DIY CXB2530 3000K 80cri U2 bin (Vero Killers!)

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churchhaze

Well-Known Member
You should have just used the Bernoulli principle and Venturi effect to change the pressure and the velocity through a small pipe... while blowing 50mph winds over it. That fixes everything, in fact it makes or breaks a light.

I call it the whistle.



Make all your fixtures different lengths for a nice chord. Space cobs (black dots) as shown above.
 
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churchhaze

Well-Known Member
HLG-120H-C500b would work great for 8. The Arctic cpu heat sinks would work just fine powering the fans at 5V, but even then it would be overkill. I guess it depends what price you get them at.

Another good option would be the 5.886" profile http://www.heatsinkusa.com/5-886/ and have 2 bars, 4 cobs each, and a 120mm fan each bar.

You could get 2 of these bars at 24" inches for $41.76 each and imo is nice because it doesn't require a rail mounting system to be designed/built. (opinion)

At 24" inches, the price of both would be about the price of 8 arctic alpine 11.
 
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Merkin Donor

Merkin Donor

Well-Known Member
Thanks for the quick reply! So are the drawer slides that they used in that DiY thread for coverage adjustments just not necessary? Or is that expecting too much coverage for these cob's? What would the coverage limitations be on 24" heat sinks?
Thanks!!
 
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churchhaze

Well-Known Member
Merkin Donor said:
Thanks for the quick reply! So are the drawer slides that they used in that DiY thread for coverage adjustments just not necessary? Or is that expecting too much coverage for these cob's? What would the coverage limitations be on 24" heat sinks?
Thanks!!
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I don't know anything about the drawers/slides. 140W (8 * 35V * 0.5A) of dissipation would cover about 5-6sqft footprint for 2-3ft plants. So maybe a 3'x2' footprint box, you'd have 11.5 PARW/sqft. 12-14 PAR W/sqft is a good number.
 
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CellarDweller

Well-Known Member
Please forgive a potentially idiotic question, but given the relative lack of heat dissipation forwards from a COB and the ability to place them close to the plant, has anyone ever experimented using COBs on a side-lighting panel to reach the lower part of their plants?
 
SupraSPL

SupraSPL

Well-Known Member
Ya I kind of wrap them around them canopy and try to get even coverage as many places as possible. Deeper in the canopy I prune away the sucker bud sites. The more you prune, the bigger the buds up top can get. There is such a thing as too big because certain varieties will get mold inside the biggest buds, even in dry air, even with slight underfert. I think that may be due to the lack of IR the buds can get extra dense.
 
Observe & Report

Observe & Report

Well-Known Member
Merkin Donor said:
So would building one of theses using 8 CXB2530's, 8 Arctic cpu heat sinks and a HLG-120H-C500b be a good first time DIYer starter light or are there better options?
https://www.rollitup.org/t/diy-led-grow-lights-with-cree-cxa3070-cobs-and-cpu-coolers.805681/
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A better option is low voltage that is much less likely to kill you. High voltage should be reserved for people experienced with electronics, at a minimum. Personally, I wouldn't use any HV in my grow area unless it's a complete fixture/system with certifications (UL, CE, etc...)

The higher the voltage, the more likely there is to be arcing or overheating that could lead to a fire, too.
 
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Devildenis69

Well-Known Member
Observe & Report said:
A better option is low voltage that is much less likely to kill you. High voltage should be reserved for people experienced with electronics, at a minimum. Personally, I wouldn't use any HV in my grow area unless it's a complete fixture/system with certifications (UL, CE, etc...)

The higher the voltage, the more likely there is to be arcing or overheating that could lead to a fire, too.
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Very true that high voltage is dangerous for the user, it needs to be well isolated ...
but even a low voltage could be dangerous, the fire/overheating hazard is linked with high current ;)
 
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churchhaze

Well-Known Member
Assuming the same total power delivered, the high current solution will have greater fire risk and the higher voltage solution will have greater shock risk.

Both are very dangerous, but I'd agree the higher current solution (low voltage) is a lot less likely to kill you if something goes wrong, assuming you don't get stuck in a burning building.

When working with higher voltages, it's very important to ground the heat sink. If's not grounded, and the 400V wire comes out of a cob holder, and touches the heat sink, the light will turn off, and it will seem totally safe. The only problem is the heat sink is floating at 400VDC, and touching it could put up to 500mA through you (limit), easily enough to kill you. If the heat sink is properly grounded, the 400VDC wire touching the heat sink will instantly cause a short circuit, and trip the breaker, fuse, or short circuit protection.

I honestly don't feel safe using a 400VDC driver myself, so I did not want to recommend it in the materials list. If i'm not dead within a year, go for it!
 
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churchhaze

Well-Known Member
In the situation I described above with the ungrounded heat sink that's floating at 400VDC, even if you unplug the driver from the wall, it's still a serious 400VDC shock risk. Because the load is not connected, it didn't discharge the smoothing capacitors. For higher efficiency, these mean well drivers don't have discharging resistor for safety, or it's very large and takes a long time to discharge.

