Need help for diy cob light

Discussion in 'Grow Room Design/Setup' started by PopeyeSpinach, Jul 2, 2017.

  1. Hey guys, ive been a long time lurker here. I have a small cabinet grow, 30x18 x 55" tall. I have one plant in there under a galaxyhydro 300 and 3 small screw in led bulbs.

    Im wanting to build a cob light, but i cant decide on size, watts or how many chips i need.

    The Cree CXA 2530 seems to be a good chip but im unsure if its too big, or how many to get. I was thinking 3 inline, or 4 at 4 corners layout.

    I will likely do a water cooled system as where my grow is it will be easier to run water lines to a reservoir in the basement which is always cold.

    So for one plant in that space w a water cooled cob setup, how much do i need. Ive looked at alot of other diy cobs but they are all in bigger multi plant setups. I dont wanna build a light and burn plants.
  2. I went with smaller sized cobs in my veg area and I wish I would have went with full sized (30mm) chips instead. The reasoning being, even though I was running the cobs at low mA it would have been much for efficient for lumen per watt as well as much easier to cool by going with a bigger chip. The slight increase in cost would be offset by being easier to cool and getting more light for the same wattage. Also it's super important to note that the cxa chips are old tech and the newer gen of cxb chips are far more efficient. Binning is also super important too. You could see a 20% in efficiency between low bins and high bins. Each different chip (from cree) will have a spec sheet that shows binning and efficiency for that model. For example a low bin cxa chip might get you 120-130 lumens a watt, while a newer top bin cxb chip could get you up to 200 lumens a watt using the same driver and set up. There are also plenty of other new chip out there that have just as high of efficiency(or higher) as the new cree chips. I'm just more familiar with cree so that's what I went with when I built my cob setups.

    If you are definitely going with cobs, I'd recommend a passive cooling setup. Oversized, predrilled and tapped, pin style heatsinks are trouble free and do great to cool the cobs without any additional pumps or fans.

    At this point in time and tech I would recommend skipping the cobs and just getting a quantum board from HLG. You'll get a much better price per watt and it will be far easier to cool and build. quantum boards and their heatsinks sell out quick though and you might have to wait till their in stock. Overall they are easier to build and more efficient then cobs atm. Cob are still great but these new boards have passed them up in both tech and cost. I bought a second Qboard the other day and will use an old heatsink from my mars light and source my own driver since the kits are sold out.
  3. Quantum boards look just like the edge lighting in LED tvs.... sounds like i gotta do some more research... thanks bongsauce
  4. I just orderd 20x cxa2520 for 100 usd, cxa2530 would cost 140 usd and i dont think theres a difference between the 2 of both driven by 700ma, i might be wrong, maybe the cxa2530 is more efficient, id like to know.
    • Like Like x 1
  5. they are pretty close to the same efficiency. On cree's site it shows the 2520's as slightly better actually. It really depends on the binning though. In this link there's a link to the binning specs and stuff where it says 'data & binning and labeling'. Then just look up the color temps of your cobs on the chart. Or post the item # of the cobs you got and I can help you figure out what bin they are.
    • Like Like x 1
  6. I orderd them at aliexpress, i think i'll have to wait till i have them to be sure what bin they are.
    If i would get the worst bin, would it still be worth it to make my grow light from them?
    He told me its CRI80, but i dont know the binning number. I send him a message and asked him.
    i bought these:
    10x originele cree cxa2520 oppervlak cob led emitting wit kleur met keramiek pcb gratis verzending in 10x originele cree cxa2520 oppervlak cob led emitting wit kleur met keramiek pcb gratis verzending van Licht Kralen op | Alibaba Groep

    20 of these only cost me 100 usd, do you think 2x cxb3590's could replace 20x xca2520? i will run the cxa2520's at 700ma.( hope thats not on the high side for them, since 1250ma is their max rated current.
    • Like Like x 1
  7. sounds good. Hopefully my pm answered everything. :)
  8. Sorry for the late reply. Ive been busy w my current grow over in 420mag forums. But i think i like grasscity better lol. Anyway, im sold on the quantum boards. But im confused on which driver to get, and if i should get all 3000k boards or mix them?? I plan to have a 4x4 room set up by late fall/early winter. Ill be busy enough til then.
  9. I went with 3000k. Some guys are mixing them but I think 3k does just fine. I run each single board off a
    HLG-120H-54A..that's the one that came with my 135w kit, so that's what I got to run my other single board off of. Just copy whatever kind of driver would come with the 'kit' you would be running.
  10. Kinda what i have been thinking. I don't know enough to know if a PC power supply would work or not.
  11. it could but chances are the voltage wouldn't be high enough..... roughly 36v per cob and they are run in series.... so like four in series would be about 154v.

Share This Page