LED Light DIY

[*mr.mike*]

One alternative to the plain old drivers is a buck puck type of current controller. I used some that do a variable voltage from 5 (I think) to 32 volts... good enough for up to 7 three-watt LEDs that I used. They even come in a bunch of different currents, and some can even be hooked up to microcontrollers (like Arduino or Maple boards) very easily for PCM effects, if you want to go all nerdy with your rigs. They even have some with dimmers, in case you want to tone down your blues, or whatever...

Another thing is power supplies, for sure. Me, I like to use wall-warts, and other easily bought and replaced (my reason for making my own LED stuff) appliances. You have to - excuse me, you MUST - use as a switching power supply trasnformer. You can buy an ac to dc adapter that reads "24 volts output" right on it... but plug it in, and touch a multimeter to it, and it's reading 32 volts, maybe 28, whatever... enough to ruin everything if you go on blind faith in what you read. A switching power supply has some sort of integrated circuit that keeps the voltage stable output, despite what may be going on in the wires in your warehouse/apartment building/home.

Building your own LED rig can be a serious mental (and possibly costly) chore, especially if you have no real idea about the math, materials, or the methods of manufacturing it. By making your own you actually run around the hype marketing hogwash of 1W vs 3W, and the 3,4,5 or 18 wavelenghth "reasoning" why you should buy something for HUNDREDS of dollars more than it costs to build a truly custom unit for primary or some really awesome supplemental lighting.

 

[rives]

Today you get electronic transformators which don't reduce voltage by a fixed ratio but will make sure the correct output is supplied, therefore controller is pretty much correct.

Got an example? I've been in this trade a long time and have never seen a transformer that wasn't a wound coil device in which the only variation of the primary/secondary ratio was accessible through taps that were fixed percentages above and below the nominal output.

http://www.energyquest.ca.gov/how_it_works/transformer.html

 

[grow101]

I found this link to be helpful in calculating heat-sinks for LEDs. It's from a guy of Greenpinelane, a site/forum dedicated to LED grow lights, but discussing cannabis is a no-no there.

 

[alkalien]

Got an example? I've been in this trade a long time and have never seen a transformer that wasn't a wound coil device in which the only variation of the primary/secondary ratio was accessible through taps that were fixed percentages above and below the nominal output.

http://www.energyquest.ca.gov/how_it_works/transformer.html

Perhaps I chose the wrong word? Of course if you look at high power transformators as used to change voltages on the power grid from 250kV to 50kV those are hard wired.

But every PC power supply will make sure the voltages are dead on, would kill your PC Hardware if those where out of range. Or, to stay on topic check out the Meanwell drivers. They can be run at allmost anything and will allways deliver what you ask them to. Just randomly picked a AC/DC powersupply: http://www.meanwell.com/search/t-60/default.htm

As said above, those are not transformators. I'm a bit behind on the correct terms, english is not my first language and I'm not a electronics guy. Sorry if I got them wrong and caused that confusion...

 

[rives]

No problem, Alkalien. Hopefully I'm not being overly anal, just trying to keep the terminology straight for people without any background in this field.

 

[T_B_M]

Or just buy a switching DC power supply and build a driver with an LM317, resistor, and capacitor.

I also built a multi driver PCB that uses 3 CAT4101 ICs as well as a driver from the NCP3065. Very stable current output on every one of them, even running parallel strings.

There are many options for drivers out there, just gotta do the homework and know electronics to an extent. Most data sheets provide application examples that help you start your design.

 

[rives]

Or just buy a switching DC power supply and build a driver with an LM317, resistor, and capacitor.

Have you come across any regulators that will run higher max voltages than the LM317? I started toying with this idea because my new fixture is using 6 drivers, but I need around 52 volts to power my strings and the LM317 appears to max out at 37 volts.

 

[*mr.mike*]

My own DIY LED rig...

My own DIY LED rig...

I pm'd Blimblom to mention I would post this, and not be trying to hijack his thread or anything. So... here...

Here's my own DIY LED rig that I made four years ago. I used now-obsolete Luxeon III LEDs. They're 3 Watt pieces, and I used red, blue, royal blue, and some white ones, which I thought would affect the light rendering as far as my eyes were concerned... they didn't.

