How do I power my LED's?

I posted before with unknown specs on the lights, but I now have the specs.

I have 50 Red LED's and 20 Blue LED's that I would like to make in an array for a grow light. I was thinking about gluing them with thermal glue on flat aluminum bars that are 2 inches wide in a rectangle with about 1 inch spaces around them because I don't have heat sinks. I think they would be able to dissipate enough heat if I use them in conjunction with a fan.

Here are the specs for the red lights (50):

2.4mV forward current

blue lights (20):
3.2mV forward current

If I'm correct, I need 84 watts for the Red LED's altogether; 44.8 watts for the Blue LED's altogether: combined wattage of 128.8 watts.

Previously, I stated that these lights were 3w, each. But I would rather save life on the diodes and run them at this lower power because they still give off a great amount of lumens.

Can anyone give me some directions on how I would construct this array? (what drivers to use, how to wire the LED's together, and how I could make the system plug into my wall outlet (standard USA socket)).


sort by: active | newest | oldest
lemonie6 years ago

If you were thinking of 12V:
10 x 5 red in series = 7A, 84W
6 x 3 blue in series = 4.2A, 50W

Is that right?


ammakrom (author)  lemonie6 years ago
Let me see if I've finally figured it out.

If i found a 12v power adapter at wal-mart, I could run that 12V to 10 parallel circuits that each have 5 red LEDs in a series. Since the voltage drop is 2.4v per LED for the reds, they would add up to be 12V total across each string. So I wouldn't need a resistor or anything and each series would be getting 12V.

I think that's right? Correct me if I'm wrong, please.

That sounds right, but you need one that'll give you the 7A.
But these high power things may need a driver - people like steve' know better than me on these things.

ammakrom (author)  lemonie6 years ago
I'm so lost haha. Thanks for everyone's help. I think I'm just going to put the LEDs in my closet and forget about it all. I guess I'll just go and buy a HPS light, instead of trying to be cool and build an LED grow light. haha
I know this isn't an answer but can someone make an Instructables for this so many people ask similar questions about LED's? I don't know enough to make one myself.
2hot2hack6 years ago
hey mango to you tube and type in 200wat led torch that will hellp you