Timeline for What gets wrong when I average AC voltage and current to get power?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 1, 2020 at 2:47 | vote | accept | hontou_ | ||
| Apr 30, 2020 at 22:11 | history | became hot network question | |||
| Apr 30, 2020 at 15:57 | comment | added | Solomon Slow | Re, "...peak voltage by...0.637..." OK, right. That's one way to calculate the RMS voltage. RMS is useful to know because, for a pure sinewave power supply, and for a purely resistive load, The relationships between RMS voltage, power, and current are all the same formulas as the relationships between voltage, power, and current in a DC circuit. But basically, you should think of RMS calculations as a handy short-cut, and not as the physical explanation for anything. | |
| Apr 30, 2020 at 14:42 | comment | added | NoumanQ | Remember, In an AC circuit simple averages won't work because the product of V and I must be computed instantaneously. If the voltage and current waveforms are not perfectly aligned, your system would sometimes be consuming power and sometimes transmitting it back. A simple average assumes a simple powerflow as would happen in a DC circuit. Now even if your load is resistive, average of a sinosoidal waveform is not Vmax/2. Thats because of mathematics. | |
| Apr 30, 2020 at 14:41 | comment | added | hontou_ | I read that "The average voltage (VAV) of a sinusoidal waveform is determined by multiplying the peak voltage value by the constant 0.637, which is two divided by pi (π)" (Google). But I also don't know the physical significance | |
| Apr 30, 2020 at 14:39 | comment | added | Solomon Slow | You said that \$V_{ave}=\frac{2V}{\pi}\$ "is the formula for averaging sinusoidal 360 degree voltage." I am curious to know where you got that formula and, what its physical significance is supposed to be. | |
| Apr 30, 2020 at 14:38 | comment | added | hontou_ | 1/sqrt2 * 1/sqrt2 =1/2 is what I mean by half | |
| Apr 30, 2020 at 14:27 | answer | added | user136077 | timeline score: 8 | |
| Apr 30, 2020 at 14:26 | comment | added | Bimpelrekkie | Power is half the product of peak AC voltage and current (or product of its RMS voltage and current So that would mean that 1/2 * AC voltage = RMS voltage? I do not agree with that. Go and look up what it really is. | |
| Apr 30, 2020 at 14:16 | comment | added | Andy aka | Why can't I use concrete to make biscuits? Power = voltage x current. Try and fit that into your math. | |
| Apr 30, 2020 at 14:10 | history | asked | hontou_ | CC BY-SA 4.0 |