Re: What is Rms?

I deserved it and you are quite right, I didn't read Jon's post
properly and I should have known better anyway.

Graham



--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Andy Wander" <awander@v...>
wrote:

>
> I didn't mean that to sound as abrupt as it did, sorry.
>
> I just want to make it clear that the average value of a time-variant
> waveform is NOT a good number to use in calculating the amount of work
> that waveform can do.
>
> Jon Elson's example a few posts back was very illustrative, and I intend
> to use it whenever I need to make this point in the futture.
>
> Andy Wander
>
>
> Andy Wander
> Verrex Corporation
>
> -----Original Message-----
> From: CAD_CAM_EDM_DRO@yahoogroups.com
> [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Andy Wander
> Sent: Sunday, November 27, 2005 7:53 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: RE: [CAD_CAM_EDM_DRO] Re: What is Rms?
>
> Graham:
>
> ...and MY point was that the "Average" of the voltage means nothing when
> it comes to the effective amount of work done by it. The only way to get
> this is by using rms clculations.
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Andy Wander" <awander@v...>
> wrote:
> >
> > Graham:
> >
> > I believe that the only voltage that will give you correct
> "effective" voltage number by averaging it to get the "effective"
> voltage, is a square wave, or strauight DC, or changing DC which changes
> as if it were a square wave(very quick transitions from voltage to
> voltage).
> >
>
> Any periodic waveform that is always positive will work if you average
> it, it can vary quickly or slowly.
>
> My point was to illustrate what RMS represents, that's all.
>
> Another point is that you can calculate an expression for the RMS for
> any periodic waveform, either from the mathematical expression for the
> waveform or even from a scope trace (if you can be bothered) you just
> root the mean square :)
>
> Graham
> O/
>
>
>
>
>
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