Where is the test?

Quote from: MileHigh on May 17, 2012, 12:59:43 PM
TK:

Note that you already have a "square" factored in when you multiply voltage times current.

Do you mean if you take the Pisnt curve and take the "rms" of that? Yes, there is another "square" in that. But that is not how you get RMS Power, which is Irms x Vrms... and this is already an "average" power. What is its sign?
If you are worried about inductive reactance X, which is positive for inductors, then the formula for RMS power is 
Prms = (Irms^2) x X, and all those terms are positive values.

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So when you look at the power waveform, let's say you could average the positive power and average the negative power as separate entities.  Both of those entities would be equivalent to the RMS positive power and the RMS negative power.

So it could be another pixel counting exercise to determine the average power out from the battery and the average power "returned" to the battery.

The fundamental thing to realize is that the power returned to the battery was was supplied by the battery in the previous microsecond.  Why it apparently measures more energy returned to the battery is something that has to be investigated further.

As long as your toaster doesn't ACTIVELY COOL OFF during the "negative power" phase..... what is to investigate?
BOTH phases of the power get dissipated in the circuit ! When you look at the "negative" current swing of an AC signal, does this indicate that you are returning power to the wall? Of course not: that "negative" power is also dissipated in the same place that the positive power is dissipated. That is why you are charged a positive number of dollars on your electric bill, rather than zero or a negative number. The "negative" power and the "positive" power are coming from the utility (or the battery) and they are dissipating  in your load (the entire circuit).

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But the bottom line is all of the "magical returned power" while in negative oscillation mode is nothing more than power supplied by the battery in the first place.  It's nothing to get excited about.  All that it really means is that some of the battery energy is stored temporarily before it gets burned off.

The net flow of current is CLOCKWISE, and the batteries are discharging.

MileHigh

That last part seems right to me. After all.... the circuit stops when you disconnect the battery. (I know my CAR isn't powered by the battery, even though the battery is necessary to start it. I know this because I can remove the battery once the car is started... and it keeps running.)

Small beer, but the author of the wiki definition for power / energy that Rosemary has been leaning on as evidence that they are equivalent has responded:


http://en.wikipedia.org/wiki/Talk:Energy#Clarification_on_Power_vs_Energy_entry


In short: they cannot be used interchangeably as RA contends and they were referred to in that manner in the article precisely to point out that usage is colloquial but incorrect.

Quote from: The Boss on May 17, 2012, 01:26:45 PM

Where is the test?

It's in the mind of RA only.

Note the date, and ask yourself..... who has been wasting time?

Quote from: mrsean2k on May 17, 2012, 03:10:29 PM
Small beer, but the author of the wiki definition for power / energy that Rosemary has been leaning on as evidence that they are equivalent has responded:


http://en.wikipedia.org/wiki/Talk:Energy#Clarification_on_Power_vs_Energy_entry


In short: they cannot be used interchangeably as RA contends and they were referred to in that manner in the article precisely to point out that usage is colloquial but incorrect.

Good for you. Thank you for taking the time to get in touch with that author and having the matter clarified.

Perhaps YKW will take it up with him in the Wiki forum, to explain why her stance is right and his is wrong.