Matching Drivers and COBs

OK so I am in the process of ordering (4) cxb3590 3500k 36v cobs and a mW hlg-185-1400b driver. My question involves passive vs active cooling. Would it be safe to assume that with active cooling the cobs are less hot? Meaning they could be setup closer to the canopy vs passive cooling?

Or would that only dictate the size of the heatsink needed?

Rahz said:

Those look nice, but there's more orange/green and far red so there's no obvious answer as to whether it would be better. Low CRI is hitting the peaks pretty good already, much better than the Sun actually. The ideal spectrum and whether/how much it should deviate from the Mcree curve is debatable.

Blurple is a strong deviation. Sunlight is also a strong deviation in the opposite direction. Perhaps lower CRI is where it's at? No obvious answers.

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You're echoing my suspicion that just because it's sunlight it doesn't mean that it's automatically the ideal spectrum balance for plants. If 80 CRI chips can cover the bandwidth bases better, then why wouldn't they produce better?

chinuh man said:

Or would that only dictate the size of the heatsink needed?

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This is the correct answer. Heatsink will only cool the chip itself, not its output.

Bonjour
You could go semi passive...I mean take a big hs...half way between passive and active...big enough... in case of fan failure not enough heat to fry your "eggs"!
I have a 250x165x35mm(10x6.6x1.4) 14 fins for 1 cxb 3590 @1400mA with a 120mm fan @7V on it...without the fan the hs is hot but I can let my hand on it...so not too hot imo!
Have a great day ★

Thank you both @ttystikk and @littlejacob for the info.

I wanted to make all of my first cobs passively cooled with each one having its own heatsink. I will fabricate an aluminum frame to hold all 4 cobs. Then run all wires to the driver thru the frame.

Is there a link to the formula for how big of a heatsink I should use per cob? I wrote down in my notes somewhere that @SupraSPL recommends 120cm²/W of heat. Is there a formula for this?

Bonjour
I believe everyone know I am bad at formula...I calculate very fast but no much...SO
Heatsink for diy thread is where you going to find it!
Or heat sink in Europe thread...
Have a good read...

SupraSPL said:

This 5000K CXA2540 looks even better
@350mA (11.8W) 56.7% efficient and cost $1.52/PAR W
@700mA (24.7W) is 47% efficient and cost $0.87/PAR W

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Howdy all. First post.

How many CXA2540's ran with a HLG-120H-C350 (which can run 12 CXA2540's @ 56.2% efficiency, from what I understand) would be needed for a 4x4 veg tent?

Should I run 24 @ 350ma? (12 per driver)
Should I run 16 @ 500ma with 2 HLG-120H-C500 drivers? (8 per driver)
Should I run 12 @ 700ma with 2 HLG-120H-C700 drivers? (12 per driver)

I'm having a difficult time determining how to calculate the amount of light being produced by these configurations, and what would be requisite for a vegetative environment.

Been lurking on the COB threads for the past two months, and am getting very close to ordering parts for the first build. I am planning on having two 4x4 tents, one for veg and one flower. They'll both be Gorilla tents.

I'm first determining the vegetative setup, but will be purchasing all of my COB's on discount clearance from newark. I can go into what I plan for the flowering environment as well, but I'd rather save that for another post. I'm trying to determine the best efficiency driver for the other COB's in the flowering tent.

I'm checking my dump for heatsinks, to see if there is anything viable, and have an eye on "no name" heat sinks online as well. Heatsinkusa is an option as well.


Just to spill the beans a bit more, and reiterate-

2 4'x4' tents

Veg
CXA 2540 5000K

Flower
CXA 3050 3500K
CXA 2540 3000K

How many would I want for each 4x4 space, and what amount of light is requisite for each of the tent conditions for the COB's? I would rather set up more COB's and run them at a lower ma if that increases the efficiency. Seeing that I can fit 12 CXA 2540 5000K on a HLG-120H-C350 is quite nice, I must say.

I want to thank all the people who have contributed to discussions and submitted information about their DIY so far. I have a lot of respect for SupraSPL, GreenGenes, StarDustSailor. There are many others I can't think of off the top of my head.

Oops. I meant 12 @ 700ma with 2 HLG-120H-C700 drivers? (6 per driver)

Solandras said:

Oops. I meant 12 @ 700ma with 2 HLG-120H-C700 drivers? (6 per driver)

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I did a build that may be of some value to you. It uses cxa2530 (same fv as the cxa2540) I went with (20) cobs total 10 per hlg185h-c500b.

Bonjour
So you use 20 cxa 2530 (which bin?)
Is it 5000ºk?
So it is 400w @500mA for a 4x4 vegg light!???
Have a great day ★

littlejacob said:

Bonjour
So you use 20 cxa 2530 (which bin?)
Is it 5000ºk?
So it is 400w @500mA for a 4x4 vegg light!???
Have a great day ★

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I am using these chips from Fasttech. the light was built to cover 5x5 but actually has fine coverage at 5.5' x 5.5' when hung high enough.

