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About a CXA3070 & Heatsink

Mega Man X

Mega Man X

Member
Hi there!

Have been lurking forums last couple of months in order to do a CXA3070 COB build, and so far Im all for a passive cooling unit, and these are the 2 heatsinks I got aviable here in M3x1co:

Mod. C125 L: 14 cm H 5.8 cm Deep 12.5 cm
Mod. C150 L: 14cm H 5.8 cm Deep 15 cm


Or the Cree heatsinks:


LMH020-HS00-0000-0000081
L: 153 mm
H: 100 mm

LMH020-HS00-0000-0000061
L: 138 mm
H: 100 mm

Which one would you choose to pair up with a Mean Well LPC-60-1400? Or should I target for a 40W - 50W driver in order to keep everything cool without a computer fan setup?

Thank you for your replies!
 
SupraSPL

SupraSPL

Well-Known Member
Hey Mega Man, for passive cooling a lamp like that I recommend at least 110cm²/W. That is a lot of surface area and from what I can tell, it is still inferior to the simplest active cooling setups. A little bit of air movement goes a LONG way to improving COB output. I am saying this from a position of humility because the heatsinks I bought were intended for passive cooling and not optimized for active cooling. I used the 10.08 profile which has the fins running sideways, so there is no efficient way for me to cool all the fins with one fan. Also, they have very tall fins so the COBs end up closer together than I would prefer.

If you have a relatively small build in mind, I recommend the Alpine Arctic 11 92mm CPU cooler. Amazing cooling power even with 5V going to the fan. At 9V it is still silent and more than enough cooling power for your CXA3070 at 1.4A.

If you have a larger build in mind, you could check out the heatsink USA profiles. 5.88" fits a 140mm fan and covers all the fins. Even with a 36" piece one fan could cool the entire thing very efficiently. It works great in 12", 18" or 24" pieces if you want more adjustability.
 
SupraSPL

SupraSPL

Well-Known Member
If you are turned off by the additional complexity of CPU fans and adapters, they can be powered very efficiently with OEM quality AC-DC adapters found cheaply on eBay. They are about 80% efficient so just a few watts is enough to cool a lot of heatsink.
 
R

rocho

Well-Known Member
SupraSPL said:
Hey Mega Man, for passive cooling a lamp like that I recommend at least 110cm²/W. That is a lot of surface area and from what I can tell, it is still inferior to the simplest active cooling setups. A little bit of air movement goes a LONG way to improving COB output. I am saying this from a position of humility because the heatsinks I bought were intended for passive cooling and not optimized for active cooling. I used the 10.08 profile which has the fins running sideways, so there is no efficient way for me to cool all the fins with one fan. Also, they have very tall fins so the COBs end up closer together than I would prefer.

If you have a relatively small build in mind, I recommend the Alpine Arctic 11 92mm CPU cooler. Amazing cooling power even with 5V going to the fan. At 9V it is still silent and more than enough cooling power for your CXA3070 at 1.4A.

If you have a larger build in mind, you could check out the heatsink USA profiles. 5.88" fits a 140mm fan and covers all the fins. Even with a 36" piece one fan could cool the entire thing very efficiently. It works great in 12", 18" or 24" pieces if you want more adjustability.
Click to expand...
at least 110cm²/W? are you sure?
it seem really too much surface, i don't not wow much is the artic surface and how much heat can the fan can get off but moduled 152100 or cree LMH020-HS00-0000-0000081 are made from engeneer for bigger power than 50w, have you made some study for say that?...neither huge passive heatsink like moduled 152150 can get 5500square mm of surface, so in your opinion a moduled 152150(5416 mm2) is just sufficient for a 50w led?
 
R

rocho

Well-Known Member
CobKits said:
prob not a great idea to dig up 2 year old threads as so much has changed in that time
Click to expand...
hi, i know, thats an old 3d but nothing changed, same heatsink on the market and same cob technology(cxa run cooler than cxb?)
 
Last edited:
welight

welight

Well-Known Member
The Cree Heatsinks were really designed for Cree 2 inch modules, not for COBs, that why they are spec'd the ways they are
Cheers
Mark
 
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