Best LEDs today? Share info!

I'm surely not an expert on the subject, but last time I checked I found one for roughly 4000$. I don't know if thats a suitable model for our purposes though and on top of that, you would need an integrating sphere. I have no clue what those cost. :)
 
You suppose UFO is making any $$ with these? Or whatever LED company. Lots of labor
 
Very, very big thanks guod! You seem to have deep knowledge of the subject, looking at the usefulness of the links you have posted. :) Any recommendations for preferably open source linux software that can handle those simulation files? I didn't even know there exists such data provided by the manufacturers.

edit:

Rrog, with spectroradiometers? Kinda missed the question, or was it even for me. :D
 
Sorry- I meant do you suppose that these companies that make LED panels. The good ones, I mean, do you suppose they're profitable selling their LED panels. Like Area 51 or UFO. Just was curious.
 
I haven't put much thought to it, but looked briefly at A51 site and came to a conclusion: almost 600$ for 72 Cree leds of unknown bin, some electronics and a metal casing contain at least some overhead even when calculating nice money for design. Taking into consideration that buying bulk will drop part prices dramatically. If i'd have to guess, the overhead is pretty good (especially with a product like hans panel), but markets are not that big and competition is fierce.

edit:

This is why you need an integrating sphere:

http://area51lighting.com/specs.html

Useless to compare very directional light source against hps/mh, just a marketing gimmick for my taste. At least they should do it by hanging the fixture at a given height and then measure readings from a grid and post the results. The above method goes to the same class as the chinese marketing of 120w panels that "equal" a 400w hps.
 
Though, I failed to think about the sad state of economics around the world, price of pot etc etc. :) What do I know, might be a good one still? At least the customers have money!
 
Any progress with that spreadsheet JMD? In the meantime, tried to do some rough estimates for the hans (ledgrow.eu) panel. Assuming 700mA drive current, 50C junction temperature, 550mW bin XT-E's, 720mW rebels:

@ 56W ~1.66PPF/W

@ 65W ~1.43PPF/W

If upgraded with XP-E2 P3, ~28% addition or

@ 56W ~2.13 PPF/W

@ 65W ~1.83 PPF/W

Quite nice performance, even with such old chips. Estimates might be rough, but couldn't stop wondering - at least the proportions vs. later XP-E2 should be right.

Sorry, just some random ramblings. Just wondering what can be done, when we have cheap chips with similar performance as XM-L2 or oslon hyper red 3T-4T driven at 350mA.. 2.5+ PPF/W. :)

edit: Thanks again guod! Need to learn to use wine or VM, or maybe grab some old junk pc with windows..
 
Rrog said:
Sorry- I meant do you suppose that these companies that make LED panels. The good ones, I mean, do you suppose they're profitable selling their LED panels. Like Area 51 or UFO. Just was curious.
Click to expand...

There isn't really a lot of labor involved in assembling the lamps. Mounting the LEDs on the boards is an automated process, which means you just need to install the boards, mount drivers and solder wires to the LED boards or attach connectors. It really isn't rocket science :)



anomuumi said:
Any progress with that spreadsheet JMD? In the meantime, tried to do some rough estimates for the hans (ledgrow.eu) panel. Assuming 700mA drive current, 50C junction temperature, 550mW bin XT-E's, 720mW rebels:

@ 56W ~1.66PPF/W

@ 65W ~1.43PPF/W

If upgraded with XP-E2 P3, ~28% addition or

@ 56W ~2.13 PPF/W

@ 65W ~1.83 PPF/W

Quite nice performance, even with such old chips. Estimates might be rough, but couldn't stop wondering - at least the proportions vs. later XP-E2 should be right.

Sorry, just some random ramblings. Just wondering what can be done, when we have cheap chips with similar performance as XM-L2 or oslon hyper red 3T-4T driven at 350mA.. 2.5+ PPF/W. :)

edit: Thanks again guod! Need to learn to use wine or VM, or maybe grab some old junk pc with windows..
Click to expand...

Currently.. slow :( I'm still studying (MSc.EE) and I work a lot as well, with sharp deadlines and tons of data to process.

The less time I need to spend on acquiring information, the more time I can spend on making the spreadsheet - so if you don't mind, please send me a walk through of how you calculated the PPF.
Do you have any idea on how to calculate the output in YPF/PPF/µmol when the datasheet only provides lumen?
 
JMD said:
Currently.. slow :( I'm still studying (MSc.EE) and I work a lot as well, with sharp deadlines and tons of data to process.

The less time I need to spend on acquiring information, the more time I can spend on making the spreadsheet - so if you don't mind, please send me a walk through of how you calculated the PPF.
Do you have any idea on how to calculate the output in YPF/PPF/µmol when the datasheet only provides lumen?
Click to expand...

Good luck with the studies! I think that is a more important goal to pursue too. Not that deeper understanding of LED technology is bad for your career, but first things first. :)

Sorry, I'm just an uneducated fool and english isn't my native language so I don't really think I can give you a thorough explanation. I don't even understand the math behind the knna sheets, I just use them by the instructions in the guide. But as I said earlier, easiest way is to use the ledengin tool and use a single multiplier for every led (ppf/100lm for example) - thats what I used in the above calculations and the earlier xml comparison sheet.

