DiY LED - Cree CXA3070

alef said:
1) vero 29 by bridgelux has 10k lumens on 80watt vs cxa3070 has 11k on 114w. vero29 looks more efficient. maybe i am losing the parameter i have to consider
2) normal hps of 250 watt has 33000 lumens. i need 3 vero 29 to reach same brightness. it results into 240 watt (not taking cooler and loss into the account). of cource the spectrum is different. anything else i need to take into account?

thank you!
Click to expand...

Your questions are understandable. It can be hard to sort through the spec sheet and get a fair comparison from one to another. The 3000K Vero29 may have a warmer color temp than the CXA3070. This is a misrepresentation on the Veros part in my opinion and creates unfortunate confusion. Here is how the 3000K Vero 29 stacks up against the 3000K CXA3070 AB bin (assuming Tj 50C in all cases). 1.4A is a common compromise for a drive current and you can see that at 1.4A they both cost the same/PAR W but the CXA is running at 42% vs the Vero 35.8%. The Vero gives us contradictory vF figures depending on whether you look at the chart or the curve and when I doubt I always assume the worst and go by the minimums, bringing the Vero down to 34.5%.

CXA3070 AB vs Vero29.png
 
Castaman, I agree 2700K might be a better flowering spectrum for many varieties of cannabis (mostly for indica dom hybrids), but there are no top bins available to us and when push comes to shove, output efficiency trumps spectrum. To make matters worse, SDS pointed out that in many cases the 2700K is simply a 3000K with less blue but no significant increase in red output and no shift toward the deep red. If that is true, then the 3000K is actually a superior flowering spectrum and the blue does not go to waste.

The high CRI 2700K and 3000K does have an actual shift in its peak toward the deep red, but it suffers a drastic decrease in output and on top of that we have no access to high CRi top bins but we DO have cheap access the most efficient warm white LED in the world (the CXA3070 3000K AB bin)
 
That's awesome the high bins are being made available. I was hoping they weren't going to make them impossible to get. :clap:

Wish I had a bigger area I'd be lining that sh@t up...:mrgreen:
 
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I bet those 3000K AB's won't last long very long. I bought a pair of vero18 5000k 90cri and some 50w fasttech drivers, I think they should be great for photography, the colors under the 3000k just aren't vibrant enough and don't seem to translate well in pictures. I'm hoping these will help do the bud shots justice, I'm sure they are good for clones also.


CannaBare said:
@epicfail Did you ever get to test your par levels at 1050mA? I was very interested in this :)
Click to expand...

I just actually started hanging them yesterday, today I will power them up as see if I can get some readings. I will draw up a little graphic and post it asap.
 
CXA3070-0000-000N0HAD50H - good choice? or BB-bin should perform better?
CXA3070-0000-000N00AB30H - also the best 3070 avaliable?
What is the best driver for 2*3000k(3070) and 1*5000k(3070)?
HLG-120H-C1050A - good choice?
Thanks for the answers.
 
2 step tends to be more more expensive than 4 step but not necessarily better. The 4 step could be better if it is shifted toward red or worse if it is shifted toward green. It is more likely to be shifted toward green because that results in more lumens but not necessarily more actual output. @Greengenes707 tested some 2 step AB bins with a spectroradiometer and they measured 3050K and very close to the BBL if I recall (not shifted toward red or green).

img_3759-jpg.3208608


PlanckianLocusA.png
 
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Just got the driver for my cxa3590 36V. Its the meanwell lcm-60da. Its a great little driver and includes dimming as well as NTC compensation. So far I have attached a push button to it which allows me to dim the light and it looks great. I am able to run 2 cobs at 700ma without dimming or 2 cobs at 900ma with 50% dimming ( so around 800ma ). The only problem I am having is finding a NTC resistor for the driver. On the pdf it says the unit was tested using THINKING TTC03 series resistors. But for the life of me I cannot find any anywhere. The pdf states a 220K resistor reduces the current after 60C, 330K reduces after 70C and 470K reduces after 80C. Does anyone have any information on this driver or the NTC I need. I want to connect it to the COB so as to limit the current from the driver if the temps get too high or the heatsink fan fails. Is there another way to protect the cob if the fan fails, like some kind of auto switch off if the fan fails. Not sure how that would work.

As a side note Super warned about using copper heatsinks, well he was right I have replaced my NOFAN heatsinks with Artic Alpin 11 cpu heatsink after I had one cxa3070 COB blow after running 24 hours. The heatsink seemed to absorb the heat fine but seemed not able to release it as fast so it go well over 80C and the next morning all I could smell was a burnt out smell. Thats a £25 lesson for not listening to super.
 
As for testing the output light I have got the Extech LT300 Light Meter as well as ASD portable HandHeld 2 Spectroradiameter to test the output of the 2700K cxa3590. It is way too complicated for me and will take a while before I know how to use it.

Any data I gather I will be happy to share with you. I will be testing my cxa3590 2700K and 3000K (36V) as well as the cxa3070 3000K and 5000K.
 
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