DiY LED - Cree CXA3070

SomeGuy said:

@Greengenes707

Do you think 6 of those CXA 3070 would cover a 3x3 driven at 1.4amps?

Click to expand...

6 is perfect for a 3x3 imo...


From 12"



My comparison/what I would be missing out on... would be what a 600w hps does...that is what I used to run in my 3x3 tent. And averaged just a little under a lb over 3 runs with it...2 of the runs were ran by a buddy at his place(just my equipment and clones).

With 6 of them you wouldn't need to pull much more than 1g/w to get decent 600hps like results...and really big boy yields aren't too far after that...all doable.
With any less than 6 chips I really don't seek it covering the whole area how it should. and you would need to have the best grow around yet to get the results I think many are looking for.

Hps is comfortably pulling 45-50g/sqft...with DIY cxa seeming to average around 1g/w across many growers(some as high as 1.3+)...tells me that about 35w/sqft is what we should be running them at. The 25 that people are using is good for the g/w...but total yields could go up in the same space imo.

cool. Thanks for that reply GG. awesome chart.

Cree 3070 +the flower Osram oslon SSL LR CPDP 625nm+SSL LH CPDP 645nm.Make the switch on the flower is a good solution.It would make the red spectrum for flowering.Once our flowers are set to bloom, it turns on red lights and flowers that much help.

Greengenes707 said:

6 is perfect for a 3x3 imo...

Click to expand...

6 @ 1400mA is good but I prefer 9 @ 1050mA for a 3x3, that works out to 1 cob per square foot which would definitely give you more even spread of photons and a bit of an efficiency boost. My tent is only 2x4 so I run 8 CXA3070 AB 3000k and drive them with 2x hlg-185h-c1050. I ordered a quantum sensor from rapidled (good price or not?) to hook up to my multimeter, when it arrives I can post some PAR readings if anyone is interested. Then I will know if I went overboard but I think it should be just right at around 35+/- watts/sf.


Different Topic, My landlord says the bank wants to inspect the house for refinancing. I guess I am going to have to tear everything down this weekend, it sucks but its actually a pretty good time for it as I don't have much going on but the party cups and some seedlings. It could be worse I guess.

Ive got a dried/curing total for the last harvest.

Sugar Jones clone 1 74g sensi buds + 9.7g seeded buds
Sugar Jones clone 2 71.4g
OX1 18.7g
OX2 13.8g
OX3 14.6g
Seeded OX buds 16.1g
PK Bubba 16.4g sensi buds +6.5g seeded buds

3.95g bubble hash from Sugar Jones trim
1.06g bubble hash from OX trim
.32g bubble hash from PK Bubba trim

209g sensi buds + 32.3g seeded + 5.3g bubble hash

Not a bad harvest for 190w LED dissipation and 220w at the plug (heatsink fans/LED drivers included).

I agree that light spread is a big issue here. GG's chart even shows it. The intensity in the center is as high as 837, and the light comes from directly overhead, while the light on the perimeter of a 3x3 box, it's as low as 141.

9 @ 1050mA does make for better spread, and more direct overhead lighting, and runs more efficiently, but has a higher startup cost.

epicfail said:

6 @ 1400mA is good but I prefer 9 @ 1050mA for a 3x3, that works out to 1 cob per square foot which would definitely give you more even spread of photons and a bit of an efficiency boost. My tent is only 2x4 so I run 8 CXA3070 AB 3000k and drive them with 2x hlg-185h-c1050. I ordered a quantum sensor from rapidled (good price or not?) to hook up to my multimeter, when it arrives I can post some PAR readings if anyone is interested. Then I will know if I went overboard but I think it should be just right at around 35+/- watts/sf.


Different Topic, My landlord says the bank wants to inspect the house for refinancing. I guess I am going to have to tear everything down this weekend, it sucks but its actually a pretty good time for it as I don't have much going on but the party cups and some seedlings. It could be worse I guess.

Click to expand...

9@1050ma(342.54w) ...vs.... 6@1400ma(313.32w)...you are adding ~200$ to your build cost and some wall wattage. Should be right about 400w total with drivers and fans going.

COBs are awesome on paper...and really good in reality...but just like other led's, you still need to "harness" all their power IMO...LENES and REFLECTORS!!!

Even though I can run @ 1050mA I only do so for a few weeks. Most of the time I dim them down to about 700-750mA. I'm not sure what kinda of umols I am getting or what distance they should be at but even dimmed they are bright as hell. I can't wait for my sensor to arrive.

9 @ 750mA = 252+/- watts with the ability to turn it up. Yes the upfront cost is more but I smoke a lot so it pays itself back quickly. I only grow for myself.

Hi all,

I have been reading all the pages on this thread and would like to thank everyone who has contributed.

In the process however I have become a little confussed as to what the ideal wattage to aim for when looking to veg and flower.

I am looking at a very small setup. A veg room 30cm x 30cm ( 1 x 1 foot ) and a flower room 60cm x 30cm ( 2 x 1 foot ). Based on Supers earlier posts I came up with 1 x CXA3070@350ma 5000 ( 12W for veg ) and 2 x CXA3070@700 3000 ( 25W for flower ). Both veg and flower lights hung 15cm above the canopy.

