IRC, red came out in the seventies, I got a "two handed wrist watch" that cost $26 back then.
Blue came along, in flash lights. I called it "blue fog" and really didn't much like the light.
White LED have only been available for a few years. Some of the new white are really great.
- . Christopher A. Young Learn about Jesus
I'm way more excited about LEDs than I was about CFLs. LEDs have the poten tial to provide incandescent-quality light (>90 CRI) in a variety of color temperatures, not just 2700-3000K, and last a lot longer.
It's possible to do that with CFLs as well, but for some reason there didn' t seem to be any will to do so, although there are high CRI fluorescents av ailable in various tube formats; I have some in my old Dazor desk light (F1
5T5) and I have seen them in a standard F40T12 format as well.nate
r. Only the batteries are more expensive than cheap D-cells like regular f lashlights use, and they also seem to run down a lot quicker.
e they cost? CFs seem to have been perfected now and are dirt cheap -- $1 or less if you shop around.
I would argue that CFLs are FAR from perfect - not dimmable, lousy CRI, and slow rise time in anything other than the standard spiral format.
They're acceptable for "utility" lighting where they're not dimmed and thei r sole purpose is to keep you from tripping on the stairs and busting your coccyx, but in a room that someone has actually put effort into decorating, I'd prefer to have a more inviting type of light.
nate
I agree.
LED lighting is an entirely new technology, and every new technology has spin-offs that allows us to do things we haven't been able to do before, or allow us to do things which were previously prohibitively expensive to do.
I very much like the colour of the light that comes from the LED bulbs I bought. It's a bright light, but at the same time a very attractive light.
I don't see the point in people like Mayayana stockpiling incandescant bulbs. I wouldn't go back to incandescant bulbs if they were free. LED bulbs are expensive, and will be for the next couple of years, but they too will eventually be selling for $2 or $3 each, just like CFL's are now.
| I don't see the point in people like Mayayana stockpiling incandescant | bulbs. I wouldn't go back to incandescant bulbs if they were free. LED | bulbs are expensive, and will be for the next couple of years, but they | too will eventually be selling for $2 or $3 each, just like CFL's are | now. |
That sounds good. Hopefully by the time my stock is gone they'll have the LED technology ironed out and I'll be able to get 4 bulbs for 3 dollars that have a slightly warm color, like halogens. :)
I think we're nearing the tipping point with LED's. With CFL's costing $4 a bulb, and with LED's still dropping in price, people are now thinking that for $2 to $3 per bulb more, they can have LED's and enjoy their much longer life span.
Mayayana: You go ahead and stockpile your incandescent bulbs. Then, when you buy your first LED bulb, you'll be upset that you invested all that money buying incandescent bulbs when you could have used that money to buy LED bulbs instead.
I remember when I was a kid watching so many science fiction shows like "1984" that predicted the future would be miserable place to live; with computers running our daily lives and effectively making people slaves of machines. The bottom line, however, is that people still vote with their wallets, and buy what they want, that they think is a good product and that makes life easier for them. LED bulbs emit beautiful white light, they use way less electricity than incandescent bulbs and they're getting cheaper by the month. If anything, the future seems to be one in which it's far easier to live in than predicted. We pay less for sufficient lighting and spend much less of our time dealing with nuisances like replacing burnt out light bulbs.
I'm changing at home and also at work. We have a light that burns out at least 3 or 4 times a year. The maintenance guy has to bring a ladder from the shop to change a $3 PAR30 bulb. For $19 we have an LED that not only looks better but will last for years. Those three changes alone have to be in the $100 range for labor.
We won't notice the saving in power as our typical electric bill is the the range of $10,000/month anyway.
| Mayayana: You go ahead and stockpile your incandescent bulbs. Then, | when you buy your first LED bulb, you'll be upset that you invested all | that money buying incandescent bulbs when you could have used that money | to buy LED bulbs instead. | | I remember when I was a kid watching so many science fiction shows like | "1984" that predicted the future would be miserable place to live; with | computers running our daily lives and effectively making people slaves | of machines..... | If anything, the future seems to be one | in which it's far easier to live in than predicted.
It's a bit of a jump to imply I'm a Luddite for liking incandescent bulbs and not being the first on my block to install LEDs. :)
There is something to be said for fears of the future. To a great extent we are now slaves to our machines. (Though
1984, as many may know, was meant to indicate 1948. It was a commentary on the mild fascism developing in England after WW2, not fear of technology.) These days, setting aside political issues like corporatism, and only looking at machines, I think it's reasonable to view it as a mixed blessing. Many people are addicted to constant entertainment due to wonderful machines like video game players and smartphones. And many people now do jobs that require them to be machines. Computerization ended up doing that. Computers don't fit well into most business scenarios unless the workers also act like computers. And have you noticed that something you buy at Home Depot is often discontinued the next time you want to buy the same thing? It's a mechanized, computer-driven business. The stock order is computerized, calculated for maximum profit.There was an interesting book by one Juliett Schoor at Harvard, some years ago. I think it was called Overworked America. She pointed out that only one modern appliance, the microwave oven, had reduced work time. The clothes washer, for example, saved time on laundry, but people then just ended up washing their clothes far more often. There had been a utopian fantasy about how we'd all only need to work 3-day weeks by the 60s or 70s. Instead we work more than ever. No one counted on two important factors:
And of course, there's the question of what easy living really means. It's nice to have vaccines and novacaine from the dentist, but making minimal effort in life is not necessarily a source of happiness. (Whatever that is. :)
A year or so ago, I read article about LED bulbs in traffic signals. Much the same, the labor saving is incredible. Problem is, they don't get warm, so snow covers the lens. Someone found out you could put a small heater filament in, to keep the lens warm enough not to cover with snow. Problem is, the filaments use a lot of electric, and they burn out on a regular basis.
