Bridgelux EB-series on a 2' x 4' SCROG

[StonerCol]

Where? With LM301b?
I bought 26 2ft. F-Series strips the day before yesterday, would be a shame if there were better strips today, LOL!
I've been waiting for 3 months on strips with new LM301b, but top bin yields does not seem good enough yet, and until now only rolls with different flux bins available but no finished products.

https://www.led-professional.com/products/led-modules-led-light-engines/samsung2019s-new-q-series-led-linear-modules-offer-superior-efficacy?searchterm=samsung+Q+

 

[Randomblame]

https://www.led-professional.com/products/led-modules-led-light-engines/samsung2019s-new-q-series-led-linear-modules-offer-superior-efficacy?searchterm=samsung+Q+

Oh no! This is just unreal!
If I hate one thing it is when a better one is available shortly after I bought the best available. LED development is so fast this days it's allmost impossible to build the best possible light.
Thank God, I have planned my lamps so that the strips get only ~525mA, which brings them to min. 178lm/w.

 

[StonerCol]

Oh no! This is just unreal!
If I hate one thing it is when a better one is available shortly after I bought the best available. LED development is so fast this days it's allmost impossible to build the best possible light.
Thank God, I have planned my lamps so that the strips get only ~525mA, which brings them to min. 178lm/w.

Perhaps it might be better if I start a thread on building a strip light fixture for a 4x2? That way it will be easier for peeps to find in the future....plus I won't be clogging up GG's thread!

 

[Danielson999]

Don't forget that these strips come in 1ft, 2ft and 4ft so you could use the smaller ones if you only have 1 large plant.

Yes, which is why I mentioned that moving them closer together would work better. I have no desire for photons in the corners of my tent, much better keeping them over my plant.

 

[StonerCol]

I have no desire for photons in the corners of my tent, much better keeping them over my plant.

And if you use 2ft strips in a 4ft space then you won't cover the corners. Nothing to do with closer together, it's the length relative to the length of the space.

 

[Danielson999]

And if you use 2ft strips in a 4ft space then you won't cover the corners. Nothing to do with closer together, it's the length relative to the length of the space.

Which is exactly what I was saying. Glad someone understands. By the way, those Q series strips are not much different than what are already out. Infact, the F series are probably close to identical lm/w or close enough to not be worth upgrading anyway. The F/M series also have the advantage of being driven harder. It seems the Q series are 'ambient' lighting meant to be around 450ma. Not sure you could even drive them at 1050ma. It lists 900ma as the max. Sounds like it might make a great seedling/veg strip but probably not much different than other strips available. On the data sheet they max out at 20w @900ma for a 44" strip. I don't think they have the same heavy pcb that the F series comes with either.

 

[graying.geek]

Yupp,
inverse-square law applies here also, but is obsolete because there are so many overlapping from multiple light sources it's allmost impossible to calculate.
But if you increase the distance to say we 2 or 3 meters and the whole lamp acts like a huge COB, you will notice that inverse-square law is better applicable.

Exactly! Because as the distance increases, the light rays become parallel and even a 2 x 4 strip light becomes a point source, so the S-C-L will rear it's head with more vigor somewhere around 2 x (the diameter of the light source). Within reasonable limits, diffuse is better than point.

 

[graying.geek]

Where? With LM301b?
I bought 26 2ft. F-Series strips the day before yesterday, would be a shame if there were better strips today, LOL!
I've been waiting for 3 months on strips with new LM301b, but top bin yields does not seem good enough yet, and until now only rolls with different flux bins available but no finished products.

I feel your pain. With LED technology moving so fast -- and being a cheap bastard -- I've adopted the same purchasing philosophy for lights as I did for CPUs some years ago: Stay a generation behind. Keeping close to the bleeding edge is both expensive and frustrating.

 

[nfhiggs]

Oh no! This is just unreal!
If I hate one thing it is when a better one is available shortly after I bought the best available. LED development is so fast this days it's allmost impossible to build the best possible light.
Thank God, I have planned my lamps so that the strips get only ~525mA, which brings them to min. 178lm/w.

