Introducing CobKits.com - specializing in DIY and Citizen COBs

mooray

Well-Known Member
any cob can be run as low as 25W but the differences in efficiency at that wattage is minimal. you could pay 2-5X as much for a 'better' cob for little to no gain so more cheaper/smaller cobs is a good bet in that range

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That's a great chart. It tells me which four I'd get if I planned on turning them up to 60w later on, or which three I'd get for 80w. Those cxm22 that chill bought would probably hit my performance pricepoint as well.
 

Go go n chill

Well-Known Member
That's a great chart. It tells me which four I'd get if I planned on turning them up to 60w later on, or which three I'd get for 80w. Those cxm22 that chill bought would probably hit my performance pricepoint as well.
Yes the price point / performance is very respectable. The passive light engines he sells will also allow you run cobs at the higher sweet spot. No fans..... No noise and no fan failure. I like it! My vipar600 and Mars LEDs could get you through a grow with decent results but I want to see great results with less wattage. Tons of thanks to @CobKits .... He answered all my ????? And rapidly too. Thanks also to @Greengenes707 for answering ???? From a noobie.
 

GrayDizzle

Active Member
I had a driver question, wanted to get some professional answers ;)
The plan is to build 2x fixtures using 15-16x CLU048-1212 for a friend and I.

For his fixture... The requirements are only the highest lumens possible. Nothing else to consider.
Price isn't of much concern, efficiency even less.
The other fixture will just run multiple HLG-185H-c1050, nice and simple.. unless there's something better along that route.
Thanks in advance
 

GrowLightResearch

Well-Known Member
Anyone known about this cob? Cree CMA3090?
Drop in Replacement for CXA2
Cree claims up to 2.5x performance over CXA2

48V and 72V
174 Watts Max
7,300 – 21,700 lumens
48V Current Range: 1800 – 3600
72V Current Range: 1200 – 2400
3000K 80CRI, 72V @ 1.2A, 11,720 lm, 81W, 144 lm/W (85°C) $28.80 (100 pc DigiKey) CMA3090-0000-000R0U0A30H
4000K 80CRI, 72V @ 1.2A, 12,070 lm, 81W, 149 lm/W (85°C) $28.80 (100 pc DigiKey) CMA3090-0000-000R0H0A40H

LINK: http://www.cree.com/led-components/products/xlamp-leds-integrated-arrays/xlamp-cma3090
Datasheet: http://www.cree.com/led-components/media/documents/ds-CMA3090.pdf
 
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GrowLightResearch

Well-Known Member
LOL, 2.5X the hype maybe
I was wrong when I said "Performance". The press release said: "CMA LEDs deliver up to 2 ½ times the lumen density of Cree’s CXA2 LEDs"

Lumen Density is not an SI Unit.
There is a Radiant Density measured in Joules per cubic meter.

Often density is erroneously used in place of intensity.
Luminous Intensity is an SI unit measured in lumens per steradian
The SI Radiant Intensity is measured in radiant Watts per steradian at the spherical surface.
 
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GrowLightResearch

Well-Known Member
We'll see next year.......
L, 2.5X the hype
After researching Intensity, Radiance, Irradiance and Density I have concluded it has nothing to do with the efficacy.

It has to do with the PCB real estate.

What they are saying is if you had a fixture designed with the lowest efficacy CXAs and replaced them with the highest efficacy CMA you would get 2.5x more lumens using the same PCB real estate.

Example: both these CoBs have an LES diameter of 23mm
Existing: CXA3050-0000-000N0HW240F 5,043 lumens (51 Watt)

Replacement: CMA3090-0000-000Q0H0A40G 12,372 lumens (81 Watt)
5,043 x 2.5 = 12,607
 

Humanrob

Well-Known Member
@CobKits -- I've been trying to get to the bottom of the 80 vs 90 CRI thing, and my head is spinning a bit because it seems to depend on the kelvin and the application.

