Matching Drivers and COBs

S

Solandras

Member
Solandras said:
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.
Click to expand...


Back when I entertained these, I did not know how COB's fit on drivers, in the sense of Fv. The COB's I had found on newark were a really good deal at the time, and I was hasty to make a purchase and start a DIY build.

Sadly, some of these COB's are no longer available, so I'm sticking with straight up CXB 3070 3500k BB, either 10 or 8 of them @1400ma in a 3'x3' tent. I can't figure out if I should stick eight or ten in, but I do know the optimal driver choice for both configurations.
 
alesh

alesh

Well-Known Member
Dr. Gruen said:
Hey there..i just bought a Hdlg 185h-1400a driver for my Little tent... 50 x 70 cm..

Also have some vero29 4k. 3 x

I m just asking myself if 3 veros Are too much for that Space..Shall i go just with 2 of them? Does it still work with the 185h ?

The Installation and cable stuff would also be easier with 2...


What Do the experts recommend?

Greetz from GER
Click to expand...
Install certainly all 3.
 
Danielson999

Danielson999

Well-Known Member
Dr. Gruen said:
Thanks for that...u have an idea how to do the positioning for the 3 Cobs with Arctic 11 and the Hlg ?
Click to expand...
Personally I would use the back half or 2/3's of your tent and grow a couple plants with the 3 lights directly above the center of your plants. 1 light directly above each plant and one halfway in between. I believe each cob would be about 59w at 1400ma. 180w over a 2x3=6sqft is 30w per sq foot. If you tried to fill the entire tent with plants you'd get 180w over 9sqft which would be 20w per sq foot, probable weaksauce.
 
YES I

YES I

New Member
Greengenes707 said:
I've been running on hlg240-36's for 5 months straight nonissue. Less than half watt difference is the worst I have put together.

Helps to test things in reality.
Click to expand...
hi green, im a noob looking to run the 240 hlg with 4 36v cxb3590s, maybe 2x this for a larger light, but im a bit lost as to the 240-36 model compared to the 240-1700/2100 models, what should i be looking at and what do you recommend ?
 
Greengenes707

Greengenes707

Well-Known Member
YES I said:
hi green, im a noob looking to run the 240 hlg with 4 36v cxb3590s, maybe 2x this for a larger light, but im a bit lost as to the 240-36 model compared to the 240-1700/2100 models, what should i be looking at and what do you recommend ?
Click to expand...
I was using the original 240's before the 240-c's were a made. It used to be the only way to get that kind of wattage out of a bar. You need to run in parallel to cut the current of the driver(6.7a/4cobs=1.675a each), which isn't recommended for a few reasons, that may or may not actually matter. But nevertheless... series wiring is the more fail safe method. So now that the 240-c's(1750 and 2100) are around, you can get that kind of power in series.
 
Danielson999

Danielson999

Well-Known Member
YES I said:
hi green, im a noob looking to run the 240 hlg with 4 36v cxb3590s, maybe 2x this for a larger light, but im a bit lost as to the 240-36 model compared to the 240-1700/2100 models, what should i be looking at and what do you recommend ?
Click to expand...
You can't fit 4 3590's on the 2100 model in series. 1700 or 1400 would be your picks depending on how soft you want to run them. 1400 would fit 5 cobs I believe.
 
alesh

alesh

Well-Known Member
Danielson999 said:
Personally I would use the back half or 2/3's of your tent and grow a couple plants with the 3 lights directly above the center of your plants. 1 light directly above each plant and one halfway in between. I believe each cob would be about 59w at 1400ma. 180w over a 2x3=6sqft is 30w per sq foot. If you tried to fill the entire tent with plants you'd get 180w over 9sqft which would be 20w per sq foot, probable weaksauce.
Click to expand...
Are you aware that 50x70cm is not even 2'x3'?
 
Danielson999

Danielson999

Well-Known Member
alesh said:
Are you aware that 50x70cm is not even 2'x3'?
Click to expand...
Being Canadian I am well aware of metric measurements. Being a stoner I was completely oblivious to his stated 50x70cm and put my own measurements in place for him. Joking aside, I swear I read 3x3 tent the first time I read his post. His tent is 20"x28" :)
Please disregard everything I've said and accept my nooblet apology.
 
S

STR8QU4D5

Active Member
I want to purchase 3590's CXB 90 CRI 3000K cobs, how could I drive the lights to 500 W per 4 cobs? What drivers are stable enough to do this? Im planning to use CPU coolers with fans on each cob because it will be cheaper than buying 36" heatsinks from HeatsinkUSA because of the duty fees and currency exchange.
 
S

Solandras

Member
STR8QU4D5 said:
I want to purchase 3590's CXB 90 CRI 3000K cobs, how could I drive the lights to 500 W per 4 cobs? What drivers are stable enough to do this? Im planning to use CPU coolers with fans on each cob because it will be cheaper than buying 36" heatsinks from HeatsinkUSA because of the duty fees and currency exchange.
Click to expand...

Why are you considering such a high CRI? Color rendering index is for our eyes. Lower CRI's give more PAR, I believe.

Look at the vF consumed for each COB at a certain mA, and see how many times a drivers max voltage can contain them.

example
COB "x" has a vf of 32 @ 1400ma. Driver has max voltage of 143v

143/32 = 4.46

One would be able to fit 4 of the COB "x", more than that would not fit on 143v driver

So, 32(4) = 128

Recall that the driver was 143v capacity?

143v-128v(there were from 4 COB "x") = 15vF you can still add to your driver in mono LED's


How large is your space? How much do you want to spread the light? From there you can determine the requisite drivers.
 
S

STR8QU4D5

Active Member
Solandras said:
Why are you considering such a high CRI? Color rendering index is for our eyes. Lower CRI's give more PAR, I believe.

Look at the vF consumed for each COB at a certain mA, and see how many times a drivers max voltage can contain them.

example
COB "x" has a vf of 32 @ 1400ma. Driver has max voltage of 143v

143/32 = 4.46

One would be able to fit 4 of the COB "x", more than that would not fit on 143v driver

So, 32(4) = 128

Recall that the driver was 143v capacity?

143v-128v(there were from 4 COB "x") = 15vF you can still add to your driver in mono LED's


How large is your space? How much do you want to spread the light? From there you can determine the requisite drivers.
Click to expand...
Thanks for the info. The space is 15x8x8. But I basically want to have the equivalent power of 8-1000W HPS, or 16-500W LEDs. Even 16-400W units is fine. In regards to the CRI, I figured having more of the deep reds and more of the blue would be more beneficial. Do you think the 80 CRI is better for yield?
 
Last edited:
bassman999

bassman999

Well-Known Member
No doubt the cobs can handle that power, but defeats the point of using cobs IMO, since efficiency is reduced so much.
CXB 3500K.png The CD bin CXB3590 is under 50% efficient at 2.1A, and just over 43% efficient at 2.8A.

At those driver currents might as well use the Vero 29 V2.0 as they about the same efficiency at those high drive currents and half the price, and dont require mounting brackets
 
Last edited:
You must log in or register to reply here.
Top