A DIY LED light using Samsung LH351H-C SMD (3535)

Milky Weed

Well-Known Member
I don’t think I have really seen any lights for sale with these SMD’s in them. They are much bigger than the 301b’s and are rated for a few watts vs .5 watts.

These are specifically geared towards horticulture and have a lense, I assume you could mount them to star boards and make your own cheap QB? I saw a YouTube video a guy stuck some 3W chips to some bakers pans.

3535 Led’s

They also have some far red for supplementation. These diodes are abit pricy compared to the others, roughly $2 a piece. The non red 3535’s are going for about $1-$2.

Has anyone ever seen a light use these and or have you ever set up something like this? I would not go in blindly I would have some more electric safety ide have to learn.

These would be expensive DIY lights I would think, but as these are much bigger you probably would not need more than 100 SMD to equal the other boards.
 

Milky Weed

Well-Known Member
I just noticed those were the Non-horticulture 3535 SMD I had found for sale, I cannot find any horticultural version that is currently for sale, I found one with a 26! Week lead time I guess they are pretty new.

I’ll have to shop around to see what chips are actually available.
 

Milky Weed

Well-Known Member
calling it a horticultural led by just having ppf data etc, dont make it so
Very true there is so much that goes into a good light. These have a much lower CRI than I would figure for chips they are selling specifically marketed as a Horticulture series. It’s about 70. That may not matter as much as I think it does though.

Until these are tested I will likely be better off with 301’s. I can’t even really find any lh351h-c or D for sale anyways.
 
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welight

Well-Known Member
Most leds, for marketing are characterised at 70CRI as this is the most efficient version of the led. The issue is that this is a power led vs midpower, so typically 350ma rating vs 65ma, respectively. That not to say that at 65ma the power led will not match the midpower but in that comparison it becomes a cost issue, around 0.10c mid power vs $1.00 for a high power
 

Milky Weed

Well-Known Member
Most leds, for marketing are characterised at 70CRI as this is the most efficient version of the led. The issue is that this is a power led vs midpower, so typically 350ma rating vs 65ma, respectively. That not to say that at 65ma the power led will not match the midpower but in that comparison it becomes a cost issue, around 0.10c mid power vs $1.00 for a high power
How do those Mah ratings affect the MAH the driver has to put out? I understand how the voltage works.

If you strap a 700mah driver on some led’s that are soldered in series would it run those led’s at 700mah? Or does the Mah add up for each chip on the series? Like 2 65mah chips would mean 130mah driver required?
 

welight

Well-Known Member
How do those Mah ratings affect the MAH the driver has to put out? I understand how the voltage works.

If you strap a 700mah driver on some led’s that are soldered in series would it run those led’s at 700mah? Or does the Mah add up for each chip on the series? Like 2 65mah chips would mean 130mah driver required?
Its is based on the layout/PCB design. No strip is all in series, typically they are laid for voltage ie 8 leds in S will be say 24v, you would then parallel all those strings up so that the current is then divided by the n(number) of parallel strings. So below is our 98CRI 2 ft strip, it runs at 48v. So it has 7 strings in series of 16 leds(3v per led x16 leds =48V nominal per string) the current that you drive at is then divided across those 7 parallel strings so if you ran at 700ma you would be getting 100ma per series string

Hope that helps
Cheers
Mark
 

Milky Weed

Well-Known Member
Its is based on the layout/PCB design. No strip is all in series, typically they are laid for voltage ie 8 leds in S will be say 24v, you would then parallel all those strings up so that the current is then divided by the n(number) of parallel strings. So below is our 98CRI 2 ft strip, it runs at 48v. So it has 7 strings in series of 16 leds(3v per led x16 leds =48V nominal per string) the current that you drive at is then divided across those 7 parallel strings so if you ran at 700ma you would be getting 100ma per series string

Hope that helps
Cheers
Mark
That helped a lot, thank you.
 

Milky Weed

Well-Known Member
Yes I can see now how these lights would be a huge issue to power, they are likely too big and meant for commercial large scale grows.
These lights have a max rating of 2000mah!
That’s pretty insane. I dont even know what drivers could handle a few running at 500 each…

it seems like I would have to run them at a lower mah, and that defeats the point of having them. I see why mid power are more suited to our needs.
 

welight

Well-Known Member
In general a lot of lights today are a compromise of the two.
for example our 3ft strips match midpower with high power deep red. It requires more complex design to balance drive, but allows a matching of efficacy and power at an affordable price

cheers
 
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