DiY LED - Cree CXA3070

indianajones

Well-Known Member
The closer to 190V you run it the more efficient it will run. It makes no difference which order you wire them in so no worries there.

The Vero 18 gives a great spread with no lenses or reflectors required, but at 1050mA (30W) the 3000K is only 33.6% efficient and cost $2/PAR W. Very good number but depending on what bin of CXA you can find, you can get up to 42% effficient for just over $2/PAR W. On the other hand the Vero 3000K does seem to act more like a 2700K which may be good if you are growing mostly indica doms.
from my understanding of the graph on page 4 of the driver's data sheet,
the closer to full load you get, the more efficient the driver becomes (up
to 94% in the case of the HLG-185H-C1050).

i was planning on using either the 3500k or 4000k, whichever goes closer
to a 660nm peak. 4000k seems to be pretty nice for grow applications from
all that i've seen so far. i don't think i can justify the cost difference of the CXA
compared to the vero for floodlight applications.

i am building some of these for things besides growing. trying to land a contract
with folks who run RV parks and storage facilities on the east coast and are
looking to become more energy efficient.will be using 5000k veros for floods
since they have a higher luminous efficiency. found these floodlight shells for the
build, check it. these shells are sold by wattage for passive cooled applications.

floodshell.jpg
 

SupraSPL

Well-Known Member
If we could get 2.1A drivers for a cheap price, the Vero29 would put up a good fight against the CXA. But since the 1.4A drivers are only $13 it makes that current more likely to be a good value. So yes I agree that if you can get a fair price on it, the CXA @ 1.4A is actually a cheaper option when you look at it from a $/PAR W perspective or how much we are actually paying per photon.

Ya CK that is true in some cases you can get very close to the canopy without harm, especially once the stretch is over otherwise they can grow right into the light. Here are some Cali Connection - 22 fem pics at 41 days. They smell very strong, like fruit and candy, reminds me of gummy lifesavers if you have ever had those. If it smokes and yields as good as it smells, it has the potential to be a keeper.
DSC07627b.JPG

DSC07634a.JPG
 
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SupraSPL

Well-Known Member
For comparison, this is the G13 Labs Sour Jack at 41 days, in the same room. This one is very strong, sweet and tropical fruit smelling. Also it is a top notch smoke requested by many patients. Definitely a top 5 favorite of mine and a great plant to work with.
DSC07635a.JPG
 
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SupraSPL

Well-Known Member
i am building some of these for things besides growing. trying to land a contract
with folks who run RV parks and storage facilities on the east coast and are
looking to become more energy efficient.will be using 5000k veros for floods
since they have a higher luminous efficiency. found these floodlight shells for the
build, check it. these shells are sold by wattage for passive cooled applications.

View attachment 3280804
Ya for human vision the 5000K is a good choice. I am not sure how that might affect depth perception outdoors, a warmer color might be better give depth to leaves and trees, but as far as lumens go the CXA3590 5000K CD bin is the very best available, and they are available in 20 packs. You could run a pair of them on an HLG-185H-C1050A at 1150mA. It would put out 25000 lumens and cost about $180. Efficiency about 44%, 180W dissipation and power draw about 200W. You might be able to sell a lamp like that for several thousand $. A friend of mine sells LED lamps to ski slopes for $3000 a piece and they are not even using COBs.

You could do something similar with the 5000K Vero29 but it would require a higher current driver for each COB (~2.4A) and it would not reach the same levels of output, efficiency and cost, maybe 37% efficient.
 

indianajones

Well-Known Member
Ya for human vision the 5000K is a good choice. I am not sure how that might affect depth perception outdoors, a warmer color might be better give depth to leaves and trees, but as far as lumens go the CXA3590 5000K CD bin is the very best available, and they are available in 20 packs. You could run a pair of them on an HLG-185H-C1050A at 1150mA. It would put out 25000 lumens and cost about $180. Efficiency about 44%, 180W dissipation and power draw about 200W. You might be able to sell a lamp like that for several thousand $. A friend of mine sells LED lamps to ski slopes for $3000 a piece and they are not even using COBs.

You could do something similar with the 5000K Vero29 but it would require a higher current driver for each COB (~2.4A) and it would not reach the same levels of output, efficiency and cost, maybe 37% efficient.

well they are switching from HPS lamps, so even 70 CRI vero 5k is
going to be a big step up. i need to make fixtures that are reasonably
comparable to the cost of a 250w system, so the cost of the 3590
would prohibit that once i added the heat sink, connectors, and screws.

the $185 you mention is close to what i would have in my whole fixture,
including heat sinks and labor. 20 cobs won't quite cut it with this project
either. ;) my proposal is to buy 1200 of the vero 18, and that lowers the
cost ~15% per COB. getting 200 of the HLG-185 lowers the cost ~25%
per unit. that's crazy your buddy charges that much, i couldn't do that for
something i only have a couple hundred in. mine will be around 450, shooting
for 400 if i can streamline the process more. the key to running a small
business of this type (replacing an item the consumer already has) is making
your product an interesting alternative to a wider target audience. the shorter
the ROI, the more interesting it becomes and the greater the savings over the
life of the fixture.
 