I wouldn't sweat it. The Q series uses the LM301B but its not a huge jump in efficiency, but it is in price. The F-series are a better bargain. Price per diode with the F-series is under 19 cents. The Q-series are 29 cents per diode.

 

[BuddyColas]

That's the kind of numbers I'm after. Which strips did you use, EB or Samsung?

I used 1120mm EB strips at 3000/80.


Here’s the math on 1 strip at 1 amp:

So at current of 1 amp the strip is 146 lm/watt (see EB spec sheet).

Then 146 divided by a LER of 324 is about 45% efficient.

Then multiply that 45% by the 45 watts the strip uses at 1 amp, so 20 PAR watts a strip.

Then 20 PAR watts times 4.7 umols/PAR watt is 94 PPF per strip.

And 94 PPF times 7 is 658 PPF for the fixture at 1 amp per strip.


Note:

I do not run my fixture at 1 amp. I find 800 ma is plenty when I run the fixture about 4” from the canopy (notice the red wires hanging down from the fixture). I figure about 730 ppfd. You will notice I have a bit of “flat canopy” OCD (no known cure). The picture is from my "tent cam!"


Personal Opinion Section:

I know many are all excited about the Samsung diodes, and they are more efficient, but the Samsung H strips are tested at 21w and the EBs are tested at 31w a strip. If you back down they EBs to 21w they would be very close to the Samsungs (like single digits percentage wise in efficiency). So I went with the 1120mm EBs at 3000/80. Why? They are cheaper, extremely rugged, and easy to mount and cool. AND, but wait there’s more, you don’t even need a heat sink at 700 ma test current!

 

[StonerCol]

I used 1120mm EB strips at 3000/80.


Here’s the math on 1 strip at 1 amp:

So at current of 1 amp the strip is 146 lm/watt (see EB spec sheet).

Then 146 divided by a LER of 324 is about 45% efficient.

Then multiply that 45% by the 45 watts the strip uses at 1 amp, so 20 PAR watts a strip.

Then 20 PAR watts times 4.7 umols/PAR watt is 94 PPF per strip.

And 94 PPF times 7 is 658 PPF for the fixture at 1 amp per strip.


Note:

I do not run my fixture at 1 amp. I find 800 ma is plenty when I run the fixture about 4” from the canopy (notice the red wires hanging down from the fixture). I figure about 730 ppfd. You will notice I have a bit of “flat canopy” OCD (no known cure). The picture is from my "tent cam!"


Personal Opinion Section:

I know many are all excited about the Samsung diodes, and they are more efficient, but the Samsung H strips are tested at 21w and the EBs are tested at 31w a strip. If you back down they EBs to 21w they would be very close to the Samsungs (like single digits percentage wise in efficiency). So I went with the 1120mm EBs at 3000/80. Why? They are cheaper, extremely rugged, and easy to mount and cool. AND, but wait there’s more, you don’t even need a heat sink at 700 ma test current!

Awesome. Thanks a lot for that info, much appreciated.

 

[Randomblame]

I wouldn't sweat it. The Q series uses the LM301B but its not a huge jump in efficiency, but it is in price. The F-series are a better bargain. Price per diode with the F-series is under 19 cents. The Q-series are 29 cents per diode.

Yepp!
And I would need a lot more strips because of their low wattage. They are like a better H-Series, but only 40 diodes per 2ft. strip. Let's see, maybe Samsung brings more strips with 301b diodes out. 4000lm/2ft./20w would be a nice F-Series replacement but between H- and F-Series availability was half a year, so I would not have waited anyway.

 

[dbrn32]

Pretty good discussion guys. A couple of things I didn't really see considered......

Even though efficiency numbers may only be off by single digits, we're talking more like in the 5-10% range than in the 0-5% range. If you're talking 50% efficient on a 500 watt fixture, an 8-10% boost in efficiency would be huge. Probably enough to justify spending the extra cash if you have it. If you don't, then you do what you can with what you have and tell the led snobs to piss off.

