OT: LED Failure Poll

Hi all,
I've noticed that manufactures of LED lighting devices really like to boast about actual LED lifespans; 10,000 and 100,000 for two different
flashlights I own. 10k hours comes to about 417 continuous days or 1.14 years; and 100k hours is almost 4,167 days or 11.42 years.
Especially in the case off the 100k hour claims, thats a good while.
Got me curious... Has anyone here actually experienced an 'in normal service' LED failure? (For the record, I haven't...)
Erik
(Who as of today is dash over 506.8k hours old; or 21.12k days.)
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I've had circuitry failures in LED flashlights but I'm pretty sure the LED is fine. Usually flashing or dimming. Karl
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I have not experiencd LED failure, but I had numerous compact fluorescent lights die on me way ahead of claimed lifespan. Many of those came from Wal-Mat.
i
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On Sun, 06 Nov 2011 05:59:57 -0600, Ignoramus14302

None of my LED flashlights has lost any LEDs yet, but I seldom use them, and even then, seldom use them for more than a few minutes at a time. Even the LED book light I used for 5 hours once hasn't given me any problems. Hmm, all of my LED lights are discrete bulbed, not.
It's hard drives and CFLs which aren't living up to their MTBFs.
Most of my CFL failures came from Feit. The 23W (100w) dimmable ULA bulbs I got from an eBay vendor last years longer. I bought a few GV 25W (100w) CFLs from Walmart a couple years ago and haven't needed to change any yet. And I haven't lost any of the 17W (60w) 4100K or 5000K Satco bulbs yet this first year. In home automation, even the dimmable bulbs flash every couple seconds when off if they're on standard lamp modules. I had to switch to relayed appliance modules. They're a buck more apiece and make a noticeable racket when switched.
GE incandescent bulbs from Walmart didn't last a year. "GE, we bring good things to life, for a very short while." My MadeInChina electric tea kettle switch started dying within the first several months. I wish I had a contact burnisher pen. Have you seen what they sell for today? Crikey!
-- Live Simply. Speak Kindly. Care Deeply. Love Generously. -- anon
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On Sun, 06 Nov 2011 06:38:22 -0800, Larry Jaques

The LEDs will make it 100K, it's the support circuitry around them.
I had a batch of landscape flood MR-16 replacements (the clustered 5mm diode style, not a single Cree) all go partially to totally out within a year, but the maker blamed it on power surges - the HOA was using the original 500W magnetic transformer.
(If your design sucks because you didn't put any voltage regulation on board to save a dime, blame it on another vendor...)
Gave us replacement lamps for free, but we had to swap out the transformer for a proper LED Driver power supply - all in all, a wash.

The lamp end of a Compact Fluorescent Lamp isn't a problem, they have the same 12,000 hour or so life as any other fluorescent lamp - It's the ballast section that almost always goes first. Surface mounted board with the cheapest components they can get away with using, and the MTBF of the components is the MTBF of the lamp.
And if you think Feit is bad, Lights Of America is worse. I've taken apart several of their fixtures that have failed, and traced out the circuits - Power to the 26W lamp channeled through a 1/8W resistor... You really do get what you pay for - and at that, only if you inspect before purchase, and really insist. Take a Sharpie or a Paint Marker and always date your lamps and ballasts, and take them back and scream at the vendor or maker if they don't make the grade. Once in a long while they'll actually give you another one.
And if you scream loud enough word might get back to the Bean Counters who specified floor sweepings for components, and the Engineering staff who designed it down to a price under orders.
If you have a choice, go for separate lamps and ballasts in the fixture. The ballasts tend to last a lot longer than the lamps then because they get better cooling away from the lamp, especially good ones like the Fulham Workhorse line.
I'd still like to get Good Old Magnetic Ballasts for 24/7/365 applications like hallway drum fixtures, but that's not happening anymore. And even certain major makers (Lithonia) are trying to use cheap imported electronic ballasts that won't take constant running usage anymore. Two to four years, and *pop* goes the ballast.

Incandescents are only going to get worse, because the US factories are long closed and they are all relegated to third world manufacture. It *is* possible to get quality still, but the US Based maker has to ride their foreign QA crews very vigilantly to keep it up. And that takes away from the profits...
--<< Bruce >>--
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On Sun, 06 Nov 2011 08:11:53 -0800, "Bruce L. Bergman (munged human

Right, and boy do those little boards stink when they melt and let the magic smoke out. Whew!

Lights of America cannot possibly, under any circumstances, meet or exceed the UL listing codes. No way, no how, never in a million years. I tossed three of their pieces of shit away (back to Home Depot) back in the '80s and warned their manager that they were liable to get some lawsuits from fires caused by the blasted things if they didn't change brands. I've never considered another LOA since then and constantly warn people away from them.

Feit sent free replacements, but they failed, too. It wasn't worth the hassle.

Yeah, I do try to give the idiots feedback, but most of the time, they don't want to hear it. So much for another mfgr...

Separable lamps and ballasts in CFLs? Nevahoiduvit. Fulham = ChaCHING, oui?

Lithonia is starting to feel a lot like LOA. I haven't liked the last couple of fixtures of theirs I've put up recently.

