DIY LEDs: Where to start?

sdf

Well-Known Member
Ok so I'm wanting to build an led light but have no idea where to start. I know a little about electronics but I am a fast learner when its all laid out. So 2 questions

1. What are the supplies and parts needed for an led light.
2. Does anyone know of a step by step guide for building lights?

Thanks guys, oh and this will be lighting a 4x4 flower room
 

SupraSPL

Well-Known Member
At this point I recommend COB LEDs over red/white/blue mixtures. The CXA3070 is the cheapest and most efficient currently available to us. Probably the first step is deciding how hard to run them. At 700mA you get 42.5% efficiency, at 900mA you get 40.3%, at 1050mA you get 39% and at 1400mA you get 36.24%. These may seem like small differences but it means that the COBs are 17.4% more efficient at 700mA than 1400mA.

So here is an example build for a 4X4. I would suggest 600W. If we assume you chose 1050mA:

(4) heatsinks $175 (heatsink USA)
(16) CXA3070 $700 (digikey or arrow)
(16) meanwell drivers $307 (LPC-60-1050) (jameco)
(1) prolimatech PK3 thermal paste 5gram $12 (eBay)
(4) 140mm fans $20 (eBay)
misc wiring, connectors, soldering gear $100

So $1314 for 600W is $2.19/W
 

Mellodrama

Well-Known Member
Well, I'm a newb at LED so take it for what it's worth. Seems to me you have to decide right off the bat. Do you want to go with COBS, or individual emitters? Or some sort of mixture of the two? I went from zero to building a couple of COB's in the last month by hanging around, asking questions, and absorbing info.

Nobody's gonna take the time to spoon-feed you. Everything you need to know to get started is on the first 3 or 4 pages of this sub-forum.

Be aware that there's no safety net. No warranties where you're thinking about going. If you break it you own it.

EDIT: Supra beat me to it while I was typing. What he said. Most of what I've learned was either from Supra himself or people branching off from Supra's efforts.
 

sdf

Well-Known Member
Yea I know no ones going to spoon feed me, I'm just looking for guidance. Thank you for the run up for a build like that but that would ass rape my budget. I can get 2 panels to cover a 4x4 for about 520 delivered (I'll post link in a bit) the point of an led build for me is to be cheaper than buying one however I think the afformentioned lights are going to be about as good as it gets
 

SupraSPL

Well-Known Member
If we assume it actually dissipates 190W, then we have to estimate how efficient the lamp is. The LEDs are not going to be top bins and even if they were they would not approach the levels of efficiency of Cree. They are running them at 580mA when max for those LEDs is 700mA so they are running relatively hard. Because they are operating at a very low efficiency, they will create mostly heat (~85%). Because of that and the fact that they are probably mounted poorly, they may be running hot which causes another efficiency penalty up front, a fading output over time and a longevity penalty. We have heard many stories of these LED actually burning out.

So overall I estimate you are getting only 25W of photons for $225 so that is $9/W. The Cree build cost $1314 and creates 234W of photons so that is $5.60/W and it will last indefinitely. Of course you could scale it down if that is above your budget. If you are growing for personal use you probably dont need 600W of LED. If you are growing for profit it will pay for itself in 1 month. Good luck!
 

sdf

Well-Known Member
Yea, it would take me about 5 months to get that much money after bills and putting aside money for the wedding. What if instead of COBs I used individual R/G/Bs to cut down the cost? What would your suggestions be
 

sdf

Well-Known Member
I am growing to supply me and my girl but I would like to maximize the yield so any extra I can sell to some friends and make a little extra cash to upgrade my lights
 

caretak3r

Well-Known Member
Look at Gaius's build - https://www.rollitup.org/led-other-lighting/792363-seeking-help-building-custom-designed.html
and scale it, maybe:

4 cpu heatsink/fan ($40)
(4) CXA3070 $160 (digikey or arrow)
(4) meanwell drivers $80 (LPC-60-1050) (jameco)
(1) prolimatech PK3 thermal paste 5gram $12 (eBay)
misc wiring, connectors, soldering gear $50
$342

160W @ 39% = 62 photon watts = 2.5X more light than your ebay panel
If you scale down to further to match the ebay light, you'll still have a better starting platform.

(2) cpu heatsink/fan ($20)
(2) CXA3070 $80 (digikey or arrow)
(2) meanwell drivers $40 (LPC-60-1050) (jameco)
(1) prolimatech PK3 thermal paste 5gram $12 (eBay)
misc wiring, connectors, soldering gear $30
$182
$80W, 39% efficient= 31 photon watts which is still better than the ebay panel
 

caretak3r

Well-Known Member
That number seems pretty solid. I did the math using my Vero 18s, and came up with a number in that ballpark.
I did lots of maths :) -- and determined if one is focused on equipment cost, a target of 30% efficiency yields Vero18s the winner, a target of 40% efficiency yields CXA3070s the winner. I initially targeted 30% efficiency so I bought Veros and don't yet have any of the Cree CXAs. I would say the consumer is probably a winner with either COB.
 
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