An analog method for detecting superimposed power line voltage disturbances

Power line monitoring has become increasingly important during the past few years as many failures in sensitive electronic equipment are due to various types of power line disturbances. An analog, low-cost solution for multichannel power line disturbance analyzers which performs a triggering function that detects changes in the voltage waveform is described. The method may also be used for other applications where deviations from a repetitive waveform must be detected. Examples of transient disturbances measured in the field are presented and described