3W LED star & heatsink ideas

Community Projects
1

I am working on a project which involves about nine 3W LEDs mounted on “standard” aluminium star heatsinks, and 5 meters of RGB LED strips (5050). The 3W LEDs are of an unknown brand, with no datasheet, bought off ebay. They are rated for 3.4 - 3.8V at 700ma, according to the seller. I will be running them at 450 to 650ma (my LED CCS is adjustable).

I need help with heatsinking the 3W LEDs.

Here is a pic of what my project might look like (think lamp with lampshade), with the red arrow pointing to the part where the LEDs will be mounted - the RGB strip at the bottom, the 3Ws towards the top. There will be six LEDs in different directions pointing outwards, and three pointing up.

http://matthengeveld.com/lamp.jpg

My problem is, I don’t know what to use as a heatsink for ~22W of closely spaced LEDs. I know the stars the LEDs are mounted on will not be enough. Some ideas I have had, and rejected, include:

  1. Coffee tin - perfect size, about 5 inches diameter, and 6 - 7 inches tall, but I doubt that would cool the LEDs enough

  2. Pipe (copper or other metal) - I can’t find a piece with a large enough diameter and not too expensive.

  3. Wood dowel and attaching each LED to a separate heatsink - bulky, and each heatsink must be large since LEDs can not share, also expensive

The first two ideas also suffer from the fact that contact between the flat star and the round can/pipe is not ideal.

Does anyone have any other ideas? They would be much appreciated!

Thanks,

Hengy

2

http://www.homedepot.ca/product/papc-1- … num/956536

Would something like this provide enough of a heatsink for two LEDs driven at ~2.5W?

3

I was going to suggest something similar. Home Depot and local hardware stores usually have 1" square aluminum extrusion in 3’ and 6’ lengths. It makes good LED heatsinks as long as you use thermal grease/thermal epoxy.

4

Thanks for the reply!

Im glad to get a second opinion on my link above. My father has a lot of woodworking tools, and he was a bit unsure if he could cut it. Wouldn’t want to go to all that work and have it be too little.

Hengy