Observe & Report
Well-Known Member
OK! I was confused about test current. All Vero models have the same efficiency at test current. Maybe all the CXAs do too, I didn't check. However, there is no correlation between the XML-2 and CXA3070 test currents.
So I took the relative flux vs current charts from both datasheets and scaled them to be the same then overlaid them. The X axis (current) is aligned but I translated the graphs slightly in the Y axis (relative flux) so we could directly compare the curves of XML-2 vs CXA3070 at 85C, which is the only Tj plotted on the XML-2 chart.
*XML-2 is black and CXA3070 is green
I was surprised to see these curves match up so closely when the current is aligned. So I recalculated the efficiencies of both parts at 800mA.
Cree CXA3070 80-CRI 3500/3000K bin Y4 @ 800ma 85C = 98.2 lm/W
Cree XML-2 80-CRI 2600-4300K bin T2 @ 800ma 85C = 98.7 lm/W
At 800ma, the CXA3070 and CREE XML-2 have the same efficiency. I would guess that is because they use the same diode and phosphor tech. When you look at the chart, however, you can see that as the current goes up the CXA3070 starts losing. Therefore, the assertion "Multis aren't as efficient at creating light as a COB " is false. Apparently, the benefits provided by COB tech do not include efficiency.
For our purposes, COBs are superior to multis for all of the other reasons that SupraSPL mentioned (cost, assembly, intensity.) The exception would be where you can't have much distance between the emitters and plants, such as PC grows or side lighting.
This is how I learn and I just got schooled, thank you!
So I took the relative flux vs current charts from both datasheets and scaled them to be the same then overlaid them. The X axis (current) is aligned but I translated the graphs slightly in the Y axis (relative flux) so we could directly compare the curves of XML-2 vs CXA3070 at 85C, which is the only Tj plotted on the XML-2 chart.
*XML-2 is black and CXA3070 is green
I was surprised to see these curves match up so closely when the current is aligned. So I recalculated the efficiencies of both parts at 800mA.
Cree CXA3070 80-CRI 3500/3000K bin Y4 @ 800ma 85C = 98.2 lm/W
Cree XML-2 80-CRI 2600-4300K bin T2 @ 800ma 85C = 98.7 lm/W
At 800ma, the CXA3070 and CREE XML-2 have the same efficiency. I would guess that is because they use the same diode and phosphor tech. When you look at the chart, however, you can see that as the current goes up the CXA3070 starts losing. Therefore, the assertion "Multis aren't as efficient at creating light as a COB " is false. Apparently, the benefits provided by COB tech do not include efficiency.
For our purposes, COBs are superior to multis for all of the other reasons that SupraSPL mentioned (cost, assembly, intensity.) The exception would be where you can't have much distance between the emitters and plants, such as PC grows or side lighting.
This is how I learn and I just got schooled, thank you!