The term ripple factor is generally used in AC filter circuit design. The filtering process involves the conversion of pulsating DC voltage into a pure DC voltage wave. Pure DC voltage is required in several applications. The ripple factor shows the amount of AC component in the signal. More AC component means more ripples, which further leads to generate some noises. In very simple words, ripple factor is defined as the ratio of the RMS value (or the root mean square value) to the absolute value of the dc component in the output voltage. The ratio is expressed as a percentage, for the sake of convenience.
A rectifier converts AC into DC, but there will some AC particles and that is why the waveform will be a pulsating. But to generate pure DC, some filter circuit should be installed with the rectifier. And in this way the pulsating output of the rectifier is directly fed to the filter circuit in order to gain purely rectified dc output. The ac component is called the ripples. The ripple current is undesirable and its value should be the smallest possible to ensure the best performance.
