Accurate Measurements on pulsed system's harder than you think.

[EMJunkie]

For a NON-Uniform, NON-Symmetrical Wave, taking the Peak Value, taking 0.707 of the Peak Value and calling this the true RMS Value just doesn't seem right to me. What is it I am missing that the scope is doing that I cant see?

I mean, we are measuring the total Area from the Scope Baseline, to Scope Trace, over time.


   Chris Sykes
       hyiq.org

[verpies]

It should be noted that the following (from the above post, but abbreviated and generalized):
PRx = Vrms² / Rx
Holds for ANY wave form, with any duty cycle.

...but only when the load Rx is purely resistive.

[EMJunkie]

...but only when the load Rx is purely resistive.

Yes, If I am not mistaken, RMS is supposed to be the DC Equivalent Figure given from a Sinusoidal Wave Form! So 0.707 of a Sinusoidal Wave would give the DC Value, of the Sinusoidal Wave Form, so the Area above the Wave, above the 0.707 would fill the missing Trace Area, giving a DC Value?

The wave Brad posted is far from Symmetrical.

See the Image below:

   Chris Sykes
       hyiq.org

[verpies]

Yes, If I am not mistaken, RMS is supposed to be the DC Equivalent Figure given from a Sinusoidal Wave Form!

Not only.
The RMS calculation can also be applied to other kinds of waveforms.

[EMJunkie]

Not only.
The RMS calculation can also be applied to other kinds of waveforms.

Yes, yes, but only if they are symmetrical? I just used the Sinusoidal Wave Form as an example.

Is this right?

   Chris Sykes
       hyiq.org