Quest for a DIY LED panel

Discussion in 'Lighting' started by Dirtbud, May 23, 2010.

  1. #1 Dirtbud, May 23, 2010
    Last edited: May 25, 2010
    So basically I'm on a mission to build my own LED grow panel as it is far to expensive to buy one. And this thread is not just about my mission but all others who also would like to have an affordable LED panel. Through the efforts of us as a collective, I hope this can be a thread that has the easiest DIY LED build eventually, and not a thread about how one person made an LED panel. I hope to have clear cut items and procedures to follow. For now we must learn:

    My idea is to modify an LED Christmas light set and replace the bulbs with high quality LEDs at specific colors. I'm trying to figure out how to increase the wattage. Perhaps if I just cut the wire at the plug in, and wire it to this 12v dc 150w power supply.


    I will have small PC fans and housing for it all if it could work. Any ideas?
  2. #2 Dirtbud, May 23, 2010
    Last edited: May 25, 2010
    Another idea (now scrapped) was to buy a $30 225 LED panel from Ebay, replacing the LEDs and then figuring out how to run 225 watts through it.

    I will try at least one of these methods, and probably the cheapest idea (first one) unless someone with some electrical knowledge can add some wisdom to the project. I have an old friend that I may have to contact (who is a licensed electrician) for help, but I prefer no one I personally know to be involved on any level of my grow.

    Hopefully this project will be something successful to be added to the DIY section on here.
  3. #3 Dirtbud, May 23, 2010
    Last edited: May 24, 2010
    According to the website that sells those power supplies for LEDs:

    To determine how many LED products can be connected to a power supply:
    divide the total current capability of the power supply by the current draw of the LED product.

    Basically if I run 3 watt LED's in sequence on a 100w power supply I will be able to use ~ 33 LED's. It said that about any wire could be used, which is what made me think of LED Christmas lights because I would think I could pretty much plug right in to the sockets.

    I will use a different power supply altogether for the fan units. I mean surely fans draw power and watts are a unit of power so if you are using a 90 or 180 watt UFO with those fans on it, how many watts are the lights actually running on?

    I may buy a cheap panel on Ebay yet, and use the panel itself as a reflective hood. I would just stagger my LEDs. The idea behind this project is to use exact wavelength LED's and achieve a 150 true watt panel at a cost around $1-1.25 per watt max. Then I'm going to x's it by 4 if it works for a 600w LED panel.

  4. Hey man I'm looking at collecting the stuff to make an LED panel or two this summer myself.

    Q: do you have a Radioshack in or around town? They have pretty much everything you will need at good prices. They have the LED,s the resistors, everything.

    But where do you find plans on making them >.<?

    And no you can't just cut and replace wires unless they have the same exact volt,wats etc. Just because something is at 12 volts or 120volts the amps may be different depending on what resistors are connected. Also using different colors on the same panel require different volts so you will need to balance the circuit with proper resistors on each color or only the lower wattage ones will light up even in a parallel circuit.
  5. #5 Dirtbud, May 23, 2010
    Last edited: May 24, 2010
    I do have a Radio shack in town. If you don't mind me asking how were you going to start yours off?

    And thank your for the info about the separate circuits and resistors. I don't think that would be too hard to pull off.

    So my idea is still similar, but this time I'll add a new string of x-mas led lights, for every color and make a new circuit. The reason I reference the x-mas lights is I'm assuming the resistor that you are talking about would be at the beginning of the circuit and that I would cut that out and replace it. Then hook it up to the power supply.

    I don't think wire has anything to do with watts. It's just voltage if I'm not mistaken. So long as the x-mas light wire could handle the volts then the wire would be usable would it not? Anything else like amps could easily be restricted.

    I hope that makes more sense. If I have to get special wire then I will. Any suggestions for that?
  6. #6 Dirtbud, May 23, 2010
    Last edited: May 24, 2010
    I really seem to think that this could be a fairly easy project. Take a look at this simple crude LED circuit, with resistor:

    Free Image Hosting by

    I'm thinking so long as the LEDs are the same color they could easily be ran in parallel. I know the information I need is here on the internet, and I plan on spending the next few days learning the ropes and drawing diagrams.

