DiY LEDs - How to Power Them

GroErr

GroErr

Well-Known Member
Yeah you're right, just being lazy. I have no problem getting my hands dirty with the connections, and they have those solderless mounts which will make it easier. I'll hold off and just start buying the components and eventually put a couple together. I want a decent fixture but I know a couple of guys in machine shops that with a little bribe may make me a nice aluminum fixture and drill/tap the mounts for me, one of them grabs a half a week through my son ;)

Cree COB's 50W x8 and solderless mounting adapters
Good size heat sink/fan combo's - I have a local source for these
Meanwell drivers
Bribe material for the fixture, mounting holes, and heat sink mounts

Thanks guys :)
 
Positivity

Positivity

Well-Known Member
For the drilling and tapping..

I was initially worried about that also. Did it the first time with my electric drill and a drill press attachment..pretty easy.

Tried it free hand with a drill recently...easy. All you need to do is use a punch to mark the spot you want to tap (will keep the drill bit from wandering and the pilot tip of drill bit won't fit in the punch mark until it's reasonably lined up straight), drop of cutting oil and drill right through, drop another bit of cutting oil in hole and start cutting the thread (soon as you feel resistance reverse direction back out...then start cutting again.

If you find you didn't go deep enough when you screw things down (I just went straight through) stick the drill back in go deeper and cut again....won't harm the existing threads.

Mess up a spot? Rotate and find a new spot...so what if it's not perfect...it will be with a tiny bit of practice.

Mandatory stuff I found is..

Drill bit and tap..extra is good to have. http://www.amazon.com/gp/product/B0006V6MNC/ref=oh_details_o08_s00_i00?ie=UTF8&psc=1

Cutting oil...you'll break bits and taps without it....http://www.amazon.com/gp/product/B0013RVDG4/ref=oh_details_o07_s00_i02?ie=UTF8&psc=1

Center punch...easy way to get drill to make a hole where you want it....http://www.amazon.com/gp/product/B0037UUO60/ref=oh_details_o07_s00_i03?ie=UTF8&psc=1

T handle wrench for hand tapping..http://www.amazon.com/gp/product/B00004YOB0/ref=oh_details_o07_s00_i01?ie=UTF8&psc=1

No drill press needed at all.
 
GroErr

GroErr

Well-Known Member
Thanks for the tips, but I'll likely try and outsource that. I can do it, built my grow room from scratch and learned everything as I went including all electrical. I just don't have the time and it's a short bike riding season up here ;)
 
only1realhigh

only1realhigh

Well-Known Member
a tip: when using the multimeter to measure Amps, soon as you are done with the reading at least remove the positive lead from the meter. At least than you will not forget to do it and damage the meter or LED's when you got to read voltage.

Now I can only hope I did not damage the driver or meter, for sure I blew 4 out of 8 LEDs.
 
Positivity

Positivity

Well-Known Member
only1realhigh said:
a tip: when using the multimeter to measure Amps, soon as you are done with the reading at least remove the positive lead from the meter. At least than you will not forget to do it and damage the meter or LED's when you got to read voltage.

Now I can only hope I did not damage the driver or meter, for sure I blew 4 out of 8 LEDs.
Click to expand...
Dang..that multimeter is capable of damage. Been meaning to watch a few videos on that. Want to check all the numbers on my light

At least the leds are a bit less expensive than cobs. I broke the base of a cxa 3070 lifting it off of my heatsink..it was bonded solidly with the thermal pad I used...$40 poof.

All avoidable stuff, just need to be more careful.
 
SupraSPL

SupraSPL

Well-Known Member
I have had trouble with that also. First I tried using bright color coding to catch my attention and that helped (two sets of wires, one for current and the other for voltage). Eventually I ended up with 2 multimeters which made the testing process a lot faster and mostly fool proof regarding using the wrong holes.
 
SupraSPL

SupraSPL

Well-Known Member
Here is a $3 driver that will power 1 CXA3590 or 2 CXA3070/Vero 29 at 88-89% efficiency. The only thing is, it runs at about 290mA :) Oh, the shipping took 6 weeks!

The CXA3590 3000K BB bin (mid bin) is available from Digikey for $56. At 290mA it would dissipate about 20W at 47.5% efficiency and would cost $5.90/PAR W. Not exactly a bargain but interesting anyway.

This driver would be perfect for a string of Vero 10s. The 5000K Vero 10s should make good vegging lights and they run at 41.5% efficient at 290mA and only cost about $2.19/PAR W.
 
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SupraSPL

SupraSPL

Well-Known Member
My understanding is, the 2 step has stricter binning for color tint, closer to the black body radiator line, so they probably retail at a slightly higher cost. Ultimately I would say it has little to do with us as growers, although when you stray away from the BBL line, a very green tint would be less desirable than a very red tint.

For those who don't know, the Planckian Locus or Black Body Line refers to the color emitted by something that is glowing hot (incandescent). So if a lump of iron was glowing at 2700 degrees kelvin, you would see the 2700K color tint that is on the BBL. When the sun is directly overhead, you can see its true color. It is about 5000K on the BBL.

So when an LED strays from the BBL, it might be considered a 5000K pure white, but it may have a strong green tint, or a purplish tint. LEDs are binned by lumens so those with a green tint may be more common in the highest bins. This is very noticeable with the XML2. I have a 4500K U2 4C tint and it has a greenish cast. But the 4500K T6 4D tint seems more of a pure neutral.

The dotted line is the BBL
CREEansiwhite.jpg
 
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grapeoptimo

grapeoptimo

Well-Known Member
so if i wanted to get some of these cxa 3590, 3500k or 4000k for flowering that'd be a good bet? also i'm planning on pushing them at 1-1.2 amps due to the upfront cost. once they've paid for themselves i want to be able to back off on the power and enjoy some of the efficiency...can you suggest drivers for me, I want to mount 2 of them on 1 heat sink and if possible use 1 driver and no fan.
 
SupraSPL

SupraSPL

Well-Known Member
Hey GO. If you have your heart set on the CXA3590, the best option I know of is the Mean Well HLG-185H series, although it may be hard to find in stock. That said, I think the CXA3070 3000K Z2 is the best bet because you can run at 1400mA very cheaply and spread the light into the canopy better than the CXA3590. Another good option is the Vero29 3000K, also runs good at 1.4A on the $13 eBay drivers.

If you use an efficient heatsink/fan setup, you can run with only 30sq cm/W and still get a reasonable Tj and spend as little as 1W of energy to cool it. If you go with passive cooling, you would need 110sq cm/W. For that reason I recommend active cooling for most new builds for flowering lamps. Vegging and cloning lamps are ideal for passive cooling because the power can be spread out more.
 
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SupraSPL

SupraSPL

Well-Known Member
That is a good question, it is hard to see how much surface area it has. The 92mm version of these has been popular because of the quality of the fan and the cheap price. But generally speaking, any decent CPU cooler works great for the CXA3070 @ 1.4A.
 
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