I'm rebuilding/adding to a light combination -- currently there are 4 (Cree 3070) 3000k COBs, and 2 (Cree 3070) 5000k COBs, and I'm going to be adding 4 Citi 1212's @4000k. I veg with the 5's and the 4's, and flower with the 4's and the 3's.

My question is: Would you recommend 80 or 90 CRI on the 4000k Citi's, and why?
 
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vidrose

Active Member
Hey cobkits, I had a question about the quantum board led's. Do you sell or can you steer me in the right direction on where to buy the individual samsung 561c led's. I found some on Digi-Key Part Number 1510-2184-2-ND

But im not sure if these would be the same as whats on the quantum boards.

Thanks.
 

CobKits

Well-Known Member
not sure, there are a handful of other threads about QBs and DIY samsung

thats a lot of soldering for most people. even with a reflow setup its a lot of placement
 

CobKits

Well-Known Member
@CobKits -- I've been trying to get to the bottom of the 80 vs 90 CRI thing, and my head is spinning a bit because it seems to depend on the kelvin and the application.

I'm rebuilding/adding to a light combination -- currently there are 4 (Cree 3070) 3000k COBs, and 2 (Cree 3070) 5000k COBs, and I'm going to be adding 4 Citi 1212's @4000k. I veg with the 5's and the 4's, and flower with the 4's and the 3's.

My question is: Would you recommend 80 or 90 CRI on the 4000k Citi's, and why?
are you vegging with the 4000K? not most peoples first choice for flower. ive got some 97 cri 4000k not up on site yet
 

Humanrob

Well-Known Member
are you vegging with the 4000K? not most peoples first choice for flower. ive got some 97 cri 4000k not up on site yet
When I started building COB lights, most people were mimicking HID, so I had 5000k for veg and 3000k for flower (pretty much the widest spread readily available at the time). Over time it seemed the trend shifted to finding a middle ground so that a single light could be used from start to finish, and looking at the charts 4000k was a good compromise in terms of covering the plants needs. Others went with 3500k or even 3000k for their single light. People who compared 3000k vs 4000k (for flowering) said the 4000k plants had less volume but were frostier, that works for me. I never did a side by side comparison myself.

I did a couple of grows with just 4000's and they were fine -- but now (in one tent) I'm mixing 4000k's and 5000k's for veg, and 4000k's and 3000k's for flower. My 4000k lights were stolen, so I need to replace them, that's part of what I'm shopping for.

In my other tent I've been growing with 3500k and 4000k from start to finish. I might add a couple of 2700k to that set up to warm it up a bit more during flower.

The discussions I've read regarding the impact of CRI seem to mostly be theoretical, and I don't have a lot of patience for that. I think I've read one or two threads on RIU where people have done side by side tests -- and what I took away from those were that with 3000k lights in flower higher CRI was preferred. I don't know if higher is always better in every kelvin range, so that's why I was asking.

What is the benefit of 97CRI?
 
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GrowLightResearch

Well-Known Member
where to buy the individual samsung 561c led's.
You may want to consider the Samsung F-Series Gen3 strips. At $14 for a 4 foot long strip it is very difficult to build your own for less than this.
They come in 2 foot and 4 foot with a single row (FB22B and F562B) of LEDs or dual rows (FB24B and F564B). Although the dual row has a better cost per LED the single row strips will cost a bout $4 more to get 2 single row strips verses 2 single row strips. With the single row strips you can improve your uniformity across the canopy. The improved uniformity will allow you to position the strips closer to the canopy.

The following post has a photo of a DIY fixture made with these strips posted by @graying.geek

Holy shit! I'm gonna need me some Foster Grants.

@Stone_Free recently comments about these strips as well.

The strips are very efficient.


DATASHEET LINK: https://media.digikey.com/pdf/Data Sheets/Samsung PDFs/F-series_Gen3_Rev0.0_2017-01-05.pdf
 
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