PPFD & Photon Efficacy of the LM301B vs LM561C

[Hyakutak]

The lumen/watt ratio of the LM301B is obviously better than the LM561C, but I can't find any lab test about the LM301B PAR efficiency.

Do anyone have info/experiences/resources about that?

On Digikey, you can get insane bulk price w/ the Q strip, but I don't know if it's really worth it, or if the F series is still a better option today (without thinking about the material cost, only the electricity/PAR efficiency factor ).

[majorana]

Part of the question is what your limiting factor is.

In real-world situations efficiency is determined not by ideal maximum-efficiency the chip can reach, but the temperature it runs at. This would depend both on cooling and how hard you drive the chip. Cooling depends, in turn, both on dissipation and light density.

If chip A is 10% more efficient at maximum efficiency (25°C) but costs 30% more than chip B, you can buy 30% more of chip B for the same price and drive it 30% softer, potentially getting even better results. This, of course, assumes pricing is a consideration. If build cost isn't a limiting factor you'd do best to get your hands on as many LM301B's as you can.

[tazztone]

using the LED engine calculator i compared F562B with Q562A.
I matched their temperature to 35°C
drove the F562B softer (at 70%) to match the wattage to each LED (Fseries has 1.8x more LEDs than qseries. 72 vs 40)

so to wrap it up:
if you get a F-series you pay 1.23x more per strip.
but also get 1.8x more light(more LEDs)
and only lose 2.5lm/W efficiency
concerning bulk rebate: by ordering double the amount of 280mm Qseries than Fseries i think you still wouldn't close this gap

for exact photon calculations i would ask user "livinglight"
but alternatively, since the spectral curves of lm561C and lm301B are similar enough, use his lumen to photon (350nm - 750nm) conversion factor from the F-Series 3000K CRI80:
lm/W * 0.01485 = photons / W
or
lm/W * 0.0130353 = mcCree weighed photons / W

LM301B vs LM561C:

[majorana]

using the LED engine calculator i compared F562B with Q562A.

Thanks for doing the math! It would be best, however, to compare LPW/$ on a per-diode basis: Digikey prices can be used as a reference, but eventually many would be interested in sourcing from Shenzhen factories where the diode distribution can vary from the standard Samsung strips.

[tazztone]

many would be interested in sourcing from Shenzhen factories

i certainly don't anymore. after dealing with mufue, bava, hansion, meijiu i was not impressed by their product transparency. and i couldn't be sure what i eventually end up getting(see supposedly lm561C with only 130lm/W).
in the end the high shipping costs led me to rather buy VESTAs by bridgelux from digikey. even though their products have no aluminum PCB

where the diode distribution can vary from the standard Samsung strips.

not just the distribution, also the model of diode can vary

[majorana]

i certainly don't anymore. after dealing with mufue, bava, hansion, meijiu i was not impressed by their product transparency.

I, too, have ended up buying a cat in the bag from Mufue. My next order will still be from Shenzhen, from the one company that told me they have no availability, Bright. I hope to get around to reviewing them early in 2019.

[unkle_psycho]

I spent a desperate month in alibaba trying to make sense of it. The greedy miser in me wanted to believe, and wanted to buy, but even the way they fill their product information is just abhorrent. Numbers don't match, product pages are always for a group of products, theres a hundred different adds fore the same product group. Everything tries to be everything finally nothing is nothing.

You should source your diodes, then travel to China and let them make them in front of you. When you go to the toilet take the diodes with you.

Nothing wrong with Asians, they are an adorable hard working group. Every Asian knows who matters to them though, and it's not a stranger from the other side of the world. Babies are hungry. The dude has to sell. And customers want unicorns. So unicorns it is, and cheap too.

[majorana]

Except for one thing: pretty much everybody buys from the Shenzhen factories. There's definitely a reliability issue, but there's no need to throw away the baby with the bath water. When buying COBs I had a great experience with KingBrite on Alibaba, and would happily recommend them to anybody building a COB-based fixture.

[unkle_psycho]

Yes he is a great example. In no way do i mean Asians are incapable. I would imagine soon someone will rise to the occasion.
And Shengzen is great, everything is there. Hope we find another unicorn, Kingbright really is one.

I would even be happy for something more modest then LM561c... Even something with 150lm/w would be great... especially if its 12v and can be chopped every 3 diodes. Actually my biggest desire would be semi efficient, but ultra low power diodes for veggie tests. But since I value the data more then the food, any uncertain specs are a threat.

[tazztone]

150lm/w would be great... especially if its 12v and can be chopped every 3 diodes.

problem with those flex strips is that they use resistors that result in a lot of efficiency wasted