nogod_
Well-Known Member
How are you calculating efficiencies for 77v 3590 < .5a?
I can only get the pct to go down to .5a
I can only get the pct to go down to .5a
Yes it would be possible to run a lot lower than 35W/ft² if we crank the efficiency, and the method you described would definitely do that along with better coverage and less light lost to scatter. There are cheap 300mA drivers that are 89% efficient with 150V max Vf. There are 120, 150 and 180mA drivers that can do 88% efficiency very cheaply. Or you could use a Mean Well HLG-185H-C350 and run a long string dimmed down to as low as 35mA.
The downside though, increased complexity of the build, increased up front cost and I suspect less "reach" into the canopy. For example, at 1400mA, the CXA3070 AB cost about $1.86/PAR W, at 700mA it is $3.40, at 350mA $6.46, at 300mA, $7.41. That is as low as my data goes, but I estimate that at 150mA it is about $15/PAR W and 62% efficient, 5W each (200lm/W).
The CXA3590 3000K CB bin could take that idea even further, maybe to 65% at 100mA (6.5W) for $15/PAR W.
Rather than experiment at that level in the flower room I have been experimenting in the veg room, running CXA3590 5000K at 280mA, or about 63% efficient. I plan to try running them passive cooled at 200mA or 67% efficient (217lm/W). It will be dimmable from 35mA to 350mA. No practical reason to do it, just curiosity and extra parts to play with. So far it is working very well but I would like to see what they are really capable of at $15/PAR W. I guess that would be very useful to keep your ladies in veg mode during an extended power outage or in a solar powered grow.