PAR test of COBs vs Samsung 561 boards

these were on the same hlg slate heatsink, the thickness of which would put the cobs at a slight disadvantage but minor at low currents. even at 150W on the 4-cob board each cob is only operating at 37W

150W in a tent is 150W in a tent. since 4 cobs are almost exactly as efficient as the qb288 they would produce the same amount of light and same amount of waste heat off the back and would be indistinguishable to plants at any reasonable distance where light was reasonably uniform (~12")

i tried to compare data from samsung calculator and citi calculator to see how close the observed data would be.

as you can see with S6 flux and AZ/A1 voltage bins im right on HLG's numbers



when i calc using citi calculator at same temps (40C Tc), the trends are different than expected



for some reason the citi calculator at a fixed Tc is a lot flatter than we would anticipate, where in actual testing both QBs and COBs had similar slopes. must be the way the two simulators estimate temperature effects.

i think its generally accepted that the citi calculator is conservative that might be another observation here. seems the citi calc is biased low (or samsung is biased high)

or theres a factor im missing

CobKits said:

for some reason the citi calculator at a fixed Tc is a lot flatter than we would anticipate, where in actual testing both QBs and COBs had similar slopes. must be the way the two simulators estimate temperature effects.

Click to expand...

Looks like the Citi simulator comes up with much higher Tj temperatures based on the given Tc than Samsung does on the Ts. Perhaps that (part of) the difference?

well thats the limits of chip dissipation, a function of the chip. im trying to keep Tc static at least. as we know temp is a big variable.

as always a big difference between datasheet specs and real-world output. its hard enough to compare cobs of different manufacturers, yet alone cobs vs boards

@CobKits you are going to have to get some of these Samsung strips and test them too. 30w/m. you can mix spectrum. I am planning mixing 3500K and 5000K on a 200w dimmable HLG-240H-C1050B driver on one veg fixture and use what iss left for a second veg light You can space them as close as you want or put them on a QB heatsink for effect. 2-5m rolls cost $65 S&H $35 first order he splits the shipping costs with you. make the first order the best:O.
namaste

sure send me a link ill test anything

CobKits said:

sure send me a link ill test anything

Click to expand...

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god luck getting one of these.
https://mufue.en.alibaba.com/?spm=a2700.8443308.0.0.dzxNCU
Pick your flavor and size. great seller just like Jerry, a real gentleman.
namaste

CobKits said:

i tried to compare data from samsung calculator and citi calculator to see how close the observed data would be.

as you can see with S6 flux and AZ/A1 voltage bins im right on HLG's numbers

View attachment 3966674

when i calc using citi calculator at same temps (40C Tc), the trends are different than expected

View attachment 3966683

for some reason the citi calculator at a fixed Tc is a lot flatter than we would anticipate, where in actual testing both QBs and COBs had similar slopes. must be the way the two simulators estimate temperature effects.

i think its generally accepted that the citi calculator is conservative that might be another observation here. seems the citi calc is biased low (or samsung is biased high)

or theres a factor im missing

Click to expand...

Samsung's calculator is spot on or slightly low. I think the citizen calculator is low and as you stated the difference between Tc and Tj helps the Samsung a bit. The 561C doesn't suffer as much from thermal droop. Generally the actual led is within 1-2c of the heatsink temp. Im going to a block of copper and spread the heat away from the cob as quickly as possible and then see where I land on output. I've got a heatsink design I'm working on and will share soon.

cobkits

Heres the average data plotted. QBs were def a cut above the other board, the other board's low current data is suspicious, i'm working on testing another sample. sorry to be anonymous about that board i dont want to throw anyone under the bus when im not sure the board was a good one. If they want to comment about it they can.

>>i sent cobkits the panel to test..and thanks cobkits

i sent the tests back to the factory..he sworenup and down its the 561 chip

i said well why don't they act the same?

he said he is sending two new samples of the same board to test..[yehwhatever]

he actualy showed the 561 packging this time.[yehwhatever]

we will see how they do and whether he was "fibbrigating"

the 6 x 22 is growing damn good though..but it really should have tested better

all i know is i am keeping my cool and the factory is not getting anymore dough until it tests like it should

i also just mentioned to the fatcory that these AZ chips may be something to intall in the coming sample

whether he can/or will take the cue i do it know

Stephenj37826 said:

Samsung's calculator is spot on or slightly low. I think the citizen calculator is low and as you stated the difference between Tc and Tj helps the Samsung a bit. The 561C doesn't suffer as much from thermal droop.