Works great with most CXA3070, although it is cutting it close in terms of vF range. In summary, the eBay driver linked may be the best choice available for CXA3070 DIYers and it ships from Cali. I have found equivalent drivers but they ship from China and are more expensive.
I am trying to understand these drivers, reading a lot but still confused. When referring to that ebay driver you said it was cutting it close in terms of the vF range, how so? Off of the ebay image it shows dc 25-37 V 1.5 A +/- 3%. I am confused about the range when looking at these drivers, is it close on the low side 25 V?
 

SupraSPL

Well-Known Member
The CXA3070 at 2.1 -2.1A draws about 40Vf once warmed up. The driver I linked has a built in self protection feature so if you start it up with a load attached that is above 40vF, it goes into "limping mode" and decreases the current output by about 25%.

Most drivers put out somewhat less current once they warm up and this driver is no exception. As the driver warms up iand current drops, the COB "draws" less voltage AND at the same time the COB/heatsink is warming up which is also decreasing the Vf. Eventually the system will warm up and Vf will stabilize at a lower figure than it started up with when cold, but if the self protection mode got tripped, it needs to be restarted to go into full output mode.

Some CXAs have a lower Vf than others and some drivers put out slightly less current than others. Some drivers have a slightly higher Vf range than others. So in practice, you kind of have to match the COBs and drivers so that they do not start up in self protection mode and then you are good to go at 2.1-2.1A. The colder the temp is when they start up, the higher the chance it will go into limping mode.

However, the CXA is not that great at 2.1A in terms of efficiency, especially the Z2 bin (~30% efficienct). So this driver might be a better match for the Vero 29 (~32%) which can take higher currents better than the CXA and may have a slightly lower Vf at 2.1A. Also, the 1.4A drivers are much cheaper so when it comes down to it, the cost savings of running at 2.1A over 1.4A might not be worth it.
 
Driver recommendation needed, small cabinet, flower side is about 6.25 sf and I plan on running 6 3070 ab's with the LPC-60-1400. Does this seem reasonable or can you recommend any other driver. I need a driver for the veg side of the box, it will be approximately 4 sf with 2 3070 ab's @ 5000, what would be a good driver for veg and cloning?
 

Kuifje76

Well-Known Member
If you read a few pages back, epicfail has a box 2'x4' with 8 cxa3070 @ 700 to 1050mA, it gives max 40? watts/sqf.
I'm thinking on doing the same thing but divided in 2 times 2'x2' (12/12 flip-flop) to level out heat (warm the non lighted area) with the same 2 drivers , but am worried about electrifying myself,
@ epicfail, which precautions did you take, i can solder a bit, but i have not much knowledge of electricity, is this dangerous with the combination of higher voltage and more then 200mA.

I would add 1 cxa3590 @ 6500K in each middle, because i want to grow Durban Poison which is 100% sativa and thus will profit from the extra blue

maybe start all from same driver (5 cobs max for 1050mA for the HLG-185H-1050B)
and later on split them to have more control over the blue and also add some (far) red strings.

What do you guys use to dim ?
 
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epicfail

Well-Known Member
Driver recommendation needed, small cabinet, flower side is about 6.25 sf and I plan on running 6 3070 ab's with the LPC-60-1400. Does this seem reasonable or can you recommend any other driver. I need a driver for the veg side of the box, it will be approximately 4 sf with 2 3070 ab's @ 5000, what would be a good driver for veg and cloning?
Like Kuifje said already I run one 3000k 3070 @1050mA per square foot and think that 1.4a might be overkill, also you can probably get away with 700mA for veg. So IMO six LPC-60-1050 and two LPC-35-700 would be perfect for that space. You can see pics of my setup in my thread here.

Instead of 6 LPC drivers you could run 3 3070 in series on the HLG-120H-C1050* (high voltage)
* = A or B

Another option is the 30w fasttech drivers for veg, those would save you some money over the Mean Wells.
http://www.fasttech.com/products/1612/10004218/1320606

@ epicfail, which precautions did you take, i can solder a bit, but i have not much knowledge of electricity, is this dangerous with the combination of higher voltage and more then 200mA.
I work with electricity and wired my own ballasts for years for my job so I have a healthy respect for electricity. If you use the solderless connectors and heat shrink all wire splices (wago connectors work also) then there shouldn't be any exposed areas for you to get shocked. Always disconnect the power when working on them and you should be fine just remember that you are dealing with high voltage with the HLG series and to be careful. I made my lights following Supra's lead and used kapton tape and soldered the connections to the CXA's. I don't recommend this and if I was to do it again I would be using the ideal chip-lok holders for sure. After SDS posted the info in the SOLERIQ data sheet on how the holders provide much better cooling I think it is a no brainer.

What do you guys use to dim ?
Dimming is achieved with an external pot connected between the white and blue wires on the "B" drivers or an internal pot on the "A" drivers

What is the cheap 1.4A chinese ebay driver being recommended nowadays?
No one has a link?

Also as I chose the HLG-185H which can handle five 3070's and I only have 4 on each driver (2 per heatsink) I was thinking about adding two 18v CXA1512 to the sting (1 per sink) to better max out the drivers. Either that or 12 XM-L2's (6 per sink) and was wondering if @SupraSPL had the 1512 numbers so I can compare the two. I think the XM-L2 are probably the better choice but wanted to see what people though.
 
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