All copper heatsinks?

[Dominick22]

I keep hearing that heat is going to be a big concern on my LM4780 project...

So I decided to go with a full copper heatsink, although I have not seen this nor can I find any such product on the net.

Wouldn't this be a better solution to heat dissapation other than it being a bit more costly?

PROBLEM: Where can I find copper heatsinks? Even something that I can do a makeshift rig with?

I might even be able to do something with plain copper plates/strips/solid blocks.

Thanks,

Dominick

[tiltedhalo]

Copper has great heat conduction characteristics, but tends to disspipate slower then aluminum. I use copper to thermally stabilize my chips then aluminum to dissipate to air. Some CPU coolers have very good thermal characteristics you should check into some copper ones

[jaudio]

Dominick


Do you have a stockpile of LM4780s that you have to use up?

If you dont,why not try lm3886?

[Dominick22]

Honestly jaudio,

The lm4780 is the only chip that I have experiance with so I am trying to use it in a variety of applications for learning purposes more than anything else.

But, isnt the LM4780 just 2 LM3886's in one chip?? I think it is so what would be the point in using the smaller 3886?


tiltedhalo, Where do you get your aluminum heatsinks?

Dominick

[Evilsizer]

the reason for using the lm3886 over the 4780 is because of the surface area that the chip has to move that heat. 4780 you have twice the amount of heat to move from the same size area as a single lm3886. As for heatsinks save wieght and get ALU. In computer heatsinks it has been shown copper does keep the cpu cool but it depends on the design of the heatsink. Keep that in mind, unless you are actively cooling the heatsinks there is no need to use copper. Some use copper bars that there lm's attach to then attach to the heaksink... A hybrid alu/copper sink would be best but not easy to find or make for this type of app.

here is one place i found with a lot of differnt heatsinks... havent bought any yet from them as i have some left over from old computers and i have cut them down.

http://www.surplussales.com/Heatsinks/HeatSink1.html

[jaudio]

2 lm3886 can dissipate more heat than 1 4780. 2 lm3886 has more suface area.

[Dominick22]

I found a good place to buy copper I think. I found the link on ebay after extensive searching. I think I will buy a 1/4 inch bar and cut it to size mating it with an aluminum heatsink. Tell me what you think.

http://search.stores.ebay.com/INDUST...232704QQsofpZ0

Dominick

[Dominick22]

Thank link didnt work---try this one:

http://search.stores.ebay.com/INDUSTRIAL-METAL-SALES

If this one doesn't work, Industrial-metal-sales is the name of the ebay store...I guess you could search it on ebay.

Dominick

[duelbox]

I have not dealt with this person myself but they seem to have pretty good prices and will cut to size. Their eBay ID is barrredboss. I know that these are not copper but at 0.375C/W per foot costing $17.50 plus shipping sounds pretty good to me. Looks like he can supply up to 49" lengths and can anodize too. They are all 5 3/8" wide and 3/8" thick base with 1" fins by whatever length you want it appears.

Good deal?

[velmeran42]

I've never had to pay shipping from them since they're really close by, but I've bought a fair bit of metal from OnlineMetals . They have copper bar for a decently fair price (and they don't charge for cutting, like many companies).

I also second using PC heatsinks if you're making the chassis yourself, as you can get some nice looking results.