Introducing CobKits.com - specializing in DIY and Citizen COBs

CobKits

Well-Known Member
yes 70-75W per cob is a good range, works well with 133mm heatsink

240h-54B also good if you need remote dimming, and has slightly larger current
 

aknoob

New Member
Hello everybody. I have 2 older LEDs with some burnt out led chips. I thought about replacing them but found COB leds. I was researching on how to build my own cob leds for 4x4x8 grow tent. Living in Rural Alaska it is hard to find the metal to build the frame because we don't have hardware stores locally. The shipping for the metal is also crazy expensive.

I stumbled upon a Mars to Cree conversion and was thinking about converting two older LEDs. I think these are both Chinese drivers :



For the orange ones I was thinking Luminus CXM22 Gen3 3000K 90 CRIs. The orange ones will also be powering a computer fan that was set up included with the LEDs.

Would the black one be able to run a Citizen CLU048-1212 90CRI GEN5 - 3000K okay? Is the stated 45-75v output too much for the 1212? I will be converting the black driver one first which has 4 TURE FULL drivers and I will put 4 - 1212 in it if possible. My budget is a couple hundred dollars. I do not utilize all the 4x4 space to grow at the moment so I am not worried about the spread of the light.

 
Last edited:

PurpleBuz

Well-Known Member
i love my korad

ive blown up some cheaper ones, this is built like a tank

https://www.amazon.com/KA6005D-Precision-Variable-Adjustable-Regulated/dp/B00G0HAY3U

not available at that link but you can find their site pretty easily. i think they are also on ebay
all I could find at a reasonable price is the programmable version. any idea if that's as well built ? I don't need to hook it up to my laptop.

if I mail you some Nichia cobs can you do a performance comparison to comparable cobs citizen, lumina or cree ? The citizen scandal has me wondering ....
 

CobKits

Well-Known Member
if I mail you some Nichia cobs can you do a performance comparison to comparable cobs citizen, lumina or cree ? The citizen scandal has me wondering ....
sure if youre patient. will take me weeks to get to it. i can pick a single well known cob and run it against it

FWIW of course confidence in LM80 data is an issue but from what i read it seems they falsified it because they screwed the test up, not because they were trying to make the chips look better than they are. the translation was hard but i read something about the power going out in the middle of the (multi-year) test which would invalidate it i guess

in any case the citi cobs are very consistent they always seem to test as expected, ive tested many samples of all different sizes and colors in both gen 5 and gen 6. While i dont have a calibrates if you want to be a worry wart about things that will have zero impact like LM80 data 10 years from now on a cob youre running at 40% of max current, then buy luminus ;)
 

CobKits

Well-Known Member
For the orange ones I was thinking Luminus CXM22 Gen3 3000K 90 CRIs. The orange ones will also be powering a computer fan that was set up included with the LEDs.
at 700 mA 2 luminus will be just under 100V so you wont have any voltage left for a fan. i assume that fan was already running off that driver and 700 mA is good for it. does the fan have a voltage on it?

Would the black one be able to run a Citizen CLU048-1212 90CRI GEN5 - 3000K okay? Is the stated 45-75v output too much for the 1212?
well the chip only wants 34-35V or so at 700 mA. so the chip will be ok but the driver might not like it

2 citis on that would work fine though and youd have 6-7V left over for a fan if needed
 

aknoob

New Member
at 700 mA 2 luminus will be just under 100V so you wont have any voltage left for a fan. i assume that fan was already running off that driver and 700 mA is good for it. does the fan have a voltage on it?
I was planning on one luminus per driver for the orange power supply. The fans are 12V 0.25A I do not like how the cooling was set up for this grow light. Only fans with no passive heat transfer unless the case does it good enough. The led pcb boards are connected with some sort of thermal pads. This was a hot led and I think it would have benefited with some sort of passive heat sinks connected at least under the fans. 800+ dollars per led I think the manufacture had a very low overhead and made a pretty good profit. If they were soldering each one of the led chips by hand I can understand the cost, this was not one of the huge led providers. Was a pretty good LED for the price but I do not want name the manufacture.

well the chip only wants 34-35V or so at 700 mA. so the chip will be ok but the driver might not like it

2 citis on that would work fine though and youd have 6-7V left over for a fan if needed
I think that it would be easier to just upgrade the cobs to a higher voltage for the Mars 300 size. I will have 4 as far as i can get them to the edge. I know that I want 3000k 90 CRI for flowering maybe I will use it for the ones with the orange drivers. I don't know if I want a higher kelvin for vegging or if I want to use only 3000k for both veg and flowering. Should I stick with Luminus or pick a later Citizen than 1212 with higher voltage?
 
Top