[AMPS] Audio amp power

Steve Thompson Steve Thompson" <rfamps@ic24.net
Tue, 18 Jan 2000 09:00:45 -0000


I have made cuts in the original.

-----Original Message-----
From: Dave D'Epagnier <DAVED@ctilidar.com>
To: QRO list <amps@contesting.com>; 'John Nelson'
<John_Nelson@compuserve.com>
Date: 17 January 2000 23:25
Subject: RE: [AMPS] Audio amp power


> >The average power is calculated as Vrms squared divided
by R. This
>average
> power is also how much heat is delivered to the load. So
what is rms
>power,
> and how is it calculated...<
>


RMS power is a meaningless concept. In my experience, it's a
term used by people who don't really understand.

> Sorry, but I still don't buy "RMS Watts".
>
>
> 73,
>
>Dave K0QE
>


You're quite right not to.

The 'R' in RMS stands for (square)root. If you take a RMS
voltage and square it when calculating power, the 'root' bit
gets squared and disappears, so the power you calculate is
the mean, or average, value.

Steve

PS Don't forget that RMS values apply to ALL voltages and
currents, not just sinewaves.


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