CREE CXA 3000°K/80CRI spectrum analysis.

SupraSPL

Well-Known Member
I use and recommend the CXA3070 3000K AB bin if you can track some down for a reasonable price. To my knowledge it is the most efficient warm white LED on the market. I run mine at 700-900mA but many growers are running them at 1400mA, a good compromise of up front cost and efficiency. SDS can run his up to 1925mA I believe.
 

stardustsailor

Well-Known Member
I use and recommend the CXA3070 3000K AB bin if you can track some down for a reasonable price. To my knowledge it is the most efficient warm white LED on the market. I run mine at 700-900mA but many growers are running them at 1400mA, a good compromise of up front cost and efficiency. SDS can run his up to 1925mA I believe.
2100 mA .
( 75% of rated Ifmax of the CXA3070 )

(:

Io max.JPG
 
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bicit

Well-Known Member
Stardustsailer, you're both a scholar and a gentleman. Thanks for taking the time to create this content sharing this it with the rest of us with some humor to boot.

Question, is bigger better? Are bigger emitters like the vero 29 more efficient than smaller emitters like the vero 10?
 

stardustsailor

Well-Known Member
Stardustsailer, you're both a scholar and a gentleman. Thanks for taking the time to create this content sharing this it with the rest of us with some humor to boot.

Question, is bigger better? Are bigger emitters like the vero 29 more efficient than smaller emitters like the vero 10?
No I think not,in that case ...
Mainly it depends in driving current If max of the COB.
Since larger Cobs have higher Amperage tolerances and max limits ,
for the same driving current ( i.e. @350 mA ) vs a smaller emitter should be more efficient ...
 

bicit

Well-Known Member
No I think not,in that case ...
Mainly it depends in driving current If max of the COB.
Since larger Cobs have higher Amperage tolerances and max limits ,
for the same driving current ( i.e. @350 mA ) vs a smaller emitter should be more efficient ...
So the vero 29 would be more efficient driven at 350ma than the vero 10 at the same current level?
 

SupraSPL

Well-Known Member
Bicit, the Vero behaves differently than the CXA. The Vero 10 is just as efficient as the Vero 29 if both are driven at say 50% of max current as SDS pointed out. Whereas the CXAs driven at 50% get more and more efficient as you increase in size. So following that logic the most efficient method is to drive a large CXA softly.

One exception is the CXA3070 AB bin. It is more efficient than the CXA3590 top bin, but that is only because the AB bin is a "new" top bin.
 
Bicit, the Vero behaves differently than the CXA. The Vero 10 is just as efficient as the Vero 29 if both are driven at say 50% of max current as SDS pointed out. Whereas the CXAs driven at 50% get more and more efficient as you increase in size. So following that logic the most efficient method is to drive a large CXA softly.
SDS, MrFlux, SupraSPL Positivity, etc. thanks for the valuable input in the threads "Cree CXA analysis", "DiY LED - Cree CXA3070", "vero 29 questions" and "bridgelux vero???". Would you mind to start once again a discourse on Vero vs. Cree and comment?

From what I remember, I summarize/ claim the following:
- The missing bin value of Vero does not really matter in real world application. For CXA3070, the Z4 bin is more efficient than Z2. But for the time being, Z4 is either not really available or for significant more $ than Z2. When using a couple of COBs, the averaged performance of CXA3070 Z2s might even be below the Vero 29s performance value (which is 25% less $ compared to the Cree Z2).
- A Vero with the same color temperature as a CXA has a more reddish spectrum than CXA. Keeping that in mind, wouldn't it be fair to compare the lm/W of i.e a 3000K CXA with a 3500K or even 4000K Veros, resulting in a slight advantage of Vero? I am wondering how the CXAs compare to Veros when taking PAR W as a measure of efficiency. Can someone supply these numbers for the different color temperatures? Any comments on MJs view on the quality of the spectra when comparing CXA with Vero (preferably when both of them have comparable percentage of light in the red and blue range)?
- Any good guess why the Vero´s performance at 50% max. current is independent of COB size while for the Cree, the smaller COBs significantly fall back?

Considering the above statements, is it still reasonable to claim that CXA 3070 has at least theoretically an advantage over Vero 29 in terms of efficiency (even when running soft)?
What is your judgment on the spectral quality of MJ preferred color temperature when comparing Vero with Cree?
 

getsoutalive

Well-Known Member
Not PAR reading but here is a quick test that I did with a 3070 z2 @3000K vs a Vero 29 @ 4000K and a cheap lux meter. Readings are directly under the chip. Wouldn't read into the hard numbers for anything more than a comparison.

Midday sunlight - 112,500
3070 z2 @ 6" - 102,000 @ 12" - 29500 @ 18" - 16000
Vero-29 @ 6" - 101,000 @ 12" - 26100 @ 18" - 12400

These were both driven at 1.4a. The 3070 drew 63w at the wall while the Vero drew 61w.

The 3070 has a 115 degree dispersion pattern, while the Vero's is 120 degrees. I assume that explains the more rapid drop off at distance.
 

MrFlux

Well-Known Member
The vero 4000k has the same LER as the 3000k cree...so they are actually fair in a lm/w comparison.
But here is the numbers you want thanks to supra..
Remember that supra's spreadsheet is based on minimum values which puts the Vero at disadvantage. Comparing typical values is more fair. Since the LER is indeed about the same it's surprisingly useful to look at the typical lm/W figures.

@getsoutalive thanks for your readings! I had not expected such pattern differences between two flat emitters. For these spectra divide lux by about 65 to get umol/s/m2.
 
Mr.Flux, these minimum values are only a minor issue for the Vero compared to what I was able to calculate from the numbers within that spreadsheet.... o_O

Greengenes, thanks for pointing me at SupraSPLs numbers and help me out of my confusion. When I looked at that spreadsheet the last time, I was irritated resulting in the above questions on PAR W. The $/PAR W value of the Vero 29 4000K vs. CXA3070 3000K is conflicting with what I thought I understood and expected. Simple explanation: $/PAR W seems to be calculated based on 40 ($) per Vero 29. I used the 30$ charged by digikey to obtain the PAR W value..... :wall:
 
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