Help me build a large CXA3070 Rig

[SupraSPL]

what do you call "long wire between cob and driver"?
Thanks...Have a great day ★

Voltage drop is related to how much current is flowing, how thick the wire is and how long it is. It is basically the resistance in the wire and it creates heat in the wire, directly decreasing the efficiency of the system. Typically I use 18 gauge because it is cheap and convenient and should be more than enough to carry the 700mA I typically run without any significant loss. But if you were running say 2.1A for a distance of 30 feet, you might want to consider using a thicker gauge wire to minimize voltage drop.

http://www.calculator.net/voltage-drop-calculator.html

 

[HockeyBeard]

So, you've got a ground wire affixed to the bracket, but what is the lens attached to? How does that stay put?

 

[HockeyBeard]

If you run the CXA3070s at 700mA you can run 8 of them on an HLG-185H-C700 at 24.5W each. If you want to run them at 52W ea, you can run 3 of them on an HLG-185H-C1400.

The Rosewill RCX-Z300 can just fit the 3070 sized COBs, the corners hang off just a bit but the entire area behind the LES is cooled by the copper core.
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Have you tested the Arctic Alpine 64 Pro Rev 2 sinks? Are they legit? I have a killer deal on some right now

 

[SupraSPL]

There a 4 10mmX10mmX2mm neodymium magnets sandwiched between the heatsink frame and the lens frame because both of those parts are steel and they line up conveniently.

I have not tested the Arctic Alpine 64 Pro Rev 2 but right off the bat I would suggest that those thin plastic bars around the fan will get broken, fingers will get into the fan. Normally I recommend fans with a more complete plastic surround protecting the fan and possibly easier to hang/mount. Also the mounting surface seems to be mo larger than the Alpine1 so it may not be 3590 friendly if you are using holders. All that said I expect its cooling performance will be very good.

 

[chinuh man]

If you run the CXA3070s at 700mA you can run 8 of them on an HLG-185H-C700 at 24.5W each. If you want to run them at 52W ea, you can run 3 of them on an HLG-185H-C1400.

The Rosewill RCX-Z300 can just fit the 3070 sized COBs, the corners hang off just a bit but the entire area behind the LES is cooled by the copper core.
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I am trying to build a similar model to this but with 4 cxb3590 3500k 36v. I need a complete parts list... from absolute scratch

 

[littlejacob]

Bonjour
You need fans,hlg-185-1400b, potentiometer(100k), resistor (10k) 18awg wires, fan psu,wago connector,holders (×4), 8awg+socket, heatsink(s),TIM (artic silver5), 1razor blade, screw (M3) and patience
CU

 

[chinuh man]

this is a start. Thank you so much @littlejacob . I will have more questions shortly.

 

[chinuh man]

Okay so after a little bit of research I need help. If I get an hlg-185-c1400b do I still need a resistor or a potentiometer? The driver has 1-10vdc pwm resistance. Just trying to make sense of it all. Sorry if this question has already been answered somewhere.

 

[BigYellowCob]

Okay so after a little bit of research I need help. If I get an hlg-185-c1400b do I still need a resistor or a potentiometer? The driver has 1-10vdc pwm resistance. Just trying to make sense of it all. Sorry if this question has already been answered somewhere.

That driver can be dimmed 3 different ways. With a PWM, 1-10vdc, or resistance (which is what the 100k pot provides). Most people use the 100k pot to dim, since the pots are cheap and it's easy to wire up. Some have recommended to use the 10k resistor along with 100k pot to prevent dimming the driver less than 10%, as there's speculation that dimming the driver too low may not be good for it. I did not use the 10k resistor, but I never dim more than 50% anyways.

 

[chinuh man]

Okay so to clarify. This has 3 options for dimming and @littlejacob is correct. I would at least need the potentiometer? Thank you for the information @BigYellowCob

 

[BigYellowCob]

Okay so to clarify. This has 3 options for dimming and @littlejacob is correct. I would at least need the potentiometer? Thank you for the information @BigYellowCob

If you want to dim, you'll need the potentiometer. If you want guidance with a build, you probably should start a thread to keep from hijacking HockeyBeard's thread any more than we have.

 

[ttystikk]

If you run the CXA3070s at 700mA you can run 8 of them on an HLG-185H-C700 at 24.5W each. If you want to run them at 52W ea, you can run 3 of them on an HLG-185H-C1400.

The Rosewill RCX-Z300 can just fit the 3070 sized COBs, the corners hang off just a bit but the entire area behind the LES is cooled by the copper core.
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Isn't that called 'overkill'? LOL

 

[HockeyBeard]

If you want to dim, you'll need the potentiometer. If you want guidance with a build, you probably should start a thread to keep from hijacking HockeyBeard's thread any more than we have.

As long as the stuff stays on topic of building a COB array, little things such as that are more than welcome in this discussion

 

[BigYellowCob]

As long as the stuff stays on topic of building a COB array, little things such as that are more than welcome in this discussion

Cool, and good luck with your build. BTW, I'm a former Michigander - most of my family still lives in W Mich, but I moved away in 2000 when I decided I had my fill of the frigid winters. I'll actually be in Grand Rapids next week on a work trip and thought about making a quick trip to HeatSinkUSA and grab a couple of heatsinks to take back with me, but then realized that TSA probably wouldn't be to happy with me dragging 3' hunks of aluminum through the airport, lol.

 

[chinuh man]

Thank you @HockeyBeard for letting me hitch hike on your thread.

 

[chinuh man]

Efficiency % is the amount of par w divided by total watt dissipation? So you can have more watts dissipated but if your driver efficiency is low someone with higher efficiency and lower watts dissipated would have a more viable light?

 

[alesh]

Efficiency % is the amount of par w divided by total watt dissipation? So you can have more watts dissipated but if your driver efficiency is low someone with higher efficiency and lower watts dissipated would have a more viable light?

Yeah, spot on. And the same goes for LEDs not only drivers. Total efficiency is LED's efficiency multiplied by driver's efficiency.

 

[chinuh man]

Time to research LED efficiency. Thank you for the information @alesh .

 

[ttystikk]

Time to research LED efficiency. Thank you for the information @alesh .

Lesson one; running LEDs more softly makes them MORE efficient, which is why you see a lot of people here running 100W COBs like the Cree CXB3590 at only fifty watts; they're paying once for double the chips, but picking up ten percent efficiency permanently. It pays for itself pretty quickly, both in terms of yield and reduced heat signature.

 

[chinuh man]

Okay, everything I have been reading in these forumns is starting to make more and more sense. Thank you @ttystikk

So LER is the total efficiency of the driver and COB? The higher the efficiency the higher the ppfd per watt dissipated?

Edited:
I no longer think LER is important. It only factors visible light, not PAR? Efficiency of both the drivers and LEDs can be sourced so learning the formulas shouldn't be big concern, right?
I plan on starting with a sea of green method style grow in a 3' x 3'. So my first step would be to calculate the PAR W/ft² correct? Then blueprint out the highest efficiency light possible for the best results?
Sorry for all the questions. Just want to feel confident before ordering the main parts needed. Thanks in advance RIU!