Does LED lighting have practical uses yet?

I saw some in B&Q for about fifty quid - apparently for outdoor use.
Trouble is - there was no indication of wattage or actual light output
in lumens.

Any facts or recommendations?

I'm wondering if these things might be useful ... and, if so, where.
--
Chris

On Tue, 13 Jun 2006 20:00:03 +0100, Chris ] wrote:

Does LED lighting have practical uses yet?

Yes if you want to look at it.
No if you want to look at anything illuminated by it.

Soon!

"Andy Dingley" wrote in message
...
On Tue, 13 Jun 2006 20:00:03 +0100, Chris ] wrote:

Does LED lighting have practical uses yet?

Yes if you want to look at it.
No if you want to look at anything illuminated by it.

Soon!


Very soon. July even. But efficiency is not that great and I guess these
little babies are gonna be expensive for starters!

http://tinyurl.com/jpcmj

Slurp

Chris wrote:
Does LED lighting have practical uses yet?

Great for mood lighting but not quite there for other uses.

Chris wrote:
Does LED lighting have practical uses yet?

I saw some in B&Q for about fifty quid - apparently for outdoor use.
Trouble is - there was no indication of wattage or actual light output
in lumens.

Any facts or recommendations?

I'm wondering if these things might be useful ... and, if so, where.

LEDs have 2 main advantages: very long life if run conservatively (not
if not) and tiny size (3mm and 5mm LEDs are the standard sizes). They
also have 2 disadvantages: its impossible to cram enough LEDs into a
lightbulb package to get a comparable light output, or even close, and
theyre expensive.

So their main appropriate apps are nightlighting, emergency exit/backup
lighting, low level mood lighting, making glass glow funny colours,
christmas tree lights, and lighting very small spaces, eg that little
shelf tucked in the corner thats a bit dark. Other uses are not really
appropriate. (Ignoring transport apps here)

The LED bulb substitutes all perform poorly. The best way to use LEDs
is to use the LEDs rather than prepackaged bundles of LEDs, and run
them off a small external supply. Since LEDs are so tiny they can fit
in woodwork just 1/4" thick. If you only have 2mm space you'll need to
use sm LEDs and solder them.

Last there is the question of white versus coloured. White LEDs have
poor CRI, uneven colour temp, and deteriorate fairly quickly. Coloured
LEDs give a single colour frequency (ie a pure colour), are long term
stable and a fraction the price. Use 28p ultrabright LEDs rather than
standard 9p LEDs.

If you need white, mixing colour LEDs is a lot cheaper than using
whites, and provides stable CCT. To do this well requires working out
how many of each colour are needed, and not forgetting to avoid
coloured shadow edges.

A note about the hype over LEDs: they have never performed as well as
fluorescent technonlogy, and there is no sign of them being about to
any time soon. Its just hype.


NT