samsung hard strips

JorgeGonzales

JorgeGonzales

Well-Known Member
caretak3r said:
also, heat dissipation could be a different experience between the lm561b vs lm301a models. I don't yet have any of the 301a strips yet to compare (the influx models).
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Do any of those lm561b models run 67W in 2ft? I think that's the "problem".
 
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MrTwist1

MrTwist1

Well-Known Member
JorgeGonzales said:
Hmm...something seems off there. 42W seems like an awful lot for that...let's see.

Yeah, only 1848cm2, so aim for more like ~16W of heat. So if you are anywhere near 30-35W thats going to be blazing hot, back of the napkin maybe 60C above ambient? Not awesome. Those particular strips are a beast.

How are these installed in real life? I know the testing temp is 65C at the test point, but the density is so high on the L09.
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84.43cm2 x approx 56cm length gives me 4728cm2... that should be good for about 42W according to Supra's 110cm2 per W guide. Maybe u muddled cm and inches in your calculation?

Anyway it's running hot, but it's manageable. It is only slightly hotter than a CXB3590 on a 140mm passive pin fin next to it at the same current. I'm getting 60C on the front of the strip between the LEDs with ambient at 30C.
 
JorgeGonzales

JorgeGonzales

Well-Known Member
MrTwist1 said:
84.43cm2 x approx 56cm length gives me 4728cm2... that should be good for about 42W according to Supra's 110cm2 per W guide. Maybe u muddled cm and inches in your calculation?

Anyway it's running hot, but it's manageable. It is only slightly hotter than a CXB3590 on a 140mm passive pin fin next to it at the same current. I'm getting 60C on the front of the strip between the LEDs with ambient at 30C.
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I didn't muddle, you did ;)

Is the 60C at the test point?
 
MrTwist1

MrTwist1

Well-Known Member
JorgeGonzales said:
I didn't muddle, you did ;)

Is the 60C at the test point?
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Hehe you are quite right sir! took me a minute to figure that out lol. #stonerlogic

Anyway yes I'm getting 65C on the test point with the heatsink hanging vertical. I do not plan to run them like this longterm... just waiting on my 700mA driver for a pair of these... they should be right around 16W heat dissipation on that driver which will be much better. Cheers
 
JorgeGonzales

JorgeGonzales

Well-Known Member
MrTwist1 said:
Hehe you are quite right sir! took me a minute to figure that out lol. #stonerlogic

Anyway yes I'm getting 65C on the test point with the heatsink hanging vertical. I do not plan to run them like this longterm... just waiting on my 700mA driver for a pair of these... they should be right around 16W heat dissipation on that driver which will be much better. Cheers
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Yep, should run cool and more efficiently like that. What color temp did you go with?
 
JorgeGonzales

JorgeGonzales

Well-Known Member
MrTwist1 said:
I went with 2 of these 5000k to replace a single 3590 @1.4A for a small veg space. I figure I'll have better spread and be able to veg bigger plants in the limited space, and hopefully the girls will like the 5000k compared to the 3500K that's in there now. cheers
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Cool, I'll try to figure out the LER later when I'm at my computer.
 
JorgeGonzales

JorgeGonzales

Well-Known Member
MrTwist1 said:
Thanks dude :cool:
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Here you go:

Screen Shot 2016-06-23 at 4.02.18 PM.png

The strips run 6 in parallel at a time, so 230mA each. I also digitized the Current vs Flux, Temp vs Flux, and eyeballed Voltage vs Temp charts from the LM301A datasheet.

That's 147% on the LM301A charts, with 150mA being typical current. Mid bin are 66 lumens at 150ma, soooo...1.47 * 66 * 96 die is 9313 lumens? Data sheet says 9380 for the L09, but that 9313 is at 85C, not 65C. So that 147% is pretty close.

