Originally Posted by dave948
You may be right, I'm not sure but I think we are on the same page but thinking of different values. Your right about peak back to zero, a quarter of a sine wave. I was referencing a full cycle, zero to peak back to zero then zero to peak back to zero in the opposite direction. 2.8 peak to peak.
We are most certainly on the same page
and my post wasn't intended to be critical of you. Rather it was a small correction of fact.
Some readers don't care to know the fine detail and that is OK
Some readers already know the fine detail and would happily pass over small inaccuracies, also quite OK
However some readers use these threads to further develope their limited knowledge of the subject matter and will (IMO) benefit from getting the fine detail correct.
So if one measures the peak to peak values over a full cycle of either current or voltage, one can determine the average and the RMS values by using the following.
RMS = P to P times 0.35035
Average = P to P times 0.25.
Conventional AC measurements are RMS values as this gives us a better idea of the amount of work or heat that any particular AC cicuit will deliver and is thus similar to the same DC value.
Thus the power avaiable in say 100 volts and 10 amps of DC is the same as 100 volts (RMS) and 10 amps (RMS) of AC.
Note, all this only applies to sine wave AC and not other waveforms.
Again, not directed to Dave, he already knows this stuff.