I just had the the center-mount stoplight in my '03 Chevy Surburban fail. Appears to be a line array of 15 leds in a moulded plastic housing. Unit is completely dark. Replacement cost is over $200 not including install labor. Less than 60K miles on the vehicle. If incandescant, replacement would be a $1.25 bulb, self installed. Bummer!
Bob King
That's one area where automotive differs from marine. In most states there are minimum requirements for headlights, tail lights, etc. You're not required to have more than the minimum but if you add any they must all function. That said, I doubt many police will ticket anyone because one of his 30 LEDs isn't working.
Drive their autos less?
Hasn't been much of an actual problem in Philadelphia PA USA.
My experience in Philadelphia and its suburbs in 2 states is that minimum of 2 face each way.
Incandescent filaments suffering significant damage from thermal shock is mostly myth, despite existence of devices to remedy this. What mainly happens is that an aging filament becomes unable to survive a cold start a little before it becomes unable to survive continuous operation.
I even tried an experiment with a soft-starting device claimed to double life of incandescents. It was a NTC thermistor, and when fully warmed up it dimmed an incandescent enough to multiply its life by at least 1.5.
- Don Klipstein ( snipped-for-privacy@misty.com)
Due to someone not knowing how to implement the LEDs properly, though 15 years ago efficiency of LEDs was a lot less and maybe they could not have been implemented properly.
This problem is very easy to avoid with the green LEDs that are available nowadays, not too hard to avoid with green LEDs that have been available since about 2000-2001 or so.
Have a look at what just one modern good InGaN green LED can do with
5-10 mA now, or what one made by Nichia in 2001 can do.Did you run controlled tests? I have heard of testing showing that most incandescents do not lose much life to cold starts. They do become unable to survive a cold start before they become unable to survive continuous operation, but not by a lot. The usual incandescent failure is from a hot thin spot in the filament, prone to temperature overshoot beyond its already-excessive temperature when a cold start is imposed upon it. This bad condition of an aging filament accelerates worse than exponentially, and an aging filament that cannot survive a cold start will kick the bucket soon no matter what.
- Don Klipstein ( snipped-for-privacy@misty.com)
The incandescents lasted forever (well at least 4-10 years) until they were turned off.
I believe I have the supplier mixed up. It wasn't OSRAM but another supplier with similiar type name???. OMRON or something..Been awhile now. These lED indicators were all crap and we tried many different styles and many different current levels. When run at their rated current (I think about
20mA) they all went up in smoke after a few years, anyway. The main (130vdc) ballast resistors were mounted elsewhere so they weren't a problem. The problem, as I saw it were they were designed as a 24v bulb with 24vdc worth of ballast in a miniature bulb....that's a no..no and did them in from localized heat. Finally, after about 15 years of experimenting with them and different breeds, the Engineering department decided to ignore the manufacturer's advice, went back to incandescents and replace the bulbs every few years when the device was de-enrgized, basically.As I stated, the LED units are back without any diffusi>>As some of the articles point out LED testing may be done unfairly, is >>many
My experience of red, yellow and green LEDs at 20 mA, for ones characterized at 20 mA:
Red - my champion experience here so far is around 1.8 lumens at 20 mA. They appear to me to achieve about .8 lumen at 10 mA. (Nichia NSPR510CS)
Yellow - I got about .6-.7 lumen at 20 mA several years ago, likely now at least a little better. My experiece is generally 60% of red - so I expect Osram to have something delivering around a lumen at 20 mA nowadays.
Green - my champion experience so far here is 3.7-4.4 lumens at 20 mA, more than half of this at 10 mA, averaging .94 lumen at 3 mA and around .58 lumen at 1.7 mA, at which their efficiency is close to peak and much improved over that at 20 mA. Part number - Nichia NSPG520AS.
Yes. The usual white LEDs have blue-emitting chips coated by a phosphor that absorbs some-most of the blue light and converts it to a yellow/yellowish broad band whose spectral content typically covers mid-green to mid-red. Some of the blue light is not absorbed but passes through the phosphor, to mix with the yellow/yellowish light so that you get white light.
Nowadays, some of these blue chips used for white LEDs are achieving around 40-50% efficiency. The most efficient white LED on the market that I am aware of, Nichia NSPWR70CSS-K1 at 20 mA, is a goodly 40% efficient even after losses of the phosphor. At 20 mA, it is supposed to typically achieve 150 lumens/watt.
- Don Klipstein ( snipped-for-privacy@misty.com)
Things are definitely improving with this technology!
I still suspect, as the article in the link I pointed out (another post) the LED manufacturers are cheating the measurments a bit as they don't include ballast energy (they can't as they don't know the circuit) and they don't include the losses of the lens and/or filter and as you article describes, the input power vs output power.
Thanx!
I have around 32 LED's on my M109R motorcycle. Once I pulled into the driveway and forgot to turn them off. After 2 days I went out to start the bike at night and noticed the LED's were on. When I turned the key and pushed the button the bike started up immediately. Nice.
Regards, Robert L Bass
I've got a real assortment of small LED flashlights, and a couple big ones. GREAT battery life. For home lighting they are still pretty pricy, but with incandescents being phased out, and the LOUSY luck I've had with CFLs, it sure is tempting!!!!!
The New York Times had an article earlier this week about a study (from a manufacturer) that indicates both CFL & LED lights use about 20% of the lifetime energy used by incandescents. That includes manufacturing and transport costs.
Hmmm, I guess early failure actually means the CFLs use even less lifetime energy. ;-)
Today's NYT has an article about a new LED lighting design from Britain that addresses some outstanding problems with LEDs.
Think of all the starving plant. The plants need carbon dioxide, to live. By reducing the carbon dioxide output, plants will wither and die.
Isn't part of the reason for the increase in carbon dioxide levels that we've cut down so many trees? IOW, there's more than enough carbon dioxide around to support the remaining plants.
Perce
Oh, bother. Another liberal educated drone bee. "we've cut down so many trees". I would imagine that you also think that mankind caused the hole in the ozone over the south pole.
"we've cut down so many trees". I would imagine that you also think
yep we probably have....
cleaner air is better for EVERYONE!
Of course we caused it. Remember the time Fred Flintstone bombed the dinosaurs (and missed) with that nuclear weapon?
How about the sheep?
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