Voltage, current and frequency measuring of non-standard waveforms

摘要

A regularly repetitive, almost periodic but non-regularly shaped waveform is amplitude sampled at an interval different from that of the waveform under investigation. For a voltage measurement, the positive samples are averaged for a predetermined count number (one set) and the negative samples are likewise averaged. Zero value samples are ignored. The highest absolute value of the two is taken as a meaningful measurement. Alternatively, one of these values can be selected. For a current measurement, a running average for a predetermined number of sets can also be developed. Finally, frequency can be developed by sensing the transitions and operating a counter on/off at the beginning and ending of a waveform cycle. The count of regular interval counts is then multiplied by the interval time to give the period of the waveform. The reciprocal of the period is a measure of the frequency.