However, in later posts, he mentioned running at 700ma ( 25W ) for the veg room and 900ma ( 35W ) or higher for the flower room.

Can anyone please clarify which would be better to ensure I dont waste my time building an under/over powered solution.

Also I have seen the CXA3590 available in 36V versions would that be better than the CXA3070.

If you think my setup is missing anything please let me know. So far the only other light I was thinking of adding was 730nm in the flower room.

Thanks in advance.

Go for 700. I run mine at 1600ma at 60w each per sqft. I used pct.cree.com to compare our lumen output. 900 would be way overkill. How are you organizing the 2 LEDs over 1 sqft?

I would aim for 7000 3070 lumens per sqft when designing these lights. 8000 max

Does anyone have cobs with lensless reflectors? I am currently in scrogg but I would love to set my girls free! if I could get penetration down unda with a lens I would be set. What angle do we think for a 60w cob?

Positivity is your guy the reflectors will burn holes in your shoes!! I would prefer the 78* personally. Ledil is the brand

CannaBare said:

Go for 700. I run mine at 1600ma at 60w each per sqft. I used pct.cree.com to compare our lumen output. 900 would be way overkill. How are you organizing the 2 LEDs over 1 sqft?

Click to expand...

Thanks for the reply. When you say go for 700 do you mean for the flowering room. Also think you got the wrong impression. I was going to use one 3070 in the veg room running at 350ma to cover 30cm x 30cm. I was going to use 2 3070 running at 700ma to cover 60cm x 30cm, so one light over each square foot.

So can you clarify, are you saying I should be ok with running each 3070 at 700ma in the flowering room. Also is 350ma in the veg room enough. Lastly regarding the distance, is 15cm as Super had said ok. Using my basic maths it would seem I would not cover the hole 30cm x 30cm at that height as the light emited seems to fall off beyound 60 degrees.

Thanks

@kkman did you think about getting a dimmable driver for your flower section? I run 1 3070 per/sf @1050mA peak for weeks 4-7 but most weeks its dimmed to 700mA. Being able to boost it up when needed is a nice feature, also to dim down while your in your garden to protect your vision is priceless. These things are damn bright.

epicfail said:

Different Topic, My landlord says the bank wants to inspect the house for refinancing. I guess I am going to have to tear everything down this weekend, it sucks but its actually a pretty good time for it as I don't have much going on but the party cups and some seedlings. It could be worse I guess.

Click to expand...

I have been through that, sucks! Worst part is I gave him the idea indirectly because we were chatting about interest rates. So I had to build a temporary structure that would not be part of the inspection and was able to stash the ladies in there for over a week with no major harm done.

If I am using the LPC-60-1400 would I be able to run the CPU fan in series with the COB? If I am understanding it correctly, I should have about 5v to run the fan as the cob heats up, but I don't know enough to figure out why this may be a bad idea.

Edit: For a cxa3070 COB

I have never tried that but I have hooked up many fans accidentally to the output of a CC driver and they go pop instantly. If you were to use a CC driver for a fan, the fan would draw its intrinsic voltage which I think is about 24V. But the driver would have to be regulated at a low current like .3 or .5A. In my understanding, DC fans are better off as constant voltage devices and diodes are better off as constant current. That said, I am not an electrical engineer just my conjecture.

To summarize, I would not recommend it. I recommend using a high quality AC-DC adapter like this. You can control fan speed by using 5V, 6V, 7V, 9V, 12V or 15V adapters or some adjustable voltage adapters. They are up to 80% efficient if you run them between 70-100% of their maximum output, but don't run them above their maximum output.

You could also control the speed of the DC fans with a potentiometer to drop a few volts from the power supply. Also, fans should be wired in parallel to the voltage source if there is more than one fan. DC motors should be driven with constant voltage-the current flow through the windings is not constant as a function of motor speed(inductance is the primary factor to consider here, I think)

SupraSPL said:

I have never tried that but I have hooked up many fans accidentally to the output of a CC driver and they go pop instantly. If you were to use a CC driver for a fan, the fan would draw its intrinsic voltage which I think is about 24V. But the driver would have to be regulated at a low current like .3 or .5A. In my understanding, DC fans are better off as constant voltage devices and diodes are better off as constant current. That said, I am not an electrical engineer just my conjecture.

To summarize, I would not recommend it. I recommend using a high quality AC-DC adapter like this. You can control fan speed by using 5V, 6V, 7V, 9V, 12V or 15V adapters or some adjustable voltage adapters. They are up to 80% efficient if you run them between 70-100% of their maximum output, but don't run them above their maximum output.

Click to expand...

The pot would still use power, the right way to slow it down would indeed be with a inductance maneuver.

I was planning on using the meanwell APC-12-350 to drive my pc fans in my small grow room, but reading supers comments I am not sure if the will work. Since I have already ordered them can anyone tell me if they will be ok to run a 12V 250ma fan with this constant current driver.