A method for the detection of the root mean square value of the current or of the voltage in a single-phase ac power supply network.

摘要

A simple arrangement of operation amplifiers is presented for extracting the root mean square value of a single phase a.c. or voltage signal. The circuit is intended for use in control networks where one of these parameters might be the controlled variable. - Basically, the incoming signal (m(t)) is fed to two phase shifting circuits one of which produces a position, and the other a negative 45 deg. degree phase shift. These, in turn, feed squaring circuits a summing amplifier (53) and a square root extraction circuit. The basic phase shifting network entails two interlinked operational amplifiers.