That means even after you unplug the driver from the wall, the ungrounded heat sink could still kill you.

In fact, this is the most likely scenario I can see people shocking themselves to death... The lights go out, the unplug the driver, touch the heat sink, and get shocked by the smoothing caps.
 
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PSUAGRO.

PSUAGRO.

Well-Known Member
churchhaze said:
Assuming the same total power delivered, the high current solution will have greater fire risk and the higher voltage solution will have greater shock risk.

Both are very dangerous, but I'd agree the higher current solution (low voltage) is a lot less likely to kill you if something goes wrong, assuming you don't get stuck in a burning building.

When working with higher voltages, it's very important to ground the heat sink. If's not grounded, and the 400V wire comes out of a cob holder, and touches the heat sink, the light will turn off, and it will seem totally safe. The only problem is the heat sink is floating at 400VDC, and touching it could put up to 500mA through you (limit), easily enough to kill you. If the heat sink is properly grounded, the 400VDC wire touching the heat sink will instantly cause a short circuit, and trip the breaker, fuse, or short circuit protection.

I honestly don't feel safe using a 400VDC driver myself, so I did not want to recommend it in the materials list. If i'm not dead within a year, go for it!
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churchhaze said:
In the situation I described above with the ungrounded heat sink that's floating at 400VDC, even if you unplug the driver from the wall, it's still a serious 400VDC shock risk. Because the load is not connected, it didn't discharge the smoothing capacitors. For higher efficiency, these mean well drivers don't have discharging resistor for safety, or it's very large and takes a long time to discharge.

That means even after you unplug the driver from the wall, the ungrounded heat sink could still kill you.

In fact, this is the most likely scenario I can see people shocking themselves to death... The lights go out, the unplug the driver, touch the heat sink, and get shocked by the smoothing caps.
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Yeah............that's some scary shit, not to be handled without respect...........should be posted more often around here.
 
ttystikk

ttystikk

Well-Known Member
churchhaze said:
In the situation I described above with the ungrounded heat sink that's floating at 400VDC, even if you unplug the driver from the wall, it's still a serious 400VDC shock risk. Because the load is not connected, it didn't discharge the smoothing capacitors. For higher efficiency, these mean well drivers don't have discharging resistor for safety, or it's very large and takes a long time to discharge.

That means even after you unplug the driver from the wall, the ungrounded heat sink could still kill you.

In fact, this is the most likely scenario I can see people shocking themselves to death... The lights go out, the unplug the driver, touch the heat sink, and get shocked by the smoothing caps.
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Are these smoothing caps built into the COBs, or are they something that has be built into the system?
 
cityworker415

cityworker415

Well-Known Member
FESTER665 said:
Great build... I just ordered some CXB3590's today, I'll definitely be going with solid core at the ideal connectors, I had the same issue with the BJB connectors on my reef LED setup, they needed to either be tinned or solid core wire to make a really good connection.

As for hanging these hunks of aluminum, I'm using a hanging kit from the company that I bought my DIY LED stuff for on my aquarium. A little expensive, but really worth it IMO. I can easily raise the lights up or down, and then if they're not sitting flat I can move them front to back as well and lock it in at that setting.

https://reefledlights.com/shop/hanging-kit/

Here's how they look on my heatsink...




Used the same hangers over my old reef tank with a ridiculously heavy T5 fixture...


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Sweet beach tank

Sent from my SM-G900V using Rollitup mobile app
 
Scotch089

Scotch089

Well-Known Member
Someone should start a sticky about diy safety.

And answer simple ass questions I don't know like (where to ground the driver) I mounted it on the heatsink strip I used for my 3 prong plug and on/off switch. Is this defeating the purpose or safe?
 
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churchhaze

Well-Known Member
Scotch089 said:
Someone should start a sticky about diy safety.

And answer simple ass questions I don't know like (where to ground the driver) I mounted it on the heatsink strip I used for my 3 prong plug and on/off switch. Is this defeating the purpose or safe?
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As long as the heat sink is connected to ground, it should work to create a short circuit if any live wire touches the heat sink, so all the current goes through the ground and hopefully trips a breaker.
 
Scotch089

Scotch089

Well-Known Member
"As long as the heatsink is connected to the ground"

Do you mean where the ground wire is grounded when saying connected to the ground (on the metal) or it needs to be grounded to the literal....ground. (rod mounted in dirt like my dad has at his workbench)

....ground, ground........ground.

Even typed something so much that the spelling starts to look wrong..? Yea...
 
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churchhaze

Well-Known Member
Scotch089 said:
"As long as the heatsink is connected to the ground"

Do you mean where the ground wire is grounded when saying connected to the ground (on the metal) or it needs to be grounded to the literal....ground. (rod mounted in dirt like my dad has at his workbench)

....ground, ground........ground.

Even typed something so much that the spelling starts to look wrong..? Yea...
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The sad looking mouth on the electric sockets.
 
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