Seeking Help - Building Custom-Designed DIY LED Grow Lights using CREE CXA3070 COBs

Gaius

Gaius

Active Member
Hello RIU! Seeking help from the DIY LED Pros.

I plan to light a 4'x3' grow space using the CREE CXA3070 family of COB LED chips, and a bit of elbow grease. I have ZERO experience building an LED panel, so any help or advice will be more than welcome. I'm fairly good with repairing electronics (soldering and such), so I believe I can do this without electrocuting myself.

If I don't die in the attempt, then I'll post regular photos of my progress in this thread. Additionally, I'll start a detailed new grow journal using the completed panels.


[HR][/HR]



Design: Nine chips on three panels. Each panel covers two 5-gallon pots.


Outer chips on each panel will be in the reddish range for flowering:
6x CREE 3070(Z230F) @ 3000k CXA3070-0000-000N00Z230F-ND - $40ea($240 total)

Center chip on each panel will be in the blueish range for vegetative growth:
3x CREE 3070(Z450F) @ 5000k CXA3070-0000-000N00Z230F-ND - $38ea($114 total)​


[HR][/HR]



I will also acquire all the materials SupraSPL was kind enough to list out for me.


SupraSPL said:
Misc materials:
Prolimatech PK3 or similar (eBay)
Kapton tape (eBay)
Zinc chain (Walmart or Amazon)
50V hookup wire for LED string 18ga (or use 600V wire from old xmas lights) (elecdirect)
600V wire for AC connections 18ga (elecdirect)
slide connectors .25" (bare, crimp on) (elecdirect.com)
heatshrink tubing .25" (elecdirect.com)
Solder 63/37 lead (amazon)
Solder flux gel syringe - MG chemicals ($10 eBay/Amazon) (this really helps)


tools needed:
cordless drill (harbor freight $15)
heavy duty crimper/cutter/stripper (walmart ebay amazon)
soldering iron (60w eBay $10)


recommended:
GFCI (eBay $7)
sand paper to lap heatsink surface (3M home depot)
Click to expand...
Now I've already ordered the chips (best available bins), so unless they're completely the wrong type I'll be using the exact models shown above.


I'll either order a custom-sized heat sink, or I'll consider mounting each diode to its own PC fan/heatsink combo if the resulting solution is superior. I must actively cool these since my grow area gets over 80°F ambient in the summer.


[HR][/HR]

Lastly, can anyone please recommend the appropriate drivers to run these? Dimmable would be awesome if the price isn't tremendously higher. Will 6 of THESE, or THESE be my best bet?
 
M

mtnstream

Active Member
Are you attempting a veg, flower or multi-use? How much area?

Personally, I would use less 5k and more 2.7k maybe a UVB at 2-4-6 hr increment increases in last 2-4 weeks of flower.

To start, I would go with a constant driver 10-20% of chip capacities. Just as Supra pointed out, they're more efficient, easier to keep cool, and longevity is believed to be much longer. Drive a few chips like this
before adventuring into dimmers.

If you do decide to dim them, do two (2) separate strings with 2 driver/dimmers. This way you can tune to the season(s) by running cool and warm Separate.

I am using 2-3050's in <2 sf setup completed Sunday, and photons are ridiculous at 8-12". Plant runners jumping to edge of screen.

Thanks to bbs as the frontier user/grower with these! There are some very talented and intelligent folks on this forum that have taught quite a few folks
including myself.

good luck and safe travels.
 
M

mtnstream

Active Member
Keep fins as close to room ambient as possible.

Correction; absolutely keep drivers outside of box. Use a small metal bar (ground) and super glue disc magnets to back of drivers, pc fan controller, and breaker strip and stick it to component bar.

ellydee said:
Might be some tidbits of info here; http://howtogrowmarijuana.com/DIY-LED-grow-light
I would want my drivers outside of the grow area. Not sure why he mounted them to the heat sinks?
Click to expand...
 
PSUAGRO.

PSUAGRO.

Well-Known Member
mtnstream said:
Keep fins as close to room ambient as possible.
Click to expand...
This makes no sense.......you want the drivers away from heat sources and/or not adding any heat to the leds and heatsink.

It's a strange design choice with passive cooling
 
Gaius

Gaius

Active Member
mtnstream said:
Are you attempting a veg, flower or multi-use? How much area?

If you do decide to dim them, do two (2) separate strings with 2 driver/dimmers. This way you can tune to the season(s) by running cool and warm Separate.
Click to expand...
Multi use. Dimmable highly desired. Assimilating a ton of material. This is going to be an adventure.
 
M

mtnstream

Active Member
Drivers outside space, pc Heatsinks with copper plate for tim/chip. I am doing forced air with 4 pc fans connected to a 6 Chanel
controller. Once upon a time, I was soldering 1 watt chips for reef.



PSUAGRO. said:
This makes no sense.......you want the drivers away from heat sources and/or not adding any heat to the leds and heatsink.

It's a strange design choice with passive cooling
Click to expand...
 