    I would like to make this thread a collective place for information on making LED grow lights. If anyone has any ideas, suggestions, or insight to this project please share. :)
  7. #7 starcecil, May 23, 2010
    Last edited by a moderator: May 23, 2010
    Indeed it can be simple to assemble if you have the right parts. I think Im going to make smaller panels of just a single color.

    I don't really know if those new led christmas lights would work, they may they may not work to full potential though.. the reason being: When you buy sets of led's that you have to attach to a panel, you can buy them in specific wavelengths. I think I red for flowering its 630-660nm is the best with 660 being prime I think?

    I'm planning on making these as strips and use them as supplemental lighting to hps/cfls

    Overall from what I have gathered though they seem to work best during vegging, but I want a mixed spectrum all the way through having heavier blue during veg and heavier red during flower but here's a lengthy rundown of what I was playing around with in my head:

    Vegging with cfls above and 2-4 strips of Royal Blue led's - not really sure how many, kinda depends on price, but I waas thinking 4-6cfls to start when they are smaller, with a a blue strip of 100 across the top and maybe 1 of 50 on long sides of the wall.

    Flowering with HPS - IDK which yet, I still need to buy one but prolly only 250 since I have all the other supplemental lighting. But anyway HPS, keep up the Royal blue leds, switch cfls to yellow or throw out now IDK which yet, and add in red panels of LEDs prolly a few 50 count on the edges.

    I've been tossing around the idea of using a san agro hps bulb all the way through and just using led's to supplement. I was also going to look into getting 1-2 uvb bulbs

    The reason for a lot of uncertantiy still is because I'm not really sure how much this will cost >.<
  8. #8 Dirtbud, May 24, 2010
    Last edited: May 24, 2010
    I too have noticed that they seem to over perform expectations on veg, but then under perform on flowering. But if nothing else maybe it could shave some time off of a grow vs CFL.

    I also plan to use known data about MJ's spectrum and order only a mix of the best LEDs, and personally will rely on a heavy red mix to aide in flowering.
  9. #9 Dirtbud, May 24, 2010
    Last edited: May 25, 2010
    Here is a diagram that represents my idea best although I would run a parallel circuit. Remember I will put each color on a different circuit.

  10. Its been kinda of dead but you might try asking in one of the forums in
    there was a thread somewhere that a person mader there own
    light, it was a few years ago, very well done, I'm looking for he link but can't find it.
    I believe the LED's are available on E-bay in bulk.

  11. Thanks for the reply. I have found a few different sites for LED sources. At this point I'm just waiting for the money to buy my materials. I'm going to start with a very small string of LED's and then will go from there.
  12. #13 Dirtbud, May 24, 2010
    Last edited: May 24, 2010
    Thanks very much for the link and info. And it appears that you can achieve very nice results with a mix of cfl's and leds.

    This is the very kind of thing I'm talking about. Bringing the info of different brains in one place.

    Hopefully at this point those who are following this thread have already learned something new today ;)

    Tomorrow is the first day of my summer semester although I hope to do some number crunching to come up with a definitive game plan for an experimental prototype. I will probably post more info on here then.

    We all have PC's and I know there has got to be a smoker out there with some advanced circuitry or electrical skills. Hopefully when they see this thread they will shine light down from above the rest of us could not see. :D

    Until then, comments? Questions? Encouragement?
  13. I was thinking of putting together a simple unit to drop in between or a belt of them around my grow box below the canopy, made out of semi-truck trailor brake lights, there red LED's, don't know if there the right spectrum of red though, but there an already mfg'd LED ligth that pop's in & out of a rubber gromets and just need to be plugged into a 12v power supply.
    The spectum might be easy to find if the DOT has a specified red for brake & tail lights.
    Just one idea I had many months back.
  14. #15 Dirtbud, May 24, 2010
    Last edited: May 26, 2010
    Okay so after doing some research over the last day or so I'm confident this project is going to happen, at least as far as skill level required for the job. But before I get too balls deep into this thing to back out I will need to make sure this project is cost efficient. This is a rough cart thrown together that does not include shipping:

    150w power supply/transformer: $84.99 Here
    This will allow upto 135 1w LEDs. What I like about this power supply is that it allows me to keep it outside of my box if I want to. That is a good thing because I did not want to splurge and get the outdoor (waterproof) PSU because it was almost double in price.

