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A Super-Efficient Light Bulb
Chroniton writes with news of a Silicon Valley company, Luxim, that has developed a tiny, full-spectrum light bulb, based on a plasma of argon gas, that gives off as much light as a streetlight while using less power. The Tic Tac-sized bulb operates at temperatures up to 6000K and produces 140 lumens/watt, almost ten times as efficient as standard incandescent lamps, and twice the efficiency of high-end LEDs. The new bulbs also have a lifetime of 20,000 hours. There's no mention of mercury or other heavy metals, which pose a problem for compact fluorescents.
I found it interesting that the tiny bulb - at least in the video - was still using 250 watts and internally generated a temperature of 6000K (no they weren't talking color temp; they were talking actual temp). Now that's certainly lower than the 400 watt conventional streetlight they compared it to; but there's no mention in the video about scalability or low-power use. So the submitter's comment about it having advantages over compact fluorescents may have no basis in fact.
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Temperature isn't the whole story. Regular tungsten-filament incandescent bulbs operate at about 3600K, but it's a tiny filament, and encased in glass, so it's not much of a hazard.
A 6000K plasma may even be safer, depending on the density of the plasma.
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Heat and temperature are not the same thing. If it produces 140 lumens per watt, I believe that makes it something like 50% efficient (which is insanely high for lighting). That means a 100 watt lightbulb of this technology would turn 50 watts or so into heat, and 50 watts or so into light. A 100 watt incandescant is turning 85 watts into heat and 15 watts into light. So even if it runs at a higher temperature, its confined to a very small space.
This isn't dangerous at all.
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It goes from God, to Jerry, to me.
I agree. The reason it hasn't killed professional ground based astronomy is that it is quite easy to subtract the very focused wavelength of sodium vapor streetlights from an image, as sodium vapor lamps are almost completely monochromatic. If we switched to these full spectrum lamps that would be much more difficult, probably meaning we would only be able to do astronomy in very remote areas or with orbiting observatories. That said, even as strong a proponent of astronomy as I am, the increased efficiency of these lights would probably make it worthwhile...
> Such high operating temperatures would not be acceptable for domestic use
> - the risk of fire would simply be too great.
Don't be silly. 6000K is the internal temperature of the gas. The filament in an incandescent lamp can reach 3000K. What matters is the external temperature, which is likely to be lower for a more efficient lamp.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
WTFV (watch the .. video). The temperature they're talking about really is 6000K in heat.
As other shave pointed out, this is not too much of a problem for household use as ordinary incandescents reach 3600 at the filament. You just need to encase it in a glass bulb.
it also affects drivers, and pilots as well. In some regions airports have pushed for local laws to limit light pollution going up into the sky as it interferes with planes landing. Spot lights can temporary blind drivers causing accidents.
Light pollution isn't so much about astronomy but being able to see when it is dark out, because some idiot is lighting up his yard like fen way park. At night less is more. I can use 5 watt 12 volt bulbs and light up your house better than spotlights. more of the house will be lit with less random dark spaces, and more importantly less shadows in which people can hid.
i thought once I was found, but it was only a dream.
Lights are not on all of the time. if less than 12 hours use which is likely than your calculations put the life at 5 years in a street light configuration.
6000K? Who cares? The thing is, this bulb is generating about 10 times the lumens per watt of input power as a standard incandescent. That means that it is dissipating more energy in the form of light and less in the form of heat. Regardless of the internal temperature of the plasma, how "hot" the bulb gets is really a function of the actual dissipated energy. For instance, a spark of static electricity has an extremely high "temperature" but it doesn't burn you. Granted, some of that energy might be occuring in the infra-red range, but I doubt it will be any hotter than a normal bulb.
Also, if you look at HPS (high-pressure sodium vapor) lamps, the orange ones they use for street lights, the vessel that produces the light is actually quite small. There is an internal tube (made of quartz, I think) that holds the sodium. For the first few minutes, the bulb appears blue because you are seeing an arc in the center of it. After the sodium boils and then turns into a plasma, it is in a higher energy state and starts throwing off photons.
The only difference in this bulb is they are eliminating the electrodes and using a different plasma. They use a high frequency RF that's tuned to the resonate frequency of the gas. Sort of like a microwave does for water, but this is more focused. The gas resonates and becomes a plasma. Then it starts throwing off photons. Your efficiency is limited by how efficiently you can make your RF circuit and amplifier and how focused you can place the RF. I imagine they are quoting the theoretical efficiency but they probably haven't achieved it yet.
Cool! Amazing Toys.
Answer is (probably) you'd need more of them to heat your house than standard bulbs. This is more efficient at converting energy into light, so it actually produces less heat than a light bulb. It may get to 6000K, but only at a very small point, so the amount of heat produced is quite small. A big radiator full of hot water will be more effective in terms of heat output. A radiator has huge size but a lower output per unit volume, whereas this has a very small volume but a high temperature.
It also says 6000K at its center; I'm not sure whether it transmits that heat to the casing or not.
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Full spectrum with an Ar plasma at 6000K ~= 0.5 eV? Yes, you can get a lot of light out of it and it looks white, but I wouldn't call it a full spectrum. There are mostly peaks in the region 900-1500 (I don't have a spectra right in front of me right now, so from memory). But I could be wrong of course.
In light physics, temperature and color temperature are the same thing. Color temperature refers to the temperature at which an ideal black body radiator will emit such a spectrum. This unit is obviously a temperature.
