Build Using CLU048-1212C4 COBS. Advice Needed :-)

Hello! I just wanted to get some opinions. I pretty new to making my own electronics but took some classes in high school so I'm familiar with some terminology (ohm's law, etc).

I'm pretty set on the COB's I want to use unless anyone has had a terrible experience with Citizen cobs. I'm wondering which driver to go with. Should I run these cob's soft (700ma) or no?

Links are available if you hover over names.

The COB of choice:

CLU048-1212C4-353M2K1 (spec sheet): I'm thinking of buying 10 cobs.

Drivers I'm looking at:

HLG-320H-C700B- spec

HLG-240H-C1050A-spec

Thanks for any assistance in advance!

@ cobkits This guy needs help...
www.cobkits.com

@HydoDan Thanks!

HydoDan said:

@ cobkits This guy needs help...
www.cobkits.com

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if youre married to a constant current driver see the voltage chart at https://cobkits.com/product/meanwell-hlg-320h-c/

there are no holders that are rated for the 428V the 320-700 puts out- youd have to solder the chips.

you can fit 6 1212s on a 240-1050. its 238V. so maybe bump up to 12 chips and do 6+6. im supposed to get the 250V ideal holders at the end of this week

of course you can avoid all of that by using a constant voltage driver- hlg 320 36B would run those 10 @ 0.89A. id personally rather do that than have 400DC V anywhere near a grow

https://cobkits.com/product/meanwell-hlg-320h-36b/

@CobKits Thanks for the insight.

I think the best route is to go with Constant Voltage. Are there any drivers that can drive a stronger current to the cobs? I heard that these chips can handle stronger currents quite effectively so, I would like to have a stronger current than .89A. Then again, I'm a noob lol. What are your thoughts? How efficient are these COB's at .89A?

klmccao4 said:

Are there any drivers that can drive a stronger current to the cobs?

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yes same drivers just run less cobs per driver

the 36B can do 10@890 mA, 9@990 mA 8@1110 mA, or 7@~1250MA before it tops out at 36V. you wanna run hotter than that you want a 36A or 42B. im gonna recommend an 1818 above 50W anyway, at which point youre into a 48A or 52B constant voltage

klmccao4 said:

How efficient are these COB's at .89A?

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pretty efficient. 50-55%ish depending on color which aint bad at 0.30/Watt chip cost

Gotcha, thanks again!

Do you guys know of any grows using citizen COB's? I've been looking everywhere and it seems to be threads with chatter but no grow.

yeah theres several on here
dawg
napalm
etc.

can you @ them so I can take a look?

same as any other cob grows really. results commensurate with grower's skill level

https://www.rollitup.org/t/northern-grow-lights-photon-180-clu1825-grow.915159/page-5#post-13045691

https://www.rollitup.org/t/dawg-house-productions-presents-citizen-cob-1812.922557/

Wow Those are really impressive!

Another question. What are my heat sink options for these cob's? I work in IT and have access to heatsink and fans. I know its a shot in the dark but could I possibly use those?

sure computer cpu+fan combos are often enough to run up to 150W+ per cob. just gotta take the time to drill and tap them

CobKits said:

pretty efficient. 50-55%ish depending on color which aint bad at 0.30/Watt chip cost

View attachment 3813447

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Did you make this chart? If so, please tell me the details of how you measured the PPFD. Thank you.

single measurement at 12" on axis with a li-cor li-190

CobKits said:

single measurement at 12" on axis with a li-cor li-190

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Thanks for the details. That has kind of become the standard on this site for measuring cob photon output.

not for long! im getting my sphere this week

more accurate total lumen/par measurements essentially

more accurate spectral readings that we can digitize

the net effect is being able to compare manufacturers claims with actual performance. particularly in regard to the fact that sometimes we tend to operate at low currents not typical of manufacturer's intended use, and this is not always accurately represented in their data sheets. for example cree provides no data at all below 1.4A for cxb3590, or in some cases, like the new vero simulator, the data is just wrong for low currents.

other manufacturers are more conservative in reporting their data. so of two manufacturers with identical numbers on paper, one may be putting a more efficient product out the door.

what about variations? mfrs may spec +/- 10% in flux but put out product that is +/- 3%

what about spectral shift at different currents? etc

basically a learning tool for us to generate the large amount of data we need to make informed decisions without paying per test at a light lab. and it doesnt even have to be perfect light-lab standards. any significant trends we see can be verified in a more controlled test in a certified lab if desired, but weve eliminated the cumbersome and expensive scoping work to weed it down to the top few chips or conditions we wish to observe

CobKits said:

not for long! im getting my sphere this week

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any link?

ill do a thread when it gets here. but heres a little info:
sphere is a 20" hoffman sphereoptics. it has a (slightly larger than) 2" port that i can fit a chip up to the size of a vero 29 or clu058 inside. I plan on building a waterblock to mount the chips to for accurate thermal measurements. the sphere has a photodiode but im lacking a picoammeter to read it right now. while i figure that out im just going to mount my li-cor in there somehow for now to take direct par measurements

measurement tools available:
licor-li190+li250a
ocean optics usb 2000
ikan/uprtek mk350s

calibration tool:
ocean optics ls-1-cal tungsten lamp with software

thats where its at as of now