Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 8th April 2004, 05:38 PM   #1
diyAudio Member
 
Join Date: Apr 2004
Location: mid-atlantic u.s.a
Default Question: Mounting heatsinks

This is sort of a half cocked question as I've yet to determine my thermal needs.
However I've read and searched through a good number of posts at diyaudio and still am unclear, if I"m building my own chassis how heatsinks are mounted.
First my chassis is going to be relatively deep and high. (5" H, 14"D)
I've looked at some flat sided heatsinks and I gather those are the ones that would work best. Do they replace the side panels of the chassis ? What type of mounting should I be looking at?
Also I've seen some posts here showing the very small heatsinks, some I think were selling for a few dollars on ebay. Would I just build a whole panel of those ?

Thanks for any ideas and answers
StuartAmbient
  Reply With Quote
Old 8th April 2004, 06:18 PM   #2
Nuuk is offline Nuuk  United Kingdom
diyAudio Member
 
Nuuk's Avatar
 
Join Date: Feb 2003
Location: Somerset, SW England
Some people have found that the case (usually aluminium extrusion) is enough to keep a GC temperature in check.

Some like PC heatsinks and some prefer a solid mass, either bar or angle.

As regards how much heatsink you need, you can either go to the data sheet for the chip that you are using and calculate the correct size, or you can play safe and use as big a one as you can squeeze in your layout.

Have a look around at what others have used, that is a good guide to what works.
__________________
The truth need not be veiled, for it veils itself from the eyes of the ignorant.
  Reply With Quote
Old 8th April 2004, 06:20 PM   #3
sam9 is offline sam9  United States
diyAudio Member
 
sam9's Avatar
 
Join Date: Jun 2002
Location: Left Coast
I have successfully used "L" brackets to mount heatsinks inside a case. (2x 50W amps) Just be sure the case has adequate ventilation.

Some people use rectangular 4 pieces of sheet metal plus 2 heatsinks to make a 6 sided box. Usually angle bars are involved. This puts the fins on the exterior where cooling is more efficient.

You can also use a chasis (4 sides + a bottom, make cutouts in two of the sides for the device to be heatsinked, then bolt the heatsinks over the sides with the cutouts.

Two decision factors A- the termal requirements, B- you metal working skill.

Unless you finf some surplus heatsinks on ebay (or whereever) that are suitable, the best deal I know of is www.conradheatsinks.com. Even when shipped all the way from Australia to the US, they are cheaper than the minimum order you can get from Aavid or MM Metals. The quality and appearance are very good.
  Reply With Quote
Old 8th April 2004, 06:21 PM   #4
diyAudio Member
 
Join Date: Jan 2002
Location: Puget Sound
The heatsink requirements seem to be so low for this amp. I have two channels on a 2" x 2" x 6" heatsink and it barely feels warm.

I have another two channels bolted to a 1/16" x 6" x 10" plate and it gets warm but not hot.

If you want to use a heatsink for a side or front panel, chances are it's going to be well more than enough for your cooling needs. Given the dimensions you state, you will have way more heat sink than you need for two channels. If you like the way it looks, go for it.

Mounting the heatsink depends on it's size and shape. It's probably easier to mount the heatsink inside the chassis or if the chassis is aluminum, try mounting the chips directly to the chassis and see if it provides adequate cooling.
  Reply With Quote
Old 8th April 2004, 07:01 PM   #5
joensd is offline joensd  Germany
diyAudio Member
 
Join Date: Dec 2001
Location: Germany
You can also get some heatsinks like these (post3) where you can directly put screw heads in and mount to front and back plate. (perfect for a lazy chassis builder like me;-))

You should also have a look at the calculation tool from National Semiconductor here to find out more about your thermal needs.

A lot of people here actually right things like the amplifier gets barely warm and so but this is running at probably moderate levels (or lower rail voltages).
Most chip amps like LMXXXX are "normal" class AB/B amplifiers that certainly dissipate a lot whilst running from +-40V for example driving an inefficient 4Ohm speaker at high volume levels. Watch your plastic case melt...
I already burnt my fingers on a chip doing some hardcore tests so donīt be fooled too easy. It all depends....
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mounting question Atilla Chip Amps 24 15th February 2009 12:25 PM
Speaker mounting question Only You Multi-Way 6 22nd July 2008 02:13 PM
Another speaker mounting question zigzagflux Multi-Way 1 31st March 2007 06:02 PM
49 cent wonder mounting question mazeroth Multi-Way 25 11th October 2004 08:07 PM
Transformer mounting question kilowattski Solid State 1 6th October 2003 03:19 AM


New To Site? Need Help?

All times are GMT. The time now is 11:08 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright Đ1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2