I made the frame out of some square steel stock I had on hand, some threaded rod, some nuts, and some washers. I liked this kind of frame because I can always just move some screws to add another rail for an extra string(s), or just to move them to a side. Also, it's easy to make a few extra strings on rails just in case I need to make a replacement, move some around, change the overall amount of whatever color I'm using, etc...

For the strings of LEDs, I just cut up some extruded aluminum rail. Based on the heat output of the LEDs, I could have used a slightly smaller size piece of metal, but the extra bit isn't bad, actually, it's even a little extra mass to take away and dissipate more heat. I used some cheap knock off artic silver-like compound to affix the LED stars to the aluminum.

The frame and the extruded aluminum allow for air to freely move around the LEDs and the metal, to help cool it. I use a little computer fan rigged to a wall wart, of course, to pull air into the space, circulate it, and push it out a hole on the opposite corner on the top. While the upper couple of inches may get to near 30 degrees C, the air in the middle never gets above 25 or so. There are a few holes in the top for passive air movement, and when it's cold, I can restrict the airflow out of the space but blocking holes, and just putting something over part of them to make them smaller. Also, the transformers I use to power some of it are located enclosed directly under the space, and air goes through and past them when it's cold (like minus ten to minus twenty) and there are other vents to unblock when it's warm. I just don't want the pots to get "cold feet." If you look at some of the commercial ones, it's all one piece of sheet metal, configured into part of a box, and some with a couple of fans, just to move air through the box. I use that little fan to move stuff around in the box, plus it pushes hot air out, with a little help from plain old convection. I don't need a big shiny piece of aluminum sheet - the light goes in a 120 degree cone away from the LED... sure, I could probably put some mylar, or what have you on the walls, but I like the plain, easy to clean white... maybe next time.

I use buckpucks to power the LEDs. The wall warts are switching transformers (nothing extra ordinary) because the buckpucks require them. I use a couple of the LED drivers like the original poster uses to power a couple of buckpucks, just as a redundancy. The buckpucks go right into little wiring harnesses from the buckpuck people. They allow for a dimmer. I like the buckpucks because they figure out the voltage needed to keep the forward voltage of the buckpucks constant, along with the current. The LEDs run at 1000mA and 700mA for blue/white ones. If I put extra reds in sometimes, I run them at 700ma, and they seem to work fine at that, too.

The reason why I went with them, besides being free, is that I like autoflowers, and I keep everything small, under 30 cm (40 something including pots). I don't use any collimators or other optics, because the 120 degree light emission is fine. If I were using them 2 feet, or a meter away from plants, then they might be necessary.

These have been burning 24/7 for most of the past four years (about 30,000 hours). Using a IR photodiode that I used to initially measure the new, fresh setup, it seems that the light has gone from 100% to 92-96% in that time, certainly nowhere near the 75% end of life that it's supposed to be after 50,000 hours.

Using autoflowers, I've definitely broken the one gram per watt barrier, but I like to grow some super strength dwarfs, too. I actually TRY by using smaller pots and transplanting late, to grow smaller plants. Others I like to see get to ten or eleven inches. What I have here are all from 24 to 31 days.

It's easy to make these lights, and certainly cheaper than buying what are really overpriced, and less lumen-throwing units. When I got these LEDs, you could get them less than $2.50 apiece, if you ordered more than 20 or so. Yhe buckpucks can be got for $10 to 20 each, depending where you get them. There are other LED drivers that are cheap, and work great for $10 and under. Everything else is at any hardware store for a couple of bucks. Of course, you'll need a soldering iron, some wire, solder, and a bit of practice before you start burning stuff (Some of these stars have been soldered a few times, and I've even used a razor knife to pry some off to adjust stuff. They still worked fine after.). I learned what little I know about electronics from university freshman physics, which included some electronics book-learning and some labs. Yhere's got to be tons of simple instructions, even here on some other threads.

If I were going to do it again (which I will in a few years), I might do something with sidelighting in it, but I think I'd stick with the 3 Watt ones, despite that there are way bigger, and smaller ones. The 3 watt ones definitely outdo the one Watt, and smaller, ones, for sure. Besides, the smaller ones just make a lot more work, besides being little pieces of suck, no matter what the manufacturers try to marketedly convince you of.

