Characteristic frequency measuring circuit - is for four-pole networks and uses only one regulated precision generator

摘要

The circuit measures the characteristic frequencies of a four-pole network (2) using one regulated precision generator (6). During the regulation period a frequency controlled voltage generated by the frequency or phase comparator (11) and the control voltage store (12) sets the frequency controlled oscillator (10) to a frequency determined by the precision generator (6) and the program generator (8). The program generator (8) sets the precision generator (6) frequency and switches it (9) to the comparator input (11). In the subsequent measurement period the precision generator (6) is switched to a second frequency and outputs directly to the measurement transmitter (1) or receiver (3).