Understanding the subtle characteristics of RMS
When we purchase electrical equipment, appliances, light bulbs, motors and more, somewhere on the “name plate” are electrical specifications including voltage, current, frequency, power, etc. For alternating (AC) current, the values for voltage and current are always shown as RMS values, though this is rarely stated on the name plate.
This application note from Dataforth will take you through an initial experiment that demonstrates the derivation of RMS. It begins with the requirement that the function of time is “well” behaved (bounded with a finite number of discontinuities), repetitive at some fundamental frequency and available for as long as needed. It also revisits the definition of RMS, shows RMS values for various time functions and explores some RMS measurement issues.
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