MMJ Dreaming 99
Well-Known Member
May I ask where you get them? EBay? How many $12 to 15 COBs will it drive? Thanks.
nfhiggs
Well-Known Member
Yes, I also find that more than a bit amusing.
nfhiggs
Well-Known Member
Yes, I get them on Ebay. I've got one running 8 cobs at about 34v/1 amp each.
MMJ Dreaming 99
Well-Known Member
If I email you at your site - can you give me a parts list for what is needed in Citizen COBs to take on a 1000 watt HPS for flower (3000 or 3500K)? O think that would be a good addition to your web site.
CobKits
Well-Known Member
9 cobs at 75W each, ~$550 including shipping and $30-$40 to build a frame. drivers have gone up a little since i did that screenshot as i went thru the huge stash of overstock.
i hope to have frames soon if i can get the cnc mill up and running
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muleface
Well-Known Member
@CobKits on the Getian 2828's in the 37.5 range, what did you say the l/w were at 45-50 watts?
also, this was a good discussion thanks for everyone's input...
I do have another question.
if i had 2 drivers and 4 - 36 v cobs, what is the difference here....
HLG-240H-C1050 running 4 cobs
HLG-240H-C1400 running 4 cobs
would it make any difference using one driver vs the other?
also, this was a good discussion thanks for everyone's input...
I do have another question.
if i had 2 drivers and 4 - 36 v cobs, what is the difference here....
HLG-240H-C1050 running 4 cobs
HLG-240H-C1400 running 4 cobs
would it make any difference using one driver vs the other?
CobKits
Well-Known Member
Well sure its considerably different in both efficiency and output wattage to run cobs at 1050 vs 1400 mA. and you can put prob 5 on the 1400 and 6 or 7 cobs on the 1050. overall wattage will be similar, but the 1050 will be more efficient (at teh cost of more cobs/holders and potentially heatsinks depending on your setup
muleface
Well-Known Member
but if you were just running 4 on each driver, would it matter?
either way, could you provide a deep dive explanation on this? Honestly, i would like to see something like that here posted as sticky on the front page of the LED forum. Its the questions everyone asks and they get explained all over this forum, but in one off discussions. Not in a central place where everyone can just point to it for newbies.
I get how FV and wattage work.
an HLG-240H-c1050a puts out 119-238v so you could run 6 - 36v cobs on this in series. 238/36=6.6111 each cob would run at 40 watts (probably a bit more, i've noticed that a 240h will put out more then 250 watts)
I think in this setup each cob is running at 1050ma, if you did the same setup in parallel each cob would run at 175ma?
CobKits
Well-Known Member
start by looking up actual forward voltage at the current you want to run at. Vf at 1050 will always be lower than 1400 for any chip
or you can use the easy way- the tables at ledgardener.com
or you can use the easy way- the tables at ledgardener.com
if you did the same setup in parallel it probably wouldnt light up as youd be below the minimum driver voltage of 119V or whatever
CobKits
Well-Known Member
you'd just have some unused driver capacity. efficiency can dip at low loads on some drivers but its not a lot, a few % at most
Budies 101
Well-Known Member
From my understanding a cheap cob can be less than half as good as a good/decent cob. Basically, to get the same growth you will be running near 2x the watts and heat just to save what, 20-30% of the build cost? I mean, you will still need a driver and heatsink (possibly bigger heatsink) and all other minor cost parts. If that's the route you;re going, why not just take less risk of poorly made cobs and just use HPS/MCH?
I'd suggest buying mid grade cobs before buying trash cobs... Buy somthing you know lights up. I believe you can get cax3070s (top bin) for like 15$ off kingbrite, that's like 60$ for 4... That's a 240 watt possible light for apporx 200$. Again, if you buy 2 dollar cobs it might take you 8 to get near the same growth, double the heat, double the watts, more heatsink and who really wants to grow under blurple?
I don't know much about other Cobs but Citizen look good too and are way less $$.
You don;t HAVE to grow with CXB3590's top bin to grow extremely well, it's mostly for efficiency at that point and really only slightly better in the end.
Feel free to correct me if I'm wrong.
I'd suggest buying mid grade cobs before buying trash cobs... Buy somthing you know lights up. I believe you can get cax3070s (top bin) for like 15$ off kingbrite, that's like 60$ for 4... That's a 240 watt possible light for apporx 200$. Again, if you buy 2 dollar cobs it might take you 8 to get near the same growth, double the heat, double the watts, more heatsink and who really wants to grow under blurple?
I don't know much about other Cobs but Citizen look good too and are way less $$.
You don;t HAVE to grow with CXB3590's top bin to grow extremely well, it's mostly for efficiency at that point and really only slightly better in the end.
Feel free to correct me if I'm wrong.
xX_BHMC_Xx
Well-Known Member
My CLU038s were $7 a pop, come from a quality manufacturer, and deliver 160lm/w(ish) at 700ma. Plus they're good all the way up to like 2.1a. I see no reason to waste money on low quality parts, regardless of where they come from.
muleface
Well-Known Member
can you give us a link to the specific chips you are running. $7 seems like a really good price.
xX_BHMC_Xx
Well-Known Member
https://led.cdiweb.com/ProductDetail/CLU0381208C4303M2K1--citizen/590599/
I'm running a mix of 3000k and 5000k. Check my sig for the thread. Holders for these are a little harder to find, but they are definitely out there. Citizen has a COB for every budget and application. Lots more than the 1212 or 1818
I'm running a mix of 3000k and 5000k. Check my sig for the thread. Holders for these are a little harder to find, but they are definitely out there. Citizen has a COB for every budget and application. Lots more than the 1212 or 1818
nfhiggs
Well-Known Member
The perceived shortcomings of the "trash cobs" are greatly exaggerated:
1. Yes, they are less efficient - 100-110 L/W or so at full power compared to 150 L/W or so for the "good" cobs. But if you run them at 30-50% you can get into the 120-130 L/W range - not fantastic but comparable to MH/HPS efficiency. So the whole "twice the watts and heat" is just an exaggeration. They will run fine on "regular" sized heat sinks.
2. The supposed reliability issues are also greatly exaggerated thanks to one youtube video. I've purchased 20 of these and have not had one issue with any of them - NONE. They work. They have been working continuously for 6 months now.
3. They come in warm white, they are not all "blurple".
Cheap cobs are a good way to get your feet wet, and experiment a bit to find out what works and what doesn't, instead of simply following the herd. The great thing about the 2 dollar cost is you can easily replace them later with more efficient cobs and not feel like you're throwing away a ton of money.
REALSTYLES
Well-Known Member
well guys it's official CXB3590 now $33 from me lol so why waste money?