Introducing CobKits.com - specializing in DIY and Citizen COBs

robins my bro love that guy

your light is gonna get a plywoodboard. to sit in the middle of my 2 cxas on cpu coolers then im just gonna zap strap the drivers in a row and mount a clip fan above them for cooling... it'll look redneck as fuck. but it should be well isolated for shock.

CobKits said:

well what is "better"?

1812 is $6 cheaper per chip
1818 is ~7% more efficient but more expensive

View attachment 3801941

1818 def a way better voltage profile for a hlg-48A driver if you want to run them hot
1812 will top out at 1250 mA/67W
1818 will go to 1900 mA/102W on same driver
(1825 goes to 2700 mA/145W)

Click to expand...

put 3200 mah in the calc and look at the f/v on the 1825.. this is why i want the 185-54 over the 48...unless the 48 can handle 55 volts

HolyGhost23 said:

your light is gonna get a plywoodboard. to sit in the middle of my 2 cxas on cpu coolers then im just gonna zap strap the drivers in a row and mount a clip fan above them for cooling... it'll look redneck as fuck. but it should be well isolated for shock.

Click to expand...

you know how i know youre a fake redneck? no stolen aluminum street signs in your garage to use for heatsinks

HolyGhost23 said:

put 3200 mah in the calc and look at the f/v on the 1825.. this is why i want the 185-54 over the 48...unless the 48 can handle 55 volts

Click to expand...

as i mentioned it tops out at 2700 ma/53.5V on that driver, so yeah - you got it right for sure.

CobKits said:

you know how i know youre a fake redneck? no stolen aluminum street signs in your garage to use for heatsinks

Click to expand...

Hey now there's an idea!! Lol Jk.

CobKits said:

you know how i know youre a fake redneck? no stolen aluminum street signs in your garage to use for heatsinks

Click to expand...

i could use a heater core from my pick up and a cpu water block....i don't live near many road signs..so maybe im way more of a redneck than you think.

CobKits said:

as i mentioned it tops out at 2700 ma/53.5V on that driver, so yeah - you got it right for sure.

Click to expand...

if you look at the lm/w the 1825 is the best at that amperage. so if you get me a 185-54 ill buy your 1825 light "engine".. i might swap out the fan for a Peltier cooler to it .. to experiment.

also runs cooler than the other chips.

VenomGrower6990 said:

Hey now there's an idea!! Lol Jk.

Click to expand...

lol i was talking with an riuer recently about the old days and he was like "im pretty sure my first growlight was a construction light stolen by my bros"

the good old days where you doubled back around on your drive to the hydro store

HolyGhost23 said:

i could use a heater core from my pick up and a cpu water block....i don't live near many road signs..so maybe im way more of a redneck than you think.

Click to expand...

cmon man. i dont know many rednecks who run more than 4-6 deep on heater cores in their front yard, what you gonna do when you run out?

CobKits said:

lol i was talking with an riuer recently about the old days and he was like "im pretty sure my first growlight was a construction light stolen by my bros"

the good old days where you doubled back around on your drive to the hydro store

Click to expand...

I'm sure a light bulb just went off in a few peoples heads

I was listening to DIY Tech Talk#2 on Greengenes Youtube channel with Greengene, Growmau5 and Robin. I found out that i prob should have went with the 80CRI instead of the 90CRI because i was looking at the calculator on Citizen and i actually lost like 27-30 Lumens/watt by going with the 90CRI because of the added phosphor in the 90CRI chip. I guess they were saying that the added little bit of far red is not worth the loss. It makes sense after i went and looked at the numbers. The 90CRI chip only adds a sliver of extra red at the end of the spectrum but at a bigger loss in Lumens/watt. Also causes a pretty substantial loss in the 620-630nm range from the spectrum chart they were showing. What is your take on it @CobKits?

thats debatable. look up emerson effect. i think the jury is still out on 80 vs 90 cri

Hey CobKits,

Wondering what's the best driver you supply for running 1212's without leaving "open room" in the driver. I've tried doing some calculations and it always looks like i'll never be able to use the full potential of say an HLG185 with 1212's because of the voltages.

Any ideas?

yup, you can get 150-160W out of it, still not a bad deal for $40

next step up are the $65 240 constant currents which will get you 250W or so

CobKits said:

yup, you can get 150-160W out of it, still not a bad deal for $40

next step up are the $65 240 constant currents which will get you 250W or so

Click to expand...

That's the one i'm watching ATM! Apparently, i could run 10 1212's at 25w each. Can i cool these with your "105 mm Passive pin fin heatsink"?

good to 40 ish watts so no sweat

Nichia J130 B

HLG -120-48 driver

king brite reflectors


tested..hydro galaxy par meter

3 nichias at 1 ft approx 550 u-mols= 103.1 w=34w each

2 nichias 1 ft approx 650 u-mols"=106.1 w=53w each

.....did not try 4 cobs yet..

woulda got 1212 's but at the time noone had em and these were available i canada with 7 $ shipping

will try my cree 3590 bars when i get time

i will be ordering from u in the future

What would a good minimum and optimal ppfd be for an 8sqft area?