SunLike 3500K 95+ CRI midpower led from Seoul Semiconductors tested

These are running at 12v 1 amp. That’s 2.4 watt/meter. It’s about right, to maybe a little dim. 3watt/meter would probably be perfect.

there is no 0.05w or 0.1w sunlike leds in this world, so, there is no led strip… I could not find any pcb like I need, so, I drawed it by myself. It is not led strip, it is pcb what need heat sink. Also you can use only 2S (2pcs) leds in one board, it will about 12v, but be carefull, use resistor.

Also the same 12w will cost 17$ from me (20 leds and 10pcb boards 99mm long) or 14.5$ if if will be 22mm pcbs.

What’s the target market for your high power led strip? Are these for grow lights?

22mm can be used in flashlights because there is not high voltage (36v) like in COB sunlike. For growing I use another leds. But if someone already use sunlike bulbs where it is possible, he can use sunlike for plants. Eyes first, plants after =) Will go to sleep, sorry.

I drawed this 99x12.5mm for alluminium profile for led lamp 60sm, but also it can be in another size. It will be about 30-36w led lamp 60sm long.

That’s some cool looking aluminum extrusion. Good job :+1:

One suggestion, it's much better practice to connect LEDs in series first, and connect those series strings in parallel.

Reason for this is LEDs Vf variance, if you connect multiple LEDs in parallel, current distribution could be unequal, LED with lowest Vf will draw highest current, and because of that if will become hotter, and Vf would drop even more, current would rise even more.. etc. I've seen this problem in LED T8 tube light, shadows and bright spots were visible because of unequal current distribution and measurements confirmed that.

With 3 (or more) LEDs connected in series first, all strings would have total Vf closer to average (more leds - more equal average total Vf among strings because of probability laws).

I understand this situation, but:

1. seoul semico recommended to use their 3030 leds to 150mA, I recomend to use it on 85mA and I will use it with 0.5w
2. quality of leds is really good and it is almost with the same voltage.
3. when 1 led will die (shit happens) when those series strings in parallel, string will not work. If here, for example, 1 of 4 pcs will die, another 3pcs will work only 1.333 times more than 4pcs
4. in my situation it is possible to use it 3S4P and 2S4P and 1S8P

I changed price to 3030 leds on my web-site to 0.5$ and power too (now it is 0.5w, was 0.6w)

But seoul semico say that it is 150mA and 200mA max current. It is not good power to this leds, because the size of crystal not 1w. I mean it will die really fast with 150mA.

I just draw mixing 3:1, 2:1, 1:1

Even "really good" LEDs (how do you know this?) have a variance in Vf from sample to sample.

When one of four LEDs dies, the other three get more current. This increases the chances that another dies (more current => more heat => Vf drecreases => more current => ...). This can continue until all four are dead.

It is if leds works with almost 100% power. I will use only 0.5w or smaller.

I agree with LED4Power’s suggestion and The_Driver’s opinion. It would be worthwhile to change the PCB layout. At the price point and quality your business targets, you don’t want customers noticing one LED is brighter than the others. It will make them nervous and could result in some warranty claims. I would take their advice if it were my PCB.

I have my own approach. If you will find at least a 20% difference in brightness, I agree to give you everything what you will choose on my web-site for $ 200

Ok. I am going to do another board. about 12.5x99mm, what will work from any 18-22v power supply from notebook. I will do their 4P3S

If you know size what will be better, let me know. For example 15x99mm or etc

I am going to use NSI50350ADT4G
or NSI50350AST3G

it is 350mA

Hello, peoples of the flat Earth!

Well done! about 6 hours (for this board)

120-240-360-480mA or etc with NSI constant Current Regulators (yes, it is not cheap)

from 18v to 25v

also you can give 12v if instead of 1 LED, you will set a jumper (wire)

also you can use led driver if you will set a jumper (wire) except CCR

12x99x1.6mm m3 holes

also you can cut up to 1.5+mm from the both sides

50%G (Grower)


It looks good. The CC regulators are not even necessary for good performance.

Backing up to the previous design, you see how the current is given the choice to take the path (the LED) of least resistance at every level? That’s not good.

But your new design is immune, even without the expensive regulators.

it is not critical. because there is only ~300mA

And I am going to not parallel this boards, because I need 36-54v. I will be S, so, current will go from left to right or etc.

Also you can do not use CCRs. It is maximum universal. Also I have 5+h video. I make it when I draw this board =) It is real 6h to do this board

On a different topic, I was curious about this:
50%G (Grower)

Is that a price? I haven’t seen percent used like that before.

Yes. It is 50perCents =)

Also it is real money in my village =)

So 50%G is about $25?

No =) it is 50% from 1$. It is 0.5$ or $0.50 if you like that style

Interesting. Thanks.

I know you don’t agree the time spent changing the PCB was necessary technically. But perhaps look at it from the business angle. This new design eliminates a possible criticism of your products. Competitors can not claim you made a mistake.