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medwatt
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Hello,
I am reading a book on Power Electronic and got confused on the actual interpretation of ac and dc power.
From basic circuit analysis, I already know that the average power delivered to a resistive load by a sinusoidal signal is : [itex]P_{ac} = \frac{V^{2}_{rms}}{R}[/itex].
When talking about a pure sine wave, the average voltage [itex]V_{dc}=0[/itex]. So it made sense why we didn't use this value to calculate the power delivered to the load by the sine wave since it will erroneously tell us that no power is delivered to the load.
Now comes a full-wave rectified voltage. Here [itex]P_{ac} =\frac{V^{2}_{rms}}{R}[/itex] and [itex]P_{dc} = \frac{V^{2}_{dc}}{R}[/itex]. But [itex]V_{rms}=\frac{V_{m}}{\sqrt{2}}[/itex] and [itex]V_{dc}=\frac{2V_{m}}{\pi}[/itex] which implies the obvious that [itex]P_{ac}≠P_{dc}[/itex].
So my question is, what is the actual power that is delivered to the load ? In the text, the author says [itex]V_{dc}[/itex] is the voltage that appears across the load. So the power delivered should be [itex]P_{dc} =V^{2}_{dc}R[/itex]. But what about [itex]P_{ac}[/itex] ?
Thanks
I am reading a book on Power Electronic and got confused on the actual interpretation of ac and dc power.
From basic circuit analysis, I already know that the average power delivered to a resistive load by a sinusoidal signal is : [itex]P_{ac} = \frac{V^{2}_{rms}}{R}[/itex].
When talking about a pure sine wave, the average voltage [itex]V_{dc}=0[/itex]. So it made sense why we didn't use this value to calculate the power delivered to the load by the sine wave since it will erroneously tell us that no power is delivered to the load.
Now comes a full-wave rectified voltage. Here [itex]P_{ac} =\frac{V^{2}_{rms}}{R}[/itex] and [itex]P_{dc} = \frac{V^{2}_{dc}}{R}[/itex]. But [itex]V_{rms}=\frac{V_{m}}{\sqrt{2}}[/itex] and [itex]V_{dc}=\frac{2V_{m}}{\pi}[/itex] which implies the obvious that [itex]P_{ac}≠P_{dc}[/itex].
So my question is, what is the actual power that is delivered to the load ? In the text, the author says [itex]V_{dc}[/itex] is the voltage that appears across the load. So the power delivered should be [itex]P_{dc} =V^{2}_{dc}R[/itex]. But what about [itex]P_{ac}[/itex] ?
Thanks
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