@Growmau5
Your Veg panel inspired my 1st venture into LED DIY grow lights. I purchased the fasttech chips and also the 3000k from newark. I will post a thread once all the parts arrive and the fixture is built. Just wanted to chime in and say thanks for the video.

Cheers,
Will

Here is a question not cob related but LED burple related i just got a smoking deal on some 192 x 3 watt led unit how or what can i do to clock this unit i mean 75,000 hrs of life time could i not clock it to possible 50 ,000 hrs by bringing up the power can a person add another driver or does he need to change the driver out ??? i might be also looking at possible re figuration meaning maybe adding this unit and designing another unit cob and intregate them both into one unit be like having this LEd unit in the middle and making like a spider style attachment where i can have like 8 cobs surounding it like octagon but move able arms ??? any thoughts
guessing i just wait for unit and open it up an see what drivers are there and upgrade them to punch out more from the 3 watts or am i thinking totally wrong

Darth Vapour said:

Here is a question not cob related but LED burple related i just got a smoking deal on some 192 x 3 watt led unit how or what can i do to clock this unit i mean 75,000 hrs of life time could i not clock it to possible 50 ,000 hrs by bringing up the power can a person add another driver or does he need to change the driver out ??? i might be also looking at possible re figuration meaning maybe adding this unit and designing another unit cob and intregate them both into one unit be like having this LEd unit in the middle and making like a spider style attachment where i can have like 8 cobs surounding it like octagon but move able arms ??? any thoughts
guessing i just wait for unit and open it up an see what drivers are there and upgrade them to punch out more from the 3 watts or am i thinking totally wrong

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your going to cook those sad little leds cranking up the current.I've never seen one of those little units adequately cooled they usually just have a thin plate

got a link?

i am just inquiring being there usaly under driven to begin with arent they ??? bumping it up a little and being 3 watts chips heat wouldn't be much of a issue being i think it would disperse better then 5 watt chips i am just wondering of course it will cuts its life expectancy

Darth Vapour said:

i am just inquiring being there usaly under driven to begin with arent they ??? bumping it up a little and being 3 watts chips heat wouldn't be much of a issue being i think it would disperse better then 5 watt chips i am just wondering of course it will cuts its life expectancy

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they are under driven for a purpose
Still no link?

i don't think it's much of an inquiry as it is your plan. I'm a little suprised thought you would have learned more by now you seem like a sharp guy

KarmaPaymentPlan said:

they are under driven for a purpose
Still no link?

i don't think it's much of an inquiry as it is your plan. I'm a little suprised thought you would have learned more by now you seem like a sharp guy

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LED Configuration: 192 x 3w Epiled Diodes
Power consumption: 350watts
Lumens: 13,000
Lifespan: 75,000 Hours
Color: Blue, Red & White
PAR Test Results @ 2ft: 800 µmol/m2/s
Wavelength/Spectrum: 430~440nm, 450~475nm 620~630nm, 650~660nm, IR, and white
HID/HPS Equivalent: 800watts
Suggested Lighting Area: 1.4m²
Dimensions: 48x56x7cm
Weight: 11kg

Darth Vapour said:

LED Configuration: 192 x 3w Epiled Diodes
Power consumption: 350watts
Lumens: 13,000
Lifespan: 75,000 Hours
Color: Blue, Red & White
PAR Test Results @ 2ft: 800 µmol/m2/s
Wavelength/Spectrum: 430~440nm, 450~475nm 620~630nm, 650~660nm, IR, and white
HID/HPS Equivalent: 800watts
Suggested Lighting Area: 1.4m²
Dimensions: 48x56x7cm
Weight: 11kg

Click to expand...

Bonjour
350w of 33lm/w led equal to 800w hps...lol
Even with cxb 3590 you need 500/550w to equal 800w hps!
It look like a mars panel...
And 192x3w diodes put out a lot of heat if not cooled properly!
And I bet it is less efficient than a hps!
Why don't you diy some cheap cxa or vero? There is many easy way to diy... (self taping screw/wago/thermopad/cpu cooler/kapton tape...)
I am hairdresser...so far from an electrician...and I had never built anything before...but with the good advices peoples gave me here and all the informations available here I was able to do it...and so far now everything run perfectly and I really love my new lights! (It work well for vegg too! With 3500ºk I was not sure but I was wrong! )
Go for 3590 you will never regret it!
Have a great day ★

Darth Vapour said:

LED Configuration: 192 x 3w Epiled Diodes
Power consumption: 350watts
Lumens: 13,000
Lifespan: 75,000 Hours
Color: Blue, Red & White
PAR Test Results @ 2ft: 800 µmol/m2/s
Wavelength/Spectrum: 430~440nm, 450~475nm 620~630nm, 650~660nm, IR, and white
HID/HPS Equivalent: 800watts
Suggested Lighting Area: 1.4m²
Dimensions: 48x56x7cm
Weight: 11kg

Click to expand...

o no lj is right those are mars lights. ...Darth you should know better i started with some of the smaller versions and no way would i push more power into those silly lights. I'm actually pretty bummed i was hoping to see you purchase a product you could be proud of