Custom DIY LED panel help

crunkyeah

Well-Known Member
Alright so for my next grow(after my current one finishes flowering) I plan on making a DIY LED panel to see if I can grow 1 good plant out of it. I'm doing this mostly as an experiment to see if I'm able to create a good grow light, and also to see how well they flower under just LEDs alone.

I have done countless hours of research all over the web about LEDs and growing, so I'm well aware of what I'm getting myself into. And I already know some people may jump on the hps bandwagon but this is what I'm going to say to that. I will be growing in a stealth converted dresser, so the initial size of the hps light with hood may crowd my plant. And I'm not sure if I'll be able to handle the heat issues, so HPS is NOT a good idea for me.

Currently my grow is a CFL/LED mix, but this one I want to be all LED due to the height restrictions I have. My dresser is 29"L x 13.5"W x 33"H(2.75 ft). As you can tell, this will be an extreme micro grow, I also plan on having this plant scrogged. I know one of the crucial flaws to LEDs is the inverse square law(light diminishes quickly) and they also don't penetrate very well. Well I figure using a screen and having 1 small canopy I'll be able to eliminate the need for penetration. I plan on having a 10" tall pot with about 10 in of room until the plant hits the screen. Leaving roughly a foot of room above the screen(which is why hps won't work, would burn my baby). I plan on having this custom made unit hanging from the top of the dresser and I also have 4 13.5w panels I will mount to the side of the dresser just above the screen so there's lots of light. They should fit perfectly if I get the screen right. They're 12" x 12" so they should fit just fine.

Now here's for the fun part. I'm in need of a little help with the electrical aspect. I've been thinking about taking an electrical class online just to help with understanding of this, but it may be possible to do this without all of that I just need a little guidance ;) I'm going to list the specs of the LEDs and everything so you can see what kind of setup I plan on making.

All items off eBay

30pc 10mm 40° 1w, 300mA 2.1v 280,000 MCD - red
15pc 10mm 40° 1w, 300mA 3.4v 250,000 MCD - blue
6pc 10mm 40° 1w, 300mA 3.4v 380,000 MCD - white
6pc 10mm 40° 1w, 300mA 3.4v 340,000 MCD - warm white
6pc 10mm 40° 1w, 100mA 3.4v 35,000 MCD - UV
63 LEDs total MCD total = 15,925,000
http://led.linear1.org/lumen.wiz 6,034 lumens for 63 watts!

Need 30 resistors for 12v, 300mA, 3.4v (6.8 ohm 1w)
-These are for white, warm white, and blue (wired in series of 3)
Need 10 resistors for 12v, 100mA, 3.4v (22 ohm 1/4w)
-These are for the UV (wired in series of 3)
Need 40 resistors for 12v, 300mA, 2.1v (6.8 ohm 1/2w)
-These are for the red (wired in series of 5)

Series of LEDs(paralleled together) - 6 sets of 5 reds(1.8A), 5 sets of 3 blue(1.5A), 2 white(.6A), 2 warm white(.6A),
2 Uv(.2A) = 4.7 amp total

Power supply - 12v 5A 65w power supply

Each LED 10mm - 17 rows = 170mm = 6.7 in
20mm on top and 20mm on bottom for lead wires = 40mm
10mm x 5 max = 50mm +40mm = 90mm = 3.54 in
Total dimensions of LED panel = 6.7"L x 3.54"W

For any electricians or fellow DIY'ers that know what they're talking about, does this look about right? The PCB I'm going to be using is 9" x 4" so it should all fit pretty snug on the board. My other question is, what gauge wire do I use for the positive and negative lead? Everything else I've been able to find through google and this website.

***Design is first attachment
**Second is dresser before I start converting it(want to make panel first)
*Third is panels I plan on putting on inside walls of dresser(along with current scrog grow:bigjoint:)


Any help greatly appreciated!
-crunk
 

Attachments

crunkyeah

Well-Known Member
Bumpity bump.

Surely there are some electricians in the house to lend a word?!

