Building LED lights from facts, no theories

I have decided to reduce module wattage to under 10 watts down from 13 to 15, driving at 350ma (max.400ma) I will have to add 4 more modules to compensate.
This will give me better top coverage, longer LED life and easier to regulate with a resistor. Of course I give up some brightness that would help with penetration.

My LED selection is based on what I have on hand, instead of what is truely optimal.
Each module will have
4 red K2s, R (second) bin.
1 k2 royal blue, Q (top) bin
1 SSC cool white, top bin
1 SSC blue, top bin.
Resistor to drop 1 to 2 volt.
I plan on using this for vegging to replace a 350 watt CFL array.
I will be playing around trying to flower. I will be adding a couple additional 2.5 foot long strips of red and far red LED during the budding period only.

I don't have high hopes for the budding and don't think it will replace HPS, but I would really like to trash the vegging CFLs and save a couple hundred watts if possible.
Do you guys think the LED color selection is close to optimal for vegging? I might be able to squeeze an extra red LED in, if real Vf's are lower then spec sheet.
I would like to start wiring LED modules this week.

Once I get things going and have unit in operation, I will probably replace resistors with regulator. I will look for one with a lower drop out voltage. With LM317s they use a much power as an LED. I hate to give up that much wasted power.

I did decide not to initially go with fans on top of each module, but instead will be blowing air across the tops of the heat sinks. Fins will be aligned in direction of air flow.

It looks like warm white and farred are providing the mechanics that are needed in early and efficient flowering within cannabis and most likely many short day flowering plants.

2 Warm white (3000k) led with red x6 630 and red 660 x 10 and farred 730 x1, blue 455 x1, blue 470 x1 with 25deg lenses on the reds and 40deg lenses on the blue are giving the results that all are after. If I could only find a good 440nm blue to replace the 455!
If cree would make a 660 and 440 :-(.

The lenses are making a huge difference. even though you loose roughly 12-15% of the lux, the luminous intensity is focused much more efficiently with little or no light scatter. :thumbsup:

I have not been able to try results of near UV {400-425nm}
Thats next. W00T!

Billyjo :pimp:

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Originally Posted by billyjojimbob11

It looks like warm white and farred are providing the mechanics that are needed in early and efficient flowering within cannabis and most likely many short day flowering plants.

2 Warm white (3000k) led with red x6 630 and red 660 x 10 and farred 730 x1, blue 455 x1, blue 470 x1 with 25deg lenses on the reds and 40deg lenses on the blue are giving the results that all are after. If I could only find a good 440nm blue to replace the 455!
If cree would make a 660 and 440 :-(.

The lenses are making a huge difference. even though you lose roughly 12-15% of the lux, the luminous intensity is focused much more efficiently with little or no light scatter. :thumbsup:

I have not been able to try results of near UV {400-425nm}
Thats next. W00T!

Billyjo :pimp:

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:postgood:


Aloha BJJB

I'm sold on lenses.
They give me penetration I wanted,
and the lensed 5 watters are outperforming the un-lensed w/reflectors almost 2:1
IMO, 160 degree/lambertian is a waste of watts.

ciao,
Weezard

Weezard, I'm planning to homebrew a version of your 4+1 x 15w. light. :thumbsup:Looks like the Ledengin LED's have a 90-110 degree beam, though. Would you recommend additional optics or did the 15's work okay for you unmodified?

Also, MPJA has a 28v. / 5.5A power supply (the 24v. is out of stock for awhile). I was thinking getting one to power 2 parallel legs of (2) 15w. 660's, with an LM317 on each leg. Am I just making extra work for myself by not running a 24v. supply into a single LM317 and parallelling (4) 660's off the 317? Seemed like a bit of current to push through a single 317, but I don't really know.

I would like to underdrive the LED's slightly, and have some extra headroom in the build. Thanks!

Quote:

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Originally Posted by Crunchypants

Weezard, I'm planning to homebrew a version of your 4+1 x 15w. light. :thumbsup:Looks like the Ledengin LED's have a 90-110 degree beam, though. Would you recommend additional optics or did the 15's work okay for you unmodified?

Mine are mounted in a deep aluminum cake pan which serves as a reflector.
Didn't find lenses for the ledengins but the 5Watt leds that I lensed are clearly better than the same configuration without the lenses.
Would call it proof if the red leds were identical.
The lensed set is 660nm., the un-lensed are 625nm.
Perhaps the difference in efficiency compensates.
Ah dunno.
I just ordered more lenses.
Will install them on the 625nm lamp and start taking pictures
of the progress.
If you find, say, 40 degree lenses that fit the 15W ledengin lens, please drop me a line.

Also, MPJA has a 28v. / 5.5A power supply (the 24v. is out of stock for awhile). I was thinking getting one to power 2 parallel legs of (2) 15w. 660's, with an LM317 on each leg. Am I just making extra work for myself by not running a 24v. supply into a single LM317 and parallelling (4) 660's off the 317? Seemed like a bit of current to push through a single 317, but I don't really know.

LM317 has a absolute maximum of 1.5A!
You might want to use an LM138 - 338 instead.

Driving an approximately. 12V led from a 28V supply will work well if you run the 2 parallel sets in series.
That will give you 4V headroom but would have to pass 2.1A.
That would require a pass transistor, etc.

So the LM138 series with a max of 5A. would probably serve better for ease of design.
Google the LM138 series for a quick and easy schematic.

The problem then is the blue led which uses closer to 15V, for peak efficiency.
I use 2 separate supplies because dissapating "excess" energy just rubs me the wrong way
My next ledengin lamp will have 2 Blues.
The goal here is to waste as little power as possible in the regulator.

