Ripple

In rectifier/smoothing circuits such as those used in power supply equipment, it is a small AC voltage that appears superimposed on the DC voltage, synchronized with the input frequency and switching frequency, and represents the AC component that could not be removed by the low-pass filter. It is expressed as one cycle from one waveform peak to the next. In rectifier/smoothing circuits, ripple is required to be small, and the ripple factor is used as an indicator of this accuracy. Let the effective value of the ripple voltage be ΔVac and the average value of the DC output voltage be Vdc, then the ripple factor γ is expressed by the following formula.

Γ=(ΔVac/Vdc)x100(%)