DiY LED - Cree CXA3070

mc130p said:
I couldn't find the 36V versions...but that was a couple months ago. These are the higher voltage versions too...did you find the 36V anywhere?
Click to expand...

Well, I received some free samples from a European dealer of Cree. When I wanted to install them, I noticed they were 70 volts (or something like that). Did not get my hands on a 36v 3590.
 
It means finding a driver with twice the voltage, but half the current.

In general, a higher voltage supply will have larger capacitors (not in capacity, but voltage requirement). Also, for switch mode supplies, stability (overdamped vs underdamped) of the output is higher when load current is higher, but this is something meanwell has to deal with, not you. If they say it's stable at the rated current load, it probably is. (i guess that part is moot point)

happy75 said:
I did not know that. What does this mean for selecting a driver?
Click to expand...
 
I was going to harvest both the Sugar Jones last night and I could only harvest one, took up over 75% of the drying tub. I pulled the Sugar Jones out that was in the front row in the tent and I was blown away by the amount of bud and weight on this thing every single branch snapped over at a 90 degree angle, I couldnt stand it up to take pictures so I layed it down in the bath tub on its side and started chopping branches off and hanging them in the drying tote. The pics do no justice for size and amount of buds, there are colas laying on top of colas in the pictures so you cant even see whats all there, again I am beyond impressed with the yield from one lady in 3L of coco and just Floranova Bloom the whole grow for nutes.

For a little size comparison this was the same girl on day 35 12/12. You can kind of tell how much fatter she got by harvest time, a bush of nuggets.

picture.php


Day 60 12/12 before harvesting

picture.php


picture.php


picture.php


Cant wait to see how much yield and the how the smoke is on this cut with this growing method vs organic.
 
Nice haul BT! That looks nice and sticky :)

Latest update for the second flowering tent (400W of ABs @ 800mA with 145W of red/blue luxeons @ 700mA), most recent batch came in at 1.33gr/W. A little lower than the last batch (1.39) but these ladies finished about 1 week faster on average so that more than makes up for it. These ladies finished at 7.5-8.5 weeks.

Cali Connection - Purple Chem #2 - 64.4
Cali Connection - Purple Chem #4 - 47.8
Cali Connection - Green Crack - 80.3
Rare Dankness - Scotts OG - 76
Rare Dankness - Lee Roy - 81.3
Dinafem - Dinachem - 79
G13 Labs - Pineapple Express - 73.4
HSO - Green Crack - 62.8
HSO - Purple Train Wreck - 42.9
HSO - Lost Coast OG - 35.44
HSO - Desert Diesel - 82


As usual the low yielders were getting shafted in terms of light, not necessarily fault of the genetics. They were slightly shaded out or on the fringes with poor coverage. This will be improved in the next batch I added a few modules.

The Lost Coast OG, Cali Connection Green Crack rboth made beautiful nugs but really lacked in flavor compared to the really dank stuff. The HSO Green Crack made much nicer nugs than the Cali Connection Green Crack but I still consider it low aroma (I might have mentioned that already, all three are getting let go.) I appreciate it when a variety volunteers to get let go because it is a very difficult job choosing what not to keep.
 
SupraSPL said:
Nice haul BT! That looks nice and sticky :)

Latest update for the second flowering tent (400W of ABs @ 800mA with 145W of red/blue luxeons @ 700mA), most recent batch came in at 1.33gr/W. A little lower than the last batch (1.39) but these ladies finished about 1 week faster on average so that more than makes up for it. These ladies finished at 7.5-8.5 weeks.

Cali Connection - Purple Chem #2 - 64.4
Cali Connection - Purple Chem #4 - 47.8
Cali Connection - Green Crack - 80.3
Rare Dankness - Scotts OG - 76
Rare Dankness - Lee Roy - 81.3
Dinafem - Dinachem - 79
G13 Labs - Pineapple Express - 73.4
HSO - Green Crack - 62.8
HSO - Purple Train Wreck - 42.9
HSO - Lost Coast OG - 35.44
HSO - Desert Diesel - 82


As usual the low yielders were getting shafted in terms of light, not necessarily fault of the genetics. They were slightly shaded out or on the fringes with poor coverage. This will be improved in the next batch I added a few modules.

