Introducing CobKits.com - specializing in DIY and Citizen COBs

kaivorth

Active Member
Finally have everything I need to start building. Working on the frame first, everything should be downhill from there. Man, .125 thick aluminum is not easy to cut by hand with a hacksaw!
 

apollo4201982

Well-Known Member
heatsink seems on the smaller side. maybe try a similar profile in @bggrass 's calculator and see what length it gives you
I can't seem to view the calculator, what part of my heatsink seem small? Is it not wide enough? Long enough? Thick enough? If I had 2 or 3 fans mounted to the heatsink would it work?

There is a good price difference in the price of the different size heatsink and I'm trying to save a few bucks if I can.
 
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CobKits

Well-Known Member
calculator is here: https://www.dropbox.com/s/2s0xo583lw10m29/CitiCalculator.jar?dl=0

i uses 1818 which are similar, 85C Tj, 1050 mA, 3.5" heatsink use profile (which may or may not be similar to yours:

1818 3000K80Min 3 COBS @1050 mA ON 3.5 PROFILE HEATSINK
5 SQ.FT. CANOPY 93% EFFICIENT DRIVER @10.5 CENTS PER KWH
Total power watts at the wall: 168.63
Cobs power watts: 156.82
Total voltage forward: 149.36
Total lumens: 23000.37
Total PAR watts assuming 10% loss: 63.11
Total PPF: 340.80
PPFD based on canopy area: 733.66
PAR watts per sq.ft.: 12.62
Cob efficiency: 44.71%
Power watts per sq.ft.: 31.36
Voltage forward per cob: 49.79
Lumens per watt: 146.66
Heatsink riser thickness / number of fins / fin's length: 0.3in/8/0.75in
Heatsink area per inch: 126.42 cm^2
Total heat watts: 86.25
umol/s/W: 2.17 LER: 328.00 QER: 4.86
Heatsink length passive cooling @120cm^2/heatwatt: 82 inches
Heatsink length active cooling @40cm^2/heatwatt: 27 inches

Heatsink cost per inch cut: $1.15
Total cobs cost: $69.0
Total heatsink passive cooling cost: $94.30
Total heatsink active cooling cost: $31.05
 

RandomHero8913

Well-Known Member
Hey CK, I recently grabbed a Gen 6 CLU048-1212 5700k from you and had a general question about the new generation: Is 90CRI 6500k a thing?

I grabbed the 5700k to replace a CXB3590 3500k that I don't trust using anymore and also to try and even out the spectrum a little. It will go on a fixture with 5 other 3590's, one 6500k and four 3500k all ran at 700ma. I also just added four Samsung 282C M-series hardstrips at 5000k and testing out some Mono's in the center.
 

CobKits

Well-Known Member
Hey Cobby, I am going to change out my 6 2700k 1212 90cri with either 1818 gen6 3k 90cri or cxm22 3k 90cri, between those two which one would be the biggest step up, i know they are probably pretty close.
id have to guess pretty close and cxm22 cheaper. if gen 6 has an edge its not by much and of course it costs more.

im plan on running these one the same driver a hlg 185a....that will be fine right?
it will be better than fine. with the 36V 1212s the 185-48a is only pushing 150-160W. with the 50V cobs you'll get 200-220W out of it.
 

Bustos

Well-Known Member
I have been trying like crazy to get these calculators to work... what program do i need to tell to open it?

i see other folks have the same problem but i never saw anyone have a solution... ???

Anybody ????

Also I got my 6 1825 cob engines and the drivers and i have attached the wiring and am hanging them as independent lights rather than as a rack mounted lighting fixture, and i really love these babies....but the plants love em more. fan leaves are facing off as if basking in the NON- sunlight... as good as it gets in the tent.

Thanks man appreciate your work and business.

from the great white north.... it is me

haha i had to edit to get my writing out of the quote... arrrrrrrgh
 

Bustos

Well-Known Member
I have been trying like crazy to get these calculators to work... what program do i need to tell to open it?

i see other folks have the same problem but i never saw anyone have a solution... ???

Anybody ????
OK now i feel like a fool i got it to work now....

head hung down in shame
 

The Dawg

Well-Known Member
Quick question,can I mix 80 and 90 cri citizen 1212s on the same driver? And can you help me understand the difference?
Short Bus Answer Yes :hump: Difference Is The 90 Cri Has More Red And Less Blue And The 80Cri Has More Blue And Less Red. Both Will Flower However I'm Noticing A Tad Bit More Stretch With The 90 Cri Than The 80 Cri :peace:
 

apollo4201982

Well-Known Member
So if I'm building both a flower and a veg light the 90cri would be better for flower and the 80 for veg. Thanks man you rock.
Short Bus Answer Yes :hump: Difference Is The 90 Cri Has More Red And Less Blue And The 80Cri Has More Blue And Less Red. Both Will Flower However I'm Noticing A Tad Bit More Stretch With The 90 Cri Than The 80 Cri :peace:
 
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