Design of a Long Period Measuring Electronic Instrument using a Phase-Locked Loop

Abstract

An electronic instrument capable of. measuring the period and the time of arrival of the peak of very long period nearly sinusoidal waveformswas designed. This design consists of an analog phase-locked loop device, which extracts the period in terms of a voltage and a digital counting device which establishes the voltage in a form for display on either an oscilloscope or a chart recorder. Tests show that this prototype instrument is capable of measuring periods between 10 to 300 seconds and also indicate the arrival time of the peak.