Cree CXA3050 100W Custom LED Grow Journal with Dinafem Blue Widow
- Thread starter bbspills
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PetFlora
Well-Known Member
Thread tools in blue header above the thread. Scroll over it it drops down for choices
Mechmike
Well-Known Member
Very nice. Another great example of how capable LED really is. Only LED could do that with only 100 watts. That ought to look awesome by the time it's ready!Tomorrow will officially be 28 full days. She's chugging right along. What I'm shooting for is to be done with 12/12 on 12/12. That would be 8 full weeks. How cool would that be
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Each LED is wired directly to a 50W driver which goes directly to 120V outlet. They couldn't be easier to wire up.
The LED drivers have two wires on one end that wire directly to a power outlet (just strip a power plug and connect the two leads)
Then the other wires out of the driver are just the +- that go to the +- on the LED.
I have both LED drivers hooked up to the same power cord that is plugged into the timer.
The pic below is the driver I got off ebay. I snagged two of them for $18 each
smokey the cat
Well-Known Member
Hey Bondoman -
For about a decade now CPU coolers are designed to roughly handle around 100W of heat - some more, some less but 100W is a nice rule of thumb. Here's a wikipedia with the heat output of different CPUs so as to give you an idea of what your heatsink was designed for http://en.wikipedia.org/wiki/List_of_CPU_power_dissipation_figures
So can a passive CPU cooler handle a 50W Cree? They don't produce 50W of heat - maybe 25W or so (guesstimating 50% efficiency).
So running without a fan: this is tough to guess at - with plenty of air circulation:maybe. With a fan, no probs.
The tight small fins of CPU heatsinks will not work so well without high pressure air flow, so a traditionally-shapped squat and square heatsink will probably perform much worse in free air than a large flower-fan type heatsink (google Zalman for some ideas - some of those style sinks can definitely passively handle that heat with only gentle airflow).
Ebay also carries some cheap Chinese passive LED aluminium sinks which will work - pretty large, but no fan needed if you have enough cool air flowing around the chamber.
The cooler you can keep your emitter the brighter and more efficient it will be. It'd be a shame to get a nice high-end emitter and run it too hot imho.
For about a decade now CPU coolers are designed to roughly handle around 100W of heat - some more, some less but 100W is a nice rule of thumb. Here's a wikipedia with the heat output of different CPUs so as to give you an idea of what your heatsink was designed for http://en.wikipedia.org/wiki/List_of_CPU_power_dissipation_figures
So can a passive CPU cooler handle a 50W Cree? They don't produce 50W of heat - maybe 25W or so (guesstimating 50% efficiency).
So running without a fan: this is tough to guess at - with plenty of air circulation:maybe. With a fan, no probs.
The tight small fins of CPU heatsinks will not work so well without high pressure air flow, so a traditionally-shapped squat and square heatsink will probably perform much worse in free air than a large flower-fan type heatsink (google Zalman for some ideas - some of those style sinks can definitely passively handle that heat with only gentle airflow).
Ebay also carries some cheap Chinese passive LED aluminium sinks which will work - pretty large, but no fan needed if you have enough cool air flowing around the chamber.
The cooler you can keep your emitter the brighter and more efficient it will be. It'd be a shame to get a nice high-end emitter and run it too hot imho.
coolbreez1
Well-Known Member
So why cant these guys be used as LED drivers?
http://www.meanwell.com/search/NES-75/NES-75-spec.pdf
http://www.meanwell.com/search/NES-100/NES-100-spec.pdf
The 48vdc versions of this seems like it would be great as LED power supplies, however, they are never listed as LED power supplies.
So what is it about these that makes them not a good choice as an LED driver?
http://www.meanwell.com/search/NES-75/NES-75-spec.pdf
http://www.meanwell.com/search/NES-100/NES-100-spec.pdf
The 48vdc versions of this seems like it would be great as LED power supplies, however, they are never listed as LED power supplies.
So what is it about these that makes them not a good choice as an LED driver?
I dont think so...
overcurrent--->heat destroys them.
I think they write e.g. 0-14A because it means you can run them when you have something consuming just low amounts of current...not every power supply is stable at low currents and requires a certain load to work properly.
In simple: As i said overcurrent->heat destroys Leds -what you linked are constant voltage sources.
So these try to maintain a constant voltage, which will allow the led take more and more current until it overheats.
A constant current Driver tries to maintain the same current Distribution to led, it adjusts the voltage, so the led will stay at its current Level and not overheat. But the Constant current has to be within the specs of the led and still you Need a heatsink.
Leds are different from other usual electronics, so you cant use just a usual power supply.
Usually devices take just the amount of current they need, leds on the other will try to get as much Amps as possible untill selfdestruct.
PetFlora
Well-Known Member
Cool DIY LED chip project https://www.youtube.com/watch?v=fSPnDY557AA
Here's one for $37, capacity said to be 250w
Personally I would use more, but smaller <50w chips to provide more balanced canopy coverage
Here's one for $37, capacity said to be 250w
Personally I would use more, but smaller <50w chips to provide more balanced canopy coverage
coolbreez1
Well-Known Member
Thanks lex, that does make sense, however, if they are rated from say 0-1.6 amps and the cxa3000 series takes 1-2.4 amps wouldn't it be impossible for them to draw enough current to fry them? Or would the increased current draw just result in the power supply frying instead of the LEDs.
it should be noted there are several versions per PDF I am referring to the 48vdc version which goes from 1-1.6 not the 5vdc that goes from 1-14.
it should be noted there are several versions per PDF I am referring to the 48vdc version which goes from 1-1.6 not the 5vdc that goes from 1-14.