Gold Leaf DWC Hydroponic

28" x 30" but i use this light to flower a 3 x3. I weights about 35 to 40lbs The drivers are running at max amps but it is only 1/3 of what the boards are rated at (3000ma) so they run very efficiently.

The plate will add a bunch to your total cost unless you already have a plate.

Plate on eBay just a tad over 100 with shipping. Don’t know if the plate will be too heavy though. Would a 1/8’ plate be suitable or would it flex.

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Would there be any advantage to going with bigger Meanwell given you are only driving 1/3 max on the boards? This is the area of confusion.

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Just the cost of the drivers. You could go with more powerful drivers and have a higher wattage light. Then get the B series driver so you can dim or lower the power you are sending the boards.

Explain please?

I am planning it to be dimmable with the wifi controller. Your 1050B’s are dimmable, right? I see they are paired onto the potentiometers.

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So the B type of driver just allows you to wire in a potentiometer. You probably will need this type to wire in your controller

Yup. So the driver needs to end in B to dim. Got it.

Again how much of an advantage if I get a higher power driver? What driver alternative?

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The biggest driver you can use with the 304 boards is Meanwell HLG-320H-C1400B.
This will drive 2 boards at 300 watts. So with 2 drivers and 4 boards you will have a 600 watt light. 100 more watts then my design.

And the HLG-240H-C1400B won’t be powerful enough to drive at max? Thus the step up to 320H.
My high school physics has been completely 420’d. Electricity (W,Amps, and V’s) baffles me.

QB304 Board Guide


Designed by Horticulture Lighting Group

High efficiency boards designed for Horticulture Lighting projects. Boards can be powered from 10 to 150 watts. Ideal for use in grow tents or grow area with reflective walls and grow spaces with limited height. No Thermal Interface Material is required between the QB304 board and flat metal heatsink.


  • 304pcs Samsung 561C top bin Diodes
  • Connectors rated 300V 9A
  • Estimated LER 321.60 lm/W
  • Estimated QER 4.86 µmol/J
  • Dimensions 6.833" x 11.25
  • Max current per board 1400mA

Flux Characteristics with 3000K, S6 Bin at 55C

Voltage VDC Current (mA) Watts at Board Lm/W at Board (55C) μmoles/joule at Board(55C)
101.46 350 35.51 190.7 2.83
102.98 500 51.49 184.5 2.74
104.88 700 73.41 177.6 2.64
107.92 1050 113.31 1167.3 2.48
110.2 1400 154.28 1158.8 2.36

This is the QB board spec. So at 1400ma (max board input) your forward voltage is 110.2 VDC. The driver output is 229 VDC max. So you can run 2 boards off one HLG-320H-C1400B driver. This driver will give you the maximum the board can take. 1400ma and 220.4 VDC for 2 boards. I’m sure this is clear as mud now.

I get your example but not all the specs listed on Meanwell site show output In VDC. There specs aren’t listed consistently. Confuses the shit out a me.

Ok so if I used the HLG-240H-C1400B. I’d have some extra power available to wire in the QB-11’s and their max current is max 1400. Diagram on the HLG site shows them wired in parallel with the 288’s. HOw would they be wired with the 304’s?



Found a friend who is really into building COBs to help me out. He provided a comparison chart between the QB boards (and drivers) and his COB set-up. Really informative:

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You would have to wire it in series,

Well, after much cogitation I am going to go with the 1050Bs. Forget the QB11’s. @MAXHeadRoom You have me convinced. ’ve seen your buds. That’s enough for me.

Total cost:
Aluminum Plate 1/8” x24”x36. - $70
4 QB304 and controller -$312
2 HLG-240-C1050B - $135
Misc connectors - $15
Toal - $532


Good deal. I’m glad I could help. You will not be disappointed. :sunglasses::us:

Babies have been settled in. Their feet are now happily soaking in the pool.

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And here’s the exhaust set up.

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All the parts are ordered. Meanwell has the 1050’s on backprder until 27Sep. My old light will do the job while the new light waits for assembly. Good thing I ordered the 304’s when I did beccause they are out of stock now. HLG says they are not going to a V2 on the 304’s. They are “thinking of doing something different.”

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Anyone have a source for the potentiometers? I am not going to do the WiFi controller. I believe it needs a hub.