Yet another DIY thread

[anomuumi]

Greetings my fellow LED enthusiasts! First of all I want to thank you all for sharing your ideas and experiences, without this valuable information I would be even more lost than currently.

Long story short! Here's what I've planned:

Modular fixture:

8 modules, size aprrox 5" * 20", each with 4 clusters of 3 leds so 12 leds per module, 96 total

Driver:

http://mouser.com/ProductDetail/Mean-Well/HLG-185H-C700B/?qs=sGAEpiMZZMvV8Y9YugmIgmy193Qkqm18MYy3MuBDghw=

LEDs:

Oslon SSL 80 deep red 3T - 32pcs

Cree XP-E2 red P3 - 32pcs

The rest 32 pcs ????

XT-E CW R5

XT-E WW R3

Neutral whites, blue??

Here's what I would need a little help with:

Initially I just wanted to do a small 50W veg lamp, even bought parts for it. Then things got a bit out of hand and... Oh, where was I. Yeah, the fixture..

I wanted something simple, and thought ideal spectrums (isled.fr) 1:1:1 ratio of CW:630nm:660nm would be fine for small clusters, but then SupraSPL stated that it might produce too much leaf. I don't want that, so where to go from there? I'm stuck.

Should I go 1:1:2:2 ratio of WW:CW:630:660, or is that too much white still? Due to the modular layout and clusters of 3 leds, I think adding blues it would be tough to maintain the good colour mixing and even intensity I'm after.

Another thing is the driver, as there are exposed contact points on top of the stars, such a high DC voltage seems like a bad idea. Or am I just paranoid? Those can be masked with, tape, plastic front cover etc. but tape is ugly and plastic fronts would add to the already immense amount of work.

Ideas, comments, suggestions? I think I might be overlooking something important here and would like to avoid any possible fuck ups before ordering more parts.

 

[anomuumi]

Let's put the problem in another form, if we could get some dialogue going:

If you were to grow single cola SOG style plants in an area of 20cm*20cm each with solid state lights, how would you build your fixture? Evenly spaced emitters or clusters on top of plants? More blue for keeping plants short? What else?

Too bad I already ordered bunch of stuff, if I had learned about the new COB's earlier, things would've been too easy.

 

[MrFlux]

That driver is very dangerous with its 285 volt, I hope you will use something else.

 

[Rahz]

I would look at the warm whites. They seem to be close to a usable par profile for red and blue light.

Figure out the expected power draw and lumens per watt and you can get a rough estimate of how many LEDs are needed per foot. I think they would work best evenly spread out. I suspect the clusters have more to do with thermal management and cost.

 

[SupraSPL]

Cool setup! If you are planning on incorporating cooler whites, check these out Cree XM-L2 T6 5000K for $3.50 shipped. They also have 4500K in the T6 bin (43.2% efficient at 700mA 50c) which is 147 lumens/watt.

Regarding color mixing, I have found that the bare emitters mix very well and I keep the modules only about 6 inches from the canopy. So I would have no worries about adding some blues.

If you really want to spend some cake getting the best, Cutter is now carrying Cree XM-L2 T5 3000K WW. I have no idea how they made the jump from T3 to T5 but it is an incredible improvement for warm whites 40.6% efficient at 700mA 50c (137lm/w). That is a 25% improvement over my XTE R3 bin at 32% efficient (107lm/watt). On the other hand it cost 2X the price lol.

 

[SupraSPL]

You and Mr Flux are correct to be concerned about the driver. Every contact point on the LED string would become dangerous to touch and it will have the ability to overcome the resistance of your skin much more easily. A GFCI would be a very good idea in that case but it would still be dangerous.

To overcome that problem I built driver boards that control 300watts each using (12) 40vF drivers. Another advantage to using shorter strings is that if a driver ever happened to fail and damage the string it won't zap your entire setup. I have lost entire strings before due to driver failure (ultimately my failure, loose connectors).

