LED Headlights Introduced

Power consumption, and maybe weight, should be lower too.

and they'll last longer too.

How can power consumption be less if heat buildup is worse than with incandescent bulbs? That would seem to imply that LEDs are less efficient than incandescent. Can anyone explain?

Hi Jared,

I'm not sure about this. Maybe someone else who knows for sure can comment..

But my understanding is that heat buildup could be a problem because LEDs have less surface area (partly because they are smaller, partly because they are directional) than incandescents to dissipate heat, especially if many are packed together.

But I could be wrong, so don't quote me on this. don't

Jared, probably that LEDs are more sensitive to heat. They generate less of it (lower power consumption) but are more easily damaged by high heat.

Jared.. its like MGR said the LED's are smaller and have less surface area to dissapate the heat. The fact that lots of them are clustered together doesn't help and that they are generally more sensitive to temperature. I'm anticipating lots of problems with these headlights but like all new techs that get put into high end cars it won't go away they'll find a way to make it better. This is definately a good thing.

I suppose one possible solution is to distribute the LEDs across a larger surface on the front of the car. Future cars might have the whole front end illuminated or use specif configurations to build brand identity.

Check out:

http://en.wikipedia.org/wiki/Luminous_efficacy

Incandecent = 5 to 35
LED = 25 to 50 lumens/watt
lumens/watt
Fluro = 50 to 100 lumens/watt
Gas Discharge = 150 to 200 lumens/watt

Typically LEDs have approximately equal efficiency to Incandescent light sources and are certainly not the "green" break through people seem to think they are although they are improving. While this story does not make this claim the fact that it is on treehugger.com certainly suggests it.

Anonymous, LEDs produce directional light, so when such light can be used, they are more efficient than incadescents because you can use less total wattage to produce as much light in the direction that you need.

Also, the efficiency of LEDs has been increasing (they've also made some breakthroughs in producing nice white light, which I think where covered on this website).

PLEASE... stop posting car industry spam...

putting two leds on an audi or a lexus does not have anything "green" about it, they could also put organic veggies in their trunk it still wouldn't be treehugging.

just so you know, i believe that if i were to count the car industry ads/info/spam that i see daily now a days, th would be number one of all my media sources... weird no?

--
editor note: This is not a post about the audi car, this is a post about the LEDs. These can be used on electric cars and plug-in hybrids to make more efficient use of the electricity in the batteries.

As noted by the second Anonymous poster, the efficiency of LEDs has been improving continuously over time. In the past, and to some extent right now, LEDs are often best used to replace small or dim light sources (for white light). Where monochromatic light is needed there is virtually no excuse not to use an LED (for anything under about a kilowatt of total output power), unless you are talking about infrared or frequencies higher than blue.
Also, as noted by dave and MGR, semiconductors and heat are not close buddies. An added problem with LEDs is that while the LED itself may be able to withstand the high temperatures caused by its operation, the mounting substrate and surface may not--not to speak of the rather glaring fact that higher current (due to greater light output) means that there will be more loss (in the form of heat) in the connections between the LED semiconductor itself and the power feeds (which are often aluminum).

Why are fluorescents not being used in the automotive industry? Are they incapabe of outputting the necessary lumens for headlights?

Probably because they are not shock-resistant enough.

"How can power consumption be less if heat buildup is worse than with incandescent bulbs?"

Incandescent bulbs create light from a white hot filament approaching 2500-3000 degrees C. Since the bulbs are mostly comprised of metal and glass, high temperatures are not a problem.

High power LEDs produce more lumens per watt, but typically break down at temperatures around 100-175C.

Heat management becomes a top concern with high power LEDs. Natural convection doesn’t typically cut it.

Very intersting. Here's what I think:

LED headlights are a great idea. I am totally sold on their performance. Although as one posted noted they may use higher voltage, they use considerably less amps, and in turn use less over all power (watts). Lets say that they find a way (and of course they will) to keep the lights cooler (or find a less heat sensitve substrate for these LEDs), and lets assume it ends up costing the same to create a LED headlight as an older Incandescent / Halegoen one. The fact that you would in theory NEVER need to replace an LED headlight is a huge advantage. This is a great idea. It's not just green becuase it may use less electricity (less emmisions, small alternator, better gas milage, more efficeint electric cars, etc), but becuase you are not manufacturing 1 million a month, but 50k a month (this is just an example, don't have any idea of actual numbers).

LEDs today generally last from 5-25 years (on all the time, so in theory they would last as long - or longer than most cars are in service).

This, like other green technologies, is an investment. It might not make sense to a lot of people now. But it makes sense in the long run, for sure. And besides that, they look cool. And no, I do not sell LEDs or anything (I buy a lot of them though!)

>>"PLEASE... stop posting car industry spam..."

Ok. I'm converting an old 1986 mazda pickup to electric (battery) power.

So - I shouldn't be interested in "car industry spam" - particularly where it regards anything that uses electricity?

Actually, I'm VERY interested in LED headlights; if they use less power, less amps, that means I get to drive further before I have to recharge (less recharges is good, right?)

How is this not relevant?

Of course, I need to heat and cool the passenger compartment... (I have some ideas, but haven't 100% figured this out yet).

Engineer:

You sure don't sound like an engineer. You definitely aren't a lighting engineer and sure don't know anything about LEDs.

You say they use more voltage... More voltage than what? Incandescent? Do you have any idea how a white LED works?

A white LED is a blue LED with a phosphor coating applied directly on the die. The very close proximity causes the phosphor to glow extremely brightly. The blue LED drops a bit over 3 volts. How much current it can handle is determined by its thermal environment, much like a computer processor. Those, as you know, have to use elaborate measures to get rid of the heat, else they will fry. Same with LEDs. 1 amp is about all you can push through one without taking such measures. That's only 3 watts. That's pretty bright, but not enough for a headlight. So you would have to use one diode with liquid nitrogen cooling, or an array of them with simple cooling, but all the problems of focussing into a coherent beam.

Moreover, all phosphors wear out with use, and the more excited they are, the quicker they wear. So in the case of a car headlight, LEDs may not last even as long as a halogen quartz lamp.

I think that car manufacturers will change xenon lamps on "S" class cars to LED untill 2010-2011.
I really believe that LED technology will be used in all the cars untill 2018-2020 or even much earlier because it not only produces good light but helps drivers to economy gas.
As for me I would like to use the LED technology in headlights of my car as soon as possible.

freddyzdead you are funny, of course they will not use one single led for headlights but a pack of it with different lenses. They could do it but the problem is that they need to cool this pack of leds efficiently and "calculate" what happens if for some reason one led is "off". Imagine a pack for each headlight that has 5 or 6 leds each one emits about 200 lm(like the new k2) so 5x200 =~ 1000 per headlight, 2000 total. They can add more leds for the high beam to combine the low beam with the high beam and these are just some thoughts

I would like to test them out, I would like to see them come out in the H3 type bulbs 1st.

acually Cadillac are already using L.E.D lighting in the new escalade, developed by hella i belive! a little dimmer than HID but without the glare

read up on it !!!

http://www.mlive.com/flintjournal/business/index.ssf/2008/10/simply_illuminating_cadillac_i.html