Luminus CXM-32 Gen3 the next big thing??

bassman999

Well-Known Member
Let me try to understand...LER tells how many lumens per watt would be 100% efficient, but that number is relevant to that chip, and other chips have their own LER.
Meaning that lm/w isnt really a relevant basis alone for comparing different cobs?
 

Ganjineer

Member
LER is the theoretical lumens per watt of a 100% efficient light source with the same spectral distribution as the light you are trying to analyze. It is independent of all other factors except for spectral distribution. A 555 nm monochromatic light source will have a LER of ~683 lm/W. This is because green light will appear more luminous for a given amount of power put in. On the other hand red or blue light will have a LER that is significantly lower because it will appear less luminous for a given amount of power put in. This is all based upon the physiology of the human eye.

As we all know, when it comes to growing, lumens don't mean very much. We are interested in the number of photons that hit our plants within the 400-700 nm PAR range. As long as they are within that wavelength range, we are relatively agnostic (in theory) to the wavelength of said photons. LER and QER are used to help put lumens into context. That way, when we evaluate grow lights our photons are all on equal footing within the PAR range. Unfortunately, most lighting manufacturers only list lumenous flux instead of PPF. So it's up to us to try and re-analyze the data they've given us so that we can compare different lights for their growing potential.

You are absolutely correct that that each chip has its own spectrum and therefore its own LER. Which means that lumens per watt is only a portion of the story. Lumens per watt can be a useful metric in some cases, but only when comparing chips with similar spectral distributions.
 

bassman999

Well-Known Member
LER is the theoretical lumens per watt of a 100% efficient light source with the same spectral distribution as the light you are trying to analyze. It is independent of all other factors except for spectral distribution. A 555 nm monochromatic light source will have a LER of ~683 lm/W. This is because green light will appear more luminous for a given amount of power put in. On the other hand red or blue light will have a LER that is significantly lower because it will appear less luminous for a given amount of power put in. This is all based upon the physiology of the human eye.

As we all know, when it comes to growing, lumens don't mean very much. We are interested in the number of photons that hit our plants within the 400-700 nm PAR range. As long as they are within that wavelength range, we are relatively agnostic (in theory) to the wavelength of said photons. LER and QER are used to help put lumens into context. That way, when we evaluate grow lights our photons are all on equal footing within the PAR range. Unfortunately, most lighting manufacturers only list lumenous flux instead of PPF. So it's up to us to try and re-analyze the data they've given us so that we can compare different lights for their growing potential.

You are absolutely correct that that each chip has its own spectrum and therefore its own LER. Which means that lumens per watt is only a portion of the story. Lumens per watt can be a useful metric in some cases, but only when comparing chips with similar spectral distributions.
Thanks for this explanation! Spectrum is the key, and now I am much closer to understanding fully these cobs we all enjoy and their potential.
 

bassman999

Well-Known Member
The lighting Passport or similar can give a par multiplier. Basically take a reading and divide umols by lux. Presto a par multiplier. Multiply lumens lm/w by par multiplier and you get par or umol/j
Still above my knowledge, maybe because I lack the meter and other tools. I am sure a decent meter will be cheap enough soon that I can buy one and get to know more about my lights.
 

muleface

Well-Known Member
I've digitized the graph for 3000k 90CRI and threw it in my calculator. Results below...

so i downloaded your program, but it turns out i have lower lm then your average cob. Any chance you could do a youtube video and dumb this down for us (me)
 

Stephenj37826

Well-Known Member
HLG-600H-54B or HLG-600-48A
Biggest driver I know of, but with 9 cobs it looks like 66 watts each
(A type) has variable voltage but controlled on top of driver thats why 48V is mentioned

Not to mention 600H is my favorite driver....... Look at that efficiency !!!! The 2% you gain you could easily negate by using a cob or 2 less and still come out at the same system efficiency as most other meanwell drivers. I call that a money saving feature ;-)
 

CobKits

Well-Known Member
i am also a big fan of the 600.

for the same cost/watt of other drivers you are getting 2%+ across the board

thats like a free zip every few mos

lets hope the 480 is up there above 95% as well

looking forward to contributing to the spectrum thread for sure
 

kaivorth

Active Member
i am also a big fan of the 600.

for the same cost/watt of other drivers you are getting 2%+ across the board

thats like a free zip every few mos

lets hope the 480 is up there above 95% as well

looking forward to contributing to the spectrum thread for sure
Any holders support the cxm22 yet without soldering anything? Looks like your light engine requires some soldering
 

bassman999

Well-Known Member
Not to mention 600H is my favorite driver....... Look at that efficiency !!!! The 2% you gain you could easily negate by using a cob or 2 less and still come out at the same system efficiency as most other meanwell drivers. I call that a money saving feature ;-)
i am also a big fan of the 600.

for the same cost/watt of other drivers you are getting 2%+ across the board

thats like a free zip every few mos

lets hope the 480 is up there above 95% as well

looking forward to contributing to the spectrum thread for sure
Do you guys balance load somehow when using this driver or other Constant V drivers?
 
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