Where do you find Heatsinks

[murat]

Hi,

In the main stores like digikey, mouser, newark.. I can't see much choises for power transisor heatsinks. I am especially looking for TO-3. What is your favorite retail supplier for heatsinks? Thanks

[dutch diy]

Hi Murat,

I had a difficulty finding large heatsinks for TO-3 also.

So I made them myself:

A large L profile (40 x 40 x 4 mm ) 30 cms long. One side drilled with holes to hold two TO-3 and one TO-216 pack.

This was bolted to a 200 x 20 x 300 mm 'normal' heatsink.

I repeated this 4 times and ended up with :

[dutch diy]

the heatsinks came from www.schuro.de and the L profile (and all the other ALU stuff) from my local hardware supplier.

[wchick]

You should be able to find some on Ebay. Search "Heat sink" or "heatsink" under the category of Industrial Electrical, test. I used to get my sink from there. Hope this help.

[murat]

Thanks a lot guys!!

Dutch man, this is really smart. Did you use some thermal compund between the L-bar and heatsinks? How many bolts did you use per one side? I presume fastening the bolts real tidht would give a good thermal conductance. Very much liked the idea!

[mzzj]

I take a look around local junkjards sometimes, last time i bought 40kg of aluminium, 4pcs of huge heatsinks. They had 600kg batch of those, some sort of faulty batch. backplane was not smooth and they were slighly warped from edges but after milling they are going to be just perfect Has to start looking for Pass Labs desings to get use for them

[Enzo]

And cruise the surplus electronics outlets, they often have heat sinks.

[wes-ninja250]

I buy mine from bgmicro.com -- oddball selection (email to make sure what you want is actually in stock), but dirt cheap and easily accessible.

I recently bought a bonded-fin copper duron(?) heatsink and cut/tapped it to fit my purposes.

Wes

[AKSA]

Try this one from downunder:

www.conradheatsinks.com

Shipping is expensive, but the product is so good and inexpensive compared to the usual fare that it's worth it.

Cheers,

Hugh

[amplifierguru]

Hi Hugh,

It's good to point out that the claimed thermal ratings are for an 80deg C temp rise and that those for a lesser rise are roughly 15-20% higher (poorer), also they are done with the HS totally exposed to the air including the normally enclosed flat or flanged surface. A good idea is to take the flanged version as the more realistic indicator of HS efficiency when encased.

No surprises.


Cheers,
greg