Btw I have found that I will need 18 gauge wire for this project.
 

crunkyeah

Well-Known Member
Haha, the 1w diodes I'm using are always going to use 1w, there's no changing that no matter how you wire them as far as I know. And btw, I linked that same exact website in my post. It's just in a different section. And http://www.ledcalc.com seems to be a lot better since it has the "GURU". It would be possible for me to get my amperage down if I used a higher voltage power source but I believe with the power source I listed, I should still have plenty available watts and amps for use. Plus, if one diode burns out, the whole series burns out. If I wire more than 3 diodes at a time and 1 or 2 go out, that's about 6 LEDs, not too bad. Now let's say I wire up 5 or 6 on one series, now you're talking 10-12 going out at once. Not too pretty considering how damn expensive these are! Especially if the red ones go out.

And for all those who know about Haight Solid State LED panels..I sent an email over to them asking a little bit more about their 90w panel. PPF-400 or something like that I believe. It uses 6w LED(x15) in deep blue, red, and warm white. It puts out 2500~ lumens. This panel I'm going to create - 70-ish watts with resistors and fans, 6000 lumens, and 2 more spectrums to boot! DIY seems the best way to make a good LED light, only time will tell.

I appreciate your help though Dragger ;) no one else has even offered any words of encouragement or advice, thank you

-crunk

*edit* Upon typing all of my LED info in that website mentioned I did find a snag which the other site didn't show any problems to.
If you type in 12 for the source voltage(power supply I will be using), type 3.4v(for warm white, white, and blue LEDs), and 300mA(current for optimum light) and put in 27(number of LEDs) it spits out a diagram that says 9 rows of 3 each with 6.8 ohm resistors(which the other site showed as well). If you scroll down it also says "!! wizard thinks the power dissipated in your resistors is a concern" and doesn't say anything more about how to fix this, anyone have any ideas about how to fix this?
When typing all of that same info into ledcalc.com it shows up just fine with no problems at all, displays 6.8 ohm 1w resistor as desired. Now I'm no electrician so I'm not positive, but it appears the 1w resistor should work just fine I just need someone with all this electrical knowledge to PLEASE help!! Thanks!!
 

IAm5toned

Well-Known Member
*edit* Upon typing all of my LED info in that website mentioned I did find a snag which the other site didn't show any problems to.
If you type in 12 for the source voltage(power supply I will be using), type 3.4v(for warm white, white, and blue LEDs), and 300mA(current for optimum light) and put in 27(number of LEDs) it spits out a diagram that says 9 rows of 3 each with 6.8 ohm resistors(which the other site showed as well). If you scroll down it also says "!! wizard thinks the power dissipated in your resistors is a concern" and doesn't say anything more about how to fix this, anyone have any ideas about how to fix this?
When typing all of that same info into ledcalc.com it shows up just fine with no problems at all, displays 6.8 ohm 1w resistor as desired. Now I'm no electrician so I'm not positive, but it appears the 1w resistor should work just fine I just need someone with all this electrical knowledge to PLEASE help!! Thanks!!
there worried about heat... your resistors are going to get very hot indeed, pulling that type of wattage through them.

have you built a prototype yet? i would suggest building a simple mockup of one led bank ( 9 diodes and a resistor) and take a look at your heat dissapation off the resistor.
a very common misconception about led's is that they dont get hot. that is the biggest crop of horse shit ive heard in awhile, to be brutally honest.
not only to the led's themselves get hot, the resistors (a current limiting device, aka a heating element) also will heat up @ a rate that is proportionate to the amount of current going across the resistor, ie the more power, the more heat.
the math works out on your setup, but its going to get really hot, pretty fast. a big solid aluminum heat sink and some pc fans are definitly going to be in order here...
look at the UFO products, and some of the other big names out there, they all have at least one cooling fan installed.

this is the current problem/limit of growing cannabis with LED's. often the heat generated (and hence need to dissapate said heat) requires cooling devices that both a) drive up the design and production cost to astronomical levels, and b) use more power than originally anticipated.
 

crunkyeah

Well-Known Member
Yeah I have noticed that most of the UFO's have 3 cooling fans on the top. Well the PCB I planned on using is 170mm x 90mm, I just planned on mounting 2 90mm fans directly above the panel to help dissipate heat. I remember reading your visitor message on how to mount the PCB to the heatsink but I was a little confused why I couldn't just use the PC fans for cooling. Like you said, it does add to the cost to add those fans. Maybe just maybe it's more efficient to just buy a decent led panel off the net somewhere. I've seen numerous companies based in California selling LED panels that aren't from overseas. I think I'm going to look into that a little bit more than I have previously.

