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JohnLED
08-11-2008, 12:50 PM
Hello, please help.
I have been doing alot of research on LED technology lately and need some help figuring out the viewing angle and light intensity/mcd and how they change in relation to each other.
I want to build my own LED grow light and I want to purchase some LEDs from a manufacturer and they gave me these characteristics:

5mm LED straw or dome type. 20mA.

461.5nm 2750mcd at 62.5 viewing angle 3.07 volt
659nm 1200mcd at 66 viewing angle 2.11 volt
and
623nm 1580mcd at 60.5 viewing angle 2.01 volt

can somebody tell me if these are any good. i've tried to compare but there are so many, i really need some opinions on these. Thanks a lot. Really appreciate it.

Unregistered
08-14-2008, 05:10 PM
John,
Please don't take this the wrong way but if your asking these questions you might getting in over your head (at least for now - but you can learn!!). Most people have abandoned the 5mm LEDs and are now experimenting with the class II "high power" LEDs.

There are many threads on other boards that have lots of technical specs (I will PM a few to you if I can figure it out...I dont want to post links to others boards as that might be rude to BGH). Also do you have experience with sodering? Some of the LEDs require special handling (like hot sodering) when being built.

There is much debate on the exact wavelengths and which manufacturers LEDs are better for which application. Some have better / more consistent forwarding voltages others are worse. Basically no one knows exactly - thats why its all very experimental at this point. Don't let me discourage you - we need people to experiment!!

Best of luck and let the board know what you decide.

tim
09-06-2008, 10:52 PM
The unregistered guy is right.
Buy your leds from here:
http://www.cree.com/products/xlamp.asp
Put together a heat sink and do teh electronics. If you wish we can do it together as I am on the same project. Email me at [email protected]

Regards
tim