Do It Yourself

Here is how to build a very good Led panel yourself, version 3.0 date 7- April 2012.

Please note that this design is for educational purposes only, growing Marijuana is prohibited in a lot of countries.
Don't grow Marijuana unless you are sure it is legal to do so :-).

The new panel is about the best you could possibly have, it will outperform almost every available ready made Led panel. The new version is 50% more powerful than the previous K2 version, the new one is based on Cree XP-E led's, still about the best you can get. To keep assembling simple I've used metal core star versions, they are glued with thermal conductive glue to an aluminum plate of 20 *40 cm. (8" times 16 "), the plate is 1,5 mm thick. The thermal performance is excellent; the amount of light only drops a few percent from the moment of switching On to after heating up. There is no need for a cooling fan.

If enough people are interested I'll consider creating a kit, please email me at (change the AT for a @)

These are the Led's:
Deep-Red 1-up Luxeon Rebel Star, 1 piece
Blue 1-up Cree XP-E Star CREEXPE-BLU-1, 2 pieces
Red 1-up Cree XP-E Star CREEXPE-RED-1N3, 8 pieces

The Leds run at a constant current of 700 mA, together they require 27-28 Volt, total power consuption is about 19 Watt. You can either buy a constant current source or build it yourself. There are several types to be plugged directly into the mains available, simple and safe. For instance:

Mean Well LPC-35-700 constant current driver

36-Watt Lightech LED Driver, for up to 25 leds at 700 mA, 100 - 265 Voltinput.

(You can use other Constant DC Current Sources as well, just remember 700 mA is optimal)

If you have experience in building electronic circuits, a nice DIY version is provided by the LM3404HV switching current regulator, input is 35-45 DC Volt, 500 mA;

Schematics of the regulator, partlist:
Elco 470 uF, 63 Volt
Capacitor 10 nF
Capacitor 100 nF
Capacitor 150 nF
Capacitor 2,2 uF
Resistor 1 ohm, 0.25 Watt, 3 pieces
Resistor 2,7 ohm, 0.25 Watt
Scottky diode, >= 60 Volt, >= 1 Amp
Inductor 330 uH, >= 1,5 Amp
DC powersupply, 35 - 45 Volt, >= 0.5 Amp

Complete Datasheet about the LM3404

Top and bottom view of 2 regulators like in the schematic

Top and bottom view of 2 regulators like in the schematic

The Led's are glued to the panel, I used Loctite 315 output kit, but a much cheaper thermal conductive glue will do fine. After gluing the Led's are wired in series, the Carclo holders and reflectors are glued to the panels. Please note the Deep-Red Led does not have a reflector, this is because there is only 1 and it's light should be spread as wide as possible on all plants. You might consider leaving out the reflectors for both Blue Led's as well. My advise is not to use lenses instead of reflectors, lenses create rather large, 15-30%, light losses.

Please note it is unadvisable to look directly into the Led's at full current.

Please send us your comment
For questions and comments, please email me at: (change the AT for a @ )

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