 

[GP73LPC]

nice work...

 

[T_B_M]

Have you come across any regulators that will run higher max voltages than the LM317? I started toying with this idea because my new fixture is using 6 drivers, but I need around 52 volts to power my strings and the LM317 appears to max out at 37 volts.

There should be drivers to drive at higher voltages, there are many different driver versions with either Boost and Buck topologies. The max. voltage allowed by the UL standards is 60V DC, so there should be a driver IC to cover 52V.

 

[alkalien]

I went for the Meanwell CEN 100 54, its 54V and arround 2A. 2A/3 strings means something like 667mA per string. The driver cost me a little less than 40€.

I did not find a single Boost or Buck driver that could drive anywhere as much LEDs as with this setup for that kind of money.

Even forcing a transistor to work as a constant current driver was more expensiver per LED than the Meanwell. The Meanwell driver is even more efficient than any DIY driver.

 

[rives]

I went for the Meanwell CEN 100 54, its 54V and arround 2A. 2A/3 strings means something like 667mA per string. The driver cost me a little less than 40€.

Alaklien, how did you handle the parallel strings - a fast blow fuse on each one or what? I was toying with the notion of a large driver with individual constant-current regulators on each string, but didn't know if this was any better than simply fusing each one.

 

[alkalien]

Alaklien, how did you handle the parallel strings - a fast blow fuse on each one or what? I was toying with the notion of a large driver with individual constant-current regulators on each string, but didn't know if this was any better than simply fusing each one.

Exactly, one fuse per string. Has been working for quite some time.

We build different Versions with different drivers and different number and combination of LEDs. Not a single problem till now.

 

[*mr.mike*]

I went for the Meanwell CEN 100 54, its 54V and arround 2A. 2A/3 strings means something like 667mA per string. The driver cost me a little less than 40€.

I did not find a single Boost or Buck driver that could drive anywhere as much LEDs as with this setup for that kind of money.

That driver is 1.77A

For the 40 euro you could get three, maybe four buckblocks running up to 32V output at currents of 1, 1.4, or 2.1A. I think a driver per string is better, costs about the same, and if one goes, everything isn't all gone... like the single power supply. Each string is a piece, easily swapped out... not a total shutdown until a big repair is made. Components, modules... like my PC - I can just replace the DVD drive in a snap, not like when a Mac breaks and you have to take the whole thing back to the store and answer a bunch of questions.

I'm just into modules that can be quickly changed and rearranged, more red, more blues, add a bar with reds and orange, tinker with the spectrum using cool/warm whites. I also like high power LEDs more, too. I could easily use smaller ones in pre-wired strips, but, for LEDs, anything less than 3 watts is really substandard for the application.

 

[alkalien]

That driver is 1.77A

For the 40 euro you could get three, maybe four buckblocks running up to 32V output at currents of 1, 1.4, or 2.1A. I think a driver per string is better, costs about the same, and if one goes, everything isn't all gone... like the single power supply. Each string is a piece, easily swapped out... not a total shutdown until a big repair is made. Components, modules... like my PC - I can just replace the DVD drive in a snap, not like when a Mac breaks and you have to take the whole thing back to the store and answer a bunch of questions.

I'm just into modules that can be quickly changed and rearranged, more red, more blues, add a bar with reds and orange, tinker with the spectrum using cool/warm whites. I also like high power LEDs more, too. I could easily use smaller ones in pre-wired strips, but, for LEDs, anything less than 3 watts is really substandard for the application.

Ok, so I'm more arround 600mA, which is even better for my 650mA rated LEDs

If one of my fuses blows, all the others instantly blow and my driver cuts the power, no loss at all. Plus I got one powersupply I can easily mount outside the growspace. The driver is IP65 or 67 protected so no need to worry about it catching fire or producing a short circuit on my electrics. The ~100W are pretty much perfect for my ~400x100mm² heatsinks too. The Meanwell drivers are more or less bullet proof, no problem with overheating or too high currents at all. And they are way more efficient than all those linear controllers.

