Average Power Computation - MEAN or RMS?

Author Topic: Average Power Computation - MEAN or RMS? - Participant Posts Only (Read 27428 times)

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poynt99

Re: Average Power Computation - MEAN or RMS? - Participant Posts Only « Reply #25 on: 2011-02-05, 01:42:07 »

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It's not as complicated as it may seem...

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

.99

« Last Edit: 2011-02-05, 04:05:16 by poynt99 »

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"Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa

Harvey

Re: Average Power Computation - MEAN or RMS? - Participant Posts Only « Reply #26 on: 2011-02-05, 02:04:32 »

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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	Re: Average Power Computation - MEAN or RMS? - Participant Posts Only « Reply #27 on: 2011-02-05, 02:33:48 »
Group: Administrator Hero Member Posts: 3216 It's not as complicated as it may seem...	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 « Last Edit: 2011-02-05, 06:21:55 by poynt99 » --------------------------- "Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa

ltseung888	Re: Average Power Computation - MEAN or RMS? - Participant Posts Only « Reply #28 on: 2011-02-05, 03:17:08 »
Group: Guest	Quote from: Harvey on 2011-02-05, 02:04:32 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	Re: Average Power Computation - MEAN or RMS? - Participant Posts Only « Reply #29 on: 2011-02-05, 06:35:59 »
Group: Administrator Hero Member Posts: 3216 It's not as complicated as it may seem...	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. --------------------------- "Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa

ltseung888	Re: Average Power Computation - MEAN or RMS? - Participant Posts Only « Reply #30 on: 2011-02-05, 10:14:50 »
Group: Guest	Quote from: poynt99 on 2011-02-05, 06:35:59 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	Re: Average Power Computation - MEAN or RMS? - Participant Posts Only « Reply #31 on: 2011-02-05, 13:01:11 »
Group: Administrator Hero Member Posts: 3216 It's not as complicated as it may seem...	Good stuff Lawrence! Looking forward to seeing that. .99 --------------------------- "Some scientists claim that hydrogen, because it is so plentiful, is the basic building block of the universe. I dispute that. I say there is more stupidity than hydrogen, and that is the basic building block of the universe." Frank Zappa