diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Pass Labs (http://www.diyaudio.com/forums/pass-labs/)
-   -   Real "cool" R-Theta heatsink simulation (http://www.diyaudio.com/forums/pass-labs/3070-real-cool-r-theta-heatsink-simulation.html)

Gabster 11th April 2002 02:01 AM

Real "cool" R-Theta heatsink simulation
 
Hi folks,

I'm experimenting R-theta's heatsink simulator. It looks very poweful, but I would like to have the seal of approval on my simulation from forum's elders.

DATA:
- My chassis design (see it here) provides a 4"x5" heatsink (R-Theta extrusion# 66414...this is actually what I'm planing to buy) for each IRFP244 FET (Aleph2). Therefore, I've set up 25W of heat to dissipate per heatsink (300W overall...12 FETs).
- From IR's datasheets I've found out that the max. junction thermal resistance is 0.83 for the IRFP244
- I've use generic grease for the simluation, Rimp = 0.1 as suggested by the simulator

You can see the output below. Temperature elevation seems not too bad...this is in fact why I'm doubting and asking your advice.

best regards,
Gabriel

Gabster 11th April 2002 02:02 AM

2 Attachment(s)
Here's the result:

Gabster 12th April 2002 01:17 AM

I forgot to mention that the ambient temperature is 20C

AudioFreak 12th April 2002 01:39 AM

it doesn't look like you've accounted for the electrical insulator ....

Gabster 12th April 2002 01:49 AM

How do I do that?

AudioFreak 12th April 2002 03:41 AM

You could just increase Rimp to about 0.75degrees/W

Edwin Dorre 12th April 2002 12:28 PM

Hello,

I am building a Aleph 4 myself. How can you reach the r-theta simulator. I tried something, but I cannot find anything on their website!

I am going to use 5 times a 80mm x 80mm x 150mm heatsink of 0.5 C/W which gives me about 3 * 21 = 63 * 0.50 = 31 C/W ...


Edwin

Edwin Dorre 12th April 2002 12:29 PM

Fischer...
 
Did any one look at the Fischer Elektronik SKE 6 400 19" case?

http://www.thel-audioworld.de/bauteile/case/case.htm

Thanks,

Edwin

Gabster 12th April 2002 03:20 PM

Edwin, website is www.r-theta.com. You can find the simulator in R-tools section. The simulator only works with netscape and some older IE version.

AudioFreak, having the Rimp increased at 0.75 doesn't change the temperature range. The only error I would see is a unit error. There're talking about "Cin^2/W" for Rimp and you're saying "/W". What is a "Cin^2/W"?

regards,
Gabriel

AudioFreak 12th April 2002 03:31 PM

it should increase the die temp....

Cin^2/W i think is C x area in square inches / Watts


All times are GMT. The time now is 08:28 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2