DIY LED Array - Help determining how many watts for Car Audio Amp Heatsink

[Californacation7]

Hello,
I'm preparing my LED Array Design and supply list.
With the idea of recycling as much as possible I have obtained two Heatsinks from broken Car Amps.
This is the first part of my project where I need some help detemining how many watts I'll be able to use.
I have attached three pics of the amps (they are identical) Aprox 24x 28 cm 11 x 9 Inches
I asked the guy who gave them to me if he had any idea how many watts he thought i could use. He was not sure but thought i should be able to use a lot.
Please any help is much apreciated.

I look forward to anybodies input or ideas.

Thanx....

 

[budbro18]

Im not sure how well the heat transfer will be on those since theyre really thick with few fins

But you could probably fit 4 COBs on there. Watts, im not sure on that one. Maybe 4 100w chips dimmed down to 50w each. Maybe?

If youre going to order LEDs online then there are plenty of super cheap super good heat sinks

 

[SupraSPL]

Hey amigo sorry to be the bearer of bad news. That heatsink probably has some good heft to it and can spread heat very well, but it lacks the surface area to dump the heat into the air and no efficient way to actively cool it. I would estimate it is good for about 15W of LED dissipation which might be very useful as a vegging lamp.

 

[stardustsailor]

I'll have to agree with Supra .
Not an appropriate heatsink for leds or led arrays ..
Good for cooling couple of power MOSFETS from an audio amp...
And a very good "frame" for DIY led projects ...

Cheers.

 

[churchhaze]

That could handle 200W, but it would have to be very hot to do it!

 

[Californacation7]

Hey amigo sorry to be the bearer of bad news. That heatsink probably has some good heft to it and can spread heat very well, but it lacks the surface area to dump the heat into the air and no efficient way to actively cool it. I would estimate it is good for about 15W of LED dissipation which might be very useful as a vegging lamp.

The reason I started collecting them to use is cause i came accross someone else using 3 of them for a fish tank LED array.

SEE
This is what he wrote±
I used 3 of them in my very first build. 30 Cree XR-Es consuming 5 amps total, and barely warm to the touch. Here's a photo of one-

I also had an idea to mount my COBs on a bar the length of the two amps and BOLT the bar to the amps.
Any thoughts
Since all of the heatsink distributors are in the states its so exspensive and therefor trying to reduce costs.

 

[Californacation7]

I'll have to agree with Supra .
Not an appropriate heatsink for leds or led arrays ..
Good for cooling couple of power MOSFETS from an audio amp...
And a very good "frame" for DIY led projects ...

Cheers.[/QUOTE

Confused by wht u wrote. U gree tht it is not a good heatsink.

And than u write that its a very good frame for DIY led projects...??????
Can u explain. From some of your comments i have thought before that u might be in europe. If that is so do you know of a GOOD link for heatsinks for the Cree COBs?
Best would be if you could tell me how i could use the TWO heatsinks i already have for three 100w Cree COBs with MW LPC 60 - 1400 drivers.
Any thoughts?

 

[SupraSPL]

The reason I started collecting them to use is cause i came accross someone else using 3 of them for a fish tank LED array.

SEE
This is what he wrote±
I used 3 of them in my very first build. 30 Cree XR-Es consuming 5 amps total, and barely warm to the touch. Here's a photo of one-

One thing to consider, if there is a poor interface between the LED and heatsink surface it will increase the temperature gradient dramatically. That results in a much hotter LED and a much cooler heatsink. Because of this we try to measure by the case temperature of the LED package itself unless you are very confident in the thermal interface, then you can judge by the heatsink temp somewhat.

 

[Californacation7]

That could handle 200W, but it would have to be very hot to do it!

Would u mind elaborating. I dont understand.

 

[Californacation7]

One thing to consider, if there is a poor interface between the LED and heatsink surface it will increase the temperature gradient dramatically. That results in a much hotter LED and a much cooler heatsink. Because of this we try to measure by the case temperature of the LED package itself unless you are very confident in the thermal interface, then you can judge by the heatsink temp somewhat.

What do u think about taking an aluminum rod where I can mount 3 COBs to and that the rod is than bolted to TWO of those heatsinks. Not quite sure of measurements of the rod. I figured maybe something i could get at the hardware store.
I really apreciate yours and everyone else´s input.

I'll have to agree with Supra .
Not an appropriate heatsink for leds or led arrays ..
Good for cooling couple of power MOSFETS from an audio amp...
And a very good "frame" for DIY led projects ...

Cheers.

Any recommendations to another Europen where to buy best heatsinks for passive cooling of these COBs from Cree?
Thanx Already,