Device for indicating phase sequences and application to power factor meters

摘要

The device comprises a phase feedback circuit 2a, 2b producing a signal synchronous with one of the periodic signals and multiple frequency signals. A circuit L1 detects the point at which the second periodic signal becomes zero. A logic circuit L2 - L8 defines regions of phase difference with the first signal and identifies the region which coincides with the passage to zero of the second signal. Application to phase sequence indicators and to power factor meters. IMAGE