At 12:38 PM 5/13/2006 +1200, you wrote:


>Tell us how you are trying to do an unknown thing and we may not be
>able to help.
>Tell us what you want to achieve and we'll tell you how to achieve it.
>         RM

I think what he wants to do is to take an audio signal (line level?)
and modulate a fan controller based on the expected power dissipation
in an audio amplifier, so that the fan tends to be quiet when the
music is quiet, and loud when the music is blasting.

Something like a precision rectifier (couple of op-amps) into a PIC ADC
and PWM output would fill the bill. The front end might not have to be
than complex, of course.

>Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
->>Test equipment, parts OLED displys http://search.ebay.com/_W0QQsassZspeff


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