Light construction with led strips - Noob

[Simomas]

Hi guys, as the title suggests, I want to try my hand at building a light using led strips.

I’ve seen that there are many guides for this, but almost all of them are geared towards very large grow spaces, which I don’t have. Below is information on the space available to me

Grow Space: the growing space will be created in an Ikea Eket cabinet, measuring 35x35x70cm (1.15x1.15x2.30 feet). It will therefore be a micro growing! How many watts would I need in such a small space? I was thinking around 40/50, right?

Led Strip: the led strips I have come from a seller on Alibaba called Bright, he is also known on other communities and I trusted to buy from him.
The strips are 27cm long and each of them has 24 Samsung Lm301b diodes (I am not sure if they are original). I am also attaching photos of both the strips and the specifications provided by the seller

I bought these strips more than two years ago, but for personal reasons I had to stop growing. Not knowing if these strips are actually of good quality or if the specifications given by the seller are correct; I might also think about buying Bridgelux EB Series Gen. 2 from DigiKey, what do you think?

Build: this is where my noob questions begin, which build would you recommend? I’m in Europe and don’t have access to cheap heatsinks, so my idea would be to run the strip on low power so it doesn’t produce too much heat.

Driver: even here, I don’t know where to orient myself, so I ask for help from you who are more experienced.
Additional question; would be better a series or parallel wiring?

Thank you for taking the time to reading this wall of text

[HolyAngel]

If those are indeed lm301b’s, which they definitely look like they are, you should only need 20-25 watts if the box is 1.15x1.15 at the base and 2ft tall. No more than 30watts for sure. I have qb288s with the lm301b and usually run around 22w in flower and 10-15w in veg.

[Shadey]

Your height is going to limit your wattage. As Holy Angel says 30w a Sq ft is good, but you might get light burn at 2ft of height.

By the time you add your pot height into the equation and the plants stretch in flower they are going to hitting those light strips. I started a small grow this year, normally my plants are 3ft to 6ft tall in flower.

The Cabinet I am using at is about 3 ft tall. The pot is is 6 inches and the plant is about 8 inches tall and mostly under a screen, I only have a few inches to spare compared with the height that burned my tester plant. I have 30 watts a Sq ft but I have to dim the light a bit, to stop light burn happening.

[Gpaw]

Looks like Holly and Shadey hit the important bits.

Nothing wrong with the strips you have, sounds very compatible to the Bridgelux Gen 2 hardware.

One important feature to have (as far as I’m concerned) is the driver must be dimmable.

Lots of folks here can help you with design and selecting a driver. (me included)

Cheers
G

[Simomas]

Thanks to all three for the replies!
Actually I am not sure that these diodes are original Samsung, looking at them closely they seem to have the characteristics of the counterfeit ones…I am seriously thinking of using DigiKey and buying Bridgelux EB series, I would be sure to receive an original product.
For the choice of the dimmable driver I agree! I thought I’d go for the B version (or maybe it’s the A? I don’t remember exactly now) of the Meanwell and add a 100k ohm potentiometer to have total control from 10 to 100%. While version A with integrated driver if I’m not mistaken only has the 50/100% option

[Simomas]

Hi guys, update!

I have thought about it for a while and I think I want to buy some Bridgelux EB series 2 strips. Their low price and the certainty of getting a verified product convinced me.

I also did some math; as I said I will grow in a space of 35x35x70 (1.15x1.15x2.3 feet), the area available to me is 1.12 square meters which equals 1.29 square feet.
On the net and in the forum they talk about using 30/40W per square foot during flowering, so I would need 38.7 to 51.6W (theoretically).

I therefore oriented myself on the build that I propose to you and I ask you what you think.
Led:
7 x Bridgelux EB Series 2 280mm
3500k
Forward voltage: 19.5V
Maximum current: 700mA
Nominal drive current: 350mA

Driver: Meanwell HLG-60H-350
Output voltage: 100 ~ 200V
Maximum output current: 350mA
Maximum power: 70W

With this build I would go to have a minimum power of 28.1W to use while vegetative, a nominal power of 40.6W and a maximum power of 47.7W.
I would then wire in series obtaining a total of 136.5V (19.5x7), is it dangerous?

This is the first idea, but I’d also be interested in considering a parallel build option to keep the Volts lower. If I wired in parallel, which HLG-60H series driver should I use?

[Shadey]

Parallel is a safer option, never done parralel myself, @Gpaw would know the right driver to use I am sure.

[Simomas]

I thought of another build, using parallel wiring.
I used the tool offered by Ledgardener even if it is no longer updated and uses the Gen 1 of the Eb series as a reference

Obviously take into account that the voltage of the Gen 2 is 19.5V and not 22.1V, but I suppose this driver would be fine anyway. I would choose the B version of the driver to be able to put a potentiometer and use a lower wattage

Tips and tricks on which build would be better are welcome!

[Albannach]

You could probably light a space that small very cheaply with ordinary household LED light bulbs 4 would probably be enough.

[Simomas]

Yes you are right. I have already grown with home leds in a 40x40x120cm growbox, but I wasn’t thrilled with the results.
The idea would be to build a led build for the current space I have and then if anything use it also in the 40x40 box

[Simomas]

I changed the build; i will go with 7 strips wired in series using the Meanwell Elg-100-C500B, but I have a question; is this potentiometer correct? If it wasn’t, would you be able to recommend one preferably from DigiKey?
https://www.digikey.it/en/products/detail/cts-electrocomponents/026TB32R101B1A1/203775

In the end, the Ikea cabinet is also different, I chose a cabinet measuring 49x37x100cm!

[Mr.Sparkle]

https://www.digikey.it/en/products/detail/tt-electronics-bi/P160KNP-0QD20B100K/2408889

more suited 100k linear potentiometer, just get a second as they can fail so good to have a backup

[Simomas]

Thank you, I’ll go with this!

[Shadey]

You will thank yourself later for getting the taller cabinet, it will be a lot less stressful for you when the plants stretch.

[Simomas]

Hey guys, these days I was on vacation, while all the pieces for the construction arrived and today I started the assembly.

Aluminum plate 30x20cm, 3mm thick. The strips are attached with thermal adhesive tape

Series connection

The driver

And here the light, I have not yet assembled the potentiometer so right now they are going to 500mA per strip, for a total of 69W, it’s amazing how much light produces, has illuminated my whole room

[Shadey]

Looks good, you should put some silicon sealant or liquid electrical tape over the silver circles on the ends of the strips that were wired. They are for soldering wires to and are live, so you will get a shock if you touch them

[Esrgood4u]

@Shadey

They are for soldering wires to and are live, so you will get a shock if you touch them

If its only 12 or 24v the driver is supplying it won’t be enough to kill someone BUT it will definitely be enough to take your advice so it doesn’t happen a 2nd time

[Simomas]

Yes that’s what I’m going to do, I had seen it in a guide here in the forum. Is electrical tape also okay or does it have to be liquid?

[Gpaw]

Those are in series…

Cheers
G

[Shadey]

You could use tape so long as you go length ways with it on each side, or it will cover the last couple of diodes on the light strip going across. Not sure if it will stay on with the heat and humidity but try it, if it doesn’t stay on, then get a $4 tube of silicone caulking from a do it yourself place, they do hand squeeze ones now that don’t need a caulking gun to squeeze it out.