At 1380mA we have 3.0125V * 230mA * 96 = 66.6W

At 700mA we have about 2.86V * 115mA * 96 = 31.6W

We land at 78% of typical lumens @ 115ma, with a 5% bump if you keep temps at 50C we get .78 * 66 * 96 * 1.05 = 5189lm @ 31.6W, or 164lm/W

Which lands us ~49.6% efficiency and about 2.27 umol/J, not too shabby. Unless I fucked up. Which is better than even odds :)
 
MrTwist1

MrTwist1

Well-Known Member
So my 700mA driver just turned up and I've got the new lights installed in the veg space. The L09s are running cooler now at 45C with 30C ambient. The light is really nice and diffuse with all the light sources spread out... I am digging this setup for vegging a small space. Seems like a great alternative to T5/T8 fluorescents for the future.
 
MrTwist1

MrTwist1

Well-Known Member
JorgeGonzales said:
Here you go:

View attachment 3715477

The strips run 6 in parallel at a time, so 230mA each. I also digitized the Current vs Flux, Temp vs Flux, and eyeballed Voltage vs Temp charts from the LM301A datasheet.

That's 147% on the LM301A charts, with 150mA being typical current. Mid bin are 66 lumens at 150ma, soooo...1.47 * 66 * 96 die is 9313 lumens? Data sheet says 9380 for the L09, but that 9313 is at 85C, not 65C. So that 147% is pretty close.

At 1380mA we have 3.0125V * 230mA * 96 = 66.6W

At 700mA we have about 2.86V * 115mA * 96 = 31.6W

We land at 78% of typical lumens @ 115ma, with a 5% bump if you keep temps at 50C we get .78 * 66 * 96 * 1.05 = 5189lm @ 31.6W, or 164lm/W

Which lands us ~49.6% efficiency and about 2.27 umol/J, not too shabby. Unless I fucked up. Which is better than even odds :)
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Wow that is really interesting stuff - thanks for taking the time to do that man!

I did some very basic math in my head before I decided to go for these, but it's nice to see you confirm my initial findings - these appear pretty legit.

One thing I don't understand is how to calculate the efficiency as a percentage from the luminous efficacy as lm/W. I'm sure I'm just being dense here, but maybe you can explain that to me? Cheers
 
JorgeGonzales

JorgeGonzales

Well-Known Member
MrTwist1 said:
So my 700mA driver just turned up and I've got the new lights installed in the veg space. The L09s are running cooler now at 45C with 30C ambient. The light is really nice and diffuse with all the light sources spread out... I am digging this setup for vegging a small space. Seems like a great alternative to T5/T8 fluorescents for the future.
Click to expand...
How big is the space?
 
JorgeGonzales

JorgeGonzales

Well-Known Member
MrTwist1 said:
Wow that is really interesting stuff - thanks for taking the time to do that man!

I did some very basic math in my head before I decided to go for these, but it's nice to see you confirm my initial findings - these appear pretty legit.

One thing I don't understand is how to calculate the efficiency as a percentage from the luminous efficacy as lm/W. I'm sure I'm just being dense here, but maybe you can explain that to me? Cheers
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That part is easy, it's just lumens/LER.
 
G

Gator44

Active Member
MrTwist1 said:
The space is about 22" square and shy of 36" high. I'm even running them dimmed down to about 25W each right now since it's 30C outside these days.
View attachment 3715539 View attachment 3715540


Ahh of course. thanks :bigjoint:
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Hey what width heatsink is that 2 inch?
This thread is badass by the way I'm ordering some strips from Samsung maybe a couple cobs as well they have multiple in the 140-155 lm/w range. Has anyone been using the cob from Samsung?
 
MrTwist1

MrTwist1

Well-Known Member
Gator44 said:
Hey what width heatsink is that 2 inch?
This thread is badass by the way I'm ordering some strips from Samsung maybe a couple cobs as well they have multiple in the 140-155 lm/w range. Has anyone been using the cob from Samsung?
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Yep, HeatsinkUSA 2inch profile. works great at 35W with a little air passing over it. I really like the diffused light from these Samsung strips and I will likely be buying more in the future. They are great for small spaces with limited headroom.
 
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