On Mon, 04 Oct 2004 07:54:11 -0700, Bill Turner
wrote:

On Sun, 03 Oct 2004 16:33:46 GMT, Gary Schafer
wrote:

Rms voltage and current are also called "the effective values".

large snip

_________________________________________________ ________

You missed my question. Who defines these terms? I know that RMS,
average and effective are often used interchangeably, but who or what
organization says there is "no such thing as RMS power", and why?

No I didn't miss your question. I thought I gave you enough
information so that you could figure out the "why" yourself.

I don't know of any organization that says "there is no such thing as
rms power". What would be the point. That would be like formally
declaring "water doesn't run uphill", since there is no proof or
evidence that water runs uphill.

I also don't know of any organization that says there is such a thing
as rms power although you will often find it referred to in many
articles and advertisements. Even some of the older ARRL handbooks may
call it rms power but I don't think you will find that in the newer
versions.

Most any AC circuit theory will explain how values of a sine waves are
found and the relation of those values. The reference I quoted from
the ARRL handbook does very nicely at explaining it. It is worth a few
minutes to read. Only a couple of paragraphs will get you there. (you
will see the absence of rms power mentioned)

The thing to consider is that once you multiply an rms value by
another rms value the result is no longer an rms value.
If it were then you could use any of the rms factors to convert it to
peak etc.

Consider 1 volt peak x .707 = .707 volts rms. .707 volts x .707 volts
= .5. Divide that by 1 ohm and you have 1/2 watt.

Using rms factors, convert the rms values to peak. .707 volts x 1.414
= 1 volt peak. OK.

Now try and find peak power like you would find peak voltage from a
known rms value.
Do that with the power value that you want to call rms power and you
have .5 x 1.414 = .707 watts. Not the 1 watt peak you were looking
for.

73
Gary K4FMX