Luxeon K2 problem

[monkeyboy]

Where can you get thermally conductive yet electrically isolating films?

You can just spread a thin layer of Arctic silver thermal adhesive over the metal and allow it to dry beforehand.

The datasheet for the driver you linked says it can only output up to 17.2Watts. I'd look for a different driver if I were you, K2's can be driven up to 1500mA if heatsinked properly.

This is what you want:
http://www.luxeonstar.com/item.php?id=449&link_str=240::242&partno=LED120A0024V18F

With this, you could drive about 6 or 7 K2's at 1500mA which would probably produce more light as 12 K2's at 700mA. Or you could drive 12 at 700mA which would be more efficient.

 

[kevinm]

Thanks. That really helps a lot and explains a lot of the problem...now..time to find some thermally conductive, electrically isolating films LOL.

JB Weld, my friends, JB Weld. It conducts heat and not electricity.

I've been running a reef tank (5.5 gallon nano) for over a year with Luxeon III's . The acropora growth is good as is that of the soft corals, briarium, and hydnophora. This is what got me adicted to LED's in the first place.

I've heard horror stories with the Arctic Silver. Have any of you tried this? It's a touch expensive...unlike reef tanks which are oh so cheap.

Kevin

 

[VoiToi]

Thanks. That really helps a lot and explains a lot of the problem...now..time to find some thermally conductive, electrically isolating films LOL.

You can try a baking film A big role for about 1$ at every store. It is a very good electrical isolator, and even a very good heat conductor (comparable to special films for isolating from heatsinks). Sometimes I used it to isolate the transistor. In the case od LEDs better way is to use the MCPCB star, but with your strings done, I think you can try this. Then most important is to press the LED with the film to the the heatsing somehow. It that is an issue, then the JB weld or something similar will be better.

 

[monkeyboy]

Voitoi,

Are you talking about greaseproof baking paper or plastic cling film?

 

[monkeyboy]

I've heard horror stories with the Arctic Silver.

I'm sure Arctic silver only causes problems with circuit boards since it is slightly capacitative. Should be fine on an LED.

 

[3rd_shift]

I did lose a red/orange Luxeon3 that was arctic silvered to an osink heatsink.
I now have an empty black annodized Osink.
I kinda like the film idea though.

But.....
What is that electrically isolated, thermally conductive material that was used on the Luxeon1 stars and the empty pcb stars? :thinking:

 

[VoiToi]

Voitoi,

Are you talking about greaseproof baking paper or plastic cling film?

I mean something like this: http://www.ifyoucare.com/Baking products.htm

I bought one role of this http://www.a1-gastro.cz/DetailPage.asp?CatID=718&DPG=49515&Nav=1 before years and used it also for baking

I am studiyng electrical engineering and one teacher showed us results a test - comparing this baking paper with some typical termal-conductive, electrical isolating film, and thermal conductivity of baking paper was only about 20% lower ... and you can buy 5 square meters for 1 $ in almost every store.