Abstract: A simplified system of recording and displaying input data signals having a multi-stage memory that provides a given magnitude output signal to a meter or recorder for each memory stage energized, with said memory having a stage, magnitude discriminator circuit, and a scaling network for interfacing signal inputs to appropriate memory stages, with a timer for resetting the memory stages to provide an update readout periodically to the meter, and with a direct display for displaying the particular memory stages that are energized, providing a direct display readout of the meter readings.

Abstract: A circuit for determining on a half-wave cycle basis the maximum and minimum voltages of input cyclic line voltages for selected time periods in which the line voltages are rectified to half-waves, and an integrating voltage to frequency converter provides output pulses proportional to the voltage magnitudes of the half-waves with the pulses being counted and placed in a memory and then compared with minimum and maximum previous counts for previous half-waves, to provide an updated minimum and maximum voltage for such half-waves over a period of time or period of half-waves, with provisions for providing resetting strobe pulses at zero voltages of the half-waves and for providing accurate measuring of the pulse outputs in the integrating voltage to frequency converter by modulating the integrator sense voltage and achieving substantially accurate compensation for the effects of timing errors in the V/F converter.