On 8/14/2007, CBFalconer posted this:
Arfa Daily wrote:
"CBFalconer" wrote in message
Arfa Daily wrote:

... snip ...

OK. I'm not sure that 'RMS' is the right term to attach to any
value derived from a ragged-arsed waveform, as it is a mathematical
function normally associated with symetrical waveforms, which the
draw by a SMPS may very well not be, but I see what you're saying.

What I am trying to say is that a chip which is designed to produce
an RMS reading from a sine wave, may well produce a meaningful
figure from a non-sinusoidal waveform also, but *only* if it is
still symetrical.

Oh? Try a square wave, for example. Nice and symetrical. You are
over-simplifying.

Explain ?

The integral is peak voltage times current. Simple. Not 0.7 *
peak voltage.

No, the integral is instantaneous voltage squared. Simple.

Current is also constant for resistive loads, not
proportional to voltage. RMS doesn't work.

You are contradicting Ohm's law, e = ir, which can be rearranged to
read i = e/r. Current is precisely proportional to voltage for
resistive loads. Simple.

I've used small letters to follow an old convention (is it still used?)
that lower-case letters represent varying values and upper-case letters
represent constant values (such as in analyzing DC circuits).

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
http://cbfalconer.home.att.net

--
Gene E. Bloch (Gino)
letters617blochg3251
(replace the numbers by "at" and "dotcom")