DIY LED red/white

[sm0k4]

So it would be nice if you could rope your cloning LEDs into the vegging LED string and enjoy the 90% efficiency, but the downside is that many growers veg for 20/4 and clone 24/0. A commercial greenhouse grower with 45 years growing experience (non cannabis) I spoke with swears by 24 hour light for cloning but advises against it for basic vegging.

One thing that comes to mind is cloning only takes a couple weeks. The little waste is probably not a huge issue. It comes to however you can make things work sometimes. It would be real hard to find a 5-6V 90% efficient supply at a decent cost. Plus with the energy savings by only running a few watts, you are already way ahead of any floro or HID for the same task.

Tit for tat in this case, IMHO.

So there are some losses through the AC/DC rectifying (less losses with a switching supply), but I can live with that for now until I get set up and have more time to do another driver design from a mains supply. It is still using less energy than a similar HPS. Its hard to design a rock solid and totally efficient product that is also modular and easily customizable to a space the first time out of the gate, but eventually we will get there.

 

[blimblom]

I second sm0k4. cloning with a 2watt LED 24/0 with Li-Ion is certainly no efficient by any measure, but its only a 2watter.

Scalling it up isnt in my interest, Im just a small time grower, growing for my personal needs and LEDs are so efficient in this small scale. So its one driver for vegging, 2 for flowering.

So where did you use your old Blue Leds from the flowering setup??

 

[SupraSPL]

Yeah in practice I do the same thing. My cloning LED dissipates 2 watts but it is powered by a tiny constant current driver and the input power is about 4 watts. The next best thing I could use would be a 10 watt compact fluoro but I think the LED could cover more area than the 10 watt fluoro.

There were only a handful of blue LEDs in my first flowering setup and unfortunately I burnt most of the out because of a faulty driver. The driver worked fine when I tested it but after I built the first few vegging modules it burnt out the string repeatedly. Luckily the were small strings but it was an expensive and frustrating process figuring out that the driver was at fault.

 

[sm0k4]

Got a new light built up with a home made heat sink. I managed to find some left over Aluminum sheet stock and 3/4" x 3/4" aluminum angle stock. So I had the bright idea to add the two together for my own customized size. I sanded the surfaces that would be mating together with 100 grit, then again with 200 grit paper. This gave a smooth but slightly scratchy surface for the heat sink compound to fill in. After a thin and even layer of heat sink paste is added, I bolted the pieces together to give me cooling fins and more surface area. The heat transfer I got was better than I expected. This might also be due to the heat pads I tried out. I decided to try a double sided tacky pad at 4.1 W/mK thermal conductivity. It is Digikey part #: 3M9593-ND. I used too much also. You could cut these to just the size of the LED and will be good to go. I over compensated for this build.

This will go into my PC case I am almost done building. Finished the light two nights ago but blew up my power supply while trying to limit the fan speed due to the loud noise it makes, haha. Its always best to tinker with electronics with the power OFF, this I know. Nevertheless, I found the part I blew up and have 2 samples from the company on the way free of charge. They should be here today. I rigged up a couple 12V supplies in series though to test my light out last night.

There are 16 LEDs on here and I ran my test run last night with 500mA. This will give me around 21 Watts. I have two circuits on here. They both run at around 21-22 Volts. They are ran in parallel off of one driver. The CAT4101 driver can handle 25 Watts. The great thing is the CAT4101 isn't even hot running it near max load. Very efficient driver as long as you keep the voltage on pin 5 close to but always over .5 volts it will run luke warm. The drawback is the supply needs to be adjusted when you boost or reduce the current. Otherwise the driver will heat up due to excess voltage coming into pin 5.

With passive cooling it took nearly two hours for the light to feel even remotely warm. I wouldn't even call it hot, probably 25-30 Celsius. The only LEDs that get my finger hot when I hold it on them were the blues. Can't tell if this is due to under driving or just due to less efficiency in that LED. Reds feel warm, whites fairly hot, blues are almost to the point of pulling the finger away but not quite. The heat sink home brew impressed me and worked better than I hoped. Hopefully it is robust enough to last 4-5 years in this small PC cab so I can use it as a clone/veg chamber.

Enouh of the babbling, here are the pics of the general idea. I will post up a DIY tutorial thread when I get time. I have more detailed pics, just busy atm.

