someday?


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## David Gretzmier (Apr 23, 2008)

LED lumen efficiency will continue to increase, and as lumens go up, heat management will have to be better. battery technology will also continue to evolve , with more mah coming from both the nimh camp and lithium ion. both of these will combine to give lots more runtime and more lumens from smaller lights. I wouldn't be surprised to see a new battery technology in 5 years or so, something with either more mah per ounce or more voltage or both. better reflectors will bring more of the lumens out the front. 

I'm not sure how fast this will happen, looking at the cree and the AA battery- the q5 was available in flashlights around Halloween last year, and 6 months later the r2 is pretty much where we are at. nimh AA's topped out at 2500mah in October as I remember, and I've seen 2700mah the past month or so. so a jump of 10-15% in lumen eficiency and 5-10% increase in battery power per year may seem reasonable.


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## 2xTrinity (Apr 23, 2008)

MikeSalt said:


> LED manufacturers need to take a little step back from the efficiency war and try to broaden the spectrum. Natural white needs some work in the LED domain.


The two aren't mutually exclusive -- improvements in efficiency, particularly in the blue dice, lead to efficiency improvements in ALL white LEDs -- cool, neutral, warm, multiphosphor/high-CRI. In fact, neutral tinted LEDs have the potential to be MORE efficient in lumens/watt than cool white, because the eye has low sensitivity to blue light, which is so dominant in the cool emitters. Many of these already exist, including 3500k warm white Crees with Q2 efficiency and good spectra -- that's still more efficient than ANYTHING a year ago. I suspect many people on these boards would be happier if their lights were loaded up with emitters like that, instead of R2-bin cool emitters. In the not to distant future I plan to go replace a lot of my old cool LED lights with neutral and warm emitters.

Improvements in both the underlying LEDs and phosphor blends will both happen over the next few yeears as there will be a push to make LEDs capable of replacing things like small halogen spotlights, and eventually more general lighting.

I suspect LED tech will eventually approach a 200lm/Watt efficinecy cap for white light with a good spectrum. When that happens, battery technology will really be the only limiting factor. Keychain lights producing several hundred lumens I believe will be a very real possibility.



> Theoretically full spectrum white can only be 242.5 lumens per watt. see all those "finally! 300 lumens per watt" threads


That's if you want a continuous spectrum simialr to sunlight. You could cut away most of the violets and a lot of the deep reds, get more like 350lm/W max, and you'd be hard pressed to tell the difference.

I suspect we may see REAL LEDs achieve 70% of theoretical maximum, or about 200lm/W with a VERY good spectrum. How do people like the sounds of a keychain light pumping out several hundred lumens for half an hour?


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## jtr1962 (Apr 23, 2008)

copperfox said:


> Correct me if I'm wrong, but 1000lm/w is far above the physical limit of converting energy into light. It's kind of like wishing for a gasoline internal combustion engine that makes 600hp per liter --it ain't gonna happen.


As mentioned perfect white light is around 240 lm/W but you can get well above 300 lm/W while still having a CRI of 98, and approach 400 lm/W with a CRI in the low 80s (still plenty good enough for all but the most critical color matching). However, these are theoretical numbers. In practice figure about 80% of that, perhaps 90% on the outside. The comparison to hp per liter though makes no sense. There is no inherent theoretical limit to hp per liter given new materials or cooling methods. The existing limits are practical limits. There is an inherent limit to how much energy you'll get out of a mass of any given fuel but that's entirely different.

Battery technology will probably be the limiting factor in the end. I see LEDs of 250 to 300 lm/W within a decade. How long lights using these will run is dependant upon discovering new battery chemistries. NiMH and li-ion both give about the same energy density per unit volume, although li-ion by virtue of its lighter weight gives more per unit mass. The sky's the limit on what new batteries may be capable of. A 5000 mAh AA in a decade wouldn't surprise me. If we can harness cold fusion in a small cell then we're really talking about unlimited runtime. Who really knows what will be ten years from now? When I bought my first 5 mm white LEDs about 8 years ago I suspected in time they would be cheaper and brighter. However, I had no idea we would ever have the high-power LEDs which exist today putting out several hundred lumens.


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## Frankiarmz (Apr 23, 2008)

jtr1962 said:


> As mentioned perfect white light is around 240 lm/W but you can get well above 300 lm/W while still having a CRI of 98, and approach 400 lm/W with a CRI in the low 80s (still plenty good enough for all but the most critical color matching). However, these are theoretical numbers. In practice figure about 80% of that, perhaps 90% on the outside. The comparison to hp per liter though makes no sense. There is no inherent theoretical limit to hp per liter given new materials or cooling methods. The existing limits are practical limits. There is an inherent limit to how much energy you'll get out of a mass of any given fuel but that's entirely different.
> 
> Battery technology will probably be the limiting factor in the end. I see LEDs of 250 to 300 lm/W within a decade. How long lights using these will run is dependant upon discovering new battery chemistries. NiMH and li-ion both give about the same energy density per unit volume, although li-ion by virtue of its lighter weight gives more per unit mass. The sky's the limit on what new batteries may be capable of. A 5000 mAh AA in a decade wouldn't surprise me. If we can harness cold fusion in a small cell then we're really talking about unlimited runtime. Who really knows what will be ten years from now? When I bought my first 5 mm white LEDs about 8 years ago I suspected in time they would be cheaper and brighter. However, I had no idea we would ever have the high-power LEDs which exist today putting out several hundred lumens.


 
Great post. Would you agree that interest in both LED's and more advanced batteries is primarily what drives the timeline for the future of these products? Had interest not taken off in the form of "Flashaholics", willing to invest in high end LED flashlights would the industry be where it is today? Just look at digital cameras and mega pixels for example, a very few years ago three to five was a high end offering, now the number is ten or twelve. The manufacturers know that if they can make a brighter, smaller, longer run time LED, we will buy it and that guarantee is all they need.


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## jtr1962 (Apr 23, 2008)

Frankiarmz said:


> Great post. Would you agree that interest in both LED's and more advanced batteries is primarily what drives the timeline for the future of these products.


I agree with this 100%. I'll go so far as to say that flashlights in turn are driving the eventual use of LEDs for general lighting. Many are looking at their LED flashlights, and wondering what else can these things do.

I've observed similar trends elsewhere. For example, interest in first digital photography and then video drove the huge increase in hard disk size. Had everything on the PC remained text-based, a few hundred megabytes would have sufficed. And same thing with processors. More complex software drove the push for ever faster processors. The fact that LED efficiency is exceeding the timeline set forth a few years ago tells me that demand is playing a huge factor. The LED manufacturers know they can sell the next highest binned LEDs as fast as they can make them, so the push is on to get efficiency up as rapidly as possible .


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## copperfox (Apr 23, 2008)

jtr1962 said:


> The comparison to hp per liter though makes no sense. There is no inherent theoretical limit ... There is an inherent limit ...



You just contradicted yourself.

I intentionally specified "gasoline internal combustion engine" and you said you agree that a certain fuel has an inherent limit to how much energy you can get out of it. That reinforces my original position.