Moreover, this lamp appears to be a high bandwidth lamp -- "full spectrum" as they said. This implies that it does not depend on the absorbsion and emission characteristics of specific atoms. Lamps like these -- fluorescents, high efficiency sodium lamps, and the like -- emit light at discrete wavelengths. High bandwidth lamps depend on incandescence to produce light. Indeed, color temperature doesn't make sense for these kinds of lamps -- no black body radiator will emit discrete spectra. (There's a "corrected" color temperature unit for these lamps used in the lighting trade)
The point is: these lamps get hot. They reach about 6000K.
After all, I am strangely colored.
This is color temperature. Color temperature has absolutely nothing to do with the temperature that a bulb operates.
Oh lord.
What do you think color temperature is? It is the temperature at which an ideal black body radiator emits a given light spectrum. It most certainly has to do with the temperature at which an incandescent bulb operates. The hotter the bulb gets, the higher the color temperature. And moreover, the smaller the light emitter becomes, the closer color temperature and operating temperature become.
In this case, it would be physically impossible for a light of any sort to give off that much energy and only consume the amount of electricity available to even a street light.
Temperature isn't energy. Temperature is energy density. For a given amount of energy, the smaller the emitter is, the hotter it will be.
My space heater uses 1500watts and requires I believe 12amps to operate and it would never be able to get anywhere near 6000k even if it were to ignite.
And? The heat emitter is huge. Scale it down to about a 10th its size and run 1500W through it. It will glow a nice bright white before melting.
After all, I am strangely colored.
1) It scales down a bit at least. I'm pretty they were marketing it last year for projector bulbs at around 150W. Not sure whether it scales further down than that.
:(
2) 6000K is very close to sunlight so yeah it's a nice warm sunny light - should in theory be nicer than incandescent light anyway.
3) No - it's a noble gas (unreactive) and naturally present in the atmosphere, making up nearly 1% of it in fact.
4 and 5) Dunno. I was just searching for the projector bulb version and couldn't find any actually for sale, which given that it was announced half a year ago isn't great going
There must be two dozen posts here already blathering about 6000K and nobody bothered to go read the company's official documentation? Here's their website, here are a whole bunch of specs and videos, now go read something before speculating.
However, their light, much like the light of this light, looks an awful lot like the light from a welder. You have to be careful about the pursuit of the almighty lumen -- it's a human-tweaked measure, not a physical measure, and lights score best by dumping all of their light into green. We probably don't want our homes to be lit by exclusively green light.
One thing to note is that there is wide spectrum (true 6000K, this new light), wide spectrum (white LEDs, a relatively smooth blob in the optical frequencies), and wide spectrum (a strategically chosen selection single frequencies, in fluorescent lights). This new bulb should produce very nice looking like, but it might benefit from some of the same phosphors used in white LEDs to down-convert the higher frequencies.
Properly run LEDs are claimed to have lifetimes in the range of 70,000 to 100,000 hours of use, and are not affected by rapid cycling (in fact, the recommended method for dimming them is to switch them on and off very quickly).
The real benefit is for radio astronomy. The far side always faces away from earth, which is a giant radio noise source, and the bulk of the moon itself blocks all the signal. It's really the only place where you won't get such interference (a few space probes notwithstanding).
The meek may inherit the earth, but the strong shall take the stars.
If you had ever spent much time in the countryside, you would know how well you can see by moonlight. I've been out during a full moon on a clear night and been able to play soccer with my friends. Driving requires that we can see dozens to hundreds of yards ahead, so need brighter illumination. We can see just fine outside at night for walking speeds. During the vast majority of our evolution we didn't have artificial light, but we did just fine, we still can.
We are all just people.
The benefits:
The Drawbacks:
They definately have some good applications, like for use in stadiums, airports, etc. However, I think there needs to be more research done to make them usable in homes and automobiles.
For any blackbody emitter (incandescent light bulb or this fancy new plasma), the color temperature IS the temperature. It's only for things that don't emit like blackbody radiators (fluorescent and LED) where you have a different color temperature than temperature.
As a former astronomer, that is patently obvious. However, humanity goes like moths to the lights. It is really hard to teach the average citizen that cutting the luminosity by 80% but tripling the number of lights will make an area much more safe. There is some bizarre connection between bright and safe, when "uniformly lit" would be far, far more safe, regardless of the brightness.
I'm reminded of a time in my youth, when I was traveling by car with a group of friends. One road out of town has intense streetlights, spaced some distance apart. The darkness between them is amazing. As I blew down the road, definitely "under the speed limit" should any adult have asked, I came across a large, black dog, midway between two streetlights. I swerved across the road, onto the shoulder, and narrowly missed a mailbox and a tree. My friends behind me in another car had no idea what I was doing, until they also almost hit the dog.
No matter how bright they make those streetlights, until there is *uniform* brightness, there will be danger. I wish I knew how to clearly point this out to people.
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It's hard to be optimistic about LED efficiency improvements these days. The announcements of improvements made by manufacturers over the last few years have yet to make it to the market, and the units I've purchased in bulk typically don't match the ratings. The last project I built with high-efficiency LEDs required that I throw out about two thirds, and that I test every one individually. Of the ones that passed, several failed within the first 1000 hours of use.
140 lumens per watt by 2012 would be nice, but I'll believe it when I see it.