As for the prototype, I don't really have too much spending money to play with, so I haven't made one as of yet. I wanted to make sure that I got everything right before purchasing a large quantity of LEDs especially driven at 300mA. That's the highest current LEDs I could find for the 10mm kind. Granted there's tons of .5w 20mA LEDs out there for dirt cheap, but I figured the strongest LEDs would be the best to use for that reason. They're stronger so you don't need as much of them. Maybe I'll have to look into purchasing a lot of the cheaper LEDs, who knows maybe there will actually be more light output with a bunch of those small ones opposed to few of the stronger LEDs.

Do you think getting a higher voltage power supply and driving more LEDs per series would make any difference? Just trying to think logically here, more power would be dissipated through the LEDs and less through the resistor. But I'm not entirely sure, I'll have to do some more research it seems. Thanks for the advice IAm5toned :)

-crunk
 

dragger

Member
if you have 1w in led consumption and a 1w resistor dropping the voltage the resistor will heat up as the heat in the resistor rises the resistance will also rise... I would over size the resistor with say a 3w... if you have lets say a bank of 4 LEDs in series and one LED was to fail the other 3 LEDs will not fire as the circuit is opened at the failed LED... you may be able to fix that issue with a zener diode in paralell with the LED...

furthermore if the resistance is higher due to heat the voltage will drop... if the voltage drops the current will increase causing more heat in the resistor... it will become like a revolving door and soon something will fail... Keep in mind that 85% of the power consumed by an LED is converted to heat... LEDs have focal angles of the angle they project light... 6500K LED's are blue LEDs with phospher (SP) on the chip to produce a whiter light then the blue LED would produce without the addition of phospher... there is an LED manufacturer in NC that makes 3w units the company is called Cree... Keep that heat issue in mind you may have to heat sink your LED's if they heat up on you...

Dragger...
 

crunkyeah

Well-Known Member
Thanks for that bit of information Dragger. I do know about CREE LEDs but the only problem I've had with surface mount diodes is that most of them require a reflow oven(according to most of their spec sheets) which I do not have access to. They say specifically to not hand solder them. I'm not sure which series you were thinking of, but the new XPE series they have are the brightest and don't appear to be hand solder-able. If I knew somehow that I could mount them to a heat sink without using a reflow oven or PCB I would do that, I unfortunately just don't know enough about electronics to do that sort of thing. If I knew how to do that, trust me, I wouldn't even be looking at the 10mm LEDs. I've also looked at OSRAM and Luxeon LEDs, and they all appear to be the same; need a reflow oven to use them.

I've seen a grow from a guy in Amsterdam(http://www.ledgrow.eu/diy.html) who used thermal conductive glue to mount K2 Luxeon LEDs to an aluminum heatsink, but it looks a lot more complicated to my eyes than the 10mm LEDs. Also, they stopped production on the K2s. Another problem that confuses me with those high power LEDs is that I'm not sure which side is the cathode and which is the anode since they don't have the little metal prongs. They just have a little bit of metal on the sides where you solder the positive and negative leads to.

If you could help me to understand a little bit more about the high power LEDs I wouldn't even want to look at the 10mm ones. They just look a lot more DIY-able than the high power(3w,5w,6w) LEDs. Thanks again Dragger :)

-crunk
 

crunkyeah

Well-Known Member
A little update here if anyone is following this thread.

I have since decided to throw out the panel for the 10mm LEDs. One of the major concerns with the panel I would have liked to create was heat. The resistors would have been taking too many watts and heating up pretty good. This diminishes the life of the LEDs considerably since they work better at lower temps.

In my previous post I mentioned not knowing a whole lot about the high power LEDs, but after doing some more research I've found they really aren't too complicated :) at least on paper anyways.

