Rotating voltmeter with sign and frequency indicator - using sign and frequency analysers driven from clocking circuit and having visible region light source

摘要

A rotating voltmeter, esp. for high voltage, charge, and electrical field measurements enables measurement and display of amplitude, sign, and frequency. It uses the signless measurement device of patent no. 2712664 with the addition of an optoelectrical clocking device driven from the screening electrode. The clock generator signal is fed to a sign and a frequency analyser whose outputs drive sign and frequency displays. The sign evaluation circuit also receives a signal from the measurement electrode via an amplifier. The sign indicator consists of a visible region light source separate from the amplitude display. The sign analyser contains a threshold circuit and a digital phase shift circuit contg. R-C flipflops. A coincidence circuit consisting of an AND element receives the phase circuit and light receiver outputs and drives the sign indicator.