- How long do LED shop/ceiling lights really last at full output anyway? - 9 Updates
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| Meanie <meanie@gmail.com>: Nov 01 11:23AM -0400 On 11/1/2016 10:59 AM, Dan Espen wrote: > They are activated when it gets dark. > So, they're on at least 12 hours a day, every day. > Construct some statistics out of that. That is the reason they last so long. What people don't realize is the life of fluorescent, whether tubes or CFL, is shortened when they are subject to constant on and off. They are not made for constant on/off action unless the fixture contains a "program start" ballast. Due to the cost of that ballast, they will not be within the common hardware store fixture. When fluorescent lamps remain on all day, chances are you can see 10 years on them. The average home will not see that life cycle since it's not common to leave them on all day everyday. |
| Algeria Horan <algeriahoran@algeria.horan.net>: Nov 01 03:20PM On Tue, 01 Nov 2016 10:59:44 -0400, Dan Espen wrote: >> Notice the package says "1.4 year life". >> https://s18.postimg.org/602tefda1/ge_bulb_burned_out.jpg > Do you honestly think that proves anything? I understand your point, which is that I can say it lasted 10,000 years. If I could prove it completely, and if it was worth the effort, I would, just like Jeff *proved* that WiFi reception in routers was NOT what the manufacturers claimed. But you are like those people who say "prove it" to everything, which is fine, but *you* have to provide some semblance of a reason to go to the effort to prove things that we just have to accept on faith. I was backing up your unproven claim that Jeff was not being balanced, in effect, when I know, from the last decade on s.e.r and a.i.w that Jeff "is" well balanced, and he proves what is worth proving. > They are activated when it gets dark. > So, they're on at least 12 hours a day, every day. > Construct some statistics out of that. You entirely and completely missed the point. Did you buy too many arguments this week? All I was saying is that your claim against Jeff's veracity are completely unfounded. You're entitled to your opinion, but if I asked you to prove that you had sex with your wife five times this week, do I really expect you to prove that? What I'm saying is simply that your criticism of Jeff was unfounded, if you look at the entire record. And, I'm saying that 11 cents per kilowatt hour is a magical number entirely unachievable by me, in California. If you claim otherwise, I'm only asking you to attempt to back up your very own claims with fact, as I did with Jeff, and as I did with the price of electricity in California. |
| Algeria Horan <algeriahoran@algeria.horan.net>: Nov 01 03:54PM On Tue, 1 Nov 2016 11:23:09 -0400, Meanie wrote: > When fluorescent lamps remain on all day, chances are you can > see 10 years on them. The average home will not see that life cycle > since it's not common to leave them on all day everyday. I don't run statistics, but I appreciate what you wrote because my fluorescent lamps don't last more than a year or two, it seems. I used to mark the bulbs with a Sharpie, but I stopped doing that long ago. I don't think I *ever* got anywhere near the claimed life. But we turn them on and off a few times each day. |
| Algeria Horan <algeriahoran@algeria.horan.net>: Nov 01 03:54PM On Tue, 1 Nov 2016 11:18:11 -0400, Meanie wrote: > I understand your skepticism as a general consumer, but I've been > experiencing the products first hand. This is good to know because the whole point of this thread is to nail down the actual life of the lamps. Of course, you can't expect me to NOT buy at Lowes or Ace or Home Depot, for quantities such as we buy for a home as replacements, so the word 'quality lamps' is to be taken with a grain of salt. But at least it's good to know that you *understand* that an LED is never as bright as it was on its first day, and that cycles, and heat, and vibration exacerbate the existing cracks between crystals, such that LEDs drop off exponentially in light output over time. As stated in the standards that Jeff kindly referenced early on in this thread, the diminished light output is very difficult to detect, since it happens over time, and since there may be other bulbs compensating for the lack of output, such that an LED bulb that has actually reached it's L70 lifetime may not be easily observed by you. Nonetheless, if the driver failed, which I think can be the weakest point (that premise needs to be explored), you'd know that. But you might not know when any particular bulb has reached its L70 point without isolating the bulb and actually measuring the output (since the gradual decline in output isn't going to be suddenly noticeable, according to that report Jeff referenced). My point is that things failed, perhaps, and you don't realize it. But that needs to be explored since you'd know of some failures (but not all, unless the bulbs are isolated, and if you have a keen eye for such things). |
