Oscilloscope conventional test method and waveform display effect
Modern electrical engineering theory holds that secondary power supply mainly includes linear power supply and switching power supply, and the output dc voltage is a fixed value, which is obtained by ac voltage after rectification, filtering, voltage regulation or high-frequency modulation.Due to unclean filtering, the clutter signal attached to the dc level contains periodic and random components, and the output dc voltage contains ac components. So in the oscilloscope measurement of any type of secondary power supply will generally be set according to the oscilloscope parameters measurement waveform.There is no clear voltage curve profile in these test pictures. Some electric signal curves are very straight, while some electric signal curves have obvious characteristics of noise signal. If the scanning time base of the oscilloscope is changed, the rapidly changing high-frequency ripple frequency value and ripple amplitude value can be read from the parameter display bar of the oscilloscope. It is difficult for engineers to interpret the exact voltage characteristics of these chaotic, irregular, and poorly reproducible voltage wave curves.At the same time, these waveforms are different from the working waveforms that should be studied in the theory of power supply, and they are not consistent with the testing effect that oscilloscope testing should achieve.