indecision has struck. Effeciency vs delivery.

Jeeyah

Well-Known Member
Ohhhhhhhhhh. Cool. That does sound tough to find. I wonder if mixing 5000k and 3500k would work? Or 3000k.
 

bicit

Well-Known Member
Ohhhhhhhhhh. Cool. That does sound tough to find. I wonder if mixing 5000k and 3500k would work? Or 3000k.
I have a pair of 97cri, 2700k vero 18's.... I wonder what I would get if mixed with three of the 5000k 70cri chips. :P

I'll just have to be patient and wait for the new vero's 2.0's to hit venders....
 

churchhaze

Well-Known Member
Given leds were free and time was unlimited, It would be better to use 4 cxb3570 at 350mA. Then you'd get the best efficiency and the best cooling/lighting spread.
 

tightpockt

Well-Known Member
I'm a thrifty ass dude and it's hard to shell out for the upfront costs but when considering that these lights should last for years, no bulb replacements and the potential to grow 1000's of $ worth of weed is makes it a little easier to buy the good shit up front.
That being said. I have roughly the same dimensions in a big Narnia style wardrobe and I'm using 4 cxb3070's at 1.5a
COB's = $160
Heatsink = $40
120mm fans = $20
 

AquariusPanta

Well-Known Member
Efficiency and simplicity. That's the two words I like.

I don't believe that 4 sources would make that much difference to justify lower efficiency.
I understand your logic but I don't agree with it. Also, having two separated heat sinks powered by a single driver (unless I misunderstood the original post Bicit made) would ultimately become a nuisance in a grow room. A single heat sink with the necessary COBs would be much easier to deal with (all in one).
 

bicit

Well-Known Member
Efficiency and simplicity. That's the two words I like.

I don't believe that 4 sources would make that much difference to justify lower efficiency.
This is what I was thinking. Have a little 75w "cube" put the heatsink and fan in a section of wire gutter cut to length. Connec the two cubes to each otherr via some aluminum c channel to keeps things level and hide the wiring.
 

alesh

Well-Known Member
This is what I was thinking. Have a little 75w "cube" put the heatsink and fan in a section of wire gutter cut to length. Connec the two cubes to each otherr via some aluminum c channel to keeps things level and hide the wiring.
Or you can bug into the driver and power the fans with small DC-DC voltage regulator. It's probably more efficient than any other small AC-DC PSU, cheap and you can get away with less wiring.
edit: I forgot I was talking about 3590's which means >75V voltage input for DCDC regulator. Not sure whether it'd that cheap.
 

churchhaze

Well-Known Member
8 cxb2530 u2 on 2 bars of the 5.886" profile using 1 HLG-120H-C500 would be pretty nice.

Edit: Forgot you already have a driver... doh.
 

bicit

Well-Known Member
Or you can bug into the driver and power the fans with small DC-DC voltage regulator. It's probably more efficient than any other small AC-DC PSU, cheap and you can get away with less wiring.
edit: I forgot I was talking about 3590's which means >75V voltage input for DCDC regulator. Not sure whether it'd that cheap.
I think with two CXB3590's on a HLG-120H I'd only have about 6-8v at the end of the string. Do you have a link to such a regulator? That would be nicer than running 5 wires(two for AC) to the lamp instead of 3.
 

churchhaze

Well-Known Member
On a side note, why do we even use DC fans? I've just been using them because I'm used to PC fans, but wouldn't we be able to just use transformers with no regulation if we used AC fans? Honest question. I don't know much about AC vs DC fans. I can't understand why we need regulation at all for fans.

Even with DC fans we wouldn't need regulation, but with AC, we'd literally just need a transformer.
 

alesh

Well-Known Member
I think with two CXB3590's on a HLG-120H I'd only have about 6-8v at the end of the string. Do you have a link to such a regulator? That would be nicer than running 5 wires(two for AC) to the lamp instead of 3.
You'd need to connect the regulator in parallel with the COB. It wouldn't change the voltage needed for the whole string but the COBs would be getting less power (power of the fan + losses on the regulator).
 

alesh

Well-Known Member
On a side note, why do we even use DC fans? I've just been using them because I'm used to PC fans, but wouldn't we be able to just use transformers with no regulation if we used AC fans? Honest question. I don't know much about AC vs DC fans. I can't understand why we need regulation at all for fans.

Even with DC fans we wouldn't need regulation, but with AC, we'd literally just need a transformer.
I was asking myself the same. Unfortunately I wasn't able to find any suitable AC fan. Everything I found was too big/powerful/noisy or unsuitable design. I did not search that well TBH.
 
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