The LEDs I plan on using are LedEngin, the LZ1 5 watt series. I will be using a total of 21 LEDs, all driven at 1A. They will be mounted to a cookie sheet(I figure it's a good heatsink since you know you put them in the oven at 300+ degrees F). Seems like a perfectly plausible idea to me, if anyone disagrees I would sure like to know the reasoning behind it! I will be mounting them with some thermal conductive glue so the sheet isn't 'live' with electricity and I won't get shocked :P

I will be using 5 different spectrums. Warm white, blue, red, deep red, and far red. My ratio will be 4 red: 2 white: 1 blue. The wavelengths are as follows:
Warm white - 3100k, blue - 465 nm(I know this isn't entirely the correct blue, but the dental blue which is closer to the correct spectrum is 10 dollars more per LED!! f that! haha), red - 630nm, deep red - 655-670nm, and far red - 725-745nm. Since the reds are all under 3v I am able to wire 4 in series using my 12v power supply. The blue and white however, have to be wired in series of 3 since they have a forward voltage of 3.6v. 3.6v x 4 > 12v for those who don't understand.

So in total I will have:
4 red
4 deep red
4 far red
6 warm white
3 blue

So in total that's 21 LEDs and each one is rated for 5w, so one would think this would be 105w of LED correct? WRONG. From my research they market the 5w units to be 5w but when you throw Ohm's Law in there it just doesn't work. One of the formulas is Volts x Amps = Watts, so here's the math on that:

Red 2.5v x 1A = 2.5w X 4 = 10w
Blue 3.6v X 1A = 3.6w x 3 = 10.8w
White 3.6v x 1A = 3.6w x 6 = 21.6w
Deep red 2.9v x 1A = 2.9w x 4 = 11.6w
Far red 2.6v x 1A = 2.6w x 4 = 10.4w

In total that's only 64.4w. Throw in the resistors in there and you're looking at a 75w panel roughly(will also be mounting 2 90mm fans to the sheet for cooling purposes). For the resistors I used www.ledcalc.com. Here's what it told me:
For the blue and white LEDs(since they have same forward voltage resistors will be the same for both) are 1.2 Ohm 1w resistor
Red - 2.2 Ohm 2w resistor
Deep red - 1 Ohm 1/4w resistor
Far red - 1.8 Ohm 2w resistor

Going off of Dragger's advice I decided to oversize these resistors(theory being larger rated resistors won't get as hot), so the resistors I will be using are:
Blue/White - 1.2 Ohm 3w
Red - 2.2 Ohm 5w
Deep red - 1 Ohm 3w
Far red - 1.8 Ohm 3w

I'm not totally sure if using these resistors is the right method for trying to lower heat output from resistors, so I would like a word of advice if this is incorrect.

I'll draw up a picture of the actual design and placement of LEDs on the sheet and post them up later, still need to look at a few things.
I'll be using a 12v 7.5A 90w power supply so it should be plenty ample. There will be a total of 6 series of LEDs(12LEDs/4per series=3A for red and 9/3=3 for blue and white, 3+3=6A) so there should be 1.5A left over for the fans I want to use. As for wattage:64.4w from LEDs, roughly 5w(will post math if wanted) for resistors, making this about 72w total.
I'll also be using 18 gauge wire to wire them all together, if this is wrong PLEASE let me know.


And for anyone curious of cost, this should be roughly 300 bucks for everything, less if I can find some of the stuff around town and only have to pay to ship the LEDs. 300 bucks for a custom made 72w 5 band light doesn't sound bad considering they want like 200+ for a cheap UFO and upwards of 500 for the good ones. Not to mention I will have a better surface area and a lot more penetration since most of the UFOs use 1w diodes.
 

crunkyeah

Well-Known Member
Just FYI, it may be a while..had a good job lined up and then they filled my spot so I'm in a bit of a 'pickle' when it comes to the finances right now >.<
But as soon as I can gather up the money I'll be trying this out for sure!

If you've got any questions feel free to let me know ;)
 

crunkyeah

Well-Known Member
It's all good, there's always another one out there waiting to be found :)

I got a question for ya, if I have a power supply that will drive 6 LEDs at 700mA, can I put 2 different colors of LEDs on that series if they have the same forward voltage?

Thanks,
-crunk
 

crunkyeah

Well-Known Member
Just an update for those following, I have decided against using LedEngin LEDs because they vary too much in forward voltage. I have found some Luxeon Stars that I can get 4 wavelengths and I will only have 2 forward voltages. From the looks of it I'll need 2 power supplies and 2 drivers. But that's ok. It's actually cheaper to go that route then buy one big power supply and wire them all up on that one supply. It looks like I'll have roughly 90w, and 36 diodes. Each one will be about 2.4-2.5w.
 

riddleme

Well-Known Member
Wow I think I have never been this confused???