To clarify: There are physical properties of the materials used in a design that establish an upper limit of possible efficiency. In the engine analogy, the fundamental limiting properties are the potential energy of the gasoline and the burn rate. So no, the upper limit of efficiency of the gasoline ICE are not practical limits (as in: configuration, materials, and losses), they are inherent (as in: unchanging physical property of the gasoline). We have not yet reached this upper limit of efficiency.


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## Frankiarmz (Apr 23, 2008)

copperfox said:


> You just contradicted yourself.
> 
> I intentionally specified "gasoline internal combustion engine" and you said you agree that a certain fuel has an inherent limit to how much energy you can get out of it. That reinforces my original position.
> 
> To clarify: There are physical properties of the materials used in a design that establish an upper limit of possible efficiency. In the engine analogy, the fundamental limiting properties are the potential energy of the gasoline and the burn rate. So no, the upper limit of efficiency of the gasoline ICE are not practical limits (as in: configuration, materials, and losses), they are inherent (as in: unchanging physical property of the gasoline). We have not yet reached this upper limit of efficiency.


 
I disagree with your example of gasoline and maybe my argument is flawed but here it goes. When internal combustion engines used carbs gasoline had not reached it's full potential, but the introduction of fuel injection increased it greatly. The advent of electronic ignition saw more horsepower derived from the same quantity of gasoline. Direct injection, multi valve engines and other technological advancements have proved more and more energy could be derived from the same quantity of gasoline. How can you know with certainty that what we believe to be the limits of potential energy from a given source will not change with technology ?


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## copperfox (Apr 23, 2008)

Frankiarmz said:


> ...Direct injection, multi valve engines and other technological advancements have proved more and more energy could be derived from the same quantity of gasoline.



I agree, but these are examples of changes in the configuration and materials used, etc. in the engine. The gasoline and its respective physical properties remained the same. We are constantly refining the ICE design, but as I already said, we have not yet reached this upper limit of efficiency for gasoline in an internal combustion configuration.



Frankiarmz said:


> How can you know with certainty that what we believe to be the limits of potential energy from a given source will not change with technology ?



Because of the laws of physics. We don't create more potential energy in a given resource, we simply refine our process of extracting it (i.e conversion efficiency). This goes for coal power plants, combustion engines, and LEDs. In the case of LEDs (to get back on topic) what you are converting is electricity into photons. The LED as a fundamental design will only carry us so far. The reason we are producing more efficient LEDs is because we are moderately clever humans and we make practical changes to the design and implementation of the technology. At some point in the future, however, the physical limit of efficiency of the LED will be reached, and at that point, no amount of tinkering or redesigning will result in more light. Fortunately, with LEDs as with engines, there is still plenty of room for innovation.


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## CM (Apr 24, 2008)

HKJ said:


> The P7 led is the next step for high power flashlights, it can handle 700+ lumens, depending on battery power and cooling. I.e. it needs rechargables or more than two CR123A batteries.
> 
> In a few years the flashlights will be better at showing colors and the leds will have improved efficiency, i.e. the 200+ lumens of today will probably be 400+ lumens.



I don't consider the P7 to be "the next step". It's just a scaling up of current technology by cramming more emitters together in a small space, just like the Lux V was for lumileds. The increase in light output is accompanied (or paid for) by requiring more current, dissipation of more power and if you do the math, less efficiency. 700 lumens would be a lot more interesting if it can be done at 350mA instead of 3A  As pointed out above, better color rendering is very much desired if led's are going to be adopted for general purpose lighting beyond flashlights. Right now, everyone is playing the "lumens/watt" game where the P7 actually loses out.


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## jtr1962 (Apr 24, 2008)

copperfox said:


> You just contradicted yourself.
> 
> I intentionally specified "gasoline internal combustion engine" and you said you agree that a certain fuel has an inherent limit to how much energy you can get out of it. That reinforces my original position.
> 
> To clarify: There are physical properties of the materials used in a design that establish an upper limit of possible efficiency. In the engine analogy, the fundamental limiting properties are the potential energy of the gasoline and the burn rate. So no, the upper limit of efficiency of the gasoline ICE are not practical limits (as in: configuration, materials, and losses), they are inherent (as in: unchanging physical property of the gasoline). We have not yet reached this upper limit of efficiency.


I think here my engineering background is causing a bit of a communication problem because what you wrote can be interpreted two ways. Please let me know which way you meant. I'll explain:

I initially assumed that when you mentioned 600 HP per liter you were referring to a liter of engine displacement. That's what I based the rest of my post on. There is no inherent theoretical limit to how much power you can get per liter of engine displacement. In theory you can make a 1 cc engine which puts out 100,000 HP given the right design and materials but you're still going to have to figure a way to get huge amounts of fuel per unit time into that engine.

Now if you're referring to 600 HP per liter of gasoline, then the units are wrong and it makes no sense. HP is a unit of power, or _energy output per unit of time_. This is _not_ the same as energy. HP-hour is a unit of energy. HP-hours would be the proper unit to use if that is what you meant, as in you can't get 600 HP-hours per liter of gasoline. 600 HP-hours could be 600 HP for a period of 1 hour, or 300 HP for 2 hours, or 1 HP for 600 hours. It represents a unit of energy, and no matter how clever the engine design you couldn't get more energy out of a liter of gasoline than the potential chemical energy. Point of fact the best engines today get less than 25% of the energy out of gasoline. In theory lots of room for improvement. In practice Carnot's law and the combustion chamber temperature limits due to the melting point of the materials used to build engines will keep the practical efficiency well under 100%. It's an inevitable result of the means by which chemical energy in the fuel is converted to motion. An electric motor on the other hand uses a different process and can in both theory and practice convert 100% of the electrical energy into motion. The best electric motor designs exceed 95%. Batteries in turn convert upwards of 80% of their chemical energy into electricity.

LEDs don't have the practical limits of gasoline engines. In fact, a good analogy is that the LED is to the incandescent lamp as the battery-electric motor is to the gasoline engine. The battery-electric motor combination can easily convert upwards of 80% of the energy stored in the battery into motion because it's not a heat engine. The gasoline engine will be lucky to manage 25% of the energy stored in gasoline for practical reasons. Likewise, the process of photon emission in a semiconductor can in theory be 100% efficient without resorting to the super exotic materials a 100% efficient engine or a 100% efficient incandescent lamp would require. We still won't get there since nothing in this world is 100% efficient, but I think 80% is realistic, 90% a possibility.

In general the efficiency of any process is constrained by both inherent physical limits and the method the process uses. A fuel cell-electric motor can in theory extract more energy from a liter of gasoline than the best piston engine designs because it's using a different process. Same thing with LED versus incandescent. A 6700K filament would be over 90 lm/W but we lack a material which stays solid at that temperature. If we did, and if we coated the lamp with materials to reflect invisible light back to the lamp so we need less power to keep the filament at 6700K, we could in theory have 100% efficient incandescent lamp. Likewise, you could have a 100% efficient engine if you could combust the fuel at millions of degrees, or if your waste heat environment were at absolute zero. In practice none of these possibilities exist, so we look for other means to do the same tasks.


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## hunter3 (Apr 24, 2008)

jtr1962 said:


> In fact, a good analogy is that the LED is to the incandescent lamp as the battery-electric motor is to the gasoline engine.



