Invasion of Red and Blue LEDs: Humble Beginnings

heckler73

heckler73

Well-Known Member
Greengenes707 said:
I am talking about phosphorus conversion whites specifically.
...
But as of now, no matter how good a chosen mono spectrum is...a white led(phosphorus conversion) can supply the same photons more efficiently.
Click to expand...
Can you back that up with data or math, please. That's the 2nd or 3rd time you've said it without qualification.
I look at typical InGaN LEDs using a Cerium-doped Yttrium-Aluminum-Garnet phosphor and see Stoke's Shift losses of 30% trying to generate 660nm, on top of a 25% quantum efficiency loss.* And that's before considering thermal losses in the original die!
How can you say it is more efficient?
It can't be any more efficient than the LED it is based on.
For example, your 3:2 White/Red setup. How would that spectrum look without the phosphor?
A big fat spike on the InGaN output, perhaps, with a reciprocal effect on the "efficient" band generated prior? You're making BIG assumptions about quantum efficiencies in your argument, and although there have been reports of >100% efficiencies being achieved (through quantum splitting), your rig is not doing it. In the end, conservation of Energy rules.
I suspect one could equate (or beat) your spectrum in intensity using 4 monochrome LEDs to each of your 5.

Ergo, R+B+G > W+R, when it comes to efficiency (i.e. lm/W). But really, it's no different than the classic Soil vs Hydro debate. It doesn't matter which method you choose, just do it right and you'll be rewarded with dank, regardless. The goal is to maximize yield and quality vs traditional "heater" lights.

But hey...if I am wrong, I am more than open to correction. However, I'm going to need to see more detailed proof before accepting your hypothesis.


* based on: Schubert, Light-Emitting Diodes, 2ed. , pp. 347-349
 
mc130p

mc130p

Well-Known Member
heckler73 said:
I suspect one could equate (or beat) your spectrum in intensity using 4 monochrome LEDs to each of your 5.
Ergo, R+B+G > W+R, when it comes to efficiency (i.e. lm/W). But really, it's no different than the classic Soil vs Hydro debate. It doesn't matter which method you choose, just do it right and you'll be rewarded with dank, regardless. The goal is to maximize yield and quality vs traditional "heater" lights.

But hey...if I am wrong, I am more than open to correction. However, I'm going to need to see more detailed proof before accepting your hypothesis.

* based on: Schubert, Light-Emitting Diodes, 2ed. , pp. 347-349
Click to expand...
I can't disagree with anything you've said here. Except I will say that you encounter the "mixing" problem with monochromes that doesn't exist with the white emitters-they act more like point sources, another advantage imho. None of the leaves will receive the spectrum estimated simply by summing the outputs of the single diodes.
 
heckler73

heckler73

Well-Known Member
churchhaze said:
lm/W is not a unit of efficiency. Efficiency is always unitless. (W/W)
Click to expand...
You are correct. I meant luminous efficacy in that case.
It still can be used to measure efficiency (i.e. lm/W of RGB : lm/W Ce:YAG), which ultimately is the issue in question.

EDIT: It turns out, I wasn't exactly wrong in the first place.
 
Last edited:
Greengenes707

Greengenes707

Well-Known Member
heckler73 said:
Can you back that up with data or math, please. That's the 2nd or 3rd time you've said it without qualification.

But hey...if I am wrong, I am more than open to correction. However, I'm going to need to see more detailed proof before accepting your hypothesis.
Click to expand...
Follow along...
A quality green led produces 114lm/...with a LER or maximum potential of 624.84255...114/624.84255= 18.244% efficient at converting watts to lights.
Screen Shot 2014-08-26 at 9.51.48 PM.jpg
Luminosity function...683lm being 1@555nm...so 683(.91485)=624.84255lm/w
Screen Shot 2014-08-26 at 9.54.16 PM.jpg

Now we go to a quality white.
Screen Shot 2014-08-26 at 9.53.54 PM.jpg

All the math beautifully laid out in a spread sheet by supra...
CXA3070 Z4 vs AB.jpg

LER of the 3000k is 325lm/w. And an output at a very doable 700ma of 160lm/w... 160/325=49.2% efficient and converting watts to light. That's ~170% more efficient producing light than a green.
 
heckler73

heckler73

Well-Known Member
Greengenes707 said:
Follow along...
A quality green led produces 114lm/...with a LER or maximum potential of 624.84255???...114/624.84255= 18.244% efficient at converting watts to lights.
Click to expand...
Sorry, teach...you already lost me. Where does LER the fisherman fit into this?

