LED Guru On InGaN-Based LEDs And The Future

Mayor Quimby writes: "EETimes reports that LED guru Shuji Nakamura predicts White LEDs to overtake the light bulb Mr. Nakamura is an amazing guy who is given substantial credit in the development of blue and white LEDs. Other articles about him can be found here and here. He "works from 7 a.m. to 7 p.m., 355 days a year, and says he has never taken a vacation." Also, check out this circuit board found in an LED flashlight that uses a single AA battery. It'll be nice when low cost knockoffs start flooding in from the Far East." I can vouch for the life of white-LED flashlights -- the ones I purchased more than a year ago from Holly Solar are still on their first sets of AA batteries. Not as bright as incandescents, but plenty for lighting up a tent or to keep from stumbling on a trail.

Comments

355?

[Fervent]

355 days a year

Back in MY day, we worked all 365 days of the year.

my experience with LED Lights

[jonnythan]

LED lights certainly have their places. I own a Petzl Tikka headlamp that runs off three AAA batteries. I use this headlamp (along with a Princeton Tec Quest and a premier carbide lamp) for the caving i do here in the Northeast (specifically around the Albany NY area).

Anyway, the LED lamp uses three white LED's and doesn't put off anywhere near the light of the 2-AA princeton tec with a standard bulb. However, by way of comparison, it produces a more disperse light and it will last up to 150 hours on a single set of batteries, compared with 6-8 on the Princeton Tec.

The light is certainly whiter than most anything but maybe a xenon bulb (which uses tons of power). It has virtually no range, though. It lights up a nice hemisphere in front of me for a good 6 feet whereas the carbide and Princeton Tec can send a light several dozen.

I keep thinking that if they made a headlamp that had so many LED's in it that it sucked as much power as the standard bulb, it would be fucking bright indeed.....

Oh yeah, and the Tikka was almost $40 and the Quest was $15.

Re:my experience with LED Lights

[Brian Kendig]

Check out Glow Bug, "http://www.glow-bug.com/". They stock all kinds of cool LED flashlights, the coolest being the Eternalight. I have that one, as well as their Photon (keychain) and NightStar (no batteries) flashlights. Very cool stuff.

Thank LEDs for laptops!

[Anonymous Coward]

Did you ever realize there were no laptop computers before LEDs were invented? That's no coincidence. The little green-power-is-on incandescent light sucked too much power and made laptops a worthless concept. Thank LEDs for solving that bottleneck!

Let Light Loose

[Applied Alliteration]

Lovely LED's letting luscious luminence lift lonely lives. Light leaves love's lost luminairies lamenting, languishing, listlessly listening lest loveless labor limit life.

Lo! Love leverages light. Light limits love. Love learns light lessens lucidity. Loss lies lurking, luring lovers 'long looping lanes lacking love, leaving little. Less. Lust.


-Intense introspection
-Into interesting interpretations
-Involving intellectual indulgences

All about LEDs

[Peter Lake]

LED museum

household lighting

[Barbarian]

I was thinking of how household lighting might be implemented with white LED's---

I guess you'd need a lot more LED's (or banks of them) then bulbs. Since LED's are also DC beasts, you'd need to convert to DC with a rectifier circuit from the standard 110 VAC. I guess this would be best done once (instead of having a rectifier at each lighting location), and seperate 5 V (or 12 V or whatever) circuits for lighting only done throughout a house. This would be best applied to new houses only. Having a seperate rectifier at each light location (i.e. to replace traditional bulbs) would probably be wasteful and expensive.

Re:household lighting

[Jeff DeMaagd]

No, not really. Practically everything ELSE in your house does AC->DC conversion. It can be done with between 70-90% efficiency. LEDs are just that much more efficient and they don't give off that much heat per unit of light power/

An L.E.D. does not have a filament to "heat-up" and thus there is not lost energy, making L.E.D.s approximately 3-5 times more efficient than incandescent bulbs.

I wonder how it compares with flourescent power wise.

Is it wasteful & expensive to have all that circuitry? If LEDs really do get 100,000 hours of duty use, that's 100-200 TIMES the claimed life of incandescent, so for every LED unit you toss in the trash, that compares to maybe 150 glass bulbs in the trash. Flourescents are claimed to get maybe 10,000 hours.

