Hmm, Let's think about this.

You have 4 leds in series.
2 red, 2 blue.
Your spec sheets say red Vf = 10.5V avg.
and blue Vf = 6.5V, avg.

So, 10.5 + 10.5 + 6.5 + 6.5 = 34V.
The total min. Vf is 32V.

So, if your supply is enabled, and you are providing at least the minimum required Forward voltage, betta call da doc, you've gone blind brah.:smokin:
(They warned us when we were teenagers, yah)

My advice, (in braille of course),
Buy a cheapo meter, horse!

Meter gonna let you "see"
what's up wit 'lectricity.

It's electric, it's expensive,
you should be more apprehensive.
What, you no kea win dis bet?
why you work wit' out a net?!:wtf:

Nice pictures.

Aloha,
Weeze
Weezard Reviewed by Weezard on . Cree Xlamp Grow-Light Schematic Design (Wanted) Been sifting through the cruft trying to find a schematic to build a grow lamp, using Xlamp LED's from Cree. Their time is now :) Yes I've seen the extraordinarily overpriced products being offered by businesses. Not worth the money if you can use a soldering kit, imo. I can solder, but I'm no engineer, so, I'm asking for help in creating a circuit design that balances low cost, simplicity of construction and high efficiency. Preferably with 120vac input (off the shelf ac-dc Rating: 5