DiY LED - Cree CXA3070

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CannaBare

Well-Known Member
I am running them each at 1600mA. I was shooting for 60w per sqft just like with a 1000w HID. Growth is amazing, I just want the temp in the low 80's.

Thats what I thought too! I will be going with the faster airflow. I was hoping to reduce noise but I would rather crank up the radio than the junction temp!

Thanks again!

edit: For the record my fan is running at less than half speed, But thats as high as I can go before ripping my walls off my room. You should be fine with 800w. The heat really isn't an issue, I am just a perfectionist.

SupraSPL said:
Cannabare how hard are you running them? I am dissipating 500W in a 7'X8' tent with a canopy of 4'X5" and canopy temps are just a few degrees above ambient. I intend to expand that to as much as 800W by increasing the ventilation fan speed if necessary.

Yes I believe that both heatsinks would dissipate the same amount of heat over time, but the temperature differential across the the heatsink will be larger with the fan at half speed. So the junction temp of the COB would be much higher.
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happy75

happy75

Well-Known Member
SupraSPL said:
I have a test in the works to compare Z2, Z4 and AB. That is awesome that you have access to the ABs! Any chance you can get 2700K Z4s?
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O cool, you are going to test those leds. Do you already know when? I am very curious about the differences. 2700K Z4 are not offered to me because I said I was interested in the 3000K. But I could ask my contacts if they have a few laying around. Are you interested in them? In only one for testing?

From my contacts I already received some nice samples of the 3590's 3000K and 5000K and with a high bin CB and CD. I cant wait to receive the chip-loks and test them.
 
Bueno Time

Bueno Time

Well-Known Member
Got my Steves LEDs order already 2 days from payment to mailbox! Highly recommend that place. My 630nm are already in the US too, fasttech driver is on the way I paid a little over a dollar extra for faster shipping so hopefully it comes in a week or two. Heatsink bars should be showing up next week hopefully I would think.

Last night, 21 days 12/12.



 
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Rooster99

Well-Known Member
SupraSPL said:
Fasttech 50W drivers? If so, to give fair warning the pair that I tested put out 1A and 1.2A but they were very efficient 90-91% if I recall. Did you set up for remote drivers?
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Aww damn that's bad news for me....I used 4 of them to make my 4 x 3070 3k rig and I epoxied them onto the baking tray I've mounted everything to.....oh well...I guess my 200w is actually a 150-170w..

Anyone got any other suggestions? Im building another one soon. I liked the fasttech ones cause they were cheap and had free shipping...I was looking at a mean well lpc-60-1400 as something similar but I was really digging the bang/buck on the fasttechs til you mentioned that.
 
SupraSPL

SupraSPL

Well-Known Member
These put out over 1400mA, 90% efficient and are power factor corrected. They ship from Tracy, CA. The meanwells are only 85% efficient and not power factor corrected so we bought a big batch of the eBay drivers and so far they are all testing to spec. Putting out 1420-1460mA warmed up and 90-90.5% efficient :eyesmoke:
 
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SupraSPL

SupraSPL

Well-Known Member
happy75 said:
2700K Z4 are not offered to me because I said I was interested in the 3000K. But I could ask my contacts if they have a few laying around. Are you interested in them? In only one for testing?
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When it comes down to 2700K Z4 vs 3000K AB, I am thinking that the 3000K (10% blue) might make more sense since it has enough blue to get the job done on its own and still get increased frosting. So that makes for a very simple installation and no worries about color mixing. But maybe the 2700K (8% blue) does as well, I would definitely love to test them, PM sent.
 
SupraSPL

SupraSPL

Well-Known Member
Wow Happy75, I just noticed that CXA3590 you mentioned is a new top bin as well. As awesome as the 3590 is, the driver issue could be a roadblock for us and also, would 80 Watts from a single COB be too much in terms of spread/distance to canopy?

Here is the comparison with the new top bin of the CXA3070.
CXA3070 AB vs CXA3590 CB.png
 
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happy75

happy75

Well-Known Member
SupraSPL said:
Wow Happy75, I just noticed that CXA3590 you mentioned is a new top bin as well. Here is the comparison with the new top bin of the CXA3070
View attachment 3161789
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Thanks for the calculations. If i am reading your calculations right, the 3070 is still better than the 3590 in terms of efficiency. Or am I missing something?

It generates almost twice the lumen, but I am more intested in the pars and efficiency.
 
SupraSPL

SupraSPL

Well-Known Member
If we compare categories based on dissipation wattage:

CXA3070@25W = 49.5%
CXA35990@25W = 53.65%

CXA3070@50W = 42%
CXA3590@50W = 46.6%

CXA3070@80W = 36%
CXA3590@80W= 41.4%

So the 3590 is solidly more efficient but because of the increased cost/PAR W and the increased cost of drivers for the CXA3590, you could afford to run the CXA3070 softer and run more of them, and therefore matching or beating the efficiency of the CXA3590. Also, you would get a more even spread and be closer to the canopy, less losses from scattering. So based on all that the 3070 is probably a better choice.
 
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CannaBare

Well-Known Member
SupraSPL said:
Fasttech 50W drivers? If so, to give fair warning the pair that I tested put out 1A and 1.2A but they were very efficient 90-91% if I recall. Did you set up for remote drivers?
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I made contact with a chinese company who made me drivers with a custom current(1600mA) at 38 volts or something like that. It is perfect for the CXAs because they were basically made for them. I'll take a picture of the driver when I get a chance! Tested with a multimeter they put out 1550-1580mA at thermal equilibrium. And the best part is they are icy cool. I do not understand the power factor concepts.
 
SupraSPL

SupraSPL

Well-Known Member
Awesome! Mind if i ask how much? You can check power factor if you have a kill-a-watt or similar. It comes into play if you are building a large driver board.

Here is an example where power factor is important. This (incomplete) board will draw 1250W or 10.5A but if it were not power factor corrected it would draw 1250W but 17A, beyond the limits of safety for a 15A 120V circuit or pushing the limits of safety for a 20A 120V circuit.
DSC07251a.jpg
 
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CannaBare

Well-Known Member
I don't think I understand it. I thought Watts was Volts*Amps. Not Volts*Amps*PowerFactor=Watts.

How do you calculate what it would be without the factor?
 
Bueno Time

Bueno Time

Well-Known Member
CannaBare said:
I don't think I understand it. I thought Watts was Volts*Amps. Not Volts*Amps*PowerFactor=Watts.

How do you calculate what it would be without the factor?
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Watts is Volts x Amps. That would be with a perfect or corrected power factor.

Power factor less than 1, the device will pull more current than it needs to operate. The amperage pulled by a non power factor corrected device, where it pulls more current than it consumes to operate, will always be more than one with a corrected or perfect power factor, where it will only pull what it uses no more. The extra amperage a non power factor corrected device draws that is unused goes back into the circuit, so the wattage used remains the same but the current draw is higher.

Its mainly an issue on larger builds like Supra said on a 15a circuit with a shitload of drivers power factor corrected drivers is a big deal to run more drivers at a lower amperage and not overload the circuit or have to use two circuits to run the lighting system. Otherwise its not really that big of a deal unless you are trying to keep current pull on the circuit to a minimum.
 
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