:twothumbs jtr1962 = WIN

As far as battery technologies go, the next step seems to be using nanotechnology to improve Li-ion. They've achieved something like 800mah per gram, with extremely rapid charge rates. Within the forseeable future of less than three years, I doubt batteries will improve more than that.

On the other hand, with boost circuitry widely available, what's stopping AAA-sized flashlights from producing 1000+ lumens, even if the runtime is reduced to a few minutes?


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## jtr1962 (Apr 24, 2008)

hunter3 said:


> On the other hand, with boost circuitry widely available, what's stopping AAA-sized flashlights from producing 1000+ lumens, even if the runtime is reduced to a few minutes?


Probably LED efficiency is the main problem here. A P7 would need to be powered with about 11 or 12 watts to put out 1000 lumens. I'm not aware of any boost converter small enough to fit into a AAA light which could supply this. On the other hand, if we had a 250 lm/W emitter then you only need 4 watts of power. A small boost converter fitting in a AAA light might only be 80% efficient so you'll need 5 watts from the battery. That's about 4 amps. Some AAA cells can supply this with no problem, albeit only for a few minutes. A 1000 lumen keychain light would be kind of cool actually. People will expect something like a dim 5mm LED. The reaction will they see it putting out as much as a 60 watt incandescent lamp will be priceless. :nana:


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## HKJ (Apr 24, 2008)

CM said:


> I don't consider the P7 to be "the next step".



In my opinion it is in flashlights, but not in led technology. Combining multiple emitters in one package makes it possible to go above the 200-250 lumen flashlight and still have a decent reflector or optic.

Look at the current market, how many commercial led flashlight can your find that is above 250 lumens (Answer: very few)? 
My guess is that in the next year we will see a lot of flashlight above 250 lumens, using either the P7 or some other multi emitter led.


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## copperfox (Apr 24, 2008)

jtr1962 said:


> I initially assumed that when you mentioned 600 HP per liter you were referring to a liter of engine displacement.



I was.



jtr1962 said:


> That's what I based the rest of my post on. There is no inherent theoretical limit to how much power you can get per liter of engine displacement.



As a stand-alone statement, I agree with you. But I anticipated that and so I specified gasoline ICE, to attempt to reduce confusion. It didn't work .



jtr1962 said:


> HP is a unit of power, or _energy output per unit of time_.



Right. And the limiting factor in how much power you can make with that gasoline is it's burn rate, a unit of time. Let's assume that we have a super engine capable of surviving 100,000 rpm. Let's also specify that it is a 4-stroke of wankel configuration. The reason gasoline is critical to my argument is because in theory, the upper limit of revolutions per minute is determined by the burn rate, not the engine's ability to survive high RPM. In reality, the upper RPM limit is probably much lower than 100,000 due to the fact that the piston can only travel from TDC to BDC in an amount of time equal to the air-fuel mixture's maximum burn (explosion) rate.



jtr1962 said:


> Point of fact the best engines today get less than 25% of the energy out of gasoline.



Right. The average car engine makes less than 100hp/l, naturally aspirated. Even the car (commercially available) with the highest naturally aspirated power output per liter only makes 120hp/l. I made an extrapolation based on these numbers that if 100% of gasoline's fuel was used that it would be near 500hp/l. I used 600hp/l to give myself some wiggle room. This number is based on some assumptions, and is likely below the true upper limit, mostly because I forgot to factor in forced induction. I realize the analogy wasn't that good. 



jtr1962 said:


> In general the efficiency of any process is constrained by both inherent physical limits and the method the process uses. A fuel cell-electric motor can in theory extract more energy from a liter of gasoline than the best piston engine designs because it's using a different process.



I agree.


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## jtr1962 (Apr 24, 2008)

I understand now what you were trying to say. Obviously there are going to be physical limits to how much HP you can get per liter of displacement. I know that. These are practical limits for the most part, not theoretical limits like the amount of energy you can get from a gallon of gasoline. I guess I was just nitpicking on the point. Yes, a given gasoline-air mixture at a certain pressure has a maximum burn rate. Also, there are limits on how quickly you can exhaust and intake the cylinder. Obviously by running everything at much higher pressures the speed of all these processes can be increased, but then there are practical limits on how high pressures can go. So in theory no limit on HP per liter if pressure and RPM goes to infinity but in practice we both know that can't happen. In other words, I agree with you.

Making a similar analogy to LEDs, HP per liter is analogous to lumens per square millimeter. In theory there is no limit to how intense you can make an LED if you could pump hundreds of amps through a small die. You could in theory get 1 million lumens from a small die without violating any laws of physics. You may need to input thousands of watts of power to do so, but you wouldn't be violating the law of conservation of energy. In practice obviously die resistance and junction saturation will cause output to level off long before current gets that high. Not to mention you'll have the problem of removing a lot of heat from your LED unless it happens to be 100% efficient at converting electricity to light.

On another note, I absolutely love how science fiction writers routinely come up with all sorts of ideas which might be possible in theory, but never in practice. One of my favorites was using a quantum singularity for power. Even if you could bottle such a thing at will, you're left with the practical problem of removing gigawatts of power from something smaller than a neutron. Talk about a difficult heat transfer problem! In light of this, a 1 cc, 100,000 HP engine seems almost tame!


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## Moat (Apr 26, 2008)

copperfox said:


> ... and piezoelectric devices into flashlights to assist with cooling...



Hey... that gives me a (probably silly) idea - why not mount the LED to a heatsink that itself is a thermocouple - thereby converting the otherwise wasted heat energy back into electrical energy - to re-charge the battery, for example. Like re-generative braking on an electric/hybrid car!

Nah, I know... I suppose the heat>electric conversion efficiency of known thermocouples is probably relatively poor, and/or the Voltages produced are in some unuseable range...

Just thinkin' out loud, again -


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## 2xTrinity (Apr 26, 2008)

Moat said:


> Hey... that gives me a (probably silly) idea - why not mount the LED to a heatsink that itself is a thermocouple - thereby converting the otherwise wasted heat energy back into electrical energy - to re-charge the battery, for example. Like re-generative braking on an electric/hybrid car!
> 
> Nah, I know... I suppose the heat>electric conversion efficiency of known thermocouples is probably relatively poor, and/or the Voltages produced are in some unuseable range...


What you're talking about isn't really analogous to regnerative braking, but rather like combined cycle engines, where you use hot exhaust gases from one engine to drive a steam turbine and generate more power. The problem is, if you're generating energy from heat, you inherently need a high temperature differential. Maximum possible efficiency of any engine is determined by the following formula:

Thot / (Thot - Tcold) 

For a heatsink, you want the exact opposite -- in a perfect world you want there to be NO temperature difference between your LED and the surface of the light.

The problem is, passive cooling, like slapping LEDs onto a big chunk of coper, won't be able to keep up with the demand for more and more throw (which requires a lot of poer to be pumped through a small area). The problem is most of the active heat dissipation systems have a lot of problems:

1) Fan cooling -- bascially, you throw away all hope of waterproofing your light, and you have a lot of fragile mechanical parts to break should you drop the light.
2) Piezoelectric cooling -- basically, these are power hungry, and would themselves cerate more heat. In a compact system like a flashlight, and not a fan-cooled computer case, they'd probasbly actually worsen the problem.

