Can somebody please tell me how to calculate the power output of a class AB power amp. If the amp supply has a +-60V swing, do you use 60V or 120V in the power calculations?
- posted
16 years ago
Amplifier Specs
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- posted
16 years ago
"Hoektoe"
** Depends on the method of calculation of course.A sine wave has a ratio of peak to rms of 0.7071
It also has a ratio of rms to peak to peak of 2.83
Power depend on the load resistance too.
Then maybe YOU are after peak power or music power or PMPO power or f*ck knows what power.
Got the faintest clue what you are on about ??
....... Phil
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- posted
16 years ago
Either, but using 60V is more convenient. P=Vrms**2/R. So for +/- 60 V swing Vrms =60/SQRT(2) = 42.4V. Now, for an 8 Ohm load, power will be (42.4 **2) / 8 = 225W. You won't actually get that much out because the voltage won't quite go to 60 V. 58 might be a reasonable guess.
Tam
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- posted
16 years ago
If the output swing is 60V above and below a DC of 0, please explain at what point in time the load would ever see 120V?
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- posted
16 years ago
Alternatively... How about just make up your own power spec... How about... The max power handling of the amp is the heat dissipated by the speakers when you almost hear distortion when playing your favorite music.
(Assuming the speakers don't distort first.)
D from BC
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- posted
16 years ago
Apparently, they haven't covered "peak-to-peak" in class yet. ;-)
Cheers! Rich
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- posted
16 years ago
Assuming a sine wave, Vp = Vp-p/2 and Vrms = Vp x 0.707