The Lost Coast OG, Cali Connection Green Crack rboth made beautiful nugs but really lacked in flavor compared to the really dank stuff. The HSO Green Crack made much nicer nugs than the Cali Connection Green Crack but I still consider it low aroma (I might have mentioned that already, all three are getting let go.) I appreciate it when a variety volunteers to get let go because it is a very difficult job choosing what not to keep.
Click to expand...

For me both the LCOG and the Green Crack from HSO gave pretty nice looking buds, but the strength and flavors were lacking for me as well....glad it wasn't just me!
 
Hello again,

Torn between cxa3070 (AB bin)
And
Cxa3590

Ive read every single post from supra, guod, and all regarding diy CoB lamps and really appreciate having these threads as a reference.

Still a little shaky on how you can underpower chips. I have supras spreadsheet re: adjusting mA and corresponding performance but what happens when you adjust voltage? Is it possible to run a cxa3590 with less than 77v?

If this is the wrong place to post let me know and thank you!
 
Thnx @Chronikool using 5 gal buckets (19L) without drainage holes. Each is filled with 16L of soil but it settles down to about 13L after a few weeks. In the future I might vary the amount of soil for each plant, based on how large the plant is vegging up. I would like to get as close as I can to "water-only" without any ladies finishing green and without a early fading. Getting it fine tuned little by little.

@nogod the CXA3070 ABs will match the CXA3590 BDs. When I wrote the first post in this thread, the best CXA3070 bin available was Z2 and Z4s and ABs came out along the way. So unless we get access to a higher bin of CXA3590, the ABs are a better choice because they are more accessible (20pack versus 50pack). They also have the benefit of giving you better spread without the need for a reflector and they can be powered by the $13 drivers.

Most of us are used to constant voltage circuits where most things are wired in parallel and current adds. Since we are running them on constant current and in series, the COBs are allowed to express their intrinsic voltage depending on the junction temp and drive current. For example when a pair of COBs are wired in series, their voltages adds. Also, the voltage will change as the COB warms up and as the driver warms up. But we don't need to worry about it as long as you are not exceeding the max voltage of the driver.

So to choose a driver we need to know the approx voltage of you LED circuit and the the max voltage of your driver. This very much depends on the drive current of the driver. You can run at 1.4A if you want to be economical and you will get excellent efficiency as well (42%). But if you are gearing toward efficiency specifically, you can run them at a lower current. The reason I run mine at 800mA is because it allows me to float them only inches above the canopy and because I am curious how high gr/W I can achieve without sacrificing quality and without requiring AC. But I think 1.4A is a more reasonable current for most builds.
 
Last edited:
It is a great pick for vegetative growth. The CXA3590 5000K CD may be the most efficient LED available for sale worldwide. I run one in my veg tent at 20W 60% efficiency but even if you drive them at 50W they would still be over 50%.

The AB CD etc are the brightness bins or flux bins. Top bins are rare because when LEDs are produced, the vast majority of them are mid bin, just like computer processors. So they are more efficient but also more expensive. Since we run our lights for such long hours, any improvements in efficiency can go a long way in regard to yield, electricity use, lumen maintenance, reliability and heat.
 
Unfortunately we cannot compare the bin designation directly from one LED model to another. So the AB bin in a 3000K CXA3070 is incredible, but AB bin in a 3000K CXA3590 would be lower than the lowest bin. So to make a direct comparison I like to use electrical efficiency as a percentage. That works great when you are comparing LEDs of the same color temp. For example:

CXA3070 3000K AB bin @ 1.4A = 52W and 42% efficiency
CXA3590 3000K BD bin @ .7A = 51W and 42% efficiency

So you could say that these are equal, but then we have to look at the actual cost/photon because if one is more expensive than the other, you could afford to run the cheaper one at a lower current, making it more efficient. In this case they are very close in cost. The 3070 cost $2.18/PAR W and the CXA3590 cost $2.28/PAR W.

So as you can see it is somewhat complex and difficult to make a comparison of one LED to another. If manufacturers provided data such as electrical efficiency, it would be a lot easier to derive the true output and cost/PAR W. But at least we have a starting point to work with. The numbers posted above are the best flowering LEDs we have available to us and if something comes out that can outperform them in terms of efficiency and cost, I will be all over it :leaf:
 
You must log in or register to reply here.
Back
Top