Basically the only viable solution I cn think of is to use heatpipes -- basically copper pipes with a fluid in them that is designd to evaporate at roughly the operating temp of the LED (by adjusting the pressure insize), then condense elsewhere. A wick then returns the condensed fluid to the "hot" side of the pipe. No input power or moving parts are necessary.


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## Moat (Apr 26, 2008)

2xTrinity said:


> The problem is, if you're generating energy from heat, you inherently need a high temperature differential.



Ah... makes perfect sense. Would need a smokin' hot LED to work - the opposite of what we want. Silly it was, then!

Although... how about using the boiling fluid inside a heatpipe to spin a tiny turbine, driving a nano-generator that recharges the battery... :duck:


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## RustyKnee (Apr 27, 2008)

Moat said:


> Ah... makes perfect sense. Would need a smokin' hot LED to work - the opposite of what we want. Silly it was, then!
> 
> Although... how about using the boiling fluid inside a heatpipe to spin a tiny turbine, driving a nano-generator that recharges the battery... :duck:


 
Wouldn't that restrict the fluids ability to travel...and therefore the heat dissipating capacity?

The biggest thing for me of increases eficacy is reduce thermal managemnt requirements. Less heat is generated so you can either use "fenix turbo" for longer for a given brightness or get more light for the same heat build up in a small package.


Stu


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## SemiMan (Apr 27, 2008)

I hope the future brings......... no more questions about that the future will bring......... cause it ends up with meaningless drivel and degenarates into debating perpetual motion or something of similar value. What will the future bring:

- LEDS will get more efficient. There is a hundred threads on here that accurately talk about the physical limit to LED efficiency. It is hard and can not be crossed. It is not even one order of magnitude away. Practically, and with white light of a reasonable color, it is only about 3x - 4x absolute maximum away.

- LED surface brightness will go up. Heck, it may go up a lot. There are not the same hard limits on this..... yes any number of things must improve..... current density versus life, phosphor if used, light versus heat, etc., but any hard physical limit is a long way away. Perhaps we will have LED flashlights with the throw of a short arc xenon?

- Batteries will get better. They may actually get much better in the very short future. We may get new power sources as well. Here is an area where there is in no theoretical limit, but expect jumps and then small performance increases.

- Boost/buck circuits will get better in terms of efficiency...but marginally as they are pretty good. They will get smaller and they will become more efficient at low voltages.

- Something may replace LED.


There, how is that for a summary?


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## Frankiarmz (Apr 28, 2008)

SemiMan said:


> I hope the future brings......... no more questions about that the future will bring......... cause it ends up with meaningless drivel and degenarates into debating perpetual motion or something of similar value. What will the future bring:
> 
> - LEDS will get more efficient. There is a hundred threads on here that accurately talk about the physical limit to LED efficiency. It is hard and can not be crossed. It is not even one order of magnitude away. Practically, and with white light of a reasonable color, it is only about 3x - 4x absolute maximum away.
> 
> ...


 
I think if anything you've proved that discussion of what the future may bring is thought provoking and worthwhile. You have touched upon many things that deserve more conversation and not less. Thanks.


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## SemiMan (Apr 28, 2008)

My point is we can discuss it all we want and we go over the same things over and over again.... it is sort of pointless. Let's just take the developments as they come and make the most of them. You can only plan so much.

Semiman


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## jtr1962 (Apr 29, 2008)

SemiMan said:


> My point is we can discuss it all we want and we go over the same things over and over again.... it is sort of pointless. Let's just take the developments as they come and make the most of them. You can only plan so much.


Exactly. My guess is even when LEDs get close to theoretical maximum and have near perfect color rendering you'll still get these types of threads. I can see the thread title now: "Cree's latest at 300 lm/W but when will we see 1000 lm/W?" 

While I do find these types of discussions interesting, it would be nice if we just collected them all on one thread and made it a sticky.


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## Frankiarmz (Apr 29, 2008)

Guys, I'm sorry. As a newbie I was hoping to get a lot of thought provoking ideas, what I didn't realize was that this kind of topic has been talked about too much. I think as new people come to the Forum they will will be curious about the possibilities the future holds and naturally they will start similar threads. I can understand how that repeated discussion of the future can grow old.


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## 2xTrinity (Apr 29, 2008)

jtr1962 said:


> Exactly. My guess is even when LEDs get close to theoretical maximum and have near perfect color rendering you'll still get these types of threads. I can see the thread title now: "Cree's latest at 300 lm/W but when will we see 1000 lm/W?"


Efficiencies that high may be against the laws of physics... but that won't deter future investors


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## Helmut.G (May 1, 2008)

I don't believe that white LEDs will ever reach 300 lm/W at a useful power consumption:sigh: (300lm/W at 0,01W won't help anyone) *but* LEDs converting 80% of the energy into light will hopefully not heat up nearly as much as current LEDs, so we're gonna be able to drive them at very nice currents:naughty:
combined with better batteries (of course here is also a physical limit) we'll have very nice LED lights


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## TMorita (May 1, 2008)

Frankiarmz said:


> ...
> What do you "Flashoholics" see for the future of LED's, beyond the mid 200 lumen range? Can the technology improve sufficiently beyond what we are currently seeing? Thanks.


 
Well, beyond the mid-200 lumen range, I see the high 200 lumen range. Then the low 300 lumen range, and then the mid 300 lumen range. :twothumbs

But I could be wrong. 

Toshi


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## AvPD (May 1, 2008)

I've heard that Osram is developing a LED tile for home lighting purposes. (news link) (press release).

A shame that full spectrum white light has a 242.5 lm/w limit, but good news that the kinds of tints we are all used to can go higher.

I suspect that LEDs will be used for most applications but there will be still be niche uses for the other technologies. HID lamps seem to have been given a shot in the arm by those new plasma emitters.


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## 2xTrinity (May 1, 2008)

Helmut.G said:


> I don't believe that white LEDs will ever reach 300 lm/W at a useful power consumption:sigh: (300lm/W at 0,01W won't help anyone) *but* LEDs converting 80% of the energy into light will hopefully not heat up nearly as much as current LEDs, so we're gonna be able to drive them at very nice currents:naughty:


you just contradicted yourself there. You don't believe they will exist except at very small currents... but because of less heat buildup they will be able to be driven at very _high_ currents :thinking:

300lm/W IS about 80% conversion of energy into light, assuming a reasonably good >80CRI 3500-4000k white LED spectrum made using red, amber, green and blue direct emitters. Upper limit to phosphor white LED blend used today is lower, at about 350 lm/W maximum. 



> combined with better batteries (of course here is also a physical limit) we'll have very nice LED lights


A doubling of battery energy density would be far far far more significant more for the world than doubling of LED efficiency would. Between the two I believe the latter is a lot more likely to happen in the near future... Only recently has a lot of attention even been paid to high power LEDs, leading to massive improvements (with still more room for improvement left) because it's a relatively immature technology. Battery tech however has been evolving very slowly for many decades, despite a comparatively large amount of research. 

