I have in the near future to look at buying all the lights to go where there are cables poking through the ceilings. (54 of them) The original intent was loads of Lo Vo lighting ... but rumour has it that LED lighting is almost mature enough to consider it's use.
Any comments form those that know on LED lighting, and any pointers to good suppliers.
Rick
Even B&Q have them. But I personally think they're still a bit dim and wait for the next generation which I expect will be a lot better.
In message , Rick Hughes writes
Still nothing like as much light as a halogen at sensible prices.
I just returned 12 LED lamps to the supplier, thankfully they took them back. Way too dim and a very cold blue'ish light.
Tony
They are around the same efficiency as LV halogens at the moment. Generally this makes them far too expensive, as watt-for-watt, they are vastly more expensive than halogens. Where they can do well is where you want a narrow beam with no light spill, since that's inherent in the construction of most LED's. That's normally completely useless for general purpose lighting though.
As already commented, LED colours currently available are not suitable for home lighting either.
Very expensive, poor light quality and efficiency no better than Halogen.
Actually, they are. At least for some. Luxeon produces a "warm white" 1W LED. I've got one, and it is more or less similar colour to conventional incandescent.
Comparing the spectrum on the datasheet, the warm-white is a smooth hump, and the normal one is a blue light, with some red and green.
Oops, forgot to mention that they are about 10% less bright for the same power.
Unlike the others, I quite like LED light, it's proper blue-white daylight coloured not guttering candle yellow colour.
The other issue with these is the separate colours are often not well mixed in the beam, particularly the blue component.
The laws of physics can be real buggers at times;-)
A year or two ago, someone was working on a phosphor which emitted two photons for each UV photon received, but I haven't heard anything more about it for a while now.
Another issue for LED lamps is that they can't be run at anything like the temperature of a halogen reflector lamp as they would have a very short life. That means that an LED lamp of the same size as, say, 50W halogen lamp is probably limited to something like 10W max. This means they either have to get very much more efficient (unfortunately improvements in LED efficiency have tailed off in recent years so that's not looking like a good bet) or you are going to need very many more of them (imagine switching all your 50W halogens for 5 times more 10W halogens).
Whilst it's an interesting technology and it may have some limited applications, it's not yet ready for prime time. I think we need a couple more step function improvements first, probably in efficiency. It may be that other technologies eventually deliver better products before then.
In message , Andrew Gabriel writes
Yeah, I had that problem on a colour mixing system. Could never get a smooth white from the RGB clusters as the colours all focused into a slightly different beam pattern.
I still think that's the biggest show stopper for high power LED stuff. Cooling is difficult with 120C max junction temperature. Its a hefty heatsink to dump 40-50W and keep within the Tj limits. BTDTBTTS.
Indeed. Special applications where the technology suits, i.e. long life in difficult access areas, architectural lighting, high vibration environments etc. And, TBH, the lifetime degradation data wasn't fantastic when examined in detail (Luxeon product).
No colour mixing, it's a blue LED, with a white phosphor over it. The phosphor is just chosen to be a "warm white" rather than just thin red/green, with lots of the blue showing through.
humungously expensive, forget it.
Regards, NT
"Andrew Gabriel" wrote | The laws of physics can be real buggers at times;-)
Time to invent new physics ... Owain
Inventing it is easy. Changing the universe so it fits your invention is a bit harder.
"Ian Stirling" wrote | Owain wrote: | > "Andrew Gabriel" wrote | > | The laws of physics can be real buggers at times;-) | > Time to invent new physics ... | Inventing it is easy. | Changing the universe so it fits your invention is a bit harder.
Ah buggrit. That'll be why I never got that job with NASA then.
Owain
Looking very much like it's 12V halogens then...
Yeah. And when LEDs get good enough to actually use they'll probably appear in a plug compatible format anyway.
| Ian Stirling wrote: | > Luxeon produces a "warm white" 1W LED. | > I've got one, and it is more or less similar colour to conventional | > incandescent.
Ian, where did you purchase yours from? I've seen some of the Luxeon products on the U.S. website but haven't found their products over here...
Thanks
Seri
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