I have been an eletronics tech for 37 years and see more bad info in this thread than I ever saw about growing

please let me help a bit,,,,,

resistors do not change value when they get hot, but can break down over time if continually run hot (but takes years)

things wired in parrallel stay lit if one goes bad, things in series will all go out if one does

an LED can be 5 watt or it can be 1 amp can't be both as 5 watts is approx 1/20th of an amp now if the specs say both then 5 watts is what it draws (consumption wise) and 1 amp is what it will take current wise before it fails

I hand solder surfacemount devices everyday, it is about technique and skill I have never used a fancy machine to solder

if you light 10 5 watt leds you have 50 watts of light, period

You should be thinking 5 volt supply rather than 12 the heat dissapated thru the resistors is all about lowering the voltage to properly feed the leds, lower voltage = lower heat and a 400 watt computer pwr supply delivers 5 volts at 30 amps,,,,plenty of power and already has a fan for cooling

There is probably more but I have at least answered the most questionable info given thus far

not hatin by the way trying to help
 

Hobbes

Well-Known Member
I read an article today about 5 MM High Brightness LEDs giving the most light output per watt, better than the higher wattage LEDs and more durable, easier to work with. Except there's more. I'll post the link later if I can find it again.

Another idea is to have the power source away from the lights like a remote ballast, will really cut down on heat in the dresser.



.

I'm in, great topic. I want to build an LED panel of my own.

.

Does anyone know about solderless breadboards? Is it easier to use one of those or just learn to solder?

.

Crunchyeah could you post a link to the ebay store you use please and thank you.

.

bongsmilie
 

crunkyeah

Well-Known Member
Wow I didn't expect so much to pop up in such a little time since I last checked :P

First off, riddleme I'm graced by your presence in my thread ;)

I can totally see what you mean by lots of bad info, this is definitely a learning process and a work in progress. I will agree that I have learned more about when a diode goes out in a series, creates an open circuit and the other LEDs will not come on..as for parallel if one LED goes out the current in the others increases and they will fry as well. Correct me if I'm wrong please!

As for the reflow soldering, that was specifically for the high power LEDs that don't come premounted to a star or something of the likes. Just the little 3mm x 3mm die, that's the part that must be reflow soldered. But I won't need to solder at all for this project in the works, I will have thermal double sided pads to mount the stars to the heatsink. The only soldering will be the wires from the diodes to the drivers and between the diodes.

And for the 10 diodes at 5w each, certainly 50w that's a no-brainer. But most of the time when they market 5w LEDs they don't actually put out 5w. Ohm's Law tells us this. Watts = Current x Voltage. 5w LED with a forward voltage of 3.6v and draw of 1A is only using 3.6w NOT 5w. You should know this ;)

As for the power supply, I have decided to upgrade to 24v from 12v. This is because you can run six 3.4v-3.6v diodes in one series. I will not be using resistors because they create heat, and waste electricity when used for the high power LEDs. I will instead be using a DC to DC current regulator, so there's no current above 700mA(current the LEDs run best at).

If any of this sounds jank please let me know. I've really done countless of hours of research to get this far, and I'm suspecting it can only get better :)


Hobbes, would you be able to link that article that states 5mm LEDs are most efficient? I'd really like to read up on that. From all the research I've done, high power LEDs are definitely the way to go. The little ones have a few problems, no real good penetration, lots and lots of soldering(margin for error), need hundreds and hundreds to get decent light output, resistors waste electricity in the form of heat(not what we want), and the list goes on.

About the power supply being located outside the dresser; for the LED driver I'm going to be using they recommend that the wires from the power supply to the driver itself needs to be as short as possible, otherwise more electrical gizmos are needed. I will be using 2 power supplies anyways so it's not like they're going to create a ton of heat for roughly 90w(estimated output of panel I'm going to make). I would have to recommend that instead of looking into 5 or even 10mm LEDs like I did, read up on high power LEDs, it's definitely worth it.

