OT, info on LEDs

I am researching LED lighting for a project, can anyone suggest a good general reference that I can use to learn how to spec these, sources, comparisons between different options, etc. there is much BS on the consumer side, much tech lingo on the OEM side,
thanks

Try this place, looks like a good starting point: http://www.theledlight.com/

Need more detail. I'm not that familiar with them, but I do play around with some of the white ones. LEDs are a broad category.

There is a lot of information (some bad) regarding LEDs and optics (reflectors included) over on candlepowerforums.com. The LEDs discussed there are primarily for hand held flashlights, generally in the 3 to 5 watt range(for single emitters). I understand that there are some DLP TVs that use higher wattage LEDs. I'm not at all familiar with those.

Generally, there is Luxeon, Cree, Seoul Semiconductor, and Osram. The LEDs are binned (sorted) after manufacture. There is variation within bins, but for the most part, the sorting system tries to organize emitters by tint and forward voltage.

The industry is on the move, emitters are getting better and better.

Led's are usually measured in mcd, micro candela, the measurement of luminious intensity.

Lux - 5/6 lux street lighting, 750 lux drawing office.

What do you want to illuminate?
How bright?
What is the surrounding area like, shiney, matt, colour, etc...

Its a complex subject, 3 months min on a BTEC certificate, and intense.

As an example. I've used 4mm oval amber leds, with 60x120 deg viewing angle, 590-1300 mcd, untinted clear lens, to illuminate boiler, vacuum and steam chest pressure gauges on a full size steam locomotive. These work very well wth good mtbf.

On the other hand, 5mm round led's, 15 deg viewing angle to illuminate a speedometer (back lit).

More info....

If your not sure, play with them, they are cheap.

Mark

mcd is millicandela.

There are some cheap high output leds and drivers on dealextreme.com

macona
"mcd is millicandela" oops, your correct, have to stop rushing around and concentrate more, too much work, not enough time....

The advantage of the oval type, 60x120 deg is that one can mount it above a gauge (in this case) and achieve a respectable gauge face illumination without detracting too much from the loco's aesthetics. (was built in 1879)

Mark

Also superbrightleds.com has a nice selection of different sorts of LEDs, cluster, retrofit lamps. I picked up a LED festoon lamp for the dome light in my car. Must be twice as bright as the stock light.

I also used some of their retrofit lamps to replace all the guage and pilot lamps on my BMW motorcycle. Looks nice. Colors are crisp. Never have to change them again either.