 

[Voidling]

2'x2' vegging area. 26 dissipation watts spread across 6 modules for vegging:

I'm not sure what you mean by dissipation watts. I used a spreadsheet that sm0k4 linked me to and it said I needed 86+ watts for a 20in x 18in cab.

I'm trying to do like sm0k4 with a perpetual grow so I'd have mothers and rooting clones in the same cab. Once roots established they'd only veg until an opening was made in the flowering room.

I need to find the spec sheets on the specific leds so I can plug the right values into that spreadsheet and trying to figure that out.

Does knna have his website up yet? I'd love to be able to get all I need in one spot. I'm in the middle of my cab build and need to get my lights figured out asap. I'm hoping to afford led for the mother/clone/veg side to keep from any additional heat problems. Rough estimate on price for this size area? It would be much appreciated.

Thank you

Edit:
sorry Sm0k4, I saw your answers on the other thread after I posted this.

 

[sm0k4]

I'm not sure what you mean by dissipation watts. I used a spreadsheet that sm0k4 linked me to and it said I needed 86+ watts for a 20in x 18in cab.

I'm trying to do like sm0k4 with a perpetual grow so I'd have mothers and rooting clones in the same cab. Once roots established they'd only veg until an opening was made in the flowering room.

I need to find the spec sheets on the specific leds so I can plug the right values into that spreadsheet and trying to figure that out.

Does knna have his website up yet? I'd love to be able to get all I need in one spot. I'm in the middle of my cab build and need to get my lights figured out asap. I'm hoping to afford led for the mother/clone/veg side to keep from any additional heat problems. Rough estimate on price for this size area? It would be much appreciated.

Thank you

Edit:
sorry Sm0k4, I saw your answers on the other thread after I posted this.

Dissipation watts is what the LED is emitting at the time. You can change up the current and that will change the watts the LED burns.

BUT, since LEDs still aren't totally efficient, they burn off 50% or more energy as heat. So the harder you run them, the hotter they get, the less efficient they get, the less lumens per watt are released. Still more lumen output, but at the cost of more burned energy. For most this isn't an issue. For some, they want max efficiency. If you aren't worried about wasted energy, 5 watt emitters would burn brighter but hotter. Weezerd uses them, they do grow some buds.

I'm looking for minimal wasted energy and minimal heat for a long lasting light. I believe I have a good start, the heat sink I made is quite effective at pulling the heat away. The LEDs I use are for my personal setup and doesn't mean they are the only ones to be used in horticulture. You can probably get away with cheaper 1W emitters like Avago for vegging. A little less output that Osrams, but you aren't budding so they might suffice.

Also that calculator is if you want to fully bud out your plants. You can modify it by changing the gray Watts per square foot cell. Figure out what the normal wattage per square foot is for veg and stick that number in.

 

[Voidling]

Thank you.

I'm worried about the heat which is the result of wasted energy so I should go for efficiency, but I'm sure jealous of weezards lights. I'm reading the thread where he helps someone build one. I think I'm going with the knova's and the golden dragon's

I plan to over build it and throttle it back. That way I have some room to play with going up or down as I need.

 

[asde²]

whoooopie

whoooopie

whooops

 

[sm0k4]

Thank you.

I plan to over build it and throttle it back. That way I have some room to play with going up or down as I need.

Thats what I did. I calculated the total power output I would need at 500 mA of current through my LEDs. I gave it room so that in flower if I want to go up to 6-700mA, I can.

Then you have to watch out for your driver max. output. Running more current and voltage requires more supply power. The driver should be selected by calculating the power draw at the maximum current you want to run, then overshoot that by 15-20%.

 

[SupraSPL]

Good looking build smok4. Thanks for the tip on the thermal pad. I have some whites running at 450mA. Same thing heatsinks are lukewarm and when I put my finger over the white it is cool to the touch but after a few seconds heat starts to build up and I have to remove my finger. Reds are lukewarm.

When I refer to dissipation watts I am excluding the losses in the driver. The reason for that is because HID bulbs are sized by their dissipation and ballast losses vary. My smallest drivers are 50% efficient and the larger ones are ~90% efficient so I am more interested in comparing the performance of the bulbs rather than the ballasts, at least for now.

 

[SupraSPL]

Finally starting to see the results that I have always expected these lamps to be capable of. This is an Apollo 13 BX seedplant from TGA flowered under the red/white LED. It was grown in 1.5 liters of recycled organic soil that is 26 months old. The plant was topped/fimmed along the way and gradual defoliation was used to expose all bud sites to light.

