budderlvr Modular LED Project

I am working on a new modular LED grow light. This thread will be a diary of my experience as I work through some of the many design problems.

Currently I am at the circuit design phase. Although I do not want to reveal too much of my design at this point I will provide some information that has guided my decisions.

The LEDs I will be using are from Lumiled. I am using the Luxeon K2s for the blue spectrum, and Luxeon IIIs for the red spectrum. The ratio of RED to BLUE (I will call this the R:B ratio from now on) is going to be 5:3 for the first board. This has more to do with cost than anything. Other threads get into more detailed discussions, but there no solid scientific evidence that I can see for any ratio - there are just too many unknown and variable factors at this time. My impression however is that BLUE LED light is at a part of the spectrum where the human eye is less sensitive. Actual luminous flux (SI unit is Lumen or lm) in BLUE LED light is deceiving because it may only be listed at say 23 lm on a datasheet, but that is corrected for the human eye - not the chemicals involved in photosynthesis (namely chlorophyll - look it up on Wikipedia). The third factor in choosing a 5:3 ratio is that RED light is more important in the flowering of the plant. More RED means more energy that the plant needs at flowering. I am totally open to comments or suggestions on this point in particular, as my science is sketchy at best.

As far as supply for each light module, the design will use a standard ATX power supply. Since this is a modular light, the wattage of the power supply is totally dependent on how many modules are used. I am hoping for a total power around 100 watts with 3 to 4 modules, and a light efficiency of about 80% of the power being used to produce light. To accomplish this, the design will incorporate LED driver circuitry for each color. This will also allow for future use of PWM drivers from a control circuit or computer which will be used to experiment on varying the ratio of RED and BLUE light.

I am by far no expert in lighting or growing. But I do have a strong electronics background and design circuits every day for my job.

Any input that you have, feel free to post it on this thread, but try to keep it relevant. Personal attacks should be done by IM.

Thanks for reading, and keep on toke'n. :rastasmoke:

Subscribed! I am at the edge of setting up and want LED's so bad! DB; WT have very interesting ones. Because I am cheap, I'd like to see cheaper, but may have to go that route, while waiting for the perfect LED and cooling system mix, as per your last post regarding matter in other thread! Thanks for doing this for us!:jointsmile:

Cheap is a ways away. My early projections would price each module around $75, so for an equivalent to the Procyon would be about $400 after you get a power supply and everything.

I have a hard time believing that heat will be a really big issue. I have a 650 watt power supply in my computer that is 85% efficient and it puts off very little heat. According to the datasheet on the K2s, they can be mounted on FR4 (regular PCB material, without metal core). The trick is using their pad design, coupled with a heat sink on the reverse side.

I am going to try digging around for some temperature info from other posters, perhaps someone could post their normalized heat sink temperature or the temperature of the metal core on their Luxeon Star.

?!?!?!?!?

Wow, all this talk of do it yourself LED boards has my brain twisted in a knot. Yikes, I'll try to watch this one if you would kindly put your process and materials in english, you don't have to, it would just make it super easy for all of us electrically challenged people out here.

:thumbsup:!!

SunnyD, this project is along the lines of an early commercial product. I am not going to get too technical because that would reveal my electronic design, which is not complete.

I do need to change one thing tho, the R:B ratio. I was hoping that the LED driver I selected would be able to drive enough current to run 5 RED, but that pushes things a bit too far. So I am going to drop it back to 4 RED Luxeon IIIs.

I am wondering why you are using the red Luxeon those are 635nm ??

veggi,

I picked the Luxeon III because it has a higher luminous flux than the K2, and they both have the same wavelength (and the same supplier - Future Electronics).

Would you recomend going with the LEDEngin red at 661nm? I am still trying to wrap my head around converting between lm and mw of Luminous Flux.

Since I have your attention, would you still recomend the K2 for the blue spectrum? Or has everyone gone to LedEngin?

