DiY LED - Cree CXA3070

Romz1

Member
Thank you Supra! I will use TE Connectivity 2-2154857-2 holders :) So guess there is not reason for kapton tape. Do you know how much Acrtic Silver 5 I need to use per COB? I have 3.5g and I am wondering if it is enough for 12 COB's? Or I need at least one more tube?
 

Blakhash

Well-Known Member
thanks so much for your reply!! as always you know whats up, but i was wondering about one last thing, you built a 200w cob with 2 cobs on a really long heat sink for someone before and i cant find the link, how was that wired up? what driver?
 

AquariusPanta

Well-Known Member
The efficiency is what your paying for. You can find AB bin for almost the same price as Z4, but they are rare.

If I were to buy Cree COBs, I'd wait until AB or upper-tier bins came available.
 

Lighterfighter

Well-Known Member
I am interested in making a flower light and supra poped in on my thread. The killer thing that makes me want to build my own is the net sol illumiteck data. Thats rediculas! just thinking about doing a diy is getting me all gitty. I got a budget and am ganna start to try and path the parts and info out. Looks like I start w which cobs or cob combo teheheheh. and Bins saying they the good bins are out? subbed.
 
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Blakhash

Well-Known Member
I guess I am just being cheap but would I be safe to run some cxa3070's Z2's at 75w? I found a great deal on them and it would allow me to fill in my hydro system with 750w of goodness(15 Sq ft) (using only 10) from the cree PDF they ran theres at 1.9a X 38.5v = 73.15, given there max is 2.8A, now i know its not the most ideal and i believe it is around 36% efficent, which honestly is fine with me. i like there smaller profile, even light distribution and especially the results Supra got with his, i have never seen any LED preform that well. I just want to make sure running them at 75w would be fine, i don't plan on keeping them for more than 2 years. i would probably end up upgrading them far before i blow them out.
 

alesh

Well-Known Member
I guess I am just being cheap but would I be safe to run some cxa3070's Z2's at 75w? I found a great deal on them and it would allow me to fill in my hydro system with 750w of goodness(15 Sq ft) (using only 10) from the cree PDF they ran theres at 1.9a X 38.5v = 73.15, given there max is 2.8A, now i know its not the most ideal and i believe it is around 36% efficent, which honestly is fine with me. i like there smaller profile, even light distribution and especially the results Supra got with his, i have never seen any LED preform that well. I just want to make sure running them at 75w would be fine, i don't plan on keeping them for more than 2 years. i would probably end up upgrading them far before i blow them out.
You're ok running them @1.9A as long as they're sufficiently cooled. Efficiency would be 30-31%, though.
 

Blakhash

Well-Known Member
You're ok running them @1.9A as long as they're sufficiently cooled. Efficiency would be 30-31%, though.
Cooling won't be a problem as I am either going to stuff them all in my existing 1000w enclosed hood, or build a rectangular tube to run the lights from, from supra, he stated, 34% at 1.9(not 36), and if I keep them cooler a bit better Gonna order them today, can't wait to start this build.
 

alesh

Well-Known Member
Cooling won't be a problem as I am either going to stuff them all in my existing 1000w enclosed hood, or build a rectangular tube to run the lights from, from supra, he stated, 34% at 1.9(not 36), and if I keep them cooler a bit better Gonna order them today, can't wait to start this build.
It'll certainly be lower 30's which is great. May I ask for how much are you getting your Z2's?
I went with Cree PCT and LER 323lm/w with Tj 50°C (I doubt it will much lower @75W dissipation). I also used minimal value and I believe @SupraSPL goes with typical (halfway to the next higher bin).
 

SupraSPL

Well-Known Member
@Blackhash I used this driver, $30, recently restocked and puts out 2.23-2.24A BUT just barely enough room in the DC voltage range for CXA3070. Could be a problem if your CXA happens to be an outlier with high Vf. Also, the seller is a good one, honest and ships fast from Cali. Just a fair warning though, one of their drivers got restocked with a very different model (1250mA vs 1450mA) and it took them at least a month to update the ebay ad. So I cannot guarantee what you will get from the 100W size, it was a long time ago that I ordered.

