DiY LED Grow Lights with CREE CXA3070 COBs and CPU Coolers

Im having trouble with my build! I attached my CREE successfully to my arctic 11 plus heatsink but I'm afraid to let it run for more then five minutes because I feel its too hot and will burn itself out. Is this possible?

My heatsink stays cool but the surface of the CREE 3070 is in the 200+ degree Fahrenheit zone within four minutes. Am I just dumb and this is actually the normal temps for it to be running at? I measured the temp by putting the tip of a digital meat thermometer on the surface of the LED, the temp continued to rise. After, I removed the LED from the heatsink and figured maybe it is because I did not sand down the heatsink?? Or because there was the factory-applied thermal paste plus some of the "Arctic silver 5 high density polysynthetic silver thermal compound" that I purchased and applied myself. Or is there another reason my LED was running so hot? I am using the $13 driver from ebay that Supra has recommended.

Any advice what my next step is to get this thing running!? I'm so ansy and love the concept!
 

Voidling

Well-Known Member
I would have either used the factory paste, or cleaned it and then put on your thermal paste.

Second choice is a little better. At this point clean it all off of the heat sink. Put just a dab of arctic silver, I think computers say like a small pea. Put the cree down and press the white corners down while sliding it around a little to spread the compound evenly.

Worked for me.

Don't sand.

I've never measured the temps. Just put the cob on arctic alpine 11 plus, wired it and the fan and let it go. Cree has survived, my driver did not
 

bizmuth

Member
I have a Question, why run them at 1400mA ?? those COB are meant to be run at 1.9 to 2.8 amp... you would have the same result with CXA2530 (36.4v*1.4A*8 = 407 watt ) but they cost 20 $, I'm curious, maybe they're something i don't understand in those datasheet............The way i see it, you should choose you power supply first (constant current), then adapt you COB to that supply and get the less expensive one that fit that current

is it a heating precaution ?
 

nogod_

Well-Known Member
Depends on your design goals. @ 2.8a per cob you are going to be producing about twice as much heat as light.

@1.4a you are producing about the same heat/light.

Plenty of threads here for you to answer your own question.

Time to hit the books!

I have a Question, why run them at 1400mA ?? those COB are meant to be run at 1.9 to 2.8 amp... you would have the same result with CXA2530 (36.4v*1.4A*8 = 407 watt ) but they cost 20 $, I'm curious, maybe they're something i don't understand in those datasheet............The way i see it, you should choose you power supply first (constant current), then adapt you COB to that supply and get the less expensive one that fit that current

is it a heating precaution ?
 

bizmuth

Member
Depends on your design goals. @ 2.8a per cob you are going to be producing about twice as much heat as light.

@1.4a you are producing about the same heat/light.

Plenty of threads here for you to answer your own question.

Time to hit the books!

Yeah, I started reading the Relative Luminous Flux VS current & the Operating Limit, I just bought 5 LPC-60-1400 and im gonna run 5 CXA2540 COB with it, operating limit should be around 105 degC @ 1400mA and RLF 120%, I think it should be safe, I bought the same fan/heatsink, what do you think ?
 

iceman3000

Well-Known Member


Easily build your own high-power LED Grow Light using COBs!

(Built with assistance of RIU contributors! - Original thread )


[HR][/HR]
Battlestar Ganjatica - A 480 Watt Multi-Mode LED Grow Light


6x CREE CXA3070 @ 3000K - $36ea ($216)

2x CREE CXA3070 @ 5000K - $38ea ($76)

8X Meanwell LPC-60-1400 Drivers - $20ea ($160)

8 Arctic Cool CPU Coolers - $9ea ($72)

Rhino 12v External HDD Power supply - $9 (for powering fans)

1 Tube Thermal Adhesive
- $8

3'x1' White Shelving board - $10

4x Bottom Sliders for Drawers - $7ea ($28)

(link is not exact model. I only paid $7 each in-store)

3x 2-way Switches - $4ea ($12)

4 heavy-duty stainless eye bolts - $1ea ($4)
(in-store)

10 Pack In-sure easy wire connectors - $2

6-Pack Blue Mid-line connectors - $2

TOTAL PANEL BOM: $599

MISC Other Materials:




Ignore the fan-speed controller. Didn't end up using it.


[HR][/HR]

Wiring is pretty basic. Just scale up the below diagram (provided by RIU member Goud)




[HR][/HR]

And here you go!






3 Modes: Veg, Teen, Bloom







Preliminary Results look good!

