RMS application

Discussion in 'General Electronics Chat' started by adwina2, Jul 23, 2015.

  1. adwina2

    Thread Starter New Member

    Jul 14, 2015
    When measuring voltage across a shunt and computing the RMS values of a PWM with dither signal on a solenoid, what time should I average this across? RMS equates the voltage across the period, so should I always use the RMS value over a period to give an output? Or do I use point by point RMS outputs? I would like to do this with hardware(possibly AD536A), but I cannot set a period to integrate across because the frequency is variable. Also, since I am using dither, should I take RMS of the dither frequency instead of the base frequency? I will have a raw shunt output, and an RMS output, so it may not be necessary to show the affect of the dither in the RMS output, in that case I would take RMS over the slower dither frequency.
    Or, is the period that I integrate across ambiguous because the average should work out the same over time, as long as the time is greater than the slowest frequency?

    Thanks in advance!
    Last edited: Jul 23, 2015