Anyone moved to LED Lighting?

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I have plenty of experience where I have been able to track individual units due to fading and/or a few LEDs being burned out and/or LEDs of a particular spectral characteristic are obsolete for the purpose due to lower efficiency than more modern ones. I can tell you that LED traffic signal units have a very high rate of lasting a lot more than 2 years - more like 5-10.
- Don Klipstein ( snipped-for-privacy@misty.com)
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The traffic light people cannot afford failures. The legal implications are too great. I am not sure if it is based on manufactures warraties, recommendations or history but we still ocasional segments missing.
With LED experience this may also be a heat problem with retrofitting old units and heat not being drawn away?? When you push LEDs too hard they don't last long. This is only from a small sample area with slightly over $500K population.
Josepi wrote in part:

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I meant being kept in service for 5-10 years. Most of Philadelphia's red ones installed in the 1990's and using an LED chemistry since superseded in traffic signal use are still working and in service, not relaced just for a few LEDs being out.
Now that they are making them with power consumption as low as 7 watts for ones 8 inches in diameter and 8 watts for the ones 12 inches in diameter, heat is not that big a deal in traffic signals that had incandescents of 92 or 116 watts. Such huge reduction in power consumption occurs in part from not having 70-75% of the light blocked by red and green filters.
If any failure is so intolerable, then why were incandescents acceptable?
- Don Klipstein ( snipped-for-privacy@misty.com)

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Incandescents were not so acceptable. They were experiemtning with LEDS to lower the maintenance on incandescent systems.
Somebody ehre was roght about the lack of heat too. Snow storms can fill the lamp projector lens in and the status cannot be told during the day. (No we aren't moving to Florida, Robert...LOL)
After a debate on the job, we ran into a traffic light maintenance crew and pulled over to chat with them. IIRC, they informed me they replace the incandescents every year or on report. We always have multiple lamps for out traffic lights. I assume you are in the USA where they classically may have only one traffic head facing each way. We have at least two and on big intersection, three or four, sometimes. (we get lower sun in the winter. There always seems to be the main one with a sunset right beside it)
I would imagine an incandescent, pushed and heated that hard and then blinked on and off would wear the filiament out (thermal shock) very quickly, too.

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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)

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Joe Pfeiffer wrote:

I have seen circuit-board type retrofits for Studebaker Avantis (notorious for dim, hard to see taillights even when everything is in as-new shape) and they work really well. Unfortunately I have a '55 coupe which has the same issue but there is no ready-made retrofit kit.
I'm thinking of perhaps taking some of the "truck-lite" oval taillights and busting them apart and seeing if that works better. Only thing I've tried that provides acceptable lighting in those taillights so far are halogen bulbs (which I don't like for heat reasons) and one set of LED "bulbs" that I got from DealExtreme that use three high-output LEDs rather than the usual array of cheap crappy LEDs. Unfortunately for those wanting a "drop in" replacement, I suspect that those particular "bulbs" will only work well in a light designed with a Fresnel type lens, and not one relying on the reflector for its optical characteristics. Even worse; one of them has already fallen apart.
If an LED "bulb" were available that would work well in reflector-type optics and would fit the same form factor as a typical 1034, 1157, P21/5W or single filament equivalent, I would be really happy. I sure wouldn't mind having LED lighting on the rear of my Porsche 944, but that uses a molded-together type lens/reflector assembly where the bulbs are inserted through little holes in the rear, so it's damn near impossible to implement a circuit board type retrofit there (OK, not impossible, but it would be an ambitious project, esp. considering that there's five different segments in each taillight - three red, one amber, one white (stop, tail, and rear fog are discrete segments) and I just don't have enough free time to build such a taillight, and I doubt the results would be worth it even though they'd be quite cool.
As I posted before, I tried some that looked like this:
http://www.urban-neon-car-lights.com/car-lights/1156ledbulb.html
I think I got them from superbrightleds.com - what a misnomer! absolutely worthless. Then I tried some of these a couple years later:
http://cgi.ebay.com/ebaymotors/1156-Super-Red-63-LED-Light-Bulb-1141-1073-3497-7506_W0QQcmdZViewItemQQhashZitem1c0dfca729QQitemZ120493745961QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
those are the ones that I said worked well but were too dim.
these are the ones that worked well in my '55 (Fresnel type lens) but fell apart:
http://www.alibaba.com/product-gs/240415486/LED_Car_Light_LED_Auto_Lamp.html
Now that I think about it, I think I also put a power resistor in series with the parking light function, as it was way too bright.
Nothing yet that I can recommend as a plug 'n' play for most people in an average car.
I haven't tried the SMD type "bulbs" yet but at $20 a pop and me expecting to be disappointed, I'm hoping that someone else will try them first and let me know :)
nate
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replace "roosters" with "cox" to reply.
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There are nav lights out there sufficiently simple and non-critical in design such that someone can make an LED retrofit for the bulb that gets the light to meet the spec - despite the difference in emitting surface geometry and directional characteristics.
Motor vehicle lights are not as easy to make LED incandescent-retrofit bulbs for with achievment of legal requirements being maintained.
- Don Klipstein ( snipped-for-privacy@misty.com)
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LED tail light are not "very bright". The illumination is very poor.
However LED lights are very focused and play on the human vision system to compete with the effectiveness of incandescents.
Many incandescent tail lights have taken a lesson in efficiency also and many of the so-called LED taillights on vehicles are actually incandescent bulbs. Take a closer look and you will see many peanut bulbs in a reflector with small pockets.
When will we see back-up LED lights on vehicles? Not likely in the near future. The total luminence is not there to illuminate an area. Something LEDs have failed at, to date.