 

[anomuumi]

Thanks for the thoughts guys! I think I should have started a thread earlier, as I've already ordered stuff impulsively which I regret a bit. I would definately have favored those XM-L's from fasttech over XT-E's, but too late now. Though now that I've added the luxeons, I might as well add some more whites. Supra, I couldn't find those T5 WW XM-L2's from cutter, are you sure that you weren't looking at neutral whites? Post a link if you find them.

That meanwell driver is just very appealing because of it's price and efficiency. It's definately not safe to run without some precautions, including proper connectors and plastic cover plates to keep solder points and wires safely hidden. SupraSPL has a point though with having security of not frying all your chips at once by having multiple drivers. The thing is that all smaller drivers that I have looked are not that efficient. Feel free to suggest ones that would suit my build. I thought about using the multichannel LDV-185-700, but it isn't as efficient as HLG-185 and isn't adjustable.. If I have to use a fixed current driver, then I would prefer 500mA drive current for efficiency.

Anyway, here's what emitters I have / ordered so far:

32pcs XTE WW R3
32pcs XTE CW R5
32pcs XPE2 red P3
32pcs Oslon deep red 3T
32pcs Luxeon deep red EX6
+ some misc blues and whites for the veg light I haven't still built

 

[SupraSPL]

With all due respect to Cutter, the site can be tricky to navigate and there are confusing typos but here are the warm white XML2 T5

Check out these drivers. I have tested them at 88-91% efficient (I tested with a Fluke 115 and Ensupra power meter). They are amazingly cheap <$6 shipped. If you load them at about 20vF they will drive at about 650mA. If you really load them up ~50 vF the output will drop to about 600mA (~30 watts each). They max out at 52vF. I'm sure the output level varies from driver to driver I have only tested a few.

The only downside is waiting and hoping for them to get here from China, especially this time of year.

 

[anomuumi]

I don't think I'm in a hurry with this build, so I wouldn't mind waiting a bit for parts. I'm a bit of an electronics idiot, so I wouldn't mind having a driver with some protections like over temperature and such. Price indeed favors those, but are they reliable?

 

[SupraSPL]

That is a very good question. I think being bare will help extend the life of the components. If one does go splat, no worries and probably a good idea to keep a few extra on hand. Also I keep a 1A ATC fuse in every LED string just in case something goes wrong with the driver.

I am warming one up right now to test it again. It is putting out .66A and power factor is near parity almost like a perfect resistive load. Not many drivers I have tested bother correcting for power factor especially small cheapos. Once it warms up I will check vF and overall efficiency.

I am sitting under (6) XML2 4500K T6 and (3) XTE 3000K R3 and it is too damn bright lol.

 

[SupraSPL]

test1 - driver and string warmed up
A=.654
vF=26.4
LED dissipation = 17.26w
input power = 20.2w
85.5% efficient

test2 warmed up a bit more
A=.654
vF=26.23
LED dissipation = 17.15w
input power = 19.8w
86.6% efficient

test3 - added a few leds
A=.627
vF=39.5
LED dissipation = 24.77w
input power = 28.3w
87.5% efficient

test4 - added more
A=.611
vF=48.5
LED dissipation = 29.64w
input power = 33.6w
88.2% efficient

 

[PetFlora]

I like where you're going with 4500 + 3000! But why on separate heat sinks?

That is a very good question. I think being bare will help extend the life of the components. If one does go splat, no worries and probably a good idea to keep a few extra on hand. Also I keep a 1A ATC fuse in every LED string just in case something goes wrong with the driver.

I am warming one up right now to test it again. It is putting out .66A and power factor is near parity almost like a perfect resistive load. Not many drivers I have tested bother correcting for power factor especially small cheapos. Once it warms up I will check vF and overall efficiency.

I am sitting under (6) XML2 4500K T6 and (3) XTE 3000K R3 and it is too damn bright lol.
View attachment 2923574

 

[SupraSPL]

That 4500K lamp was supposed to be a work light but now it doubles as a grow lamp for my bell peppers on the kitchen table (and reserva privada seedlings). The 3000K light is my living room light, normally installed in a pole lamp shining on the ceiling. I borrowed it to do the test on the driver, my wife very tolerant having an LED nerd husband

 

[anomuumi]

Awesome stuff, thanks for testing Supra! I understand those are very simple devices and might even be fixed by an amateur when some component fails. There's just something that bothers me using cheap stuff like that, maybe it's just my lack of knowledge.

