This company makes them. They give the thermal resistance for any heatsink in their catalogue.
Here they also offer calculators for each product group. The calculator recommends a heatsink for the application (or processor) and shows the thermal resistance of that heatsink.
Here they also offer calculators for each product group. The calculator recommends a heatsink for the application (or processor) and shows the thermal resistance of that heatsink.
They also offer passive heatsinks for processors and the corresponding calculator. If there is none available for the Pentium IV, it probably needs more heatsinking than a passive version can supply. They show one active model with 0,6K/W and one with 0,7K/W. The biggest passive versions for Pentium III Xeon (107x130x25mm feature 1,8K/W, and for the Pentium Pro(62x67,5x40mm) 2,7K/W.
You could check the design and dimensions your favoured heatsinks have. Then compare it to a similar model from that site, which will give you at least an estimate about the thermal resistance.
Several people in this forum are using processor heatsinks, and report satisfying results. Depends as usual on the application (rail voltage, speaker impedance and efficiency, and of course listening volume).
You could check the design and dimensions your favoured heatsinks have. Then compare it to a similar model from that site, which will give you at least an estimate about the thermal resistance.
Several people in this forum are using processor heatsinks, and report satisfying results. Depends as usual on the application (rail voltage, speaker impedance and efficiency, and of course listening volume).
I'm using some cheap and nasty extruded heatsinks for all my chipamps (and I build a lot of 'em, trust me!). They may be about 3 c/w or so, no specs are available. They're finned flatbacks, unfortunately I can't find an equivalent profile, but they're about 5 inches by 3, and with 14 fins with a gap for mounting devices. they'd be about 5 mm thick.
The most inefficient load I own is a pair of Dynaudio studio monitors. Using a BPA LM4780 to drive tham at deafening levels (near my ears' threshold) for about 15 minutes results in a heatsink temperature of about 57 degrees. The heatsinks are mounted with vertical fins for best heat dissipation, and have one LM4780 mounted to each of them.
These chips are coupled directly to the heatsink using no washer (but with paste of course).
A parallel amp which drives the monitors now has the same heatsink for two LM3886, and it doesn't cross 50 degrees on the hotter heatsink (one channel heats up slightly more due to inequal chips/resistors).
Here's a pic, sorry about the quality and the banged-up P2P.
http://www.flickr.com/photos/srakshit/2809982525/
http://www.flickr.com/photos/srakshit/2809981621/
The most inefficient load I own is a pair of Dynaudio studio monitors. Using a BPA LM4780 to drive tham at deafening levels (near my ears' threshold) for about 15 minutes results in a heatsink temperature of about 57 degrees. The heatsinks are mounted with vertical fins for best heat dissipation, and have one LM4780 mounted to each of them.
These chips are coupled directly to the heatsink using no washer (but with paste of course).
A parallel amp which drives the monitors now has the same heatsink for two LM3886, and it doesn't cross 50 degrees on the hotter heatsink (one channel heats up slightly more due to inequal chips/resistors).
Here's a pic, sorry about the quality and the banged-up P2P.
http://www.flickr.com/photos/srakshit/2809982525/
http://www.flickr.com/photos/srakshit/2809981621/
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.