By the way, I believe the future will be in direct emitters, not blue + phosphor. Consider that the blue emittesr aer already greater than 50% efficiency. If you were to use red, amber, green and blue emitter all at great than 50% efficeicny, a reasonably good white LED could be made to have 200 lm/W. Increase all those figuers to 75%, whihc I believe will happen, and you have 300 lm/W.


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## Helmut.G (May 2, 2008)

2xTrinity said:


> 300lm/W IS about 80% conversion of energy into light, assuming a reasonably good >80CRI 3500-4000k white LED spectrum made using red, amber, green and blue direct emitters. Upper limit to phosphor white LED blend used today is lower, at about 350 lm/W maximum.


it all depends on where the limit is, of course
from what I have read some time ago, 100% with technologies similar to what we use today would be only about 230 lm/W:thumbsdow
of course if I'm wrong (let's hope for it) and the limit is more, LEDs could reach the 300 lm/W sometime
the small currents were only relating to LEDs converting more energy into light at lower currents


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## 2xTrinity (May 3, 2008)

Helmut.G said:


> it all depends on where the limit is, of course
> from what I have read some time ago, 100% with technologies similar to what we use today would be only about 230 lm/W:thumbsdow


230 lm/W is for a broad spectrum white similar to sunlight, with portsions aboev 700nm and below 400nm excluded. A spectrum that cut some of the near-IR, and near UV from that woudl be nearly indistinguishable, could be 300 lumens/watt. Current LED tech (blue plus yellow phoshpor) has a limit of about 350 lumens/watt. This has been confirmed experimentally -- the best LEDs today when underdriven are around 150 lumens/watt, and convert 40% of their electrical input into light, the rest into heat.

As I said in my previous post, a Red/Amber/Green/Blue approximation of white with similar color rendition as existing CFLs would be 400lm/watt. Using all 75% efficient emitters -- which both you and I believe will be a reality, you would have 300 lumens/watt white.



> of course if I'm wrong (let's hope for it) and the limit is more, LEDs could reach the 300 lm/W sometime
> the small currents were only relating to LEDs converting more energy into light at lower currents


This is true, but as you said yourself, as LEDs get more efficient, they will inherenly be able to be pushed harder. If you look at the efficiency curves of the old P4 emitters, compared to current R2 Cree emitters, the efficiency doesn't "drop off" as rapidly between 350mA and 1000mA as in the past, because the newer more efficient ones produce significantly less heat. Once we start getting into territory where more than half of all electrical input is converted to light, small changes in efficiency will lead to HUGE changes in maximum current limit -- and _that_ will actually be more significant than the marginal efficiency improvment.


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## [email protected] (May 4, 2008)

*Q: What Will The Future Bring?

*Well for me many more LED projects... with the P7 and it's eventual successors equaling if not superseding current hot-wire output realms, eventually I can also see a significant migration to LED tech from the last remnants of incandescent applications ie. the automotive/domestic lighting industry, hopefully they'll work on the colour spectrum issue 

Till then... let there be Lumens! (of all persuasions) :rock:


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## IMSabbel (May 4, 2008)

copperfox said:


> Right. The average car engine makes less than 100hp/l, naturally aspirated. Even the car (commercially available) with the highest naturally aspirated power output per liter only makes 120hp/l. I made an extrapolation based on these numbers that if 100% of gasoline's fuel was used that it would be near 500hp/l. I used 600hp/l to give myself some wiggle room. This number is based on some assumptions, and is likely below the true upper limit, mostly because I forgot to factor in forced induction. I realize the analogy wasn't that good.
> I agree.



Er. That analogy is as wrong as it can be, as they are per liter _displacement_, and not gasoline...
That 500hp/l engine will be MUCH less efficient than a average car engine...


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## IMSabbel (May 4, 2008)

2xTrinity said:


> A doubling of battery energy density would be far far far more significant more for the world than doubling of LED efficiency would. Between the two I believe the latter is a lot more likely to happen in the near future...



I disagree a lot.
Doubling led effiency at this point would be one of the greatest break-throughts of the century. It would make fluorescent and HID illumination of factories, parking lots, offices, ect around the world possible with 1/2 to 1/3rd the current energy usage.
Lighting stuff up takes a non-neglectable part of the worlds energy consumption, and 1/3-1/4th (IIRC) of the worlds electricity. And the future will only need more light.


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## copperfox (May 4, 2008)

IMSabbel said:


> Er. That analogy is as wrong as it can be, as they are per liter _displacement_, and not gasoline...
> That 500hp/l engine will be MUCH less efficient than a average car engine...




I can't understand you. Can you explain that again?


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## 2xTrinity (May 4, 2008)

IMSabbel said:


> I disagree a lot.
> Doubling led effiency at this point would be one of the greatest break-throughts of the century. It would make fluorescent and HID illumination of factories, parking lots, offices, ect around the world possible with 1/2 to 1/3rd the current energy usage.
> Lighting stuff up takes a non-neglectable part of the worlds energy consumption, and 1/3-1/4th (IIRC) of the worlds electricity. And the future will only need more light.


There haven't been very many breakthroughs since 2001, even the _last_ doubling of LED efficiency is a pretty big one  

As far as your point about lighting, most of those applications could ALREADY get by with 1/2 - 1/3rd the gross lumens if they implemented their lighting intelligently, IE using more efficient fixtures, not lighting up ditches, and inaccessible places, and not doing things like lighting many square miles of abandoned parking lots to intensities bright enough to solder tiny printed circuit boards. Light pollution could nearly be eliminated if they did that, too.

If there's a big switch to LEDs, I'd like to see people rethink lighting on a wide scale entirely, not just reproduce what we already have (which is crap IMO) using half the power. ie use LED's inherent focusability to only throw light where it's actually needed, and use the fact that LEDs don't require warmup times, to put all exterior lights on motion sensors so they only turn on when people are actually around could reduce street lighting energy cosnumption by more like 90% rather than half, and it will be possible to see the stars again, too. There's been talk about doing a similar effect using dimming ballasts even with today's streetlights, and it is technically possible, but it hasn't really happened. Something like that would be so nice, and such a no brainer, that's it's almost certainly never going to happen... 


I should have qualified my point about the batteries, if they could double energy density while still keeping them cheap, and with high cycle life, I still believe that would be more significant. That would make plug-in hybrid, and all-electric vehicles much more feasible. In the past EVs have been hindered by the poor energy/weight ratios of Lead Acid, and to a lesser extent NiMH on one hand, and the high cost and finnicky nature of LiIons on the other.

Soemthing with double the energy desnity of the best LiIons, which could have a long cycle, excellent power density, good safety/durability, and excellent cycle life with a reasonable price tag could make plug in hybrid and pure electric vehicles on a large scale a reality. Energy consumed for lighting is small compared to the energy consumed in vehicles/transportation -- and most of that is in the form of scarce highly refined petroleum as opposed to the far more abundant coal, nuclear, and natural gas fueling the electric grid.

Not to mention things like portable electronics. Handheld devices and laptops desperately need more battery life as they try to cram more and more features into smaller and smaller packages. Althogh at this point, a switch away from inefficient LCDs to a workdable OLEDs would probably double battery life on most portable devices. Doubling energy density on top of that would be huge.