    Leds: (I want red, blue and IR)

    Red: 114 total,
    57 660nm: $25.86
    57 640nm: $5.13

    Blue: 14
    7 470nm: $4.55
    7 440nm: $9.73

    IR: 7
    880nm: $9.03

    These prices were found from a combination of 3 different websites. Because prices may change and this is just a rough estimate I'm not going to list the sites until I order. I may also change my mind on colors, and number of colors.

    I'll probably go through about $3 worth from Radio Shack.

    I'm going to use Phillips LED christmas lights which will run two parallel circuits with up to 30 LEDs each circuit.
    (I'm over estimating this by a strand, in case I need parts). Also I'm going to most likely use a separate strand for each color and figure out a way to use the same driver from the one power supply. It may be tricky but doable I think.

    All of this will give me ~ 130 true watts of LEDs of my choice in color spectrum based from information gathered by LED grow manufacturers information.

    Total Estimated Cost: $178.29

    Equivalent LED panel from trusted grow sources: ~$400-500

    So that is a pretty substantial savings. The cost of making this project is about $1.37/watt (which stays about the same even on smaller watt systems if you want a smaller panel). I will continue to go on with this project so far. My next phase is mapping out the circuits exactly, and running them in CAD simulators. This will take me some time (with my schedule I'm saying a fortnight). If anyone can beat me to some diagrams make sure you download some sort of freeware simulator to test for soundness (these can easily be found searching google).

    I have yet to decide how I will make the panel. My first thought is to use tool board and mylar. I don't think that part will be hard. I also have a ton of PC fans from a graveyard of towers and a wall adapter to power them. Other needed items that I have already are a solder iron, and solder (and yes I know how to use them).

    Until then, :wave::smoke:

  15. This could be easily done as well for a small amount of leds used in supplemental lighting. However when you look for LEDs, the ones you use should have a clear lens cover and about a 50o viewing angle.
  16. #17 Dirtbud, May 24, 2010
    Last edited: May 25, 2010
    So for comparison, here is the reason why I want to use the plugs from the Christmas light set:



    Notice how easily I could change out old LED lights with proper spectrum LEDs. All I would need to do is cut the resistors out and replace them and test that the wire would be able to handle the power. Also it's already separated into parallel circuits.

    Here is where I got this information for those interested:
    LED Christmas Lights and How to Fix Them

    I also want to quote and point out some information that I'm interested in from that page:

    "LEDs on AC

    For an imaginary cycle of 360 degrees of the AC line, about 26.5deg (1.2msec) pass before the line gets to 75V and the LEDs start to emit light. Then the LEDs are on for 127deg (5.9msec), and off for the remaining 206.5deg (9.6msec). That means we get a 5.9msec hump or pulse of light every 16.7msec: The LEDs are actually ON only about 35 percent of the time (the current and light ramp up then down during the pulse). The pulsing effect is similar to what we see in fluorescent lights, but worse because it is slower: only one side of the AC wave is used. In particular, it is possible to move a hand in the LED light and see a stroboscopic effect. Flowing water is particularly interesting. But I have no problem reading; the light does not seem blinky unless it is the sole illumination for something moving. In 5 strings I have tested, both circuits in each string each use the same line polarity, which is wise.