As for the solderless breadboards, I have not tried them, and hell I don't even know how to solder 100% :P I would just rather stay away from that since I don't want to lose a bunch of money to user errors if you know what I mean ;)

And about the eBay thing, I believe the user was shop-4-leds, but if you search 10mm 1w LED you'll find a ton of different listings. Those were the LEDs I originally planned on using, but I have since decided against using those, in favor of the Luxeon Tri-star Rebels.

@sickstoner, I have seen a few 'ghetto' rigged rubbermaid buckets with those mounted in the lid, but I really wouldn't recommend them. They likely won't have enough power to do anything other than veg, and you would need hundreds of them! Not worth it if you ask me.

If you're gonna make an LED panel, you might as well fork out the cash and buy the good stuff. Otherwise you're just wasting your time. CFLs are cheap and you can grow decently with them. So if it's a cash issue LED probably isn't the best way to go.




If anyone has any more advice or questions I'll be happy to listen/answer :)
I think I'm going to post up the specs of my new design with the luxeons, but it may take a little time to do so.
 

crunkyeah

Well-Known Member
Like I've said in my previous post, this is my newest design for my high power LED panel. I will be using the Luxeon Tri-star Rebels. There are 3 diodes per star, and I will be using a total of 12 stars. 36 total die. Each die puts out roughly 2.4-2.5w. Here's the math:
3.6v(reds) x 700mA(.7) = 2.52w
3.4v(blues and whites) x .7 = 2.38w
3 die per star:
2.5w x 3 = 7.5w
2.4w x 3 = 7.2w
Will be using 6 reds, 3 whites, and 3 blues.
7.5w x 6 = 45w
7.2w x 6 = 43.2w
45+43.2 = 88.2w

Also, I will be using a current regulating LED driver(700mA) for each series. Blue and white gets one and red and red-orange gets one.
Now to show why I picked a 24v power supply:
3.6v x 6(Red LEDs in series) = 21.6v, couple of volts to spare
3.4v x 6(Blues and Whites) = 20.4

Each series will draw 700mA for a combined total of 1.4A, total wattage drawn 88.2w. So I need to get a power supply that draws 24v and more than 4 amps(remember ohms law!). 24v x 4A = 96w, if I found something say 3A, it wouldn't work. 24v x 3A = 72w, not enough to power LEDs. So I did some searching around the web, and I found 24v 4A power supplies are expensive! Like roughly 90-120 USD! So I thought to myself, what can I do about this to make it cheaper. Ultimate decision, 2 power supplies. On eBay there are tons of 24v 2.5A power supplies for like 20 bucks. So buying a power supply for the blues and whites and another one for the reds sounds a lot better. 2 power supplies and 2 LED drivers are actually about half as cheap as the big power supply and 1 LED driver. So I'll have one for each series of my LEDs.

24v 2.5A 60w power supply is the one I will be using btw. And this is what I love about the drivers, you hook up the power supply to the input on driver, then connect output to series of LEDs and you're DONE! That's it. It's so practical and easy I don't know why I ever looked into 10mm LEDs!

My heatsink will be roughly 8.5 inches x 12 inches. I will be mounting my LEDs in 4 sets of 3, still wired together to make 2 series though. They will be mounted with a double sided thermal tape that's electrically isolated, so no parts will be 'live'.

Will look like this kind of:
R W B R
R B W R
R W B R

Each driver and power supply will be mounted on the side of the heatsink or maybe on the dresser wall closest to the bottom side(R W B R). I have yet to figure this out. The heatsink will have 1 fan blowing air on the top and 1 circulating air underneath. Then I will have 2 exhaust fans rigged up to some kind of carbon scrubber(if anyone knows PC capable carbon filters or scrubbers LET ME KNOW!!). And I'll have 1 intake fan as well.

I hope this makes more sense to the readers now. There are absolutely no reasons to use 5 or 10mm LEDs after reading up on the specs for these tri-stars. These should penetrate quite nicely and be very intense for only 90w! We shall see when I get the money rounded up to purchase everything. My total without the lenses(will be waiting to purchase lenses until after the unit is assembled to see if I even need them or not, most likely will) is just under 300 bucks.

And the UFO from HidHut is like 500+ for the good one? No thanks I'll just make my own that I will be able to modify and improve down the road! DIY is really where it's at for LEDs atm, just my opinion though.

Any questions? Do ask!
-crunk
 
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