Sso

so..how do you change the bulbs when they go out? speaking as a guy that cant do that shit and has to buy it.

looking at the prices of a whole unit and never having seen replacement bulbs or anything,

i gotta ask.

they gotta last a frigging long time for me to even consider buying them. electricity is cheap here though, 1 kwh a month is maybe 15$

silence is golden though, id be glad to be rid of some fans. i dont like much the leds so far though, they are interesting, but i have the above questions and more issues (depth penetration for one.)

about the colour spectrums.. ive read that lps outperfoms hps if you simply add a incandescent bulb to fill out the spectrum.

so basically the plant is fine with just one colour (orange lps) if even just a mininum of the other spectrums are there too.

so basically you could just use the most efficient ledlight and then add a incandescent or whatever to fill in the spectrum, doesnt have to be much, but i doubt they were using large wattage incandescents in that test, maybe 100w or 50w

actually testing that wouldnt be such a bad idea,

or just get a lps and some incandescent (oh i hate writing that word) 200 lumens per watt...

probably if you think about it, using just red light for flowering with a mininum full spectrum along...should be interesting, hps after all is just orange and misses the chlorofill peak somewhat, doesnt really have much real red, insome cases less then a mh...

though i hear white are the most efficient leds. from mr knna. i believe?

OzricTentacles

Oh i make a mistake, you can improve efficiency by using collimator lenses, i'm interested to use these lenses too, i have to read the Paulo Pinho disssertation. I'm french, french peoples are know for having big mouth, you can remove a thank from my bulletin. ;-)

After reading 2/3 of disssertation i'm not really convince, what i'm searching is mostly the interract of the photons with environment. I will continue my reading of spanish version of 'what is the light' from Knna. ;-)

mx5spd

On my never ending hunt for materials I found this site, it seems a little more noob friendly than some.

Luxeon Star LEDs, High Power LED Products & Accessories

knna

Hi, Algae grower and evreybody else.

Im back with my batteries full, but with lots of work in front of me. Please be patient while I take time to answer the questions, surely it will take some days.

You are right in the waste of using an inverter to AC and then again rectify to 12VDC. If you have an stable source of 12VDC, its way better to use drivers working directly from it. I have some of them on test right now, as Im very interested on building systems runnig off of solar panels. They are avalaible as well as drivers running from 120 or 220VAC.

There are two main types of 12V drivers. Those with linear control, that are cheap but only allows to run very short strings, generally no more than 11V, and switching drivers on boost (or buck-boost) configuration, than are more pricey, but allows to run larger strings, in some cases up to 60V.

Its possible to build your own linear constant current drivers using an LM317 or LM517 and a resistor, wich is a cheap alternative, or using cheap IC (integrated circuit) for constant current control, as the Infineon BCR 4xx and a power transistor (check Infineon page, you will find diagrams and all the info required to do it), that waste very little power, so you can get a system with efficiencies well over 90% for cheap (those ICs cost less than 15 cents on the industrial level, I dont know on the retail level). This is the way that uses most cheap arrays working from 12VDC. They are usually built with low power LEDs running at 50mA max, but in order to run the string at higher currents you only need to add a power transistor.

BTW, if you have several sources of 12V, you can wire it to get 24, 36, 48V...that allows to reduce the drivers required when using linear ones. Its done typically when using solar panels or batteries.

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mb777

Hey knna, love what your doing with LEDs. I was interested in doing a diy led set up. I read some of your posts, but to be honest your alot more educated than me in this area. Electronics talk is like chinese to me....Im sure that I wouldnt have any trouble assembling it (with instructions), but i lack conceptual knowledge required design my own. Do you have any suggestions on LED set ups that i could purchase? I feel that over time my saving in energy and maintaining temp. will eventually make up for the price of the light. My main concern is getting the right spectrums for cannabis and that it will last me a long time.

mb777

knna, if i may suggest this......i think you should go into business. you seem to know more about cannabis and led's than most of the people making them. I know I would definitely buy an LED setup that had a grow journal actually proving it worked on weed, not just letuce or tomatoes.

