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The Great Lightbulb Conspiracy
HughPickens.com writes: Markus Krajewski reports that today, with many countries phasing out incandescent lighting in favor of more-efficient and pricier LEDs, it's worth revisiting the history of the Phoebus cartel — not simply as a quirky anecdote from the annals of technology, but as a cautionary tale about the strange and unexpected pitfalls that can arise when a new technology vanquishes an old one. Prior to the Phoebus cartel's formation in 1924, household light bulbs typically burned for a total of 1,500 to 2,500 hours; cartel members agreed to shorten that life span to a standard 1,000 hours.
Each factory regularly sent lightbulb samples to the cartel's central laboratory in Switzerland for verification. If any factory submitted bulbs lasting longer or shorter than the regulated life span for its type, the factory was obliged to pay a fine. Though long gone, the Phoebus cartel still casts a shadow today because it reduced competition in the light bulb industry for almost twenty years, and has been accused of preventing technological advances that would have produced longer-lasting light bulbs. Will history repeat itself as the lighting industry is now going through its most tumultuous period of technological change since the invention of the incandescent bulb?
"Consumers are expected to pay more money for bulbs that are up to 10 times as efficient and that are touted to last a fantastically long time—up to 50,000 hours in the case of LED lights. In normal usage, these lamps will last so long that their owners will probably sell the house they're in before having to change the bulbs," writes Krajewski. "Whether or not these pricier bulbs will actually last that long is still an open question, and not one that the average consumer is likely to investigate." There are already reports of CFLs and LED lamps burning out long before their rated lifetimes are reached. "Such incidents may well have resulted from nothing more sinister than careless manufacturing. But there is no denying that these far more technologically sophisticated products offer tempting opportunities for the inclusion of purposefully engineered life-shortening defects.""
Each factory regularly sent lightbulb samples to the cartel's central laboratory in Switzerland for verification. If any factory submitted bulbs lasting longer or shorter than the regulated life span for its type, the factory was obliged to pay a fine. Though long gone, the Phoebus cartel still casts a shadow today because it reduced competition in the light bulb industry for almost twenty years, and has been accused of preventing technological advances that would have produced longer-lasting light bulbs. Will history repeat itself as the lighting industry is now going through its most tumultuous period of technological change since the invention of the incandescent bulb?
"Consumers are expected to pay more money for bulbs that are up to 10 times as efficient and that are touted to last a fantastically long time—up to 50,000 hours in the case of LED lights. In normal usage, these lamps will last so long that their owners will probably sell the house they're in before having to change the bulbs," writes Krajewski. "Whether or not these pricier bulbs will actually last that long is still an open question, and not one that the average consumer is likely to investigate." There are already reports of CFLs and LED lamps burning out long before their rated lifetimes are reached. "Such incidents may well have resulted from nothing more sinister than careless manufacturing. But there is no denying that these far more technologically sophisticated products offer tempting opportunities for the inclusion of purposefully engineered life-shortening defects.""
I've tried 3 brands.
1. One cheap generic (long center square stack with LEDs), this model failed quickly and had poor light.
2. Discount sale LED bulb at Home Depot, with a soft rubber like coating on the exterior. Poor non-uniform light, returned.
3. 3 pack of LED bulbs from Costco. 60 watt replacement. These bulbs have about 50% more lumens than the CFLs. I've had one failure out of about 20+ bulbs. The light is in fact brighter and more uniform than even my incandescent bulbs. At $9.99 for 3 when on sale at Costco. I've decided that ALL my bulbs will be replaced by these LEDs.
(Oh and the one failed bulb was replaced by the the manufacturer.)
CFL have electrodes at the end of the tube, which will fail over time. You can tell by the fact that the ends of the tube start to get black.
Hey it's your wallet..
I do totally agree on the CF - i had some break but, that was actually not the glass tube with the poisonous mercury vapour, but the electronics inside it with -going by the smell- even more toxic ingredients. One actually 'exploded' leaving the bulb hanging on some wires. I do not know yet if LED lights are any safer in that regard as they require some, albeit less, electronics.
For dimming, you might look at the better LED lights as some of them are dimmable - in Europe they are quite common, and if dimmable, explicitly say so.
I was unscrewing one of the twisty CFL's that died after probably 1000 hours use. It basically exploded in my face, about the top 15% of the bulb was small shards though the rest was intact. Yes, we got screwed by the government forcing them on us before they were ready for prime time, just like the water saving toilets that don't flush unless you cycle them a few times.
The Department of Energy had a pretty rigorous test regimen set up for testing LED bulbs.
http://www.lightingprize.org/6...
What is needed is a good (and trustworthy) rating agency to test and qualify the bulbs.
But, of course, everybody wants to buy the cheapest ones, not ones tested to long lifetime.
For what it's worth, I have about 60 LED bulbs in my house, from about fifteen maufacturers. So far, four have failed.
Further - no viable light bulb replacements will work with dimmer switches (Which my house has many).
That was true five years ago-- these days it seems all of then are rated to work with dimmers . I have some Philips LED bulbs on a dimmer in the dining room-- they work fine.
http://www.geoffreylandis.com
Every led I've purchased (I only buy energy star , because they are actually testing them for light quality ,unlike with CFLs ,so that may make a difference ) , has said it was dimmable , to the point I thought it was intrinsic in the technology .
They're also the only bulbs that have any real life in my old house . My porch light lasts 2-3 weeks incandesant . I'm 4 months on the led I put in it , on convenience alone it's worth the price .
You sound like a neighborhood in a town not far from me.
Apparently the houses close to the power substation routinely got something like 20% overvoltage. The lights burned bright, but they burned out fast.