SupraSPL

SupraSPL

Well-Known Member
Awesome setup! Check these drivers out. $15 cheap and has a 12v fan output which might save you a few watts of losses in a separate AC DC converter. They only go up to 1500mA but the CXA3070 will dissipate 52W @ 1400mA @ 36.25% efficient which is a pretty good compromise. Good luck!

CXA3070 3000K Z2 bin and 5000K Z4 bin
CXA3070 3000K and 5000K.png
 
caretak3r

caretak3r

Well-Known Member
SupraSPL said:
Awesome setup! Check these drivers out. $15 cheap and has a 12v fan output which might save you a few watts of losses in a separate AC DC converter. They only go up to 1500mA but the CXA3070 will dissipate 52W @ 1400mA @ 36.25% efficient which is a pretty good compromise. Good luck!

CXA3070 3000K Z2 bin and 5000K Z4 bin
View attachment 2984290
Click to expand...
my satisled order arrived and I happened to have picked up one of the round 50-70W drivers (12v out as well) in addition to the driver I pointed out to you in your thread. I can report on it within the next few days. I still need to lap my heatsinks and get the COBs clamped down for testing.
 
Gaius

Gaius

Active Member
Regarding Power Supply/Drivers:

SupraSPL said:
Awesome setup! Check these drivers out. $15 cheap and has a 12v fan output which might save you a few watts of losses in a separate AC DC converter. They only go up to 1500mA but the CXA3070 will dissipate 52W @ 1400mA @ 36.25% efficient which is a pretty good compromise. Good luck!
Click to expand...
I don't mind spending a little more $$$ to have a nice tweakable knob to easily dim the chips with. I'm curious to see how the ones you ordered play out.

Is there perhaps an easier solution though? Like what about hooking up a 600w PC power supply and just using a few fan speed controllers? I would imagine that going with a larger power supply than what is required would mean less heat generated, so maybe spending a bit more on an 800+watt power supply would even be better.

[HR][/HR]
Heatsink Design:

CPU Coolers:
Here's some PC heatsinks I'm eyeing. Feedback greatly appreciated.

  • Option 1 - $8.99 ($90 total) - Inexpensive, and looks cool.
  • Option 2 - $19.99 ($200 total) - Pricey, but comes with it's own fan-speed controller and has a fairly low profile.
  • Option 3 - $18.13 ($169 total) - Super quiet, but maybe Overkill?

Keep in mind, I'll need 9 of these if I go this route, so it may be actually be cheaper to go with custom sinks and only 2 fans per 3 chips. With the less-expensive option 1, or option 3 I'll probably have to buy a separate controller to adjust the fan speeds properly. A good 6-port controller will run about $50, putting the least expensive option #1 at about $150 total. If I go with a fancier cooler, then this gets a lot pricier than a custom heatsink.

Custom Heatsinks
Three 24"L x 4.85"W heatsinks from heatsinkusa.com will set me back about $100 shipped. I'm guessing on the width I'd need, but 4.85 inches seems about right for mounting 120mm fans. Adding 4 good 120mm fans will run me about $50. So for about $150 total I can do custom-made heatsinks for this design. Surely it'll be easier to hang 3 panels instead of dealing with nine independent CPU coolers, right? I dunno, perhaps the dedicated CPU coolers would provide superior performance and life for the chip? Less fans is less noise & less power consumption, so I'm leaning towards this approach.

[HR][/HR]
Here's what I'm theorizing would work:​


​
 
smokey the cat

smokey the cat

Well-Known Member
Damn those Satisled drivers look nice. The one with round with 12V fan output could be especially really interesting - being able to adjust the output might be a decent replacement for lack of dimming.

I've found dimming really handy. Being able to turn the array down while it's running is awesome when you're working with ya plants. Given this light array will eat any commercial unit alive - spend the pennies and get a driver that dims imho.

The non-generic option is probably the Meanwell LPF series - the 60W version runs for about $33 from US retailers. A lot more pricey, and you'd need to organise a pot for dimming too.


Given that these are open PCBs, what sort of covering would people recommend for them - a large "driver box" like a PC size case or something?
 
SupraSPL

SupraSPL

Well-Known Member
My experience with PC power supplies is that they have a relatively low efficiency (or very low depending on the load) and a large standby power consumption. I did those tests before I had very accurate equipment to measure with and I am sure not all power supplies are created equal.

The AC DC conversion is a major factor in the total system efficiency of our lamps and since digital ballasts are so efficient ~90% I figure that should be our mark (for our drivers and fan power supplies). So in the case of driving PC fans, if we use wall worts we probably get 50-70% efficient with a very poor power factor. Maybe the drivers with built in 12V output can do a better job. Looking forward to your testing caretak3r.
 
Mellodrama

Mellodrama

Well-Known Member
Gaius said:
Now I've already ordered the chips (best available bins)...
Click to expand...
How do you know they're top bin? I followed your link, and DigiKey is probably a great choice, but I don't see anything about binning. Probably missing something really obvious...
 
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