    I would like to see the manufacturer add a single line-voltage power diode to avoid depending on summed LED reverse voltage limits. One can imagine various other design alternatives:
    An alternative AC design option is to put more lamps in series, and thus eat up more voltage before light can be produced. A smaller resistance would be needed for the same current, which should waste less power. However, such a circuit would use even less of the AC cycle and produce light in even shorter pulses. It also would also magnify normally hidden variations in the AC line voltage.
    Another AC design option might be to bridge-rectify the AC power to use both sides of the AC cycle. That would double the pulse rate, which might be better. But it would also double the average current flow, which would require a larger resistor to reduce it, with more power loss.
    Alternately, a power supply with current control could produce high-voltage DC, which would eliminate light pulsing. That would come at substantial cost, and introduce potential reliability issues when compared to the resistor alternative.
    Yet another possibility might be to use a transformer power supply and run the string on low-voltage DC. In this case LEDs would be used more or less in parallel, with a separate resistor for each or perhaps each small group. That would produce continuous non-blinky light, but at greatly reduced efficiency. A transformer for each string would be expensive, and a large transformer to handle multiple strings would be even more expensive.
    In the future we may see LED strings with custom integrated circuits (IC's) designed to work directly off the 120VAC line and control the intensity of the LEDs. A custom IC could improve efficiency, offer intensity adjustment, blinking and remote control features at the same time."

    By reduced efficiency he is referring to energy consumption. Although for grow light use this would actually be considered to be highly efficient.

    But basically this describes a very similar setup to the one I'm trying to achieve.
  17. #18 Dirtbud, May 25, 2010
    Last edited: May 25, 2010
    So if you have read up to this point then you should now be able to see through bullshit marketing ploys on cheap and expensive LED arrays. And not just LED's. All kinds of electronics and appliances pull this crap. A lot of vacuums for instance will proudly display their volts or amps, as if that has anything to do with actual power or performance.

    Any LED array that plugs into the wall and uses an A/C current will be no more powerful than regular LED Christmas lights. Also I noticed a lot of sellers on Ebay advertising that their lights use 120 volts. When in reality it only plugs into 120 volts as an input, and then has AC/DC converter to DC power. This also means that unless it has a circuit driver, it is depending on summed LED reverse voltage limits and will cause a strobing effect that is not always visible by the naked eye. This is caused by giving the LEDs calculated minimal power for them to operate and the LEDs do not actually power on full time. For instance when I drove past LED X-mas lights last year I noticed they would almost flicker and appeared to be cop car lights at first. Come to find out, they were flickering/strobing and the faster you move around them the more noticeable to the human eye it becomes.

    What is my point? A proper LED setup will use a AC/DC setup that has a high watt output on a 12 volt DC circuit to prevent this from happening. Don't be fooled by advertisements or gimmicks.

    Also be aware of companies that have a nice evenly rounded number for watts as that is usually only the amount of output of their AC/DC converter and not the actual amount of watts being used by LEDs. Even the 150w output on the LED power supply I'm getting has a true output of 135 which is about 90% efficient. I'd be willing to bet that is why UFO's are mostly 90, and 180. They are probably running on 100w, and 200w outputs that are also 90% efficient.

    And as far as power supplies go in general, if the actual output is about 90% of rated output that is pretty good. I think the 800w power supply running my I7 is only rated at 86%. It's nice to finally know how they come up with these numbers.
  18. I've heard of people making arrays that can connect to a car battery. although I didn't see how long the battery last, but none the less a good idea.

    I have a charger for them already that plugs into the wall, or I could just run down to the different part stores every so often and gett it charged there free... but it would be a 12 volt source.

    I don't think I'll buy led's on ebay, Id rather buy straight from a site that many led's with specifications I can choose.

    One website was 50 cents for each if you bought 100, pretty good deal especially for the higher quality and the fact you can buy their led's many different wavelength variations within each color.
  19. A car battery would do a very good job at powering a strand of LED's actually because it essentially replaces the need for a power supply. Although you would have to charge it. It's possible to get a batter with side and top mounts and a charger for it, charge with top terminals, and use the side ones for power.

    Only downsides to it are the size of the battery + charger, and the fact that if you did not already have one it would cost more to buy than a LED PSU.

Share This Page