First day over plants:


Week or so later:


Hi was thinking of using 80mm cpu cooler for cob cxb3590 @50w hlg 120 1400c how did they work out for you and do you think they can get the job done
any input would be great

iceman3000
 
Hi was thinking of using 80mm cpu cooler for cob cxb3590 @50w hlg 120 1400c how did they work out for you and do you think they can get the job done
any input would be great

iceman3000
I didn't try it yet but I'm sure it will work much better then a standard diy with cpu fans. CPU coolers work much much much better then your standard cpu fans by far.....even more reason to use a water cool setup or an all in one cpu cooler (such as the corsair h80i gt or/and corsair h100i gt).
 

iceman3000

Well-Known Member
ARCTIC Alpine 64 GT Rev. 2 CPU Cooler - AMD, Supports Multiple Sockets, 80mm PWM Fan at 22dBA
something like what was used in the build in this thread would cut the weight way down and price
 
ARCTIC Alpine 64 GT Rev. 2 CPU Cooler - AMD, Supports Multiple Sockets, 80mm PWM Fan at 22dBA
something like what was used in the build in this thread would cut the weight way down and price
Those are good to but I rather do an all in one cpu cooler. It's maintenance free as well. I personally got a h100i and it's been running fine for roughly two years.
 

hillbill

Well-Known Member
The CXA3070's are pretty much the most powerful/efficient COB's that the retail shopper can get their hands on. But the highest bins are often unavailable. I just bought a couple of 5000K CXA3070's. Had to settle for the CXA3070-0000-000N00Z450F because nobody's offering the higher bins. Not to the person who wants to buy 2 or 3 of them.

You have to be careful about lm/watt. They're more efficient when they're not being driven hard. You can get more light out of the device by driving it harder, but you're losing efficiency as you crank up the amperage. So it's a story of diminishing returns.
Diminishing returns or ideal compromise?
 
Diminishing returns or ideal compromise?
Good question.

@hillbill proficiency goes down when then shit gets too hot. This is where the cpu cooler comes in broski. If one does a custom cooling DIY then I would highly suggest getting your parts from http://www.frozencpu.com. I may actually go with a custom build instead of using an all-in-one cpu liquid cooler. Here's an example of many wall-mounted computer builds. They are all water cooled. Just picture all the "cooling blocks" as cree-cobs instead of your conventional cpu and/or gpu. With this setup, you can crank to cree's to 100% because it the water cooler setup will dissipate heat much much better then your standard cpu fan cooler.
 

rickymac21

Well-Known Member


Easily build your own high-power LED Grow Light using COBs!

(Built with assistance of RIU contributors! - Original thread )


[HR][/HR]
Battlestar Ganjatica - A 480 Watt Multi-Mode LED Grow Light


6x CREE CXA3070 @ 3000K - $36ea ($216)

2x CREE CXA3070 @ 5000K - $38ea ($76)

8X Meanwell LPC-60-1400 Drivers - $20ea ($160)

8 Arctic Cool CPU Coolers - $9ea ($72)

Rhino 12v External HDD Power supply - $9 (for powering fans)

1 Tube Thermal Adhesive
- $8

3'x1' White Shelving board - $10

4x Bottom Sliders for Drawers - $7ea ($28)

(link is not exact model. I only paid $7 each in-store)

3x 2-way Switches - $4ea ($12)

4 heavy-duty stainless eye bolts - $1ea ($4)
(in-store)

10 Pack In-sure easy wire connectors - $2

6-Pack Blue Mid-line connectors - $2

TOTAL PANEL BOM: $599

MISC Other Materials:




Ignore the fan-speed controller. Didn't end up using it.


[HR][/HR]

Wiring is pretty basic. Just scale up the below diagram (provided by RIU member Goud)




[HR][/HR]

And here you go!






3 Modes: Veg, Teen, Bloom







Preliminary Results look good!

First day over plants:


Week or so later:



I love this. It seems relatively simple yet effective.
I do have a couple questions for you thought
1. For the wiring of the drivers. In the diagram it appears that you simple connect them all toget her by wiring all positives together and all negatives together. Correct? Then you simply connect that outcome of wires to your power supply cord? I'd love to see a complete diagram, just to ensure I do it correctly.
2. Connecting the cob lights to the fans. Was that done using the thermal adhesive? So they're basically taped or glued to the fan coolers ?

Thanks much,
 
I love this. It seems relatively simple yet effective.
I do have a couple questions for you thought
1. For the wiring of the drivers. In the diagram it appears that you simple connect them all toget her by wiring all positives together and all negatives together. Correct? Then you simply connect that outcome of wires to your power supply cord? I'd love to see a complete diagram, just to ensure I do it correctly.
2. Connecting the cob lights to the fans. Was that done using the thermal adhesive? So they're basically taped or glued to the fan coolers ?

Thanks much,
Check out these two videos Fam.


and

https://www.youtube.com/playlist?list=PLFeGgzTAA8vkzWTM7SWiQPlYAhNe3GMGi

(Watch all six of his videos. They are extremely informing)
 
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