I think you will understand it better if you look closely how the bulb analyzer is built and what it calculates. Basically my understanding is, that you turn the graphical presentation of spectral distribution chart into numbers, use the numbers to estimate output %/nm (thats what the spectral chart visualizes). With those percentages, divide the lumen output to nm increments and obtain radiometric output etc. from there. For further calculations of output at different forward currents, for cree there was that wonderful site that gives all you need with different junction temperatures etc. Other leds you just need to look at the datasheets and turn the "droop" curve into numbers and try to estimate further from there.

But theres the problem which I presented earlier, and guod kind of visualized it. The lack of proper spectral charts for every colour/chromacity bin, which is a problem when wanting to calculate white leds with any accuracy. I don't even know if cree has those simulation files shared as osram does, but that is the kind of information we would need for better accuracy. Lot of work, so I'd guess if someone doesn't have a lot of spare time, it's better to settle for accuracy of 10's of percents and just use the ledengin tool. If theres some leds that aren't represented there, just use the knna sheets for those.

Bad explanation, but what can you do, being dumb as a left foot boot - as they say :D
 
026.jpg<<<<Yes the Hans panel leds are driven at 700ma,

it's 56w for the leds , 65w total from the wall. As you know Drivers are not 100% efficient :P it consumes 8-9w.

We don't know if he goes the ALL xpe2(blue-red) route(still hasn't officilaly updated the web site/ he is shipping the new panels though), but like I said I wouldn't ever doubt goud;-) the deep reds(660nm) are gonna be osram oslons IMO and guod's........
 
Thanks for the confirmation PSU! If the price is still same with all new parts, I think the panel is pretty good value for money, At least for me would be, after calculating just the cost of emitters from cutter and other sources + taxes and such. I wonder if you could mount a heatsink to the PCB for better cooling? I kind of dislike the small fan, otherwise very nicely implemented product. :)
 
PSUAGRO. said:
Yes the Hans panel leds are driven at 700ma,


it's 56w for the leds , 65w total from the wall. As you know Drivers are not 100% efficient :P it consumes 8-9w.
Click to expand...


Question here is "what drives the fan?".... 12V / 100mA


i think 600mA for the blue leds + 100mA for the fan
700mA for all reds.

my version for this schematic of the Hans-Panel
eugrowpanel.jpg
 
guod said:
Question here is "what drives the fan?".... 12V / 100mA


i think 600mA for the blue leds + 100mA for the fan
700mA for all reds.

my version for this schematic of the Hans-Panel
View attachment 2773571
Click to expand...

Who doubts you?......damn I forgot about the fan! Lol, yeah I think Hans said around 1 watt or so idk.

Always wondered why he would drive them all at that ma, but your schematic makes sense as blues put out more energy /photons(knna) vers the reds@the same ma.
 
PSUAGRO. said:
Who doubts you?......damn I forgot about the fan! Lol, yeah I think Hans said around 1 watt or so idk.

Always wondered why he would drive them all at that ma, but your schematic makes sense as blues put out more energy /photons(knna) vers the reds@the same ma.
Click to expand...

Less photons, but ones with more energy. :)

..but yes, blue leds tend to be more efficient, in terms of radiometric output. For example cree XT-E 550mw royal blue @ 1 watt is over 50% efficient, but puts out less photons than red XP-E2 P3 @ 1 watt that is under 50% efficient.
 
Hans updated his site, he uses Cree XB-D for new leds, too bad he does not reveal the bins used. Overall I think this XB-D is Crees "budget" lineup of emitters, little lower output of whites for example. Reds should have similar output as XP-E2, little cheaper price, but at least yet you can't buy the best bin in only couple of pcs, only bigger amounts available at mouser. In bulk reel amounts, red XB-D are under 1 euro per emitter :)

edit: Checked the difference with the cree tool guod posted, yes, there is a small difference in efficiency between XP-E2 and XB-D in reds, but VERY small.
 
anomuumi said:
Hans updated his site, he uses Cree XB-D for new leds, too bad he does not reveal the bins used. Overall I think this XB-D is Crees "budget" lineup of emitters, little lower output of whites for example. Reds should have similar output as XP-E2, little cheaper price, but at least yet you can't buy the best bin in only couple of pcs, only bigger amounts available at mouser. In bulk reel amounts, red XB-D are under 1 euro per emitter :)

edit: Checked the difference with the cree tool guod posted, yes, there is a small difference in efficiency between XP-E2 and XB-D in reds, but VERY small.
Click to expand...

Lol he did add two white leds, well shows you how much I know.......very little:-P

He must be having a good laugh, the old Bastard!

Now we need guod to give us his take on the "improvements", was really hoping for a better cooling system.
 
Now that I read more carefully, Hans stated that he expects over 15% improvement over the earlier model in light output. I think that could be counted just for better thermal performance of XB-D chips vs. older XP-E. For oslons, if they were 3T bin overall improvement would be larger. So my guess is that they are 2T, or even Hans doesn't know and estimates conservatively. Added white I see as a good thing maybe for slightly better plant morphology and health, performance wise, maybe not. Blues should be also a little more inefficient vs. XT-E depending on bin of blues in older model panel.

Same thoughts with PSU on the cooling thing, but that would most likely affect the price. I think he would have to change the design radically for that, or at least the pcb would become a lot more expensive to manufacture. But overall, nice boost to output, even if it was slightly less than I anticipated. Now lets see what this upgraded version can do!

Would love to hear what guod has to say about this upgrade too!

:)
 
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