Reddit mentions of Fineuu® AC 110V / 220V To DC 24V Switch Power Supply Driver,Transformer,120W / 240W / 360W / 480W (360W)

Original post is here with discussion and calculations. Excerpt from there:

As for the description, let's begin from the bottom:
As you can see here the lower part of the barrel is filled with 15-20l of nutrient solution. The solution is oxygenated by the aquarium air pump, then the solution is top-fed to the plant 24/7 the first couple of weeks (to promote faster growth).
A ball valve allows for easy filling and draining.

After that a disk out of thick plastic makes the floor which the mesh pot sits in. On that level there's also the air intake which at the moment creates positive pressure, but once I flower in there it will be fixed to the air outlet to create negative pressure. That air will then be pushed through activated carbon.

The pot is nothing special, I even made it myself out of a regular pot and a dremel. It's filled with small-sized hydroton balls.
The bottom, walls, and lid are all painted with a 50/50 mixture out of flat PU-white (sticks to plastic) and BaSO4 (Barium sulfate). This pushes reflection throughout the whole spectrum into the high 90 per cents. Thanks /u/superangryguy for finding that study.

On two levels on the wall I can fix self-made trellis rings for ScrOGing. There's a large door on one side to get to the plants easier for training etc. On the edges it's insulated to be light- and air-proof with foam tape. The tape will be fixed to the door with neodymium magnets which will also improve the insulation.

In/on the lid there's the heat sink with the two COB-LEDs mounted with screws. Thermal grease was added to improve thermal conduction (duh.. :D). The chinese LEDs are definitely not driven at 100W (like you could do with Crees or Vero 29s) but kept at about 50-70W. That also makes thermal management easier.

As for the general supply of energy: the 360W driver brings the voltage down from 230/120V down to 30V. From there two small buck converter bring it further down to 5V (microcontroller) and 12V (fans and maybe later LED strip). For the LEDs there's the 150W boost converter to bring the voltage up again to in between 30 and 36V, thus controlling the output power (visible on the amp- and volt-meter).

The chip controls the on-off-times of the LEDs (18/6 and 12/12), regulates the cooling of heatsink and air inside the barrel, and it can also output the sensor values of sink and air temperature as well as humidity. The lights can also be switched on and off manually and of course the user switches from veg to flower.

I think that's it for the concept so far. If something isn't understandable or I left something out, just ask :)


Here are the Parts:

part | price
-------|-----------
barrel with lid - 120l | $20
100W LEDs - 3500K and 5000K | $2 each
360W driver - 24V 10A | $25
150W boost converter | $3
Heat sink | $18
Volt + amp meter | $2
Thermal grease | $1
Aquarium air pump with air hose and air stone | $10
Water pump | $5
2x Power supply for microcontroller and fans | $1 each
ATmega 328P | $2
3x 12V fans | $2 each
Electronics (cables, transistors, resistors, LEDs etc) | $5
Connectors | $3
Hygrometer | $2
Mesh pots + hydroton | $5
Ball valve| $2
(coming soon) pH and EC monitor | $36

and here's the code on GitHub: https://github.com/linkcharger/barrel-control

At the moment I'm just growing some lemon balm in there, as a kind of test run before I move to the UK, but I'm very excited to see how it works out with trees.. how the plant will behave, training, vigor etc.

Already I can see the immense power of hydroponics: I dug the small lemon balm plants out of soil 4 days ago with small-ish roots and only 3 days later I could already see the beautiful, white new roots flowing out of the pot. Hydro is amazing!

(on the other hand I also had to fight with green goey stuff because a lot of light was getting into the reservoir. Now it's sealed though :) )

It's all a big fun learning process though and I'm sure my little barrel will bring me immense joy in the future.

Happy growing everyone! ;-)