Aren't 'they' somehow phasing out incans as early as 2012? Oh, that's China. LoCal does it by 2018. http://goo.gl/LIRc
-- Live Simply. Speak Kindly. Care Deeply. Love Generously. -- anon
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On Sun, 06 Nov 2011 08:11:53 -0800, Bruce L. Bergman (munged human readable) wrote:

Trust me, the engineering staff already knows. And getting screamed at by bean counters for process failures caused by the bean counters' unwillingness to appropriately staff a design project doesn't make the next product come out better, it just shortens the service life of the engineers involved.
I can't understand the attitude of folks who drive BMW's and Mercedes, and who won't listen when an engineer tells them that "quality costs money".
--
Tim Wescott
Control system and signal processing consulting
  Click to see the full signature.
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On 11/6/2011 11:27 AM, Tim wrote:

There's a quote to keep...
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Gunner Asch wrote:

The OEM was a big contributor to Obama?
--
You can't have a sense of humor, if you have no sense.

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"Bruce L. Bergman (munged human readable)"
WHich is really a meaningless observation, as you well know. Depending on the other factors involved. A 27 W lamp could be drawing .01 A, or 100A depending on the voltage, or a 1/8 W resistor could easily handle 100A at that rating or .001A all depending on its resistance.
But on the other hand CRAP is CRAP, true enough.
jk
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Oh yeah - I'd sit down and do the math with the voltage and wattage and resistance/capacitance ratings on those components - but they're blown to heck already, so you can't read it.
And the factory in Nankang isn't going to share the wiring diagrams and parts pick lists and layout diagrams with you or me - you're probably a competitor looking to copy their crap even cheaper. This is why they came up with Un-marked discrete components and proprietary User Part Numbers for the IC's - to make it harder to reverse engineer things.
Suffice it to say the components usually don't blow up if the circuits hadn't been "Muntzed" (over-simplified - Google it...) and weren't being overdriven or over-voltaged in the first place.
Hint: http://en.wikipedia.org/wiki/Muntzing
I may not be an electronics engineer, figuring out the block diagrams and finding all the blowed up parts and changing them is about my limit. But I can see it when they do it - they tend to leave the same circuit board design and component location masks with a lot of vacant holes. "We don't need any over-voltage protection there, eliminate those four MOV's on the power lines, and the three on the Input leads..."
--<< Bruce >>--
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I used to take an ink eraser from the office stores cabinet to clean contacts. In some companies the washroom paper was rough enough.
jsw
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Jim Wilkins wrote:

In some places the Toilet Paper is rough enough to polish metal.
--
You can't have a sense of humor, if you have no sense.

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Wal Mart is at best, a crapshoot.
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I have, several. But on boat interior lighting and all appeared to be over voltage problems. But if you are talking about flashlights they likely will go the distance as every one I have encountered is substantially under powered. A 3 watt LED, for example, running at a measured 1.75 watts, using the flashlight case as a heatsink.
-- John B.
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On Sun, 6 Nov 2011 08:10:26 -0500, "Stormin Mormon"

I'm not familiar with a LED Mag but every light that I have looked at - quite a few as I use them for bicycle lamps - two things seem to be universal. (1) the output (1 watt, 2 watt, etc) marked on the case has no relationship to actual output and (2) the actual power, referencing the LED, not the marking on the case, is always very conservative. However, I think that this is not so much a matter of the LED but on the relative ease of fitting batteries. i.e., how can we fit the batteries in the case.
In bulk LEDs are cheap and I suspect that the cost difference between fitting 1,2,or 3 watt LEDs is insignificant in reference to the retail price of the light. I see 1 watt White LEDs quoted for $0.30 each, for example, and it is very likely that a negotiated price would be substantially cheaper.
Of course, heat is the enemy of a LED but normally flashlight LEDs consist of the LED fitted to a circular aluminum heat sink which should suffice. I have never actually tested 3 watt LEDs using only the supplied heat sink but I have fitted them to reading lamps and drove them with a 2.75 watt constant current driver and they didn't get hot and they lasted at least two years. I can't say how much longer they might have lasted as I sold the boat.

-- John B.
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LED traffic lights develop many failures.
jsw
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And they get covered with snow under the right conditions.
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different
1.14
The big problem is that most LED lamps and flashlights are not built with premium, top-name, first-run diodes, but mostly with rejects, out-of- current-spec devices, and 'cosmetic rejects'. It takes a big search to find a currently made, reasonably-priced LED _anything_.
I bought a 4 Watt (3 C-cell) flashlight with a Sylvania 4W LED. It's a hell of a good light, and damned-near burns grass at ten yards.
It has a limited lifetime warrantee -- as follows. It is warranted for the lifetime of the original owner except it is _not_ warranted against the following: Accidental damage, water leakage (It's a "waterproof" flashlight), or LED failures.
Ray-O-Vac, "premium", Hecho in Chine
So, don't believe ANY of the lifetime claims on LEDs in consumer crap from overseas. All the LEDs are production culls. I've had numerous ones fail in the multi-LED flashlights, which I use as equipment illuminators and inspection lights.
LLoyd
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On 11/6/2011 4:39 PM, Lloyd E. Sponenburgh wrote:

there is a good article in Spectrum a few months back about LED drivers, led lighting and poisoning of the substrate at high currents - if you actually want to understand, it would be worth searching for. otherwise, suffice it to say that running a chip near its limits shortens the lifespan
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