I hope I can get my point across. I know the maths and integrals of average peak and rms voltages and currents. But why for example should one even bother with the average voltage value at the output of a AC/DC rectifier bridge (controlled by scr's or just a plain diode bridge) since the rms voltage is the "real" voltage in the sense that the rms voltage will be the one used to calculate true thermic power on a resistor. (I am aware of the fact that most voltmeters will register the average output voltage of a rectified sinusoidal). Could the answer be that the average power is used to calculate ripple etc? Thank you in advance for any help. I am really stuck with that question... To put it another way - what do i gain by knowing the average voltage or current and what can i use it for?