Thanks for your post veggi! Made me rethink some things.

Okay, why even stack LEDs when you can buy 1 10w LED from LedEngin?
Now I am thinking about putting 1 BLUE LED (LZ1-10DB05) and 1 RED LED (LZ4-00R215, this is a 15w device).

Would it be okay to assume that the luminous power efficiency of the LedEngin High power lights is about 20%, meaning that 20% of the electrical power is converted into light energy?

Thanks again veggi, this is what has been bugging me since I started working on the controls for the Luxeon K2 and the Luxeon III.

Now I am thinking of just having 12v across each high power LED bank with space for a relay or transistor that I can add in the future.

EDIT: A lot of these devices are back ordered.

Quote:

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Originally Posted by budderlvr

Would you recomend going with the LEDEngin red at 661nm?

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Well I certainly would recommend 661 over 635, since it produces roughly double the chlorophyll activity.

Keep up the good work.

budlvlr it seem you might be miscalculating your red to blu ratio's/ approx 80% red / 20% blue yours seems close to a 50/50 ratio, am I reading your ratio correct??

veggii,

I know what you are saying, I should have thought about that post a bit more before I hit the post button. What would you say to 3 RED to 1 BLUE.

These are the RED lights I am looking at:
LZ1-00R205

These are the BLUE lights I am looking at:
LZ1-00B205
EDIT:
These are in Stock
LZ1-00DB05

Please be patient with my questions in this thread as I am trying to ease myself into the world of LEDs.

Have you decided to go with LEDengin with both your red and blues? and if so did you say they're both rated at 661 nm?

SunnyD,

I think you are confused about what "661nm" means. 661nm is a particular wavelength of electromagnetic radiation. It happens to fall inside the visible light portion of the Electromagnetic Spectrum (Electromagnetic spectrum - Wikipedia, the free encyclopedia).

Plants (any by plants I mean GREEN PLANTS) have a process known as photosynthesis that transforms electromagnetic radiation into energy for the plant. Studies have shown however that it is specific wavelengths of light that the plant uses. Until LED, there were few viable options to test this theory (putting filters on full spectrum lights would be an example). There have been a lot of other posts that describe what wavelengths the chemical chlorophyll (the primary chemical in photosynthesis) respond to most. If you don't want to do your research, there are basically two areas of the spectrum that chlorophyll responds to and they fall in the extreme blue visible and the extreme red visible. These colors appear to humans as deep red, and true blue.

I am sure if I don't say this someone will correct me. Plants also respond to other colors, including green. Blue and Red are the two that plants absorb the most. Colors near green and green itself are the least useful because they are mostly reflected, not absorbed.

I just re read your post before I put this up, and this may all be information that you already know. The BLUE LedEngin that I am looking at for my design emits light in a range from 445-475 nm, and the RED 655-670nm.(EDIT: I MAY STILL USE K2s for the BLUE, I need to sit down and do some serious math before I spend some serious cash)

On a slightly off-topic note, "Procyon" means "before the dog" in Greek, and is the scientific name for the raccoon. I wonder why they named their LED light after raccoons?

Quote:

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Originally Posted by khronik

On a slightly off-topic note, "Procyon" means "before the dog" in Greek, and is the scientific name for the raccoon. I wonder why they named their LED light after raccoons?

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lol...i think it was named after the star, its one of the brightest in the sky.
sorry for the jack. keep up the good work though:thumbsup:

db:smokin:

Word of caution on the LEDengin's. I couldn't find any binning info listed for the LEDengin offerings on the Mouser website. My guess would be that they are selling the lowest bin. The 660nms, I received seem to bear this out.

I would only use their 660nm since they are the only game in town. For everything else no reason not to consider Luxeons, especially since they are cheaper and you can hand solder the bare emitters.

I am also wondering how much better penetration you get with multi-die LEDs compared to singe die. What is better using 3 single die leds at 2 watts or a triple die LED at 6 watts?