Something else that doesn't seem to be taken into consideration very often is having reflective surfaces on our grow spaces. Most of us do to at least some extent. Which can offset actual par readings between having a stronger light source higher and not as close to canopy edges. When you run a weaker light right on top of your canopy you give most of this up. I haven't done the leg work to say one way is better than the other scientifically without a doubt. But with the fixtures I have, it seems like more of a wash than anything else.

 

[BuddyColas]

I wouldn't sweat it. The Q series uses the LM301B but its not a huge jump in efficiency, but it is in price. The F-series are a better bargain. Price per diode with the F-series is under 19 cents. The Q-series are 29 cents per diode.

And, the EBs are about 15 cents per diode...just saying.

 

[nfhiggs]

And, the EBs are about 15 cents per diode...just saying.

Yeah, but pretty much a wash when you factor the efficiency difference.

 

[nfhiggs]

Pretty good discussion guys. A couple of things I didn't really see considered......

Even though efficiency numbers may only be off by single digits, we're talking more like in the 5-10% range than in the 0-5% range. If you're talking 50% efficient on a 500 watt fixture, an 8-10% boost in efficiency would be huge. Probably enough to justify spending the extra cash if you have it. If you don't, then you do what you can with what you have and tell the led snobs to piss off.

Something else that doesn't seem to be taken into consideration very often is having reflective surfaces on our grow spaces. Most of us do to at least some extent. Which can offset actual par readings between having a stronger light source higher and not as close to canopy edges. When you run a weaker light right on top of your canopy you give most of this up. I haven't done the leg work to say one way is better than the other scientifically without a doubt. But with the fixtures I have, it seems like more of a wash than anything else.

Run the numbers on the diodes - LM561C vs LM301B- its not anywhere near a 10% increase. At literally the same power, its 30 lumens vs 31 lumens - that's barely 3%.

 

[Randomblame]

Run the numbers on the diodes - LM561C vs LM301B- its not anywhere near a 10% increase. At literally the same power, its 30 lumens vs 31 lumens - that's barely 3%.

Totally agree!
A quick look at the datasheets says 34-36lm for both top bins for the 3000°k diodes. A1 voltage bin, 65mA, 25°C and the LM561c seems to have a better heat dissipation.. Max. for 301b is 180mA while max. on 561c is 200mA.
With the 5.000°k diodes the max. is 39lm for 561c vs. 40lm on 301b.
So, not worth the extra costs actually.

 

[Randomblame]

BTW, the stripes and COB's arrived yesterday. Thursday shipped and monday arrived!
The guys of Arrow did a really good job, because they have informed in advance about the import regulations and then decided to split the consignment at their own expense, so that each consignment remained under $ 200.
That saved me another $50 in VAT, so I've saved even $100 now compared to digikey prices and their shipping practic!

 

[StonerCol]

I can understand people wanting an efficient light source but I feel sometimes that it's easy to lose sight of the fact that it's about growing weed, not trying to win any kind of "efficiency competition". If a light source is more power efficient but less effective at growing then it isn't more efficient. There are many types of efficiency involved in what we do - equipment, growing style, lighting rig config, power company rates for kW/h etc.
I don't really see any massive differences between the efficiency of the different smd's we are discussing. I think it is better to concentrate on what will grow the best weed then try to dial that efficiency in, rather than just buy what appears to be most efficient according to the data sheets.
I'm not knocking anybody at all, just noting that it is easy to get so concerned with theortical efficiency that we can forget the actual goal.

 

[StonerCol]

BTW, the stripes and COB's arrived yesterday. Thursday shipped and monday arrived!
The guys of Arrow did a really good job, because they have informed in advance about the import regulations and then decided to split the consignment at their own expense, so that each consignment remained under $ 200.
That saved me another $50 in VAT, so I've saved even $100 now compared to digikey prices and their shipping practic!

You are gonna be busy now that that lot has arrived Are you in the UK dude or?