Re:household lighting

[Jeff DeMaagd]

LED diodes are not power diodes, for one thing they often can't handle 5V in reverse or forward current mode. Power diodes can take a significant beating because they aren't designed in a delicate manner to give off light. I would want protection circuitry in there, as well as the fact I'd just want straight DC fed to it just so that the duty cycle per LED isn't on/off/on/off, that way fewer LEDs are needed to produce a given amount of light, and the circuitry can be packed behind the lights somewhere.

Still, even with conversion circuitry, that's pretty cool. Many don't like the slow startup times and colors of flourescents, many are used to the "warm" color of incandescents to use in the home.

This is really for those hard to reach places

[Thalia]

The real place for the white, or colored LEDs is in locations where replacing the light is a pain in the *ss. Think about it. If you need to replace a traffic light, you need to turn off the light, put a cop there, and drag out the truck and the guys to replace the bulb. Instead of incandescent, by using LEDs you can have replacements every 5+ years (because you'll have 40+ LED's and a few burned out ones won't be a problem). This makes perfect sense, and makes the added cost of the LEDs an excellent investment. (trust me, traffic cops on overtime make way more for the hour plus it takes to replace a bulb than the cost of 50 green LEDs.) This is why in the Bay Area, almost all red lights are already LEDs, and more and more yellows and greens are being changed.

Similarly, think about lights in places where they are difficult to replace. Embedded lights in offices come to mind. Anywhere were work has to stop to replace a light, it makes sense to pay $30 for a bulb. In the home, on the other hand, the cost of replacement is negligible. So, LEDs probably won't take over until they are almost as cheap as standard bulbs. On the other hand, I'd love to replace the pool lights with LEDs, because I have to lower the water level, which is a complete pain, to replace those lights.

Thalia

Re:This is really for those hard to reach places

[maggard]

Er - couple of facts:

• Incandescent traffic lights get changed out ~every 5 years.
• LED traffic lights last ~15 years.
• LED traffic lights initially cost more but generally pay back in power-savings in 3-5 years.
• LED traffic light manufacturers are corrently operating at capacity to supply the increasing demand for their product.
• Incandescent & LED traffic lights are built to put out about the same amount of light although the LED ones appear brighter. This has to do with the numerous bright-points of a LED-lights vs. the single uniformly bright surface of an incandescent.
• Studies have shown that having folks rely on light-positions is unsafe. It requires too much cognition while the training of ColorA=Stop/ColorB=Go is easy & effective for human brains.
• Traffic signals aren't uniformly laid out in North America. While many are vertically arranged horizontal is popular too. Of the horizontal ones many use red lights on both ends.
• Masking incandescent or shaping LED lights is also becoming popular. I can't recall the shapes but the some lights now use them to indicate the colors (I live a few blocks from a city that does this.)

On a related topic:

• Color-blindness is much more common in men then women.
• It is also much more common in European-stock folks then non-European
• It's most common in Americans of Irish descent although there isn't a correpsonding percentage of color-blind folks in Ireland. It is theorized that perhaps color-blind folks were greater affected during the Potato Famine (unable to distinguish bad potatos) and so selectively left Ireland in greater numbers then interbred in the US.
• Green LED lights use about the same percentage of blue as incandescent green lights.

Next hurdle - omni-directional LED lighting

[Sodakar]

If you don't have a LED light, go get one - it's compact, durable, extremely bright, and battery life is awesome. Quite enjoyable! I personally love the Photon II, but be sure to read Brock's LED Flashlight Page first, before buying a dud like the NightHawk, which is not bright at all.

Now that I'm done with links - I'll say this - while LED lights are great for directional lighting, they are not good at all for omni-directional lighting. This is because the reflector is housed inside the LED itself, and the light will always be facing the direction of the LED plate.

Now... I wonder how difficult it would be to get that LED plate inside the plastic/resin housing into a shape of a cylinder, and install it in place of a standard tungsten filament? If that is possible, then the LED light will truly be able to replace all lightbulbs... Not just the directional ones.

Hmm, I guess I don't have much to say other than the good links up top, and my hope for tomorrow's LED, household lightbulb. If you experts have something to say about the possibility of the cylindrical LED plate, I'm all ears. I surely don't know if it's possible or not.

(Insane_work_ethic == BAD)

[-=[ SYRiNX ]=-]

He "works from 7 a.m. to 7 p.m., 355 days a year, and says he has never taken a vacation."

And this is supposed to be a good thing? Obsessing about anything to the verge of lunacy, and sacrificing all the other things that really make life worth living, is hardly a healthy way to live. The quality of life on this planet is only going to get worse as long as people keep praising this kind of unreasonable work ethic.