Notice on Mouser's part numbers they drop the last four digits which is the bin code? I wonder why?

I noticed the same thing today, but didn't really think anything of it until you mentioned it now. For those who don't know, LedEngin has multiple "bins" for each part, and some are better than others. Much like how intel used to use the inferior pentium dies to make celeron processors(or at least so the rumor was).

Multi die comes back to weather it is better to focus more light in one area or spread it out. With LED the advantage will be for situations like SCROG, where you can place the lights very close to the plant. In that case its really price as the limiting factor - how much are you willing to spend per light. If you could have an 8sqft array with all LedEngin multi die leds, that would be ideal. Then your limiting factor would be more about heat dissipation than anything else.

Has anyone tried a cluster type lighting system? Where you would have small clusters of n LEDs and then strategically placed in nodes around the SCROG. My thinking here is that the plants would cluster around points of light and be easier to manage when the screen is removed. I was thinking each cluster would be around 30 watts of leds (80% RED and 20% BLUE?). This would make the ATX power supply really easy to implement, and would solve some of the cooling issues by spreading out the heat.

Quote:

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Originally Posted by budderlvr

I just re read your post before I put this up, and this may all be information that you already know. The BLUE LedEngin that I am looking at for my design emits light in a range from 445-475 nm, and the RED 655-670nm.(EDIT: I MAY STILL USE K2s for the BLUE, I need to sit down and do some serious math before I spend some serious cash)

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Ha, don't worry about that one man, I knew all about the first two paragraphs you posted but it was good information to put out there nonetheless, YAY PHYSICS AND BIOLOGY CLASS! There's nothing wrong with recapping stuff!!

I guess I could have phrased my Q a little differently but no matter. What's the major differences between your LedEngin Blue's and your K2 blues? Maybe we can help you decide?...just a question

Bud,
That is what I am building now, small light modules spread out over the grow. I have had most of the material for a couple months and am now just finding a few moments to get started on it. I got a seperate thread going that gives construction details.

Bud,
I think the limiting design factor for LED Arrays should be watts per square foot of grow. The whole point of spending all this time and money is to use less electrical power to get an equal to a higher power HID.

I have limited my designs to a max of 35 watts per square foot. I would say most HID users are at 50 to 60 watts per square foot. I feel getting even a 30% power reduction would be highly significant and well worth the extra $$$.

Quote:

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Originally Posted by budderlvr

For those who don't know, LedEngin has multiple "bins" for each part, and some are better than others.

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All LED manufactures have multiple bins, they're just not talked about much at places like ebay. When you buy the cheap ones, you get whatever bin they happen to be selling, and good luck finding out exactly what that is. You need to be careful you are getting the correct bin # for what you want. There may be 8 bin numbers for a 465 nm, and some may actually be something like 440 or 490. You especially need to be careful because the slightest adjustment in wavelength can make a huge difference in chlorophyll activity. (see chart)

Quote:

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Originally Posted by budderlvr

Has anyone tried a cluster type lighting system? Where you would have small clusters of n LEDs and then strategically placed in nodes around the SCROG.

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This would defeat the purpose of the scrog, which is of course to spread out the canopy evenly to take full advantage of all bits of light and space.

If people have done much reading they've seen these charts I've fine tuned, but here they are again for your convenience:

Thanks for the post Opie,
Shows my inexperience with growing. Someone keyed my vehicle last night which wouldnt matter, except it blows my budget for building a light for a while.Keep on posting, I will keep updating with anything I find.

Man, what a bummer. I think I hate vandals more than thieves.

About the ratios: Nasa recommends 9 to 1. that's 9 blue in veg, 9 red in bud. Sounds good to me. Before I read that I always said 85/15, but it's not critical. I think you could do without any red in veg, but I've noticed some blue in budding increases bud density and resin.

Hope you can continue with the project soon.

If you ever find out who the punks are...

