Instrument for the registration of small and fast variations in the rms values of an alternating voltage
N. Nielsen · European Transactions on Electrical Power · 1991
Abstract It is now possible to register small and fast voltage variations in the supply network by means of a recently developed measuring instrument. Within the fields of both measuring technique and automatic control technique, there is often a need for a simple apparatus capable of a fast transformation of the instantaneous difference between the RMS value of an alternating voltage and a fixed reference value into an analog output signal. With the chosen construction, the time response of the instrument allows for the measurement of the RMS of every consecutive period consisting of two successive half periods. The accuracy of the measurement is higher than the accuracy obtainable by means of a peak‐to‐peak measurement made on an oscillogram. The new instrument, which makes allowance for any distortion of the curve form, processes the signal analogically.