OzricTentacles

I reply for him, i’m french ;-)

Resume of the Knna DIY

You need :
Anodised aluminium surfaces
Kapton tape (electric isolator)
Copper tape( 1 face and 2 faces adhesive)
Leds (Osram Golden Dragon plus) : (following bins or better)
-Red: 638-642nm peak, bin JX (45-52#400mA, 1.13W)
-Coolwhite: Tone 6Q (6200-6400K), bin KZ (97-112lm#350mA)
-Royal Blue. Bin 1U (450-500mW#350mA)
Drivers for (90-264VAC, 50-60Hz, depending your region) to( 24v to 48v, depending your culture space) (700mA) or (600mA and 700mA)
Soldering material (that’s it)

First you have to determine you culture surface, you can go small for led culture but the harvest will be small too. ;-)
The minimal set for growing is : 3 red 1 cool white 1 royal blue (9Watt) (for approx 1,25 cubic feet)
and the minimal set for blooming is : 9 red 2 cool white 1 royal blue (35watt) (for approx 2,4 cubic feets)

Like a cuisine recipe you can add set in proportion for more space ;-)

You need to cover your square area in your leds distribution, the best is not using fan for cooling your aluminium heatsink, if you can find aluminium scrap is the best but you need surfaces, there’s only one solution about commercial heatsink’s it’s Heatsink USA iic.

You have to place kapton tape first on heatsink and after you place copper tape adhesive one face, the led leg will be soldered there, put a horizontal double face adhesive for heat dissipation contact with the heatsink, put another single adhesive copper tape for other pole contact, you will solder the other leg there, you make the same for all leds, the positive and the negative have to be in the same way, this is what called serial connection.
Check my drawing model here:

http://www.gardenscure.com/420/1321340-post168.html

Oh i forget electricity :
Red - bin JX
at 600mA-2.34V (1.4W): 22.4% 1,63µE (1,16 µE/W)
at 700mA-2.44V (1.708W): 19.1% 1,69µE (0,99µE/W)

Coolwhite - bin KZ
at 700mA-3.46V-(2.422W) 2.05µE - 0.85µE/W

Royal blue - bin 1U
at 700mA-3.42V - (2.395W)- 2.6µE -1.09 µE/W

For compute the driver needed you add all the voltage on your line and multiply by amperage.
EX : for one set for growing (3 red 1 cool white 1 royal blue ) = (3 x 2.44v +3.46V + 3.42V) * .7A
You need 700mA - 14.2V (preferably more than 15V) and 9,94watt (preferably 12W)

The µE is the mol of photons emitted, what is the real light energy absorbed by plants, a 400w HPS emit approx. 650 µE but the plant have to share with some parasital receptor this large amount of photons. ;-)

That’s all

Now Chinese lesson 1 : - equal 1 = equal 2, you know 2 Chinese symbol now ;-)

PS : Knna you can correct my mistakes. ;-)

knna

That system will work. But its possibe to do it with less work. Put a katon tape strip of 16mm in the center, and two paralell rows of LEDs on it, one at a 8mm side with the Red LEDs and the other on the other side with the Whites and Blues.

This way, copper traces may be straight, saving lots of time to build the circuit.

Anyway, remeber to give an small solder point if you build 90º changes with copper tape, joining both tapes. Although initially it may work, with time and temperature adhesive may fail, cutting current flow sharply, that is one of the most common causes of catastropic failure (meaning that often it damage LEDs). Always ensure the copper circuit is complete and wont break at any point, aswell as all wires are well conected and secured.

If you build the string the way Im saying, the thermal pad of LEDs will go over the electrical conection traces. There is no problem in that, as far as you put a strip of kapton between both copper tapes, so they are electrically isolated. Indeed, this configuration is good from a thermal viewpoint, as it uses the copper traces as extended thermal pads.

Pic of a double circuit built this way:



Notice the darker areas where narrower copper traces goes over copper thermal pads of the other color's circuit

Attached Thumbnails

 

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knna

You can run several drivers from the same power cord plugged to the mains, still if its not thick. Just wire all drivers in paralell from that cord.

Be carefull with drivers that state a given range of LEDs to connect. They always refers to white LEDs, that runs on higher forward voltages than red ones. 5-9 LEDs usually mean it have an output of 20-36V or so. 36V will allow to connect up to 15 red LEDs to that driver.

PS:sorry, Ive seen Ozric Tentacles had addressed thip topic before. Thanks, mate!

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knna

Hi, AK-Northern, thank for your kind words.

LEDEngin build their high power LEDs using low power chips arrays, at least on the deep red, which is the wavelenght range they have avalaible that most manufacturers dont. They are of old AlGaAsP technology, little efficient compared to modern AlInGaP and with little room for improvement.

They work very good, but IMO are very expensive attending to their 22% max efficiency, when there is several other red LEDs with efficiencies past 30%.

If manufacturers insist on not selling 660nm AlInGaP chips for a little more, Ill order them directly from chip makers. They are not only technically possible, but have the highest efficiencies (radiometric, not photometric) into the red range. I know for sure that some chip makers are doing them and yielding efficiencies well past 30% and premium wafers reaching 40%.

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