Most efficient white LED's for general lighting?

[twentysixtwo]

Most efficient white LED\'s for general lighting?

Disregarding throw, what readily available, reasonably priced white LED's have the best flux per unit power? I'm assuming it's a 5mm or SMT from Cree or Nichia, but which ones?

I'm looking to make some stealth display lights for a bookcase....

 

[cobb]

Re: Most efficient white LED\'s for general lighting?

No one responded? Ive often wondered how the led bulbs to swap out the ones in your car would work for something like that. They seem priced right and you can get them in white, amber, red colors. If I do my math right, you could use 10 12 volt bulbs in series and run it right off your house hold current. I would line them up like track lighting around the eves of a room or like you mention a book shelf light.

 

[SemiMan]

Re: Most efficient white LED\'s for general lighting?

In addition to efficient, you really need to watch out for how long the LED will last if you want to keep these on all the time. Most 5mm and small SMT white leds are epoxy encapsulated and tend to have drastically reduced and color shifted light output after 5-10K hours. Cree is claiming fairly high efficiency on their XLAMP and I think you can buy a specific brightness bin, but you will pay a premium. I have yet to see product life estimates though. Luxeons have good efficiencies these days and obviously have very long life so you could get 5-10 years without replacing if you heat sink them well. OSRAM has some SMT whites in that 1/4 watt range. They claim 100K hours, but you need to watch it as it is only at 25C. At a more reasonable temp, that will drop considerably.

Semiman

 

[Doug Owen]

Re: Most efficient white LED\'s for general lighting?

Probably the most efficient would be underdriven ones which will drive the purchase price up. For sure, most bang for the buck will not be from Cree or Nichia. Chinese clones should do better I'd think.

Probably a better way to go (than a pile of 5 mm parts) would be a few LS emitters on some sort of rail. You could put several in series and make the driver easier to deal with.

Doug Owen

 

[NewBie]

Re: Most efficient white LED\'s for general lighting?

XL7090WHT-L100-0010 White, 50 Lumen Typ. @ 350mA
Color WC Brightness Bin N (WC-N-0002)
6.00 ea at 1 ea quantity, must buy 10, but you can mix and match different parts/colors, such as the 1W UV LED, XL7090UVV-L100-0001

www.etgtech.com

Total shipping/packaging going UPS ground is 4.25 USD.


For flood, Nichia's NCCW-022 works better than the NCCW-023.
Datasheet http://www.nichia.co.jp/specification/powerled/NCCW022.pdf
Try to get the Nichia Jd rank parts, 51-72 lumens at 350mA.