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## SemiMan (May 5, 2008)

RE: LCDs .... if you have fast enough response time on your LCD display, you could use a monochrome display and sequential color using RGB LEDS. That could reduce backlight power requirements 70-80%..... maybe not as good as OLED, but not sure which will be available first.

On the electric vehicles, etc. lets hope that the replacement for refined petroleum is NOT coal. With currently used technology (i.e. no CO2 recovery) Coal is nasty. And while I think conservation is the best way to go, the environmentalists still need to get off their high horse and realize Nuclear is a far better thing to have versus Coal.

Semiman


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## 2xTrinity (May 6, 2008)

SemiMan said:


> RE: LCDs .... if you have fast enough response time on your LCD display, you could use a monochrome display and sequential color using RGB LEDS. That could reduce backlight power requirements 70-80%..... maybe not as good as OLED, but not sure which will be available first.


I read a patent about an even better scheme than that--

Instead of a white LED, with color filtering. Use blue backlighting LED, then put red phosphor behind the "red" pixels, green phosphor behind the "green" pixels, and a simple diffuser behind the blue.

But even that won't nearly be as efficient as OLED -- LCD inherently absorb at minimum 50% of the light incident on them, because they work using a polarizing filter. The LCD itself is essentially a variable polarizer -- when a LCD pixel's polarization is parallel with the fixed polarizer, the display is "white", when it is perpenicular, it is "black".

However, there's another significant advantage of OLEDs -- when a pixel is black on an OLED, those emitters are actually OFF and consume no power. When they are displaying green, ONLY the green pixels will be on, etc. This is unlike even the best LCDs where the backlight must be on 100% of the time.

So for something like watching a movie, which is generally pretty "dark" most of the time, energy consumption on an OLED will be next to nothing.


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## IMSabbel (May 7, 2008)

copperfox said:


> I can't understand you. Can you explain that again?



Hp/l is a performance stat. 
It means power per volume of displacement.
You can increase it by 3 options:

- more complete burn of the fuel (by direct injection, ect)
- putting more oxygen into the cylinder , to allow more fuel to burn per cycle (== turbo, supercharger)
- increasing the the RPM of the engine.

Only number 1 helps effiency. no 2 and 3 improve the power, but reduce efficiency.
>500 Hp/l is only possible with insane boost pressures and lots of rpm, which causes bad fuel efficiency.

----

But if your hp/l is something you invented on your own, and that has nothing to do with the way everybody else uses that figure, then its still wrong: 
HP is POWER, not energy. You can get near infinite power from a liter of gasoline by just blowing it up in a few ms. You would be more interested in kWh...


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## copperfox (May 7, 2008)

IMSabbel said:


> Hp/l is a performance stat.
> It means power per volume of displacement.
> You can increase it by 3 options:
> 
> ...



Everything before your "----" I agree with. If you go back and read my examples, I qualified all of them except for the first by saying "naturally aspirated." Nothing you've said has made my statements untrue. Allow me to respond to the latter part.

Of course HP/l isn't something I invented, what the heck are you talking about? HP (Horse*power*) is *power*? REALLY!??! ARE YOU SURE?! How earthshattering! 

As jtr1962 already pointed out, power is energy (work done) over a span of time. And since the burn rate of gasoline is finite and greater than 0, there is a theoretical maximum RPM at which an engine can spin, and thus, a maximum amount of power that can be obtained. So no, you can't get an infinite amount of power "just blowing it up in a few ms." I'm not even clear what you mean by this.

I have already conceded the point that my original analogy was more along the lines of output efficiency given the physical size, rather than energy efficiency we reference when talking about LEDs.


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## IMSabbel (May 8, 2008)

copperfox said:


> Everything before your "----" I agree with. If you go back and read my examples, I qualified all of them except for the first by saying "naturally aspirated." Nothing you've said has made my statements untrue. Allow me to respond to the latter part.
> 
> Of course HP/l isn't something I invented, what the heck are you talking about? HP (Horse*power*) is *power*? REALLY!??! ARE YOU SURE?! How earthshattering!
> 
> As jtr1962 already pointed out, power is energy (work done) over a span of time. And since the burn rate of gasoline is finite and greater than 0, there is a theoretical maximum RPM at which an engine can spin, and thus, a maximum amount of power that can be obtained. So no, you can't get an infinite amount of power "just blowing it up in a few ms." I'm not even clear what you mean by this.


Well, if you agree that its power, why did you make that original post in the first place? You might have realized that its totally wrong...

Oh, you could increase the burn-rate of gasoline quite a bit. You could also use smaller combustion volumes or different geometries (e.g. wankel). Why are you trying to nickpick now if you didnt bother to be exact in the first place.


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## r-s (May 10, 2008)

Jarl said:


> I hope for an EDC that will give 1, 10, 100, 350 and 1000 lumens with an adjustable focus from crazy spot to pure flood, and a good CRI and colour temperature.



I want the laser flashlight Louis Wu used in Larry Niven's Ringworld  

Just think -- a pocket-sized light with a beam that could focus from wide-beam bright light, down to needle point cutting beam that would go through every imaginable substance, and a battery that never goes flat!


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## r-s (May 10, 2008)

David Gretzmier said:


> LED lumen efficiency will continue to increase, and as lumens go up, heat management will have to be better.




The more efficient the LED, the _less_ heat it will put out.

At 100% efficiency, it would add no heat at all -- 100% of the electricity would come out in the form of light, with 0% in the form of heat.


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## SemiMan (May 10, 2008)

Moderator please close. As predicted this thread has degenerated into CRAP.

Semiman


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## r-s (May 10, 2008)

SemiMan said:


> this thread has degenerated into CRAP.


 
Um... excuse me?


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## SemiMan (May 11, 2008)

Not your post r-s, just the whole thread in general. There is about 1 post every month or two like this and it just degrades into meaningless drivel that has all been discussed about a 100 times.


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## Frankiarmz (May 16, 2008)

I've already apologized for starting this thread, but as a newbie I was curious to hear some feedback from those in the know. I'm sure there must be some way to prevent this same Thread from appearing over and over again and at the same time giving us newbies some insight into the future. I understand now after being here a while that patience and reading posts by those in the know does serve to answer many questions and educate.


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## jtr1962 (May 17, 2008)

Frankiarmz said:


> I've already apologized for starting this thread, but as a newbie I was curious to hear some feedback from those in the know. I'm sure there must be some way to prevent this same Thread from appearing over and over again and at the same time giving us newbies some insight into the future. I understand now after being here a while that patience and reading posts by those in the know does serve to answer many questions and educate.


Easy to do. Since this is the LED section maybe have a sticky FAQ written by several members who have responded ad infinitum in threads like this. If I had the time now I'd gladly start collecting relevant information and links to articles but unfortunately I've had some work lately, and when the work is done my carpal tunnel syndrome will keep me from doing much typing for a few weeks at least.


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## guiri (May 17, 2008)

MikeSalt said:


> LED manufacturers need to take a little step back from the efficiency war and try to broaden the spectrum. Natural white needs some work in the LED domain.