Step One -:cursing::cursing::cursing:
Step Two - :asskick:
Step Three - :chainsaw:
Step Four - :jointsmile:

But really I'm just kidding about steps two and three...

Opie and redline,

Where would you recomend to get LedEngin lights to get the correct bin code? Contact their office directly?

It may not be a bad idea. At least complain about the distributor marketing their product without full disclosure. I find dropping the bin nonmenclature to be a bit on the tacky side for a major US distributor.
But since they are the only game in town you got to roll with the punches, just assume the worse case scenerio...that you are getting the lowest grade. I ordered 28 of the five watters and all of them had a Vf of 2.5 or lower. Which means max power is 3.75 watts, not 5. Niiiice.

Budderlvr: heat from my environment, not the light!
This is a busy thread! Sorry to hear about your car: I double Sunny D's sugg! Just hanging out and watching. Thanks for all the info! :thumbsup: :jointsmile:

Quote:

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Originally Posted by budderlvr

Opie and redline,

Where would you recomend to get LedEngin lights to get the correct bin code? Contact their office directly?

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You need to ask the vendor what bin numbers they are selling. The manufacturer probably won't know or won't want to look up, or disclose what they sold a particular vendor.

SHIVA SPECTRA

bud lvlr I called and talk too Ledengin as I live close too them .I was gonna drive and get straight from them,but they want a huge purchase order todo business. I would call mouser and and try to setup purchase buy bin #
i would also grab atleast one of the 10 and one of 15 watters for experiment.
I was gonna build a 300 watter with the 10w bulbs. but major problems happened and have no $$ know. also have you seen the Enfis Quatro
well fuck know I cant find it anywhere fuck LEDS

http://www.sunshine-systems.com/specs/growpanelspec.pdf

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Originally Posted by veggii

fuck LEDS

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I know how you feel. My LED project is on hold, but when I was into it man I went crazy. I felt like I just kept spinning my wheels trying to research and get stuff figured out. It doesn't help that this is a fairly new field. I found that if I just tried to forget about it for a couple days I could finally sleep at night, and when I got back to the project I had a fresh approach, new ideas, and solutions to problems.

So I tried a couple people at Mouser and got the same response as I was expecting from their e-mails. "Whats a BIN number?" or, "We disclose all of the information we have on a product on our website." I don't know anyone at Mouser so its unlikely that I will get further service than this.

I totally know how you guys feel. I am lucky and can sleep in when I need to, otherwise I would have been a zombie for the last 2 weeks. I swear thinking about LEDs occupies too much of my brain! So to take my mind off it, I bought a metal halide and a cool tube. Only 400watts, but at least I will have something to experiment with.

That said, do you think I could get anything out of just buying Red LEDs (having positions for blue on the board in the future)? I only want them to supplement the metal halide.

I really wanted to buy something today so I went to Ikea.
Hosle Wardrobe with Sliding Doors
I had been looking at tents and enclosures, but this was $99 at my local Ikea. I am going to cover the inside with Mylar, and have the air exit from the top shelf through carbon filters. The plan is to use a MH (might spring for a HPS, but the MH was free), and create a BOG style SCROG. The clones will be from an indica strain (which from what I have read does better in a SCROG type setup, and I have seen this strain grow both tall and also trained to grow bushy).

No new news on the LED front. I am going to focus on getting a benchmark with this enclosure using MH or HPS first. LED tests will probably happen in November or December.

It sucks when people that sell stuff don't even know what they're selling.

I do think you can grow weed with just red, which is of course more important than the blue. Many people grow weed with only 3000K fluorescents. Without blues your plants will end up stretching to some degree, and end up less bushy. It's not a problem as long as you are willing to work around it. Your yield will not be quite as high, but again, not a problem.

Instead of mylar I would paint the interior of the wardrobe flat white. It does a better job at reflecting and diffusing light. Also your walls will get dirty and the mylar will soon dull, and splashing another coat of paint on is easier than replacing the mylar.

Looking forward to your tests.