In theory, LED bulbs would actually be a better bet, since they're current-driven, not voltage-driven and the voltage is stepped down. So as long as the LED voltage was less than what it took to fry the LEDs, they might burn a bit brighter, but that's about all.
No, LEDs aren't inherently dimmable, since, like I said, they're current-driven and running on reduced voltages internally. Furthermore, a lot of dimmers are not rheostatic, but instead work by modulating the "pulse width" (for lack of the proper term) of the A/C waveform. An incandescent bulb has thermal mass, so that results in dimmer light (and color change thanks to lower temperature). A flourescent light will generally not be amused, and an LED light is only likely to work if it has some sort of way to convert the pulse width to relative current level (such as via capacitors).
I have some dimmable LED lights and they work great, but it was unusual seeing the same lamp color as the light dimmed. And the light curve for the LEDs doesn't match what resistive lamps do, so there is noticable non-linearity in the brightness relative to the dimmer setting.
I've read that the Energy Star people admit they screwed up with CFL, but are determined to not make the same mistake with LED
In order to get the Energy Star label, a CFL bulb has to meet certain efficiency requirements. But the rating says nothing about longevity. In theory, fluorescent bulbs should last a long time. But the built-in electronics are the usual source of failure. This is particularly the case with ceiling lights and other bulbs where the electronics are on the top, and often in an area where they do not get much cooling. So, the cheap - or more importantly *Crappy* - bulbs can carry the same certification as the good ones. So, CFL got a bad name, which is also fail for the Energy Star folks.
With LED bulbs, the Energy Star people wanted to make sure that they don't make the same mistake. So, in order to get the label, a bulb has to meet the efficiency standards, plus demonstrate that they can handle the run-length requirements. And there are many different requirements, depending on the type of bulb and its intended usage. In order to get the Energy Star label, they are tested for something like 9 months.
So, the moral of the story is that if you buy an LED that carries the Energy Star label, it should not fail prematurely. But the down-side is that LED technology continues to improve, with the most recent chips putting out something like 250 Lumens/Watt. An agile manufacturer might be able to quickly get this technology to market with an excellent new bulb. But it cannot carry the Energy Star label until it has been through rigorous testing, which takes nearly a year.
I have worked in the solid state lighting industry. You typically hear 50,000 hours but there are a few points that must be met to achieve that:: - The LED must not exceed a certain temperature (usually 135C at the die though that can vary a bit between manufacturers) - The LED must not exceed a rated level of current flow - The 50k hours rating allows for a dimming over time of ~20% though again that varies between different manufacturers The most common failure points for LEDs are heat, over driving the LEDs, poor regulation circuits resulting in over current, and using too cheap of components which fail before the full lifetime is met. A lot of claims are made regarding both brightness and longevity that don't hold up, especially if it's an off brand from China. Those will always claim 50k to 100k hours of operation at 100% (or more) of the LEDs full rated light.
Where's your controlled, statistically significant comparative study data? Or are we supposed to go on an anecdote? Because we do have lots of data - for example, here Consumer Reports talks about their testing results.
Mercury? Every bulb CF tested contained less than 5mg. Let's go with 4mg as our figure (even though some are under 2%). 17-44% of said mercury will vaporize if you leave it sitting around for 8 hours. Let's say you clean it up and 10% gets into your air, which is probably a gross overestimate. What percent of that will you breathe and have actually get incorporated into your body? Probably in the low single digits, but lets be pessimistic and say 20%. So 80 micrograms. The mercury of a mere 1 1/2 cans of tuna.
But wait, there's more. The mercury in CFLs is "inorganic" (metallic, unbound) mercury, while mercury found in food is almost exclusively "organic" (methyl and dimethyl mercury). "Organic" mercury, being much more bioavailable, has many times worse health consequences per microgram.
The short of it? Don't stand in a closet and smash dozens of CFLs and then fan them while hovering over them and breathing deeply for a day or so. Otherwise, you're fine.
Fox: "I think we should call it... your grave!" Cast: "Curse your sudden but inevitable betrayal!"
You don't PWM an AC waveform. You PWM a DC output (as it has no waveform, it peaks and stays peaked.)
You do in fact PWM an AC waveform for dimming (less fires that way). You're cutting apart a sine wave, so the result is less obvious than simple DC duty-cycle, but it is PWM nonetheless.
No, PWM dimming is caused by a PNP transistor circuit, not a capacitor.
Or this fantastic invention called a thyristor. You have probably encountered one of them in your average wall dimmer.
Chances are your dimmers and bulbs just aren't compatible. There are at least four kinds of dimmers out there -- those labeled for incandescent only, those labeled for magnetic ballast, those labeled for electronic ballast, and universal.
These labels are typically wrong, of course (nothing's ever easy).
An incandescent-only dimmer is a leading-edge (forward) phase cut dimmer. It works by turning on the power partway into the sine wave, cutting off the rising edge. It requires only two wires (hot and load), and obtains power for its own use by using the low-resistance path through an incandescent filament when it is off. Generally works poorly if at all with an LED fixture.
An electronic ballast dimmer is a trailing-edge (reverse) phase cut dimmer, and works by turning the power OFF partway into the sine wave. It requires a neutral wire as well as hot and load. Originally intended for low-voltage halogen fixtures using an electronic ballast.
A magnetic ballast dimmer is also a leading-edge (forward) phase cut dimmer, but requires three wires. Originally intended for low-voltage halogen fixtures using a magnetic ballast.
A universal dimmer is a two-wire forward phase cut dimmer that is supposed to work well with both types of ballast, but in practice just sucks.
Your LED lights will likely dim properly with either an electronic ballast dimmer, or a magnetic ballast dimmer (even though the LED certainly uses an electronic ballast), but not both, and will work poorly or not at all with the other types. And of course if you have multiple brands of LED they could require different types.