| Jeff Liebermann <jeffl@cruzio.com>: Nov 01 09:02AM -0700 On Tue, 1 Nov 2016 02:38:46 +0000 (UTC), Algeria Horan >You would bring up *more* complex LED-lifetime terms to figure out! I should have guessed it was you. I like to explain how things work, without offering a judgment or opinion. This type of question really belongs in Candlepower Forums. >And, you would also find MARKETING BULLSHIT in the mix! It happens. I have some marketeering experience somewhere on my resume. Speaking of bullshit: "How LED Lighting May Compromise Your Health" <http://articles.mercola.com/sites/articles/archive/2016/10/23/near-infrared-led-lighting.aspx> >L90 = time to degrade to 90% of its original lumens >Reported TM-21 = predicts lifetime using LM80 + optimistic magic math >Calculated TM-21 = predicts lifetime using LM80 + more optimistic magic math Nice summary. Sounds about right. I believe there are a few other standards that I missed. Standards are a good thing. Every company should have one. >Seems to me that the "LED lifetime" figure everyone is quoting in this >thread and in other threads is total bullshit, so far... Nope, because it's all we have to work with. Like I ranted, nobody does 30,000 hr life tests. Therefore, nobody knows the "real world" lifetime of an LED light. The best we can do is parametric testing, accelerated life tests, and the usual guesswork. The first two are quite valid and result in numbers that usually come fairly close to reality. The guesswork, you can guess what I think. It's much like MTBF (mean time between failure) which attempts to estimate the life of a device based on historical tests and operating conditions. These component estimates are conglomerated into a figure for the device. However, the intent is not to estimate the lifetime, but rather the number of expected failures in a population of LED's. "What Every LED Engineer Needs to Know About MTBF" <https://www.fairchildsemi.com.cn/Assets/zSystem/documents/collateral/whitepapers/LED-Lighting-MTBF-White-Paper.pdf> (Note: I haven't read through this yet) >fluorescent bulbs, so I bought the LED light fixture from Costco just to get >rid of the non-standard wacko shaped bulbs that kept burning out anyway. >http://uk.rs-online.com/web/p/non-integrated-compact-fluorescent-lamps/4075597/ 600lumens / 9watts = 67 lumens/watt. Barf. Philips claims 200 lumens/watt and Cree claims 300 lumens/watt: <http://www.philips.com/consumerfiles/newscenter/main/design/resources/pdf/Inside-Innovation-Backgrounder-Lumens-per-Watt.pdf> <http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2014/March/300LPW-LED-barrier> You may not see that at Costco for a while, but maybe if Philips and others get back into the LED biz. <http://www.memoori.com/samsung-joins-philips-siemens-in-led-lighting-exodus/> It's not too obvious, but both claims assume that the LED is cooled to approximately room temperature. >What irks me is that they seem to never have run into someone who doesn't >accept that bs as an "answer" to the question of how long the light fixture >is expected to last. For good reason. From the point of view of the manufacturer and vendor, the ideal product blows up 1 day after the warranty expires. I've ranted on the topic before, where simulation and modeling tools are used to insure that multiple parts all fail just after some preset time limit. My favorite example are GE(?) water heaters with 6, 9, and 12 year warrantees, and roughly proportional pricing, but where the only difference is the type and size of the anode rod. Details if anyone wants them. >I'm guessing the LED light fixture I bought lasts no longer than a couple >sets of incandescent bulbs would have. Talk to me in 30,000 hrs and we'll compare notes. >Time will tell. You have a talking clock? -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| scott@slp53.sl.home (Scott Lurndal): Nov 01 04:06PM >> experiencing the products first hand. >This is good to know because the whole point of this thread is to nail down >the actual life of the lamps. Which is impossible to do based on unreliable anecdotal evidence in an usenet newsgroup read by perhaps a hundred people. |
| Jeff Liebermann <jeffl@cruzio.com>: Nov 01 09:08AM -0700 On Tue, 01 Nov 2016 09:02:59 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote: >>L90 = time to degrade to 90% of its original lumens >>Reported TM-21 = predicts lifetime using LM80 + optimistic magic math >>Calculated TM-21 = predicts lifetime using LM80 + more optimistic magic math One more. ARL: <http://www.bulbs.com/learning/arl.aspx> "Average Rated Life (ARL) is how long it takes for half the light bulbs in a test batch to fail" I seem to recall others, but I'm too lazy to Google. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| scott@slp53.sl.home (Scott Lurndal): Nov 01 04:10PM >Dan, >You come across as challenging the facts, but, you provide few facts on your >own. It's easy to challenge, but it takes effort to back up your challenge. How does the cost of a Kwh contribute to the rated lifetime of an LED-based illumination device? I smell a red-herring. Costs of electricity vary widely nationwide. Yes, California has more expensive electricity (specifically to encourage conservation) than other parts of the country, but that is not a factor in rated lifetime. Tj and cycles (on/off) would seem to be the two major controlling factors, just as they are for incandescents. Tj = Junction Temperature. |