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Josepi wrote:

I've seen LED back up lights on a couple of newer Luxury cars. BTW, The 2009 Cadillac Escalade Platinum has LED headlights.
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On Sat, 21 Nov 2009 11:06:21 -0500, Congoleum Breckenridge

Careful. You'll make Josepi's head explode.
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salty wrote:

That's not helping.
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I would like to see cites of this. This is quite interesting. Apparently the Lexus (2008) used LEDs for low beam headlights. Here is an exepr from a sirte discussing that. The heigh heat put out by LED inefficiency is a problem. --------------------------------------------- Automotive headlamp applications using light-emitting diodes (LEDs) have been undergoing very active development since 2004.[38][39] The first series-production LED headlamps were factory-installed on the Lexus LS 600h / LS 600h L starting with the 2008 models. Low beam, front position light and sidemarker functions are performed by LEDs; high beam and turn signal functions use filament bulbs. The headlamp is supplied by Koito. Full-LED headlamps supplied by AL-Automotive Lighting were fitted on the 2008 V10 Audi R8 sports car except in North America. The Hella headlamps on the 2009 Cadillac Escalade Platinum became the first U.S. market all-LED headlamps. Present designs give performance between halogen and HID headlamps,[40] with system power consumption slightly lower than other headlamps, longer lifespans and more flexible design possibilities.[41][42] 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.[43]
The limiting factors with LED headlamps presently include high system expense, regulatory delays and uncertainty, and logistical issues created by LED operating characteristics. LEDs are commonly considered to be low-heat devices due to the public's familiarity with small, low-output LEDs used for electronic control panels and other applications requiring only modest amounts of light. However, LEDs actually produce a significant amount of heat per unit of light output. Rather than being emitted together with the light as is the case with conventional light sources, an LED's heat is produced at the rear of the emitters. The cumulative heat of numerous high-output LEDs operating for prolonged periods poses thermal-management challenges for plastic headlamp housings. In addition, this heat buildup materially reduces the light output of the emitters themselves. LEDs are quite temperature sensitive, with many types producing at 30 C (86 F) only 60% of the rated light output they produce at an emitter junction temperature 16 C (61 F). Prolonged operation above the maximum junction temperature will permanently degrade the LEDs and ultimately shorten the device's life. The need to keep LED junction temperatures low at high power levels always requires additional thermal management measures such as heatsinks and exhaust fans which are typically quite expensive.
Additional facets of the thermal issues with LED headlamps reveal themselves in cold ambient temperatures. Many types of LEDs produce at ?12 C (10 F) up to 160% of their 16 C (61 F) rated output. The temperature-dependency of LED's light output creates serious challenges for the engineering and regulation of automotive lighting devices, which are in some cases required to produce intensities within a range smaller than the variation in LED output with temperatures normally experienced in automotive service.
Cold weather also brings another thermal-management conundrum: Not only must heat be removed from the rear of the headlamp so that the housing does not deform or melt and the emitters' output does not drop excessively, but heat must in addition be effectively applied to thaw snow and ice from the front lenses, which are not heated by the comparatively small amount of infared radiation emitted forward with the light from LEDs.
LEDs are increasingly being adopted for signalling functions such as parking lamps, brake lamps and turn signals as well as daytime running lamps, as in those applications they offer significant advantages over filament bulbs with fewer engineering challenges than headlamps pose.
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Congoleum Breckenridge wrote:

The only problem with high output LED lights is the need for cooling. Like most semiconductor technologies, excessive heat will damage them. The Cadillac LED headlights have built in cooling fans.
TDD
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Once again, you are COMPLETELY wrong. The only thing in this conversation that is not very bright, is you.

Once again, you are COMPLETELY wrong. Just so I could say I knew for certain, I just went out and looked again. LED's, dopey. Nine in each tail/brakelight. Looked in the manual and in the list of replacement bulbs, there is nothing listed for tail lights. They are not expected to need replacement in the lifetime of the vehicle. If they are damaged in an accident, you replace the whole light array as an assembly.
Game, Set, Match

Once again, you are COMPLETELY wrong. Have someone (who can read) look up the word "array" in a dictionary and explain it to you.
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You base your whole argument and insults on the back of some vehicle parked at the back of your scrap yard? Show me the money.
At least if you are going to use over 2348 (your figures) different nyms you should attempt to change your stupid insult style of words. It would make trolling and stalking much more effective for you.
**sigh** The newbies.
You can run but you can never hide. Better luck next time.

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Now you have become pretty much incoherent. I have been on usenet since... well, a very long time. I have changed my nym maybe 5 or so times in 20 or so years. I only use one at a time, usually for many years, before changing to another.
And you remain completely wrong on everyting else, too. Now the list of things you are confused about is just longer.

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My experience is that they are usually LEDs. Most but not all cars with LED tail/brake have dimming for tail function achieved by pulsing at a low duty cycle. (This is done because most LEDs do not have low-current performance sufficiently predictable from one run to another for certification.)
Such LED tail/brake lights in tail mode usually show a stroboscopic pattern if I move my eyes while looking at them.

There are now legal LED backup lights, although so far I have only noticed these as aftermarket replacements for truck backup lights or for manufacture of truck bodies and trailers.
- Don Klipstein ( snipped-for-privacy@misty.com)
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I haven't seen that but some of the cars have one incandescent bulb and a reflector with many small domes that make it look like many small lights. I have had friends mention them as LED lights because they look like an LED array until you look close and find the one actual bulb.
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salty wrote:

That's a problem we don't have to deal with in Sarasota. :^)
--

Regards,
Robert L Bass
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Bitch!

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