Question. Why is spectrum or color temperature so important to you?

Me, I don't care as long as I have a lot of light, long burning time and reasonable size.


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## guiri (May 17, 2008)

kramer5150 said:


> I really like what Nichia is doing with their LEDs.... more of that will hopefully spread across the industry.



I suck at this so can you explain briefly the above..?

Thanks

George


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## guiri (May 17, 2008)

TONY M said:


> As far as flashlights are considered in my mind LEDs are now king (except for very high output lights).
> 
> I think that over the next few years reaching 1000 lumens per watt is a mark to hit. That coupled with batteries far superior to what we have now is a killer combination. Battery technology is also very important too.
> 
> What we have right now is great. As we all know very well most unlightened people still believe that a minimag running on duracell alkalines is the holy



Won't LED's spank bulbs in the future as a better technology? I mean, it IS possible to make them as bright as Xenon bulbs or not?

As for battery technology, I think that THIS is where they need more work and that's where the bottle neck is. We have kickass lights but that don't last all that long simply because they ARE too powerful for the little batteries. How about butane (or similar gas) powerpacks like they are going to do with digital cameras. Wouldn't that work?

As for the minimags, I'm surprised they still sell. To me now, they're like holding a candle.


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## guiri (May 17, 2008)

Hooked on Fenix said:


> Knowing how companies are, they'll probably hold something back that you want so you'll buy their next light.
> 
> I know that as soon as l.e.d.s become a viable option to replace fluorescents, fluorescents



So, let them hold it back and then someone here will make a custom light and we will be able to buy one 

I'd love to see LED's replace fluorescent because I am tired of the high prices of them and the stupid prices of ballasts AND their size.

I'm raised abroad and not only are our ballasts MUCH smaller, they are also much cheaper and last more than a couple of years. When they finally go, they don't burn up and start stinking either.

I don't know how yall put up with this. To me it's a big scam. I don't suppose it has something to do with 110v vs 220? I know nothing about this stuff


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## guiri (May 17, 2008)

Frankiarmz said:


> The above is a quote and while it refers to your theory it makes me wonder



Franki, I'm with you on this one and have for many years felt that the scientific community take themselves way too seriously. Everything being absolute and certain.

Just because the evidence POINTS in the direction you want doesn't meant it IS so.

Scientists have been wrong sooo many times before and they will again. I think the laws of physics aren't really laws. We THINK they are but I don't think this is true. Time will tell if I'm right


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## Frankiarmz (May 17, 2008)

guiri said:


> Franki, I'm with you on this one and have for many years felt that the scientific community take themselves way too seriously. Everything being absolute and certain.
> 
> Just because the evidence POINTS in the direction you want doesn't meant it IS so.
> 
> Scientists have been wrong sooo many times before and they will again. I think the laws of physics aren't really laws. We THINK they are but I don't think this is true. Time will tell if I'm right


 
Thank you for your open minded attitude. We sometimes think we have all the answers only to discover we have only scratched the surface.


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## IMSabbel (May 17, 2008)

guiri said:


> Franki, I'm with you on this one and have for many years felt that the scientific community take themselves way too seriously. Everything being absolute and certain.
> 
> Just because the evidence POINTS in the direction you want doesn't meant it IS so.
> 
> Scientists have been wrong sooo many times before and they will again. I think the laws of physics aren't really laws. We THINK they are but I don't think this is true. Time will tell if I'm right



Well, i personally think that randomposters on the internet _contantly_ take themself too serious. For example by talking about stuff they dont know anything about.
Too bad science, especially cutting edge science, squarely falls into the "they know nothing about" area, which _never_ stops people to talk crap like:
-But once they thought the speed of sound was inpenetrable, so we will also break the speed of light
- Absolute zero cannot be the end. it has to go deeper.
- Hey! I got something with magnet that moves. I use the resources of Free Energy!!11
- I got that great idea for a perpetuum mobile. Because i am the smartest person in the world and nobody got the idea to glue magnets to flywheels before in history!!11
- Look at my antigravity device!! it can fly up just by being charged with electricity!!11

If i got a € for every, erm, person blogging stuff like that as his personal contribution to the world of science on his livejournal, i would be typing this from my private submarine. Most of them dont even have the grasp on basic things like the fact like the definition of temperture and absolute zero, or how volume integegrals over an dipol field are not initite, even though "the field never ends, so it has to be infinite if you count that stuff far away" (yeah, i had one idiot use that (or similar) wording. I guess they dont teach calculus where he came from..

The thing is, the _real_ problems of modern science are rarely even touched by crackpots, because they are simply ignorant of it.
I know this sounds reactionary and anti-web2.0 hip, but how just accepting reality as told by people who actually know their stuff? Because as a scientist, you dont spend many years trying to get a level of knowledge that enables you to start tackling the bleeding edge problems just to decieve the general public about stuff you learned back in the undergrad days.


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## guiri (May 18, 2008)

Frankiarmz said:


> Thank you for your open minded attitude. We sometimes think we have all the answers only to discover we have only scratched the surface.



Generally I think that's the sign of arrogance and again, being complacent I think and wanting things to be the way you THINK they are. Ie, scientists.

This also happens in many forums (ie, DPReview.com) where people think they know everything.
Very knowledgeable people there but also very rude and quick to harass people. Not so here. I've seen some of it but it's more knowledge than rudeness 

Have you seen the movie No way out with Kevin Costner? I always use it as an example of what I tried to say earlier


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## guiri (May 18, 2008)

See, I dont know as much as you guys and I"m not as smart as you are but a lot of that is common sense.

It always frustrates me to no end when they tell me that the speed of light is 300 000 km per second. How the F do you measure that when you have nothing that goes this fast?

Let's not get into the whole universe or creation or god discussions.

I have no problem that people believe what they want to believe but geez, at least acknowledge that there MIGHT be something else or other options..
Isn't that the intelligent thing to do?


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## guiri (May 18, 2008)

Reminds me of a comic book I was reading many years ago. Two planets at war with each other and finally, the big bomb and one of the planets blows up.

Next scene, a scientist looking through his microscope going, what the hell..?

Turns out their whole universe fit under his microscope..take that scientists


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## SemiMan (May 18, 2008)

Moderators, I ask you once again.... PLEASE CLOSE THIS THREAD.... as predicted it has degenerated into everything that is bad about a public forum.

Guiri, I suggest looking up how the speed of light is measured. It is really quite simple. Actually electronics today are fast enough that pretty much anyone could buy the electronics and make a crude speed of light measurement tool and get pretty close to the actual value. That said, will we ever make an "object" go faster than the speed of light? Quite possibly, but we don't know how to do it today.

That said, there will never ever ever ever ever ever be a flashligh that puts out 1,000 lumens per watt. The definitions of lumen and watt are fixed, as are the conversions. It is not open for debate and it is not a matter of what we know and don't know, it just is.

In terms of cost of flourscents .... $3.00 - $5.00 for a 3,000 lumens bulb that lasts 20,000 if not 40,000 hours (>90% lumen output).... that does not seem expensive. I have no problem (Canada or U.S.) buying a ballast for said bulb well under $20 and it will power 2-4 of said bulbs. One can't compare the many old magnetic ballasts in place to a modern ballast that is easy to obtain. You can buy dirt cheat ballasts of course, but you can buy good ones too. You get what you pay for.

