Budzbuddha
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See ? … I had similar grabs
GML Accusations..
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Gregshed
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The spectrum graphs indicate no gaps, put all the bands and luminescent coatings and there are gaps. I've said every way possible for you to work this out.
Let's back to those graphs, the sun's spectrum has lots of tiny gaps if we look on a spectrograph, do your now saying LEDs have more wavelengths than the sun.
Either way you want to put it you come out wrong, were not talking peaks and troughs just electromagnetic wavelengths, come on how have you made a light with more wavelengths than the sun!
PJ Diaz
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Do you have evidence to support your assertions, outside of a manufacture's claims?
Kassiopeija
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I believe he's refering to the equalized nature of the SPD
Grow Lights Australia
Well-Known Member
I don't wish to cause an argument but I am confused by what you mean as "gaps" in LED spectra. We use a Danish Viso Systems LabSpion Goniometer to measure our lights and this system is regarded as not only one of the most accurate light measuring devices on the market but it measures every single nanometer. If you look at the exploded view of the report below you will see all the little jagged peaks where each nm has been measured. You may be correct that each nm is then blended but how big a gap are we talking? I am very interested to know this.
I have included a typical hand-held spectrometer reading of the same spectrum for reference. It is a Lighting Passport that measures every 8nm and you are correct that it "blends" the spectra which is why the two measurements look different even though they are the same light.
I apologise, I uploaded the incorrect files at first. I have fixed it now.
Goniometer
Lighting Passport
Kassiopeija
Well-Known Member
it's nice to see this comparison, in the less-precise one the area-under-the-curve is more, less spiky peaks and less pronounced troughs
personally I think it won't matter much, if at all.... considering the spikey nature of other light-sources
personally I think it won't matter much, if at all.... considering the spikey nature of other light-sources
0potato0
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Kassiopeija
Well-Known Member
ok so picking up on that I can understand that if one would want to create a brighter light, or: a more high-energy photon, one has to make "the electron jump down" from a higher energetical point.
in consequence blue light would create less photons than red light even though their radiant flux would be equal.
now where does diode efficacy comes into play? like, less photons generated at the expense of more heat. IF any electron is always forced to jump down that 1-way street.
grotbags
Well-Known Member
more waffle...
now you dont seem to understand the difference between continuous spectrums, absorbtion spectrums and emission spectrums.
a continuous spectrum the type that can be generated by a tungsten filament right here on earth contains every wavelength of light, yes more wavelengths than the sun!.
the sun outputs an absorbtion spectrum ie some of the wavelengths of light get absorbed by the gases that make up sun, the wavelengths that get absorbed appear as black lines on a spectrograph (fraunhofer lines).
grow lights like a sodium create an emission spectrum these are the exact oposite of absorbtion spectrums, ie instead of light being absorbed by a gas you exite the gas or ellement to give off photons. this looks like a nearly all black spectrograph with lines of colour which corospond to the element that was doing the radiating.
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PJ Diaz
Well-Known Member
Nope. I'm fairly certain I know exactly he's made that statement, I just want to hear it from him. At the end of the day, he's repeating old news, which is now out of date. Not to mention that the main manufacture who made such a claim is now out of business.
Kassiopeija
Well-Known Member
As this is a theme here, I wonder how private persons/buyers could backcheck on the binning of their racks generally?
Are diodes marked with something like a production stamp or comparable?
Are diodes marked with something like a production stamp or comparable?
PJ Diaz
Well-Known Member
I can't speak to how they are marked, however they definitely do have different identifiers. My speculation is that when you buy diodes from Samsung they are shipped in packages which are marked with the bin identifier:
PJ Diaz
Well-Known Member
Also, my understanding (which could be mistaken) is that they are tested for binning AFTER they are manufactured as part of the quality control process. At that point, depending on how much luminous flux is produced, they are binned accordingly. So perhaps they are not individually stamped.
Milky Weed
Well-Known Member
Gonna have to start calling him Shillington
Rocket Soul
Well-Known Member
Not thursday but heres a throwback to lm561c times...
Way back when it used to be said you could spot non top bin diode by The Back Spot.
It wasnt a curse, it was the zenner diode...
Lm301b i dont think anyone ever got a way to distinguish mid/fake from topbin.
J232
Well-Known Member
Ohh that’s pretty good, Poopwan Shillington the first, aka, the creeper.
PadawanWarrior
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J232
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Grow Lights Australia
Well-Known Member
Hi Kassiopeija yes the bins are marked on the reels when you receive them. There will be a model identifier with the CCT (Kelvin temperature, including colour shift), voltage and luminous flux bins marked on the sealed package, as well as the reel itself. This is the case for all the LEDs we purchase from Nichia, Seoul Semi, LED Teknik and others. It is possible for a manufacturer to mislabel a reel and there is no way of knowing if the individual LEDs inside are what the manufacturer says they are, but you can find out through individual testing.