- . Christopher A. Young Learn about Jesus
They should use a heater element instead of a filment. That would last for years.
Do we have evidence to support that longer life span? I'm sure you can make an argument that a led chip can last longer than a CFL bulb. But, the last led I took apart had 15 chips in it. If any one of 'em goes, the lamp is dead. Drops the effective chip MTBF by a factor of 15 right there. Yes, the CFL fixture has higher voltage that affects the failure rate, but does it make up for the 15X the number of LEDs?
Every one of the dead CFLs in my junkbox failed because of the electronics. A power surge doesn't care whether it kills a CFL or LED lamp system. If you adequately protect the electronics and have big enough heat sinks, you price yourself out of the market.
If you've ever taken one apart, you know that the workmanship is horrendous. I'd expect that to be a significant part of the failure rate.
So, at the cheap end of the price spectrum, in real-world consumer applications, I'm not convinced that LED lamps last any longer, unless you turn them on/off frequently.
I replaced most of my perfectly good CFLs with LED only because I couldn't resist a bargain and I got carried away. I put LEDs in fixtures I haven't turned on in a decade. I bought more LEDs than I have fixtures, so I have spares. Yet, when I go to Home Depot, I still look to see if they found any more I could buy dirt cheap. When emotion gets hold of you, logic is irrelevant. :-)
True blue LEDs were the last colored LEDs developed.
I remember in the 80's all the idiot lights in the dash of my various VWs were large red LEDs but the high beam indicator was a blue tinted bulb, because blue LEDs hadn't been invented yet at the time that the cars were designed.
The guy responsible for that breakthrough just won a Nobel prize very recently.
After skimming the article, it appears that while my cars were using red LEDs back in the early 80's the blue one wasn't even a functional prototype until 1993.
My understanding, limited though it is, is that the blue LED was critical to the development of the "white" LED as the latter is basically a blue LED that excites various phosphors that emit other frequencies of light.
nate
No, I think you're getting the different technologies mixed up.
Fluorescent tubes work on the principle that when an electron hits a mercury atom inside the fluorescent tube, that mercury atom emits a UV ray. When that UV ray hits the phosphor coating on the inside of the tube, those phosphors then emit light in the visible spectrum.
My understanding is that blue LED's don't involve any phosphor coating at all. They just emit blue light when electricity is applied to them very much the same way as red LED's emit red light when electricity is applied to them.
I think that the 2014 Nobel Prize in Physics given for blue LED's revolves around the fact that being able to make blue LED's makes it possible to make WHITE LED's and that makes it possible to replace inefficient incandescent bulbs and CFL bulbs with the much more energy efficient LED bulbs. It was really the magnitude of the change that white LED's would make in reducing carbon emissions into our planet's atmosphere that justified the Nobel prize being awarded for their invention/discovery/development of blue LED's.
this pretty much summarizes how I understood this to work
now I know that some remote phosphor lights e.g. Philips use both blue and red LEDs to excite the phosphors
nate
That is new information to me. Until now, I understood that only the insides of fluorescent lights were coated with phosphors.
If what that naked scientist web page says is correct, then LED lights use some of the same technology that fluorescent lights do, and can be made into "redder" and "blue-er" white light light by changing the kinds of phosphors used to coat the inside of the tube or LED, just like they do with fluorescent lights.
You can tell by watching what happens when you turn it off. The LED quits emitting instantly. If the light continues to glow for ANY time at all, it's a phosphor.
That is new information to me. Until now, I understood that only the insides of fluorescent lights were coated with phosphors.
If what that naked scientist web page says is correct, then LED lights use some of the same technology that fluorescent lights do, and can be made into "redder" and "blue-er" white light light by changing the kinds of phosphors used to coat the inside of the tube or LED, just like they do with fluorescent lights.
Yes, there are phosphors in use in addition to the actual led element.
Blue were required to make white.
*****
I am just beginning the LED trip. I went to HD and bought one 100watt bulb to use in the lamp where I sit to read. Left there and went to Walmart fo r some other things and looked at their LEDs. I bought a 100watt LED there - Great Value brand. The warranty for the HD (Phillips) was for 33 years. The GV is for three years. But the difference is great! I returned the P hillips to HD -- and went to Walmart and bought a second one. The differen ce was that the GV brand is "soft white" and the Phillips was something els e. Trying to read by that Phillips bulb was not very enjoyable. I am keep ing the box covers the bulbs came in along with the sales receipts and if t hey stop working before the end of 3 years I will take them back to Walmart . I had spoken with a customer service rep from Phillips and she said to k eep track of all the stuff and return the bulbs that didn't work ... and Ph illips would make good on the guarantee. As far as heat goes -- the bulbs will get hot if you put them in a lamp that is not designed for that partic ular wattage. I know because I put one in a lamp that says use 60watt bulb s. Took it out when it got too hot and its still working fine in a proper (3-way) socket. But the regular 60 watt bulbs I still use are even hotter than the LEDs... had forgotten they got that hot. CFLs get really hot, too .
There's a new fix for this problem that doesn't use electricity at all. You know the cylindrical visor that fits over each colored lens on the traffic signal? It has been redesigned to include an air scoop at the top and an opening at the bottom. With the air scoop, the wind that had been blowing snow into the visor now blows across the lenses all the time. The lack of a bottom ledge on the lens keeps the snow from accumulating. Cheaper to replace the visors than to implement heating elements.
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