Audi LEd Headlamps

[Victor Roberts]

I received an e-mail announcement from Lumileds on Friday
that stated the 2007 Audi R8 would use Luxeon LEDs for both
high and low beam headlamp functions. I cannot confirm this
on the US Audi site. The information there says only that
the R8 has full LED tail lamps.

There is no reason why this can't be done if Audi is willing
to spend the money for enough LEDs. I think this is the
first production car that uses LED headlamps, but I could be
wrong.


--
Vic Roberts
http://www.RobertsResearchInc.com
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[TKM]

I received an e-mail announcement from Lumileds on Friday
that stated the 2007 Audi R8 would use Luxeon LEDs for both
high and low beam headlamp functions. I cannot confirm this
on the US Audi site. The information there says only that
the R8 has full LED tail lamps.

There is no reason why this can't be done if Audi is willing
to spend the money for enough LEDs. I think this is the
first production car that uses LED headlamps, but I could be
wrong.

Hmmm. Didn't think there would be enough intensity for the headlamp
application just yet. The right beam pattern shouldn't be impossible
though. Maybe DS has heard something.

Terry McGowan

 

[SimonLW]

I received an e-mail announcement from Lumileds on Friday
that stated the 2007 Audi R8 would use Luxeon LEDs for both
high and low beam headlamp functions. I cannot confirm this
on the US Audi site. The information there says only that
the R8 has full LED tail lamps.

There is no reason why this can't be done if Audi is willing
to spend the money for enough LEDs. I think this is the
first production car that uses LED headlamps, but I could be
wrong.


--
Vic Roberts
http://www.RobertsResearchInc.com
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replace xxx with vdr in the Reply to: address
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I can see this costing much less than HID, but much more than halogen. They
must spend extra for color matched parts. I bought several Luxeon
flashlights on closeout for $9 each and each one has a different shade of
white. I opened the head to confirm it was a real Luxeon and not the Chinese
knockoff.

I see that you can buy a 3 watt Luxeon Maglight at Home Depot for $16 now,
so the price is getting quite reasonable. I was wondering when these LEDs
might start appearing on the front end of cars, but already were!
-S

 

[Victor Roberts]

For a lot less money I would think they could equip their vehicle with a set
of 9011 and 9012 bulbs in a adaptave fixtures. Self aiming, aiming into a
turn and all. Close to HID intensity and easy for the consumer to replace
the bulbs. I have used these bulbs in a Toyota RAV4 and a PT Cruiser and the
improvement over non-IR bulbs is significant and the cost is quite
reasonable. [But what do I know?]

Richard.

This is not about saving money, it is about spending money
to show off.

--
Vic Roberts
http://www.RobertsResearchInc.com
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[Victor Roberts]

I'm just not sure how PWM would help increase the output. For
stop/tails as Daniel pointed out, It's used to decrease the output from
a steady burning stop lamp to a tail lamps to get the required ratio of
intensity between a stop and tail instead of cutting the current down.
I recall that this is mostly due to the HB LEDs not necessarily
operating reliably with the lower currents.

Because of the high output requirements for headlamps, the HB LEDs used
in these applications are probably driven near or close to their max
current ratings already. How would PWM increase the amount of light
available? Even if they are at something like a 33% duty cycle, you
would need to run 3X the maximum steady state rated current to get the
same brightness. Seems to me this might cause some color shifting or
life deprecation for little if any benefit. Maybe I'm missing
something.

There is an urban myth that states you can fool the eye by
pulsing a light source at rates higher than the flicker
fusion frequency. It doesn't work.

--
Vic Roberts
http://www.RobertsResearchInc.com
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[[email protected]]

As LED technology continues to evolve, the performance of LED headlamps
is predicted to improve to approach, meet, and perhaps one day surpass
that of HID headlamps.

Do you think that the technology will eventually be good enough to
create a self-contained LED headlamp module that would be a drop-in
replacement for a plain ol' sealed beam? If the technology does get
there, will there be enough cars with sealed beams still on the road
for any of the manufacturers to care?

As far as I know, there aren't yet any (legal) HID modules that can be
installed in place of a sealed beam. I think the main problem is that
the reflector still needs most of the volume of the lamp, which leaves
little room for the power supply. But it seems like the working part of
an LED headlamp could end up being a relatively thin LED - reflector -
lens "sandwich", leaving plenty of room for electronics in the rest of
available space.

Cold weather also brings another thermal-management conundrum: [...]
heat must in addition be effectively applied to the front lenses of
the lamps-which are not heated by the cold light beam produced by
LEDs-to provide rapid and complete thawing of snow and ice
accumulation.

How are the current designs doing this - blowing the LED-cooling air at
the lens? Using resistance heat like a rear window defogger? Or...?

The regulatory debates centre around the colour issue and whether &
how to standardise LED light sources or light source modules -- the
latter idea being to see to it that a vehicle owner facing a dimmed
or dead LED emitter isn't faced with the choice of driving with
degraded headlighting (possibly failing a roadworthiness inspection)
or spending a large sum of money for a unitised replacement headlamp.

Given the number of cars I've seen on the road this winter with no
apparent accident damage but only one working headlamp, apparently
US$10 qualifies as "a large sum of money".

Matt Roberds

 

[LEDNeonFlex]

This market is moving fast, Edison Opto is manufacturing 100watt led's
in China and Nichia has LED's that 150Lumens/Watt CFL is at most
80Lumens/Watt... You will see this year home and commercial lighting
drop in replacements with many many cool mini light power house fixtures.

Derek Breneol

LED Flex Lighting Co.
www.ledneonflex.com
www.ledflexlight.com

 

[Victor Roberts]

This market is moving fast, Edison Opto is manufacturing 100watt led's
in China and Nichia has LED's that 150Lumens/Watt CFL is at most
80Lumens/Watt... You will see this year home and commercial lighting
drop in replacements with many many cool mini light power house fixtures.

Derek Breneol

LED Flex Lighting Co.
www.ledneonflex.com
www.ledflexlight.com

I'm not sure what you mean by "cool mini" but if you mean
decorative, very low lumen fixtures then I have no issue
with your prediction. However I do not expect that we will
see fixtures producing a useful amount of white light for
general lighting this year, except for a few very expensive
concept fixtures designed to replace incandescent-based
fixtures.

That wonderful LED efficacy we read about is still confined
to low power devices that are tested at a junction
temperature of 25C and often don't have any light absorbing
packaging. Real world devices do not perform as well. The
DOE just concluded a round of tests of LED-based fixtures
and they were surprised to find that the fixture
performance was far below the performance that they expected
by reading the LED data sheets. They should not have been
surprised. They seem to have ignored at least the junction
temperature issue, plus perhaps driver efficiency and the
"typical" vs. "minimum guaranteed" issue.

--
Vic Roberts
http://www.RobertsResearchInc.com
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