I would like to underdrive the LED's slightly, and have some extra headroom in the build. Thanks!

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Good idea!
I limit mine and use a thermal switch in series with the fan to keep everything under 50C.
Better Photons:Watts = less waste heat to deal with as well.

Easy lamp to build and it will work for flowering.
Mine covers app. 2 sq ft. and takes 2 or 3 weeks longer, start to finish, than HPS.
But the quality?
Wicked good!:stoned:

Let me know if I can help.

Aloha,
Weezard

Quote:

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Google the LM138 series for a quick and easy schematic.

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Okay, glad I asked.

Quote:

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The problem then is the blue led which uses closer to 15V, for peak efficiency.
I use 2 separate supplies because dissapating "excess" energy just rubs me the wrong way
My next ledengin lamp will have 2 Blues.
The goal here is to waste as little power as possible in the regulator.

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Yes, I think I've read everything you've offered on this board (and Steve F.'s as well) and had already planned using a 19.5v Dell PS for the blue(s) as you have mentioned. I am still deciding whether to add a second blue to my plan, or a warm white instead. I realize the white is a crippled blue, so to speak, but I might like the WW just so I can view my hobby better. Not so sure I need all the blue 2 x 15w. would provide. I have a Procyon and although it is probably the best thought-out compromise of ratios for overall use, it's a bit blue-heavy for mid-late flowering, IMO. (Works great as for transition into 12/12 from veg, though.)

Anyway, thanks. I have read a lot of posts, and of the many knowledgable folks contributing on this subject your explanations are by far the clearest to me.

Yes, the lenses are far more efficient than without IMO. Also, the light is culminated which, from what I understand, makes absorbing the photons more efficient. I think lenses will be an absolute must when building a highly efficient array, unless the emitters use a very narrow angle already.

I've been researching LED's for a couple of weeks now. Reading everything I can on the subject mostly from this forum but from others as well. This thread is the most comprehensive on the subject of what LED's (and their various qualities) to use and how to use them. Really good stuff.

But what I haven't been able to find is a clear picture of exactly how to build a proper, efficient, and effective LED lamp or strip or board or square. Whatever you would call it.

What I'm talking about is some instructions on how to put together your own LED grow light from parts easily available on the internet or your local Hardware/Electronics store. But I'm not asking for a beginner guide such as.

"Hook up a 12v power supply to your LED's with this resistor."

I want something that will actually work and work well.

If I had the option of requesting such a guide I would ask that it contain the following:

A guide where you actually build or explain how you would build a decent size array of high powered LED's such as the Cree LED's that would function in the real world of a grow room.

A brief explanation on Power Supplies and why you are using this particular Power Supply and which ones work best for LED's and why.( I realize this may depend on your setup and how large or small it is. But answering the question for the array you are building and then giving a small tidbit on what might work for smaller or larger LED's arrays would be helpful to everyone whatever kind of LED grow light they are trying to adapt to their current setup.)

An brief explanation on LED drivers and how to apply them to your LED grow light.

How to pulse LED's using cheap and easy to program micro chips such as the Picaxe Micro Controllers ( PICAXE ).

The best way to limit current without using a bunch of resistors that burn power and create heat. I've heard allot of technical names thrown around such as "transistors" and many others. And many good explanations and threads are out there on what these things are but not so many on how to apply them to your LED grow light.

How to put the Power Supplies, LED Drivers, and Micro Controllers all together to do advanced techniques such as the "Martian Method". Whereby you might have a string of Far Red LED's continue to pulse for a predetermined amount of time into your Dark Period or Lights out Period of your grow.

Touching on things such as Pulse Width and Variable Frequency(for different types of LED's)

How to string LED's together and a brief explanation on stringing LED's In Series and Parallel and how doing this affects the final results as well as the voltage/amperage/wattage/current and the pros and cons of each.

What to mount your LED's to. And how to string them together.( As in the actual material for connecting them.)

How to apply proper cooling methods such as mounting your LED's to cooling fins.

And anything else that would come up in the building of an LED grow light.


I realize that many of these questions have been answered before, some even in this thread but none of them have been put together in an easy to understand practical format that even beginners can start to grasp.


Now I'm not asking for everything to be handed to me on a silver platter.
I've personally started my quest for building a LED grow light by picking up some cheap LED's, a power supply and I even ordered a Picaxe micro controller to start playing around with. And I have no dout I might eventually figure it all out. But that will take quite some time and many people won't make it through the journey, choosing instead to give up on LED's and stick with HPS/MH or buying LED Lights such as the UFO or Pyrcon. Never being able to realize the benefits of building your own custom arrays and spectrum's in a way that fits your own grow room and style.

I believe even a small guide to building a basic LED grow lamp that covers all the material above would improve the communities understanding of LED's and bring LED's down to a level that everyone could get involved with. What could spring from this is more people using LED's and more and better styles and techniques being developed. With a large enough community behind building their own LED's group buys could be organized such as those going on at the Spanish forum that Knna is apart of. Making top notch LED's such as Cree more affordable for everyone. Even those looking into smaller projects.

If this is beyond the scope and discussion of this thread then I ask that someone create a new thread dedicated to showing people how to build LED's and answering questions they may have along the way.

Thanks for reading.

" I ask that someone create a new thread dedicated to showing people how to build LED's and answering questions they may have along the way."

Aloha Nodestar

You might want to look at;
"Calling out to Weezard for led advice"
In the indoor lighting forum.
Sounds like it's just what you are looking for.:cool:

If not, tell us why.
We aim to please.
Regards,
Weeze