I have the CXA3070 3K Z2 @ 1.925A -32%min, 33.3%typ assuming Tj50C which might be a bit higher in practice. I agree with Alesh, it is OK to run them at 1.925A. But if you are planning on ordering more, I would recommend the Vero 29 3K, 37.3%typ at 2.1A (79W) and a good match for that 2.23A driver.

To clarify, I built the lamp with CXA3070 3K Z4 @ 2.23A because the customer overrode my 1.4A recommendation to fit their specific setup.

If you email the seller directly you might be able to get a discount. Tell them Supra sent you :) dalilu88@yahoo.com
 
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SupraSPL

Well-Known Member
TH Seeds - Critical HOG @ 8 Weeks. It was sharing 640W with 10 other ladies so average 58W each. Very strong unique smell but to be honest it did not get A+ ratings from the testers in terms of potency. But it was a nice plant so I had to run it again and see if it tests the same before I cut it loose.

Hard to get a fair representation of it in a full shot with everything flopping. After I cut it down I realized it had only about 3 gallons of soil in that bucket I usually aim for about 4 gal.
IMG_0021a HDR CrHg.JPG
IMG_0028a CrHg HDR.JPG
 
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midsummer

Well-Known Member
If I had to start all over again, I would stay with CXA3070 3000K AB but I would have used HLG-185H-C700B drivers and 5.88X14" or 4.9"X16" heatsinks.
Supra;
Once again I want to thank you for sharing your expertise. I am grateful and would love to someday have you and your family over for dinner. I know that the current legal situation would leave this on hold at present; but the invite is there for when the environment is not so threatening to those who may grow herb.

When I have time I will finish my lights and restart my garden. Right now I am still considering design. I have some AB's but have been debating heat sink driver combos. In the scenario you have above, how many COB' s per sink?Passive? and how many Cobs would be best run with the HLG-185H-C700B. And would you have to add an external Pot to dim that one? If so which one?

Thanks for any guidance; and again thanks for the great threads.
 

SupraSPL

Well-Known Member
THNX maybe someday we get legalized and we can have a RIU party bongsmilie

Id estimate the the ideal spacing between CXA3070 @ 700A is about 10". So a piece of 4.9"X 16" would give great passive cooling, 10" spacing for 2 COBs and 3" of heatsink on each end. You could scale that up and put 4 COBs on a piece of 4.9"X32", then a single HLG-185H-C700B would power a pair of heatsinks.

Ya the B version can be dimmed by external pot which also allows you to tie the dimmers for all drivers together on one knob and allows the option for a multi-position pot for very quick adjustments. The A version has an internal dimming pot covered by a rubber plug.
 

Lighterfighter

Well-Known Member
I wanted to do a cree 3590 ab if top bin will be out within the month. I was looking to make a fixture that is dimmable, that will allow for 12-18 inches of canopy height with plenty of penetrations for flower (greens and reds may need added. I tyhink the whites cary enought green, but yall know besst. IT will be for a 2x4 area for now and got a 600-700 budget. I would need to decide what ampage to run, after I find available bins. I believe i read i should get 3070 if mid bins are the only ones I can get of the 3590. Just from a previous post of supras. If I cant get them do I go vero or the 3070s?
 

SupraSPL

Well-Known Member
If you run 2 HLG-185H-C1400 drivers, you could use (6) CXAs, 3 on each heatsink. That would give you 312W at max (39W/ft²) and dimmable. That would rock the 2X4 for sure. If you can't get ABs, the Vero29s would be a cheaper alternative to the Z4s and should be about equal in efficiency.
 

Lighterfighter

Well-Known Member
quick question, benefit of each and negative light and negative? I am really having trouble finding the 3590 at any good bins. I contacted kingbright on ali req bin info as it isnt listed. I cant find good bins in 3500k only bb bin and I msg ebay provider here to see what bin they got is there a huge spectrum diff in 3k vs 3500? if vero are more readily available is there a huge benefit in the 3590, I Think I read they were the best if you got a higher bin then bb, if not the go vero? this chineese new years really affects global economics lol.
 

SupraSPL

Well-Known Member
Ya if you are planning on running at 1400mA and cannot get CXA3070 3K AB bin, then I would recommend the Vero29 3K as the next best choice. If you are in no hurry, there are new Veros and new CXBs coming out.
 
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