When we design a LED panel we will calculate on paper the total efficiency of the combined LEDs to get to where we think it should be. We will then produce and test a board to see if it matches our calculations. We will also swap LED types over and test those to see the difference in efficiency between individual diodes types. It is an exhausting process!
We love Nichia because it is one of the few companies that under-promises and over delivers on its LED efficiency bins. We always get what we pay for and sometimes are surprised that the LEDs are slightly more efficient than promised. I will go a bit further into this below.
LEDs are not individually stamped but they are individually binned after production. Each batch goes into a type of centrifuge which spins the LEDs around so that they come out one at a time on a conveyor where they move over an electrode which briefly pulses the LED and the subsequent voltage, flux and CCT are recorded. The individual LED is then directed to a plastic bin (which is why it is called "binning") depending on the requirements of the customer. Binning often happens after you place an order so that desired bins can be grouped together on reels to the customer's requirements. Leftover LEDs may be sold in batches to the retail market where they have wider tolerances or "steps". This is common when colour accuracy is required and the CCT will be binned in steps of how far away each LED is from its locus line or "ideal" colour for each Kelvin temperature.
When we purchase LEDs we always voltage match to within 0.1V and we also pay a premium for the highest flux bins available due to the extra steps of having to bin each reel to our requirements. Because we are not as interested in true colour rendition (there are only minor fluctuations in CCT anyway) as we are in efficiency and voltage, then this makes it easier to purchase "top bin" diodes.
There is a lot of confusion over what a "top bin" diode is. In LED manufacturing everything is based on yield. For example when a batch of 1 million LEDs is produced there will be many parameters under which each LED will fall due to slight variances in manufacturing tolerances. You may have three different voltages each 0.1-0.2V apart. Any LEDs that fall outside those three voltage bins may be discarded. Most of the LEDs will fall under one of those voltage bins, known as "typical voltage" and so will have the highest "yield". It is easier and more economical to order the most common voltage bins.
Efficiency bins are tricky. There is really no such thing as a "top efficiency bin" diode. You would expect the diodes with the highest flux to be the most efficient but this is not always the case. A diode that falls into the top flux bin may have a higher voltage, so it may not be as efficient as a diode that is in a lower flux bin but also has a lower voltage. Flux is a measurement of human eye sensitivity and not total number of photons, so it is possible to have two "top flux bin" diodes and the diode that has more red shift will produce more photons and have a higher umol/j efficiency.
Now we get to the interesting part. Out of 1 million diodes perhaps only 10% of those diodes are in the top flux bin. Of those perhaps 60% are in the typical voltage range, 30% are in the highest voltage range and 10% are in the lowest voltage range. Those last diodes that make up just 1% of the total yield are the most efficient (highest flux, lowest voltage). But even those will have some variance depending on colour shift. It may be that only 0.1% of those 1 million diodes (1000 in total) are "true" top bin diodes. These diodes will have the highest flux, the lowest voltage and the most red shift. But all these things are contradictory as higher voltages normally produce a higher flux and higher green and blue content also produces a higher flux.
So you can see how hard it is to buy "top bin" diodes based on yield alone. Now we have to compete with other buyers, so often you must pay a premium for what you want. Especially if everyone else wants them!
Everyone thinks Samsung diodes are the best but there is one big problem with that thinking: the more manufacturers who use Samsung diodes, the less "top bin" diodes there are to go around. I would suggest that companies that have a good relationship with Samsung, or those who pay the most money, would have first access to the most desirable LEDs. But it also depends on what LEDs are most in demand – typically 3000K CRI80 3030 LM301B/H etc. You just know that any manufacturer that uses these diodes is competing with all the other manufacturers and there simply is not enough yield to go around. Some have to settle on lower flux bins or mix their voltages.
Grow Lights Australia has a good relationship with Nichia (which are better than Samsung, despite what many people believe). We also use diodes that are not typically in demand. One of our favourite diodes is the 757 series 2700K CRI90. These diodes have a lot of red and far red in them and we always get the top flux bins because we are one of the few buyers (and because we also pay a little more for them). These diodes have been tested at 2.77 umol/j which is very high for a 2700K CRI90 diode. We also pay LED Teknik a premium for our 3535 series diodes which is why we have 660m monos that are just 2% off the very top "G Bin" Cree XP-G3 diodes. The problem with the Crees is that you cannot buy the "G" bins anyway. There is not enough yield to go around.
I know this is a long post but I hope it explains a little bit about how the industry works and why there are really very few manufacturers out there who have access to "top bin" diodes even though everyone claims they do. It is simple mathematics.
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