Simplified detection of periodic quantities

摘要

The relative change in the amplitude of an essentially sinusoidal periodic quantity is intended to be detected in a simple manner by a parameter. This object is achieved by measuring the time period which elapses between passage of the periodic quantity through two constant threshold values. For this purpose, use is made of a device having a threshold-value stage (1) to which a flip-flop (2), an AND gate (3) and a counter (4) are connected in series. The desired parameter is provided at the counter (4) as a digital value. <IMAGE>