Click to expand...

In real live tests the Tj difference doesn't help the Samsung though. As CobKits measurements show, there is no difference in temperature droop between the 1212 COBs and the QB's. Four version 5 Citi 1212's perform pretty much identical to a QB 288 over the whole range.

Only the Citizen simulator does seem to overestimate the Tj change with increasing current. That was my idea at least. Or perhaps the fault is somewhere else in their Excel. Either way, it's only an issue in the Excel/datasheet and not in how the COBs actually perform

wietefras said:

In real live tests the Tj difference doesn't help the Samsung though. As CobKits measurements show, there is no difference in temperature droop between the 1212 COBs and the QB's. Four version 5 Citi 1212's perform pretty much identical to a QB 288 over the whole range.

Only the Citizen simulator does seem to overestimate the Tj change with increasing current. That was my idea at least. Or perhaps the fault is somewhere else in their Excel. Either way, it's only an issue in the Excel/datasheet and not in how the COBs actually perform

Click to expand...

Not true.... 4-5 1212s have many more blue diodes. Each Samsung is 1 blue diode btw. As I've said the tj is only 1-2c higher than heat sink temps. This isn't the case with any cob. Think of package size (footprint per watt).

Point is, 4-COB 1212 (version 5) and QB288 perform the same:



So whatever the ideas behind Tj are. It''s not making a difference in real live. So the datasheet is wrong here.

II ordered 90 and 175W chilled boards last night to play with. Since i have the tent setup i might as well run the clws as well. I like their new solarsystem 275 (efficient augmented adjustale spectrum lights),and im all about the 'smaller' fixtures which can be spread out better. Their newer fixtures should have the latest osram 120 or 150SSL

Problem with this type of test is its just measuring gross PAR, which is fine when comparing white phosphor LEDs of similar spectrums. When we start to compare white spectra to red-and-blue augmented its truly apples and oranges and we need to start considering relative plant absorption as well as completeness of spectrum for non-photosynthetic processes. With the li-cor sharp cutoff at 700 nm its also biased against spectra with far red

I think they should buy the new boards with samsung diodes combined 3500k, 2700k 6500k and 660nm,
Offer up to 188 L / w.
Above and beyond the citizen.

loook photom fandon desings in IG.

yeah ive seen them. i really dont get the point of mixing different color phosphor-based LEDs on the same channel. 4000k would look about the same as mixing lower and higher colors. that spectrum has way too much blue for flowering imo. it would throw down some PAR in a test but not necessarily in the spectrums that are most useful

CobKits said:

yeah ive seen them. i really dont get the point of mixing different color phosphor/based LEDs on the same channel. 4000k would look about the same as mixing lower and higher colors. that spectrum has way too much blue for flowering imo. it would throw down some PAR in a test but not necessarily in the spectrums that are most useful

Click to expand...

Then a single of 3500k would be with some red would be ideal.?

linderstein said:

Then a single of 3500k would be with some red would be ideal.?

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That's a good all around light, I've used it. 3000K 90CRI seems to be the sweet spot for bloom.

[Quote = "ttystikk, de la publicación: 13620977, miembro de: 324297"] Esa es una buena todo alrededor de la luz, lo he usado. 3000K 90CRI parece ser el punto óptimo para la floración. [/ Quote]
But the vegetation? How about 3000k 90 cri?

linderstein said:

[Quote = "ttystikk, de la publicación: 13620977, miembro de: 324297"] Esa es una buena todo alrededor de la luz, lo he usado. 3000K 90CRI parece ser el punto óptimo para la floración. [/ Quote]
But the vegetation? How about 3000k 90 cri?

Click to expand...

¡Muy bueno! Lol

I've run my veg under HPS with fine results, so if expect that veg under such a sourcing would also work just fine. I think the difference would amount to the plants being a bit more leggy, with longer internode spacing. It would not be significant, however.

that photon fantom board is actually more like 5000K with red. here is 4000K+ 660nm red (fluence physiospec indoor)