Supra, could you post a pic or explain those driver boards you mentioned earlier? I'm thinking more of a fireproof box to house the drivers, fuses and connectors IF I end up using open drivers like these.

edit:

Compared to something like this:

http://320volt.com/wp-content/uploads/2012/07/led-driver-circuit-smps-lnk419eg.png

those cheapos look just too damn simple. Uh, dunno what to think of them.

 

[anomuumi]

Ordered those cheapos from Fasttech while ago, along with some XM-L2's. They do take long-ass time to ship! I dislike the drivers already, might have to rethink them further down the road. Satisled seemed to have a good deal for 450mA drivers. Good news is that everything else has arrived, just need some time and motivation to make progress.

If I would have started the build now, I would have based it on the new COB's. Less hassle with soldering, easy to arrange heatsinks and amazingly efficient with lower drive currents etc. Also I was really impressed by the CXA grow by bbspills! Big respect to Supra and other pioneers, the amount of work it takes to build a fixture with these small leds is definately not a small task!

Anyways, just wanted to thank everyone for their contributions again on this forum, exciting place to follow! Happy, bright & efficient 2014 too, let's see what Cree & others have to offer us in the near future!

 

[anomuumi]

No - this project is not dead, just moving along slower than a snail. A couple of do's and dont's learned so far:

-If you have trouble sourcing good heatsinks, get a quote for C-channel aluminum from your local steelshop, you might be surprised by the price!

-CPU heatsinks are utterly useless as passive heatsinks, they pretty much are as good as a similar sized lump of solid aluminum due to the fins being so close together

-Ordering stuff directly from chinese companies leaves a bad taste usually, can you be sure you got the emitters in the bin you ordered? Cheap shit has it's problems in quality too, referring to those 6$ drivers in this case

-Thinking about using thermal adhesive? Think again, hard to correct mistakes, it's messy, emitters are hard to clamp during curing and so on. Works better on a smaller scale maybe, not for me unfortunately.

If anyone has suggestions for AC switches for drivers, fuse holders & quick fuses, DC connectors for up to 50V please feel free to share!

edit: What do you guys running those bigger amounts of panels use for timers and relays? Does anyone use solid state relays?

 

[SupraSPL]

What went wrong with the $6 cheapos? I bought 5 and they tested very well but I have not tested their long term reliability.

Here is one of the first driver boards I built


There are no switches but each driver is connected to the power terminal by .25" slide connectors. If I need to turn one driver off I disconnect the hot wire. One mistake I made was that the hot wire ended up being male on the live side and it would make a lot more sense if it were a female.

The bare crimp-on .25" slide connectors are awesome. There is no jiggle to them whatsoever and there is no way to beat the price which is especially noticeable on a large build. I use them on the AC and DC side. They eliminate the possibility of mixing up polarity and make you drivers and LED modules easily swappable.


They also work great as DIY fuse holders on the DC side. These are 1A fuses and they are not quick blow but I figure it is better than nothing, especially to protect the COBs which are 3A anyway.


The plastic covered crimp ons don't seem as secure IMHO so I get the bare ones and use heat shrink tubing. I got all this stuff from elecdirect.com. They have cheap 600V color coded wiring for the AC side and 50V wiring for the DC side.

 

[SupraSPL]

You can make switches that can bug in anywhere

 

[anomuumi]

Thanks for the advice! I guess I would like to have 2 pole on-off switches on the AC side, I looked some at mouser and they weren't that expensive. DC connectors aren't fully necessary, more like "nice to have". Those cheapo drivers seem to have a fuse on the AC side, so I'm not that worried about protection in case of shorts or other malfunction. Though those quick fuses would be nice anyway.

At least one of the bunch of those cheap drivers I ordered was broken and few had globs of some glue all over the board. Couple seem to be working so far. They might be fine in the long run, but still left a bad impression at first