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

[guod]

cheap and simple

 

[caretak3r]

View attachment 2990257

cheap and simple

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either go with Guod, or with a driver that Supra or bspills or smokeythecat has specifically tested to work with the CXAs. the 3070 spec actually asks for over 36V so you don't have any guarantees that the 30-36V drivers will work unless someone has already tested them. Don't be the guinea pig here - copy someone that has made this work with the CXA cobs.

 

[guod]

minimum Vf for 1400mA at 25°C --> 37.5V
at 85°C about 36.8V

the Meanwell driver can delivery up to 42V

 

[Gaius]

Guod I can't say how much you rock.

I cancelled the order for the scooter chargers.

Is there a dimmable model you'd recommend? I'm curious to see how much more I'd spend to add that feature.

 

[MrFlux]

The dimmable version of what the guod suggested is LPF-60D-42, at a little less than twice the cost.

 

[Gaius]

Thank you Mr. Flux. I just ordered 10 of the non-dimmable ones. Not worth the doubled price just to dim these when I'm in the room.

I think from here on out I have pretty good idea what comes next. Once I get all the parts in, I'll start posting updates on the build!

 

[SupraSPL]

Awesome your project is well on its way. 470 dissipation watts @ 36% efficiency that ought to get you some serious bud

 

[ellydee]

Gaius, what color/temperature cobs did you decide on?

 

[Gaius]

Gaius, what color/temperature cobs did you decide on?

These are the chips I purchased:
6x CREE 3070(Z230F) @ 3000k CXA3070-0000-000N00Z230F-ND - $40ea($240 total)
3x CREE 3070(Z450F) @ 5000k CXA3070-0000-000N00Z230F-ND - $38ea($114 total)

[HR][/HR]
I have 10 drivers now though, and I'm going to significantly modify the design from the OP.

• Reducing pot size to hempy-style white 2-gallon home depot buckets (highly recommended pot)
• Removing the 5000Ks from the flowering area
• A single 3000k chip over each of the 6 pots for ~300watts of CREE goodness
• Using the 5000Ks to build a small vegging cabinet

This way I'll have a segregated 18/6 veg area, which will allow for more of a perpetual grow.

 

[SupraSPL]

LED is ridiculously efficient at vegging. For example I use the equivalent of 60W LED to veg for 1200W LED flowering room. So unless you need to veg up huge amount very fast, you could probably get away with just 1 of the 5000k in the Veg room.

 

[Gaius]

Supra, you are most likely correct. The design for my vegging cabinets is modular, and each only uses a single 5000K CXA3070. If I find that one is not enough, I'll add a second chip and a driver over the other exhaust fan.

Here's a sketch-up of the ~$120 vegging "cabinet" design I'm working on:

2x - 27-Gallon Storage Bins from Lowes ($30)
1x - CXA3070 @ 5000K ($3
1x - Arctic Cool 70watt-rated CPU fan ($9)
1x - Meanwell LPC-60-1400 ($19)
2x - 140mm Case Fans ($20)

Misc other supplies:
Aluminum Foil Tape (Line the inside of the bins with this stuff for extra shine!)
Rubber Foam Tape (for gasket between two bins)
Thermal Adhesive (For chip on heatsink)
Kapton Tape (Tape down wires)
Solder
Shrink Tubing
18-guage wire

You can't see so well in either of these photos, but there are some passive-intake holes cut out of the bottom bin to allow incoming cool air.

 

[mtnstream]

........................

 

[ellydee]

What are you using to power your fans?

 

[Mellodrama]

The LED's you ordered - how can you tell what bin?

I have a separate question for you or Supra - how much more does it cost to buy these LED's mounted on stars? It seems like the extra expense might be worthwhile if it makes for safer soldering...

 

[Gaius]

What are you using to power your fans?

For the BudBin thingy I'm just using a molex 12v power supply I had lying around.

Edit: The molex adapter won't work, so I'll buy 2 of those meanwell DC drivers Guod recommended to power all 6 fans on 2 BudBins.

Edit2: See below post, it actually works!

 

[Gaius]

Just tested this power supply I had. This is the "molex" one I was referring to. $10 at Frys.

Using my new 6-port fan speed controller, this power supply easily handled two 140mm fans plus an additional CPU fan. So for $10 I can fully power all the fans on a single veggiebin at >80% efficiency.

For the 6 CXA3070 CPU fans in the main room, I'll probably just hook up a PC power supply since I have a few lying around. The Meanwell PLC-30-12 is also on my list of options though.

 

[Gaius]

Just got most of the BOM in!

Just out of curiosity I tried using the external hard drive power supply with the fan controller and six of the new CPU fans. Worked perfectly! Ran it for a few hours and the thing didn't even get warm.

Pretty nice little fan driver for $10, and no soldering necessary.

 

[smokey the cat]

Woohoo buddy, that looks awesome. You're gonna be busy!

regarding your sketch-up Veg bin - if it were me I probably wouldn't go to the effort of putting the driver over your fan like that. My 60w Meanwell run warmish at full power, but don't generate enough heat to bother cooling.

YMMV of course, but I'd just let her passive cool somewhere out of the way.


Unless there is a big efficiency gain to be had with extra-cool drivers of something?????

 

[Gaius]

Good point. If they run that cool then I'll just mount the driver elsewhere.

This is so much more fun than buying a pre-made panel!

 

[anomuumi]

Cool project! I like the idea of those veg units, with light traps those could sit in the corner of a flowering space too.