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Norbert
TSLA will win
For most LED's, multiple ones would be needed, including the Cree XP-G mentioned above. I'm not sure how efficient this LED is, but it seems to have more than needed with a single large LED:
SST-90 White Series PhlatLight LEDs (up to 2200 Lumens)
I've been reading a few high-power-LED flashlight reviews, and those reviewing flashlights with 700 Lumens (which are usually about $150-$300) often claim that they are as bright as a car headlight. However, it might be that these cover a smaller area than a car headlight, and I wouldn't know (yet) how many Lumens a car light would really need.
Norbert
TSLA will win
I've been reading some more, and should improve these numbers (for those who are interested, though probably some of you already know much more than this):
A halogen bulb commonly used in cars is the H7 bulb. It has about 1500 Lumens at 55 Watt. That's about 27 Lumens/Watt, much less than HID(Xenon) or LED lamps.
HID(Xenon) Lamps used in cars seem to be typically 3200 Lumens at 35 Watt, but I've also stumbled across some advertised to be 5300 Lumens at 50 Watt and even 8300 Lumens at 75 Watt.
Again, the typical value seems to be 3200 Lumens at 35 Watt, which is about 91 Lumens/Watt
So the latest generation of LED's (those which are currently becoming available commercially) appears to be better than that (or at least comparable). Considering that LEDs seem to be improving continuously, the next generation will probably clearly surpass HID lamps. Plus, LEDs appear to be much more reliable, as far as I can tell.
Back to VFX's question of how many LED bulbs are needed:
The SST-90 mentioned above has a max of 2200 Lumens (according to the manufacturer), so at least two would be required to be equal to an HID lamp in output.
However, there is also the CSM-360 (although I'm not sure whether it is already available, and whether it would be a good fit for automotive applications):
http://www.luminus.com/stuff/conten..._csm_360_w_product_datasheet_illumination.pdf
According to the manufacturer's data, it has (for the highest rated version) a range of 3600 Lumens to over 6000 Lumens, and at 3600 Lumens, an efficiency of over 100 Lumens/Watt.
If these numbers actually mean what they seem to, the CSM-360 LED is preferable to a typical HID bulb in probably every regard.
Now, the other choice might be to take advantage of the Cree XP-G LED's high efficiency of almost 150 Lumens/Watt at 200mA (according to the test referred to above). (It is available now.)
At 200mA, it delivers about 100 Lumens, so one would need about 35 of them. Printed circuit boards like the following (with matching optics) can be used to assemble 7 of them into one unit of 40mm diameter:
Cutter Electronics
So 5 of these, each with a diameter of about 2 inch, would be needed on each side of the car. I don't know if it would be worth the effort, compared to an easier-to-manufacture solution using the CSM-360 LED, but it doesn't seem impossible.
Norbert
TSLA will win
Or, since the availability and price for the CSM-360 LED is unknown to me at this point, using the already shipping Cree XP-G LEDs, but just 2 bulbs, since 5 seems a lot:
So with 2 bulbs (2 PCBs, 40 mm diameter, with 7 LEDs each), running each LED at 625mA, it would be:
At this current, they have 120 Lumens/Watt, and 2 bulbs would generate about 3500 Lumens (more than the HID lamp's typical 3200 Lumens), and use 29 Watt (less than the HID lamp's typical 35 Watt). Cost: about $42 per bulb in single quantities.
So with 2 bulbs (2 PCBs, 40 mm diameter, with 7 LEDs each), running each LED at 625mA, it would be:
At this current, they have 120 Lumens/Watt, and 2 bulbs would generate about 3500 Lumens (more than the HID lamp's typical 3200 Lumens), and use 29 Watt (less than the HID lamp's typical 35 Watt). Cost: about $42 per bulb in single quantities.
Jaff
Active Member
They look cool too TEG!
Does anyone know if TM has ever looked at LED's to replace their "underpowered" current stock headlamps?
Does anyone know if TM has ever looked at LED's to replace their "underpowered" current stock headlamps?
Much discussed on TMC; but we think EM has xenon on his car and that new headlights cost about $1/2M to design, test, approve.
There's a story on LED headlights saving 6 miles doing the rounds today:
http://venturebeat.com/2011/01/24/led-headlights-give-your-electric-car-an-extra-six-miles/
This was my response:
http://venturebeat.com/2011/01/24/led-headlights-give-your-electric-car-an-extra-six-miles/
This was my response:
http://green.autoblog.com/2011/01/20/led-headlights-add-6-miles-electric-car-range/
The "6 miles range" quote is squishy and dubious, but the technology does offer a noticeable improvement.
(And LED vs bulb longevity is way better.)
http://www.electronicsweekly.com/Ar...5/led-headlights-beam-beyond-premium-cars.htm
The "6 miles range" quote is squishy and dubious, but the technology does offer a noticeable improvement.
(And LED vs bulb longevity is way better.)
http://www.electronicsweekly.com/Ar...5/led-headlights-beam-beyond-premium-cars.htm
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Yeah, I'm not denying that LED isn't better, but the 6 mile range thing is way off the mark. It's yet another FUD thing that can be seized upon by the range anxiety crowd if you look at it from the reverse angle.
To be honest I'm just sick of these tech sites parroting out company press releases which can easily be checked with two lines of junior school arithmetic.
To be honest I'm just sick of these tech sites parroting out company press releases which can easily be checked with two lines of junior school arithmetic.
Reminds me of a good book "Innumeracy: Mathematical Illiteracy and Its Consequences".
Even before I owned a Tesla and had a reasonable idea how much energy it took to run an EV, I'm pretty sure I would have still thought that the energy to propel a car 6 miles would be equivalent to significantly more time lighting headlights.
Yeah I was dumbfounded how much energy it took to move an EV versus running the accessories. "Holy @#$! forty-THOUSAND watts to keep my car at 70 MPH on slight incline" (versus 130 watts for headlights). I'm a pretty geeky person but just had no concept of the power required to move and keep moving a vehicle. I can't believe I'm drawing 200KW and ~700 amps when I'm flooring it. That's an awesome amount of power.
Then you start thinking how a 56 KWh battery pack is the equivalent energy potential as ~2 gallons of gasoline ... and then thinking about the 20 gallons you're sitting on in an ICE vehicle.
Back to LED lighting -- I for one would love it. I have a friend who has one of these flashlights and it's mind-bogglingly bright. It severely outshines the headlights of any car. 2,200 lumens, 30 watts. And I believe it's a single LED component.
Try starting a turbine engine as in an airplane. I fly a Pilatus PC-12, and to start this moderately large turbine engine, we supply 28 volts and it needs 1500 amps peak and draws 600 to 800 during the remainder of the start cycle, and all from a 30 lb NiCad battery.
If I understand it correctly, adding LED headlights to the Roadster would have very minimal impact (improvement) on the range, right? I still want them mainly for longevity and for better light. And they look cool I think.
felixtb
RsEU502,Sp+14274,XpEUSig4
do you think tesla will allow for LED headlights? or will they void the warranty there as well considering they can always claim possible interference........?! or do you think they would be fine if one decides to change the standard bulbs to LED equivalents?
/fb
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Norbert
TSLA will win
Like so many things being discussed here, LEDs are evolving and (last time I checked) about to surpass halogen in usability within the next few years (in so far as they haven't already)... just a matter of time. In 10 years, so many things will be different... unless we all have been deceived big time... 
bonnie
I play a nice person on twitter.
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