It was just a single test bean so there was no selection for yield and it does not seem to be any sort of huge yielder like NL. It was in flower (11.5 day/12.5 night) for 62.5 days and yielded 17.9 grams of pine flavored bud. It received an average of 8.3 dissipation watts so that works out to 1.94 grams/watt/56 days



I am excited by the results but still there are some easy improvements. I faded it too early, it stretched too much because it was a seed plant and it was not selected for yield or necessarily a high yielding strain. More cuts will finish and get measured in the next 3-4 weeks so hopefully they are somewhat close to this result so it is repeatable.

As far as the lamp I think I have a more efficient spectrum to try out next and the new deep reds we have on order are 30% more efficient. I am blown away!

 

[Weezard]

Well done!

Well done!

Good job, brah!

 

[sm0k4]

Excellent Supra, more evidence LEDs are not Leggo toy laser lights of the future with no growing purpose

Who needs tennis ball sized nugs when you get that kind of quality and almost 2 g/W from half the wattage.

Thanks for the build props, I got a good system down and building panels is a cinch now. Just need the right tools for the job.

So that was just Red/White then? Weezard relies on Red/Blue spectra, so it appears that the whole range will work.

I think its suffice to say that LED will grow some good MJ plants, now what spectrum or spectra combo is optimal? That is the million dollar question. KNNA might be the first to break that code though. He is a mad scientist when it comes to lighting.

 

[SupraSPL]

Yes that was red/deep red/cool white spectrum, probably with an excess of white. Next time I will stick closer to KNNAs recommended spectrum for the new deep reds.

I agree I could care less about nug size as long as the trimming is reasonable. If this girl had not stretched as much trimming would have been much easier and colas much longer. If I needed larger nugs I would have to use a lollipop SOG method which is more work than topping in this case. Pics coming soon of a caramel ice from positronics that looks very promising with long running colas and great classic skunk structure.

 

[blimblom]

SOG on sativas isnt exactly a winning solution I think. Sativas with their stretching potential are more apt to SCROGs.
SupraSPL if you dont mind hijacking your thread, I'll upload a pic of my heatsink which is quite ready (just waiting KNNAs LEDs)

 

[SupraSPL]

I used to spend a lot of time on LST but laziness lead me to topping fimming and defoliation which has been working great and still keeping short enough in most cases for LED without side lighting.

Sure lets have a look at it. What do you plan to use for thermal path?

 

[Voidling]

Defoliation can sure keep a plant with tight internodes. Mine all ended up male, not even hermies, flat out male. The one that turned out to be female I accidentally killed by over doing the defoliation though might of been more to it. It had split in half after the second node.

What is the more efficient spectrum you're planning on trying Supra?

 

[FreezerBoy]

It had split in half after the second node.

D'oh!

When this happens to me from super crop (folding the stalk over) I just straighten her up, wrap a twist tie around the break and she usually heals in a few days.

 

[SupraSPL]

Sorry to hear about the defol problems and males. I missed out on trying NYCD and Mandala #1 due to males and fungus gnats killing seedlings so I'm with you in that boat. I don't normally defol a plant much before it is sexed and when I do defol I do it gradually. A few leaves a day per plant if it looks like it needs it, maybe that will help in the future.

My next spectrum will add blue back in, use much more efficient deep reds and decrease whites. I will be running the white/blue string slightly lower and the red string much harder. KNNA posted this on GC 11/18/2010:

"For the bins Im carrying now, a 18R:3W:2B (10 635nm/8 660nm if wanting to use 660nm red [1T]) is a little more accurate than 9:2:1. But this ratio is based on reds running at 570mA, and B/W, at 670mA. If you run them at same current level, then use 16R:3W:2B, give or take. Anycase, those are orientative figures, spectrums work fine if you dont use a drastically different ratio."

Since then he has upgraded from 1T to the 2T bin for the Golden Dragon 660s and downgraded from the 1U to the 4T bin for the GD blues.

He posted this more recently when someone inquired about cost:

"For example, a configuration with 28R (635nm)+22DR (660nm)+8W (6500K)+5B(450nm) on 2 drivers (about 100W) would cost about 258USD . Heatsink, about 55$. A minimum configuration of 70W, consisting on 20R+16DR+6W+4B on 2 drivers, 185$ and 39$ of heatsink. If budget is reduced, always is possible to use just the cheaper reds and skip deep reds, reducing cost."

 

[SupraSPL]

+1 thank goodness for twist ties