Noob looking for help

[Simo]

Hello guys! I got hold of 15 led strips from Alibaba; each strip is composed of 24 Samsung Lm301B, power 12w MAX, voltage DC20-28V and the emitted color is 3500k. The length of each strip is 27.5cm. The space available to me is very little, and I wanted to try my hand at a micro growing in an Ikea shelf measuring 35x35cm, 80cm high. How many strips should i use? It would be more for fun and hobbies than to get big yields, so I don't have a lot of pretensions

[Rocket Soul]

Before you start this i rec you think about how you want to extract that space, how you want to deal with smells and carbon filter etc. Theres a lot more than just light + plant

As for lighting: the most realistic thing would be to do autos, since you dont have a lot of clearance. The shorter their to-flower-days the shorter the plant. For that space, considering autos will need less watts as they run for 18-20hrs instead of 12, you could do it with 20-30w. Id spread that out over 10 strips, if the wiring isnt too much of hassle. The more you spread the watts out over more diodes the better.

[Simo]

First of all, thank you for your reply! I have already grown indoors in a 40x40x120 growbox, but I had used various CFL lights, however now I wanted to try this experiment.
Staying on 20/30 watts and 10 strips; which driver would you recommend me?

[PeteR_1]

First of all, thank you for your reply! I have already grown indoors in a 40x40x120 growbox, but I had used various CFL lights, however now I wanted to try this experiment.
Staying on 20/30 watts and 10 strips; which driver would you recommend me?

MeanWell LED Driver; XLG-50-AB;

• 22 - 54 Vdc,

• 50 Watts,

• Internal adjustable Pot; 25 - 50 Watts,

• Optional External 100K Ohm Dimmer Pot; 0 - 50 Watts

... https://www.digikey.com/en/product-high ... r-supplies
... https://www.meanwellusa.com/upload/pdf/ ... 0-spec.pdf

Sizing: (35 cm * 35 cm)
0.1225 sq m. @ 400 PPFD = 49.0 PPF / 2.5 PPF/W (PPE) = 19.6 Watts
0.1225 sq m. @ 600 PPFD = 73.5 PPF / 2.5 PPE = 29.4 Watts
0.1225 sq m. @ 800 PPFD = 98.0 PPF / 2.5 PPE = 39.2 Watts

[Simo]

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?

[Rocket Soul]

First of all, thank you for your reply! I have already grown indoors in a 40x40x120 growbox, but I had used various CFL lights, however now I wanted to try this experiment.
Staying on 20/30 watts and 10 strips; which driver would you recommend me?

MeanWell LED Driver; XLG-50-AB;

• 22 - 54 Vdc,

• 50 Watts,

• Internal adjustable Pot; 25 - 50 Watts,

• Optional External 100K Ohm Dimmer Pot; 0 - 50 Watts

... https://www.digikey.com/en/product-high ... r-supplies
... https://www.meanwellusa.com/upload/pdf/ ... 0-spec.pdf

Sizing: (35 cm * 35 cm)
0.1225 sq m. @ 400 PPFD = 49.0 PPF / 2.5 PPF/W (PPE) = 19.6 Watts
0.1225 sq m. @ 600 PPFD = 73.5 PPF / 2.5 PPE = 29.4 Watts
0.1225 sq m. @ 800 PPFD = 98.0 PPF / 2.5 PPE = 39.2 Watts

That driver is not a great choice for 20-28V strips as the driver is not very efficient in low V situations. You want to be as close to the max V as possible for good efficiency and at least within 70% of max. However you could use 2 strips in series and get close to max V.

[PeteR_1]

That driver is not a great choice for 20-28V strips as the driver is not very efficient in low V situations. You want to be as close to the max V as possible for good efficiency and at least within 70% of max. However you could use 2 strips in series and get close to max V.

Yes, your recommendation is for "Constant Current" LED Drivers like the HLG Series not for "Constant Power" LED Drivers like the XLG Series, which are more versatile...

Constant Current (CC) LED Drivers have a 'Fixed Current' / 'Fixed Amps' and are "De-rated by Voltage" e.g.;
A typical 50 Watt CC Driver rated 12 - 24 Vdc output.
@ 12 Vdc (* 2.1 A) = 25.2 Watts (50% max)
@ 18 Vdc (* 2.1 A) = 37.8 Watts (75% max)
@ 20 Vdc (* 2.1 A) = 42.0 Watts
@ 24 Vdc (* 2.1 A) = 50.4 Watts

Constant Power (CP) LED Drivers have a 'Fixed Power' / 'Fixed Watts' e.g.;
A typical XLG 50 Watt CP Driver rated 22 - 54 Vdc output.
@ 22 Vdc (* 2.1 A) = 46.2 Watts
@ 24 Vdc (* 2.1 A) = 50.4 Watts (44% max)
@ 40 Vdc (* 1.26 A) = 50.4 Watts (75% max)
@ 54 Vdc (* 1.0 A) = 50.4 Watts


And yes, I do recommend 2-Series/Parallel wiring for the XLG - xxx - AB LED Drivers when applicable, individual strip Forward Volts less than ~ 27 Vdc