I even prefer to at maximum blow up a single LED and a few fuses, they dont cost a thing and finding out which blew is easily done.

I'm afraid, I'm a Meanwell fanboy now...

 

[T_B_M]

Yeah, MeanWells are the way to go unless you have some electronics background to tinker with your own designs. Very easy to set up and no troubleshooting required. They are very stable also.

I like to have varying sizes of arrays around the room, so I make my own drivers and use AC/DC switching supplies to power them. I had power supplies laying around and at work we have plenty of electronic components, so it was cheaper to go this route for me. I only had to buy the driver ICs and design the PCB. It was $20 to get some boards cut using Seeed Studio and $3 per driver IC.

 

[blimblom]

@mr mike your led porn was kinky . very clean as every cabinet design should be. do you keep the hight of your fixture constant? Im always trying to put it near my SCROG

T_B_M , ALkalien, While I am also a meanwell fan (after what I saw on the chinese driver),
I respect the notion of using one driver for each string. It is bulletproof by design.

I also use 2 parallel strings for my B/R LEDs and a quickblow fuse and a Zener diode also, but Im not very confortable with the idea. Will the quick blow fuse be quick enough before it destroys the string? Will it burn only one LED or the LED will stay open and destroy everything?

all these questions are solved if you use one constant current driver per string.

also another request (but in no way Im trying to smack you or anything). Let us please not over-nerdify the thread in order to make it more accessible to the non nerds that are afraid to take the extra step of doing a DIY.


@T_B_M the price you got by designing and sourcing the driver yourself was awesome

 

[*mr.mike*]

For now the frame is at a fixed height. It would be all-too-easy to just hang or suspend a module or string from it, a few inches lower, though. I have some aluminum tubes (hunting arrow shafts), long screws, and threaded rod that can easily do this, with stability. That's all part of the plan behind separate modules and a frame. The whole thing is under a half meter inside, anyways.

Props to TBM for going the extra economical step... too good. I'd say "sell some," but it's obvious that you have a day job, and need the time for burn.

I'm waiting to read or see pics from someone who has taken the "higher step" up to some of those 20Watt or larger LEDs that I see in whites, and colors... I wonder how hot those run at, and if they can do the job needed?

I hope this thread can keep on keepin on.

 

[blimblom]

which 20watt LEDs do you mean? I have one from deal-extreme, but in reality it is more of 9x3watt LED running not so hard.

Right now I think the single most bright LED is the XM-L from cree, a real gem if you ask me.

But as for other colors, Blue are in the 3watt vicinity and Red are way behind (1,5watt) .

I dont know, maybe someone can make a setup with only white LEDs , but I think one of the advantages of having LEDs is choosing the spectrum.

Luminosity of white LEDs is not better than HPS .
warm white XM-L running @2000mA is giving around 80-85lm/w (500lm per LED)
Cool white XM-L "" " " 100lm/w but cool white I think wouldnt be so good for flowering.

of course as any who has used LEDs knows that heat production is way way better in a LED setup, and thats a real concern for small spaces and small footprint. Electricity consumption also. In my 65x35cm flowering cabinet a 150W HPS would probably produce super nice buds, but also more than 3times the heat and consumption my current setup has. And as I have it in my bedroom, the noise from the fans would be considerable

So for small spaces and small footprint there is nothing better than LEDs. I have seen a very sophisticated setup by SUPRA-PL with PL lamps that was a charm, but he too converted to LEDs long ago


PS and anyone wanting some help or have questions, please dont hesitate. Knowledge is not our prerogative or property

 

[alkalien]

I use XM-L cool white for additional white light. I run them at 2A (they can do up to 3A) but am experiencing minor problems.

With those Golden Dragons at 650mA I can let the plants grow almost into the Light but the XM-L also mounted on the same heatsink always burn holes in the leafes! Keep in mind, I don't use lenses. But those XM-L are far too good to run them at lower currents, I find it's a waste.

I did a panel with just 630nm and 660nm reds and XM-L cool white, that's why I chose the cool white, no need to add blue LEDs, plus the fact that you just mentioned, they put out more light per watt.

Actually I love the XM-L diodes, they are the brightest things I have ever seen! I'm at this moment working on getting them to light my living rooms and stuff too