| Jeff Liebermann <jeffl@cruzio.com>: Nov 01 09:33AM -0700 On Tue, 01 Nov 2016 00:14:43 -0400, Dan Espen <despen@verizon.net> wrote: >Actually, 3 years wouldn't be useful for anything but the decidedly >"not realworld" test case of continuous use. Well, you're entitled to invent a new testing standard, along with yet another collection of artificial test conditions, that will satisfy your vision of a "real world" test. I've only had three LED light failures. All were in the bathroom, all were failures of the driver electronics, two were mounted inverted (base up), and all were retrofitted into incandescent fixtures with miserable ventilation. Therefore, I propose a bathroom LED test, which includes heat, condensing and non-condensing humidity, on-off cycle time, over voltage, erratic power glitches by PG&E, limited ventilation, and dust accumulation. Such a test will clearly define what might be expected from "typical" bathroom LED service. The EU micro managers have specs and tests for almost everything and will surely appreciate your efforts on their behalf. >It would take considerably more than 3 years to test the common >on at night, off during the day test case. I think you need a major dose of testing reality. Instead of LED's, let's try drug testing. In order to release a new drug, one of the tests that a pharmaceutical company must survive is a cancer test. This is usually done with mice or rats. However, they're not ordinary mice or rats. If such a cancer test were performed on the common and ordinary breeds of mice and rats, the number of tumors found would be very small and therefore statistically useless. In order to get statistically significant numbers, mice and rats that are genetically predisposed to developing cancerous tumors are used. For LED testing, much the same trick is used. If you don't have a sufficient number of failures during the test period, and you can't extend the test period, you do whatever it takes to produce those failures. The easiest is to elevate the temperature. For incandescent lamps, raising the filament voltage also works. By plotting a trend line of different temperatures or voltages, one can extrapolate the graph to obtain a fairly good approximation of the expected lifetime at more sane temperatures and voltages. That's how one avoids multi-year tests. <http://www.powerelectronictips.com/seeing-light/> >> produces the necessary inflated figures: >You could have left the word "inflated" out of that sentence. >It's an insult to the rather clever testing that you described. There are quite a few products that suffer from inflated specifications. Battery capacity (in particular 18650 cells), flashlight output in lumens, wi-fi range/speed, laptop battery life, laser printer toner cartridge pages, inkjet cartridge pages, etc. All of these are characterized by inflated claims contrived to make the numbers bigger. I can explain any of these in detail if you want to know how it works. The reasons are competitive pressure and product differentiation. Every manufacturer and vendor are trying to sell on the basis of everything except price. So, they push service, warranties, packaging, bonus junk, etc. Eventually, they run out of these fringes, and start inflating the specifications on the assumption that the typical customer doesn't understand the specs. I think this thread demonstrates that this is true. Instead of inflated, perhaps "grossly exaggerated" might be more accurate. >... snipped test description. Sniff... -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| N_Cook <diverse@tcp.co.uk>: Nov 01 03:53PM Thats enough of this malarkey for today. About 10% mains for 20 seconds or so , the only thing warming up on IR thermometer was the 2 fuses, so something big presumably taking the power. That with about .2 amp mains current draw, 5V ac over secondaries and +/-1.8V on the DC rails |
| N_Cook <diverse@tcp.co.uk>: Oct 31 08:35PM > Any thoughts will be most appreciated! > Best, > ED From cold , heat the ps electros, what happens to functions? let cool down When warmed up normally blast electros , in turn, what happens to functions |
| N_Cook <diverse@tcp.co.uk>: Oct 31 08:37PM On 31/10/2016 20:35, N_Cook wrote: |
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