how much brighter can a led get?

raggie33

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is there a limit or are they like cpus. will some day we get a 1000 lumens per watt
 

camelight

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Well there is a limt and this idial source is a green light (555nm) and it is 683.002lm/w
I don't know if it will ever be posspole in led or any other kind of light bulb
But it is the limit of luminous efficiency
 

CelticCross74

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LED technology has barely just begun to truly advance. How much brighter can an LED get? I believe in 10 years LED will have surpassed HID in any application. Cree just keeps advancing. There are cars now that have LED lights instead of HID. There is only so much you can do with HID. The potential of LED technology is nearly limitless. Take the XHP35 HI. If someone had told me 10 years ago there would be an LED that ran efficiently and cooler than a halogen bulb that cranked 1300 lumens I would have thought they were drunk.
 

easilyled

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Take the XHP35 HI. If someone had told me 10 years ago there would be an LED that ran efficiently and cooler than a halogen bulb that cranked 1300 lumens I would have thought they were drunk.

In fact the XHP35 HI cranks out 2600 lumens in the Acebeam K70!! Admittedly its probably overdriven and hopefully has massive heatsinking. Nevertheless, it just shows what leds are capable of now. The thow of the K70 is 250,000 lux.
 

romteb

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Well there is a limt and this idial source is a green light (555nm) and it is 683.002lm/w
I don't know if it will ever be posspole in led or any other kind of light bulb
But it is the limit of luminous efficiency

You can't make it more to the point and relevant than this answer, wich also implies that white leds will always be less efficient than this theoretical monochromatic source.
 

chillinn

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You can't make it more to the point and relevant than this answer, wich also implies that white leds will always be less efficient than this theoretical monochromatic source.

Does it?

I was pretty sure white light LED's will always probably be the most efficient LED's that actually are available, due to demand. I read a thread from a few years back regarding more r&d going into white LEDs due to popularity made them more efficient than most narrow band LED.

555nm also happens to be the precise wavelength that the human eye is most sensitive to, and that is a telling coincidence. And the way I read the OP's question was without the constraint of rational, purposeful engineering other than to learn the limit of how bright an LED could be... efficiency, safety, durability or purpose be damned, how bright could the theoretical brightest LED be before it fails? If power and efficiency were not a concern, but the prime goal was merely at least one second of as bright as its brightness level possibly could get... how bright could that be?
 
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FlashKat

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10 years ago we use to be impressed with 100 lumens, and wondered if LEDs would ever reach 500 lumens.
 

Stereodude

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is there a limit or are they like cpus. will some day we get a 1000 lumens per watt
There are absolutely limits. It's a function of the color temperature and the CRI you want. ~350lm/W is probably the practical limit for anything that doesn't have a low CRI.
 

Stereodude

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10 years ago we use to be impressed with 100 lumens, and wondered if LEDs would ever reach 500 lumens.
That's a totally different discussion from luminous efficiency. As LEDs become more efficient they can become much brighter because there is far less heat to deal with.
 

KeepingItLight

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There are, indeed, limits to the number of lumens per watt. All that means is that we will see other ways to increase output. The Cree XHP family of emitters is the obvious example. It created a leap in output simply by putting more LEDs on a single emitter.

The future is easy to predict. Emitters will get brighter.
 

sidecross

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As LEDs become more efficient they can become much brighter because there is far less heat to deal with.
I thought the limit today is how to reduce heat as an unwanted result of increased brightness.

EDIT: I might have misread your intent of your post; is the increased brightness a result of dealing with excess heat?
 
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U2v5

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The law will probably be the limit of LEDs.
Some day someone will feel the are too bright.

Who needs an all that light! Candles and torches have been the standard for centuries!

Just sayin... [emoji6]
 

Stereodude

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I thought the limit today is how to reduce heat as an unwanted result of increased brightness.

EDIT: I might have misread your intent of your post; is the increased brightness a result of dealing with excess heat?
Heat is a problem. A 30lm/W LED putting out 100lm generates about 3W of heat. A 150lm/W LED putting out 650lm generates about 3W of heat. You get a lot more lumens for the same amount of heat. As luminous efficiency continues to increase you can continue to get more or more lumens without overheating the die. However, luminous efficiency can only continue to advance so far. We're pretty close to peak luminous efficiency.
 

romteb

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Ohh the cringe...

The maximum efficiency of a light source is derived from fundamental physics, it has nothing to do with LEDs, YOU CAN'T PRODUCE MORE THAN 683.002lm/w WITHOUT BREAKING THE LAW OF PHYSICS, it's there on internet for you to read.
 

bykfixer

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When Nano technology gets involved there's no telling. Micro-mirrors adding to the output.

Then if the heat can ever be recycled... no telling.

Right now some dudes in Korea are working on "light bulbs" that recycle heat to generate electricity and MIT guys are developing micro mirrors to make the light bulb brighter.

Yup, there was a thread in the incan section with links to the stories. Light bulbs with the same efficiency as current LED's and they are in the infancy stage.

So imagine that technology in an LED.
 

PeterRamish

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Well there is a limt and this idial source is a green light (555nm) and it is 683.002lm/w
I don't know if it will ever be posspole in led or any other kind of light bulb
But it is the limit of luminous efficiency

Upon rereading all this, I see that the OP asked two different questions, so I will address one of them (the other is a simple energy units conversion question that is really not that interesting anyway..:rolleyes:

If I understand your question to be *exactly* in your title " how much brighter can a led get?

then the answer to your questions is "that there is no limit"

The answers to your question that site 'luminous efficacy" as a limiting factor are not really correct. We have to be very careful asking and answering questions like this in plain language. Physicists and engineers use mathematic notation to express these relationships. Plain language is not precise enough and has a bunch of fuzzy trap doors. Efficiency is involved, of course, but not exactly the way you think when discussing Lumens which are a measurement of 'the perceived' amount of 'luminous flux'. If you could convert all energy into your 'light engine' to visible light then the 'luminous efficiency' will go to 100% and you are well on your way to the worlds infinitely brightest LED.

So in plain English I will defend my answer. Imagine a steam engine, it converts heat energy to rotational power at the end of its output shaft. We all easily understand that if our steam engine has no internal losses then your could, in theory, pour an infinite amount of heat into it and get an infinite amount of rotational power out the shaft at the other end. The same is true for a 'light conversion engine'. If I can design such an engine with a 100% conversion with no loss then there is an output directly relational to the input energy without limit.

A confusion arises with the LED engine, is that there are TWO conversion losses involved. One is the traditional losses that everyone is familiar with, that is conversion into heat energy, the other is the loss into other wavelengths that do not contribute to, what is known as the 'luminous flux' . If you can design a LED with no loss outside of luminous flux, and no conversion loss into heat then there is no restriction on 'watts in = luminous flux out' . Just to be clear 'lumens' will not convert directly to a measurement of power, just as 'rpm' is not a correct expression of the power output of the example steam engine. 'Luminous flux', however is a measure of converted total power of electromagnetic radiation which is adjusted to the wavelengths that your eye perceives.
 
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