RMS-to-DC converter

EE July/August 1986 13rms-to-DC converter For some obscure reason, estab- lishing the root-mean-square (rms) value of an alternating voltage seems to be among the least familiar pro- cedures for many an electronics hob- byist; measuring the alternating volt- age may be easy, but deciding on the relevant unit expressing quantity - rms, mean, or peak-to-peak value - is quite another matter. Since the rms value of an alternating voltage is the most frequently used of the above mentioned three, some convenient means of obtaining that value without calculations may be of interest in practical measuring tech- niques. The rms value of an alternating voltage U across a resistor R equals the direct voltage causing the same dissipation level in R. Example: a 50% duty factor, 1 Vpp rectangular voltage across a resistor R. Find the rms level of this voltage. The mean dissipation in R, caused by this periodic signal equals 1 (Upp)//R = 1/(2R) The direct voltage causing the same dissipation has...