[Amps] Muffin Fans and hot exhaust/2

[alex]

 If you value your output device, you will stop playing hooky with the most
important device of your amp, the heat exchanger (blower/fan etc.. etc..
etc...)

The best solution for Fans is a DC operated fan with enough CFM and PWM
driven by
a controller.

In 2xMR154 module, I use two 48V/145CFM Fans from Mechatronics. They are PWM
controlled by the microcontroller and mounted on the top of the finned part
of the heat sink. A third fan 100CFM is right on the top of the output
transformer and
it is controlled by the same controller as the first two.

This arrangement keeps the die at only 120C forever when running full 1500W.

Please observe, that the fans will never see a temperature greater that the
ambient.


Get serious about heat management. It is your Enemy No. 1.

About noise. The more noise your fan is doing the better you are off as it
is an
indication of air movement . If you want a quiet Fan you will have to reduce
the amount of heat generate and implicitly your output power. Certain
Thermodynamics laws can not be circumscribed :) FANS DO NOT PRODUCE NOISE!
AIR MOVEMENT DOES!


Alex