Root mean square measuring circuit, in particular for measuring the effective value of an AC voltage

摘要

For measuring the root mean square value of an alternating voltage in a frequency range extending from very low to very high frequencies, the alternating voltage to be measured is divided by means of a frequency filter into a low frequency and into a higher-frequency voltage component; after digitisation, the low-frequency voltage component is mathematically squared and the higher-frequency voltage component is squared by means of an analog squaring circuit and only then digitised; these two digital values are added to form a total value from which the desired measurement quantity is calculated by forming the mean.