LED efficacy Schubert.jpg
Cree reports that the LED efficacy was measured at 303 lumens per watt, at a correlated color temperature of 5150 K and 350 mA. Standard room temperature was used to achieve the results.

http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2014/March/300LPW-LED-barrier
 
P

PurpleBuz

Well-Known Member
Greengenes707 said:
I love this statement...Light is the plants food. Spectrum can be looked at as food groups...plants needing a balance diet of light to perform at their best.
If you just ate only one type of sugar and one type protein would you live a very healthy and physically superior life?...no. As simple and unscientific as that may be sound to some on here, it is true that more than just simple monochromes are needed.
Click to expand...
lol sounds like something I would have derived on my last acid trip .... sorry just poking fun.

can't really compare digestible food directly with sunlight, only in an abstract analogy.
 
hyroot

hyroot

Well-Known Member
regardless of math and what has to do with what. More times than not having what is shown on paper doesn't match real world results. The results from white leds vs monos we have all seen first hand speaks for itself. You can debate all you want. Let the grow prove everything. Which has already been proven hundreds of times just on here.
 
PetFlora

PetFlora

Well-Known Member
There's a old joke, wife comes home and catches her husband on top of a woman in their bed. He turns to her and says " Are you going to believe me, or your lying eyes?"

A person, or a plant, can look healthy, but inside can be developing or harboring any number of dis-eases. Some trained eyes can spot a healthy person from an unhealthy one, or one about to develop a dis-ease, or health issue. Ditto with our plants

Daily exposure to Natural sunlight goes a long way to helping humans regain their health, when combined with eliminating the cause of the dis-ease, and returning to a proper diet

IMHO, the closer to natural light spectrums and umoles, the healthier the plants
 
PetFlora

PetFlora

Well-Known Member
Not meant definitively

Too many people here are into the ABSOLUTE, no other reality exists

But, if you look at outdoor crops, typically, they are planted in the spring (5000k+) and harvested in the fall (~ 3000K)
 
SomeGuy

SomeGuy

Well-Known Member
hyroot said:
regardless of math and what has to do with what. More times than not having what is shown on paper doesn't match real world results. The results from white leds vs monos we have all seen first hand speaks for itself. You can debate all you want. Let the grow prove everything. Which has already been proven hundreds of times just on here.
Click to expand...

Im with you HY! The proof is really in the doing. There has been enough doing from others that I have got on board too. The white LED Cobs I have running are doing incredible. I am excited to see what they do in flower first hand.
 
heckler73

heckler73

Well-Known Member
I realized something, too, in reading Schubert's text (along with some other stuff), when talking about things such as lumens, the variables in the equations are very important.
When one reads tech stats from CREE, for example, they're using a sensitivity function, V(λ), based on the eye (CIE1931).
We are interested in the sensitivity function of plants. Not the same thing.


LED flux Schubert.jpg
 
guod

guod

Well-Known Member
PetFlora said:
Not meant definitively

Too many people here are into the ABSOLUTE, no other reality exists

But, if you look at outdoor crops, typically, they are planted in the spring (5000k+) and harvested in the fall (~ 3000K)
Click to expand...
Outdoor on Berkeley - CA, we see the biggest spectrum change in December.


Seasonal Spectrum Shift
(tilted at Latitude Angle)
Spectrum_Berkeley.jpg

http://pvidealab.berkeley.edu/topics_solar_irradiance.html

i call that winter...
winter.jpg

http://www.pveducation.org/pvcdrom/properties-of-sunlight/average-solar-radiation
 
heckler73

heckler73

Well-Known Member
hyroot said:
regardless of math and what has to do with what. More times than not having what is shown on paper doesn't match real world results. The results from white leds vs monos we have all seen first hand speaks for itself. You can debate all you want. Let the grow prove everything. Which has already been proven hundreds of times just on here.
Click to expand...
I can accept that disposition from a general practitioner.
However, the thresholds of control cannot be fully grasped without understanding the components of a system in more detail.
I'm interested in the science and its advancement from a practical standpoint.
Trial and error is slow, usually. Having some sound theory to act as a guide is more efficient :lol:

That's why we use fora, such as this, to solve our own problems. Tapping into the wisdom of others is also an efficient process.
But at some point, a wall of knowledge is reached. There comes need for explanation.
In the process of exploring a topic in debate, higher truths can be realized. New hypotheses can be developed and then tested, as a result.
And all can benefit...

So, yes, in the end it's about the grow, yo'.
But understanding it is worth a lifetime of zips ;)
You know,
"teach a man to fish..." and all that other good shit.
I ain't OG, I'm G^O (G to the O)

Lookin for the ROOTS...oots...oots...oots...oots
 
You must log in or register to reply here.
Top