LED Light Design and Build Diary

[puggle6]

My 150w 300x300 panel is only adhered to a 3mm thick sheet of aluminium. If you drive them harder you will need fins.

 

Your extrusion should be fine [emoji106]

 

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[putt4dough]

My 150w 300x300 panel is only adhered to a 3mm thick sheet of aluminium. If you drive them harder you will need fins.

 

Your extrusion should be fine [emoji106]

 

Posted from the OZ Stoners mobile app

 

Nice, I'm looking forward to giving it a test.

[pedro de pacas]

Reckon you have enough aluminium to make a small tinny

 

ya wont have any problems, not with the heat sink anyway 

[NakedMonk]

I don't think there will be any problems either for the most part. Just a thought in my head makes me wonder if the channeling on the extrusion will trap heat and reabsorb it back in, I don't think it will, but just something to keep an eye on just in case

 

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[papasmurf999]

So the industry standard at the moment seems to be the Samsung or osram diodes with some added Cree 660nm red. Then it's just a matter of dialing them in with a par meter for uniformity. A par meter is next on my list of purchases.

 

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[putt4dough]

I don't think there will be any problems either for the most part. Just a thought in my head makes me wonder if the channeling on the extrusion will trap heat and reabsorb it back in, I don't think it will, but just something to keep an eye on just in case

 

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That's a good point and I'm not 100% sure. I think there are two things in play. One, heat in a chunk of something will always move towards the coldest part of the chunk to try and reach thermal equilibrium. Two, heat acts like electricity and will prefer a path of least resistance. In the case of the extrusion, the aluminium has an 8000 times better thermal conductivity than air. What this means is that heat in the extrusion will always tend to stay in the aluminium and move towards the naturally coldest parts of the extrusion that will most likely be the top and sides. I think this means that there will be very little heat convection inside the extrusion and in channels not in the cool areas of the extrusion. I might be wrong though!

Edited July 10, 2019 by putt4dough

[putt4dough]

I found some 10W resistors in my collection today so I attempted to have a go pumping some heat into the extrusion to see how hot it gets. I was able to run the resistors at 130W (approx. 22W each) for about a minute until the solder joints started melting!   I think I'll take the advice I've been getting here and not worry about the heat issue. If I eventually strap on the LED PCBs and find that the extrusion is getting too hot I can attempt a solution then.

[Porky 1982]

The majority of heat comes from the driver why not just mount it so there is a gap between the aluminium and the driver. My drivers are only hot to the touch from about 5mm away.

 

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[putt4dough]

The majority of heat comes from the driver why not just mount it so there is a gap between the aluminium and the driver. My drivers are only hot to the touch from about 5mm away.

 

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Good suggestion. That can be done with a spacer between the controller and the body of the light. If I find it's needed during testing I'll give it a go.

[putt4dough]

I got some more of the electronics parts today. I've fitted them to the lights and I'm happy with how everything looks. Next step is to actually get some light out of these things.