Semiman




guiri said:


> See, I dont know as much as you guys and I"m not as smart as you are but a lot of that is common sense.
> 
> It always frustrates me to no end when they tell me that the speed of light is 300 000 km per second. How the F do you measure that when you have nothing that goes this fast?
> 
> ...


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## Gomer (May 19, 2008)

guiri said:


> It always frustrates me to no end when they tell me that the speed of light is 300 000 km per second. How the F do you measure that when you have nothing that goes this fast?




Just because you can't fathom it, doesn't mean it is impossible to measure.
I in essence measure the speed of light almost every day doing cavity ringdown spectroscopy.


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## saabluster (May 20, 2008)

SemiMan said:


> Moderators, I ask you once again.... PLEASE CLOSE THIS THREAD.... as predicted it has degenerated into everything that is bad about a public forum.


I have to agree. But "I don't mind" these threads being opened all the time as technology is changing lighting so fast these days there just might be something new on the horizon. They do have a tendency to degenerate VERY quickly though.


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## guiri (May 23, 2008)

SemiMan said:


> The definitions of lumen and watt are fixed, as are the conversions. It is not open for debate and it is not a matter of what we know and don't know, it just is.



Again, says who?

Bet that might change 100 years from now but again, I'm just speculating and NOT making claims


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## SemiMan (May 23, 2008)

They are definitions.... we as HUMANS define them as what they are. This is not a case where we say the world is flat because we don't know any better or that the earth is the center of the universe. This is more like UP is UP and DOWN is DOWN. They are simply definitions and as such as not disputable. There is a conversion factor between watts and lumens at a given frequency of light. Again, this is a definition.... not really up for debate, but potentially refinement as the CIE curve which defines the conversion has changed. To that end you will never get more than 683 lumens/watt ... ever... as that is what the definition allows.

There are some "arguments" that people use against this, but they are wrong:

1) I put in 0.2watts and through some magic process (call it cold fusion), the equivalent of 10 watts of light comes out.... the reality is that while you may be putting in 0.2watts through some external source, some other mechanism, (call it cold fusion) is generating another 9.8 (or 10) watts of energy. You are not magically getting more than the theoretically maximum lumens/watt, you are generating extra power through another mechanism.

2) Increase in perceived brightness. There has been a lot of research that shows that pulsing LEDS at a specific duration and repetition can make LEDs be perceived as brighter than the amount of "total light emitted". This is absolutely true....running continous with power X may generate Y lumens but pulsed with power X may be PERCEIVED to be 2Y lumens. Again, it is PERCEIVED. The definition did not change. Is it "brighter"... as far as anyone that is looking at it, of course it is. But the definition of watt and lumen did not change.

Does that make it any clearer?


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## maxa beam (May 23, 2008)

Batteries are advancing so fast it's not even funny, we have good enough batteries to run _cars_ now. (Google Tesla roadster.)

So I don't see them as an issue. Here's how I think advances will go as far as LEDs.

1: 200-300ish lumen per watt cap. Improved energy loss form heat.
2: Improved color tempurature, along with improved thermal efficiency.
3: Manufacturers start working on variable wavelength.
4: Smaller LEDs get brighter? 

Imagine a small, single-die LED with 250 lumens per watt and no real need for a heatsink, along with multiple wavelengths and enormous run-time.


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## guiri (May 23, 2008)

SemiMan said:


> Does that make it any clearer?



Well, kinda. I just still think that 100 years from now if we are still alive, things are going to be very different and a lot of stuff scientists took for granted or as absolute or definite will change but again, that's my opinion and as such is not absolute either


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## guiri (May 23, 2008)

maxa beam said:


> Imagine a small, single-die LED with 250 lumens per watt and no real need for a heatsink, along with multiple wavelengths and enormous run-time.



At this point, I would trade output, or rather, more future output for longer runtime. Lights are basically bright enough to do just about anything practical but we need more runtime.

I would love to have a light that will give me 1000's of hours on low. You know, if you get stuck in the wilderness or a deserted island or something.


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## maxa beam (May 23, 2008)

guiri said:


> At this point, I would trade output, or rather, more future output for longer runtime. Lights are basically bright enough to do just about anything practical but we need more runtime.
> 
> I would love to have a light that will give me 1000's of hours on low. You know, if you get stuck in the wilderness or a deserted island or something.



No, LED lights aren't. When a LED light can out-throw and out-perform the Maxablaster is the day I say LEDs are done with brightness. You can't signal a boat miles away with a low-low.


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## guiri (May 23, 2008)

Well, no, but you can have one that you can switch to low for all your normal uses and when you really need it, you can switch it into high gear for signaling or blinding someone.

Bottom line is, in really dark woods, I don't need much output but if I'm there for a week, it would be comforting to be able to use it when you need it and face it, if you're stuck on an island like tom hanks, you need 3 years worth of output


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## jtr1962 (May 23, 2008)

guiri said:


> Bottom line is, in really dark woods, I don't need much output but if I'm there for a week, it would be comforting to be able to use it when you need it and face it, if you're stuck on an island like tom hanks, you need 3 years worth of output


In the desert island situation, you just need a solar powered rechargeable light with enough runtime to get you through a few cloudy days.



> Well, kinda. I just still think that 100 years from now if we are still alive, things are going to be very different and a lot of stuff scientists took for granted or as absolute or definite will change but again, that's my opinion and as such is not absolute either.


The converse of that is how many things which were absolute 300 years ago still are today. The Earth is round, it orbits the sun, etc. Trust me, the limit on lumens per watt is absolute. The only way we'll get around that is if we change the definition of lumen because the human eye sensitivity changes. Fat chance of that happening on anything less than a geological time scale. And regardless of how lumens are defined, the ultimate conversion efficiency of an LED can't ever exceed 100%. If it did, then by definition it would be generating energy by some internal mechanism. This energy would have to come at the expense of lost mass so it couldn't continue forever. A good analogy here is using a tiny electric spark to detonate tons of expelosive. You could in a manner of speaking say the spark liberated more energy than it consumed, but the fact is it was just a catalyst for the larger explosion. Same thing with a hypothetical >100% efficient LED. It wouldn't be >100% efficient. The power input would merely be a catalyst for some other form of energy release. In short, you can't get something for nothing. People have tried for years to push such perpetual motion machines. They're always frauds as they violate basic tenets of physics.


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## guiri (May 24, 2008)

Well, I didn't know/understand that the previous numbers meant 100%, if I had, then I would have felt differently but regardless of the LED's or anything else, I still think that in the future, some of the laws of physics as we know them might change although I don't expect to be around for that 

Thanks for the explanation


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## Burgess (May 24, 2008)

_*Re: What Will The Future Bring?*_



And* maybe* . . . .


Just *MAYBE* . . . .



Mag Instrument will *finally* get their act together,

and give the world a nice line of LED flashlights.



We can always *Dream*, can't we ? ? ?

:sleepy:
_


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## guiri (May 24, 2008)

and boy are they behind..


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