Average Power Computation - MEAN or RMS? - Participant Posts Only

[poynt99]

Lawrence, what is the average power in the following circuit?



.99

[Harvey]

With the greatest respect for Lawrence, I find in favor of declaring Poynt99 the winner of this debate.

While it may be possible to use a math setting on the scopes to multiply the RMS values of voltage and current this would only work for purely resistive loads where no phase angle exists. In order to accurately calculate the Average Power using the RMS method the phase angle must be included in the calculation.

Using the MEAN of the instantaneous power automatically handles the phase angle problem by removing the reactive power from the total, thereby leaving the Average Power, or Real Power.

Good Job Guys!

[poynt99]

Well put. That deserves repeating:

Using the MEAN of the instantaneous power automatically handles the phase angle problem by removing the reactive power from the total, thereby leaving the Average Power, or Real Power.

Thank you Lawrence and Harvey for your efforts in resolving this interesting debate.  

.99

[ltseung888]

With the greatest respect for Lawrence, I find in favor of declaring Poynt99 the winner of this debate.

While it may be possible to use a math setting on the scopes to multiply the RMS values of voltage and current this would only work for purely resistive loads where no phase angle exists. In order to accurately calculate the Average Power using the RMS method the phase angle must be included in the calculation.

Using the MEAN of the instantaneous power automatically handles the phase angle problem by removing the reactive power from the total, thereby leaving the Average Power, or Real Power.

Good Job Guys!

Congratulations to Poynt99.  His posts really revealed something I did not realize before.  I shall write them up at my bench later.

Thank you very much to Harvey for a job well done.  The two spreadsheets were very enlightening. 

Guys, I believe it was a good debate.  Many good points were raised.  It will be a good example for future debates in Open Forums.

God Bless you all.  Amen.

[poynt99]

So, one last question for you Lawrence;

From now on, what computation are you going to apply when analyzing any power trace in your scope?

.99

PS. I hope either the professor has been following along here, or you will pass on the message. 

[ltseung888]

So, one last question for you Lawrence;

From now on, what computation are you going to apply when analyzing any power trace in your scope?

.99

PS. I hope either the professor has been following along here, or you will pass on the message. 

Mean, Mean and Mean.

Thank you.

[poynt99]

Good stuff Lawrence! 

Looking forward to seeing that.

.99