smoothing circuit
When supply voltage is generated in power supplies, the line voltage is rectified after transformation in rectifiers and then smoothed in filter elements.
Since rectifiers generate sinusoidal half-waves that form a strongly pulsating DC voltage that cannot be used as a supply voltage, the DC voltage required for the supply is generated from these sinusoidal half-wave signals in downstream filter elements.
The smoothing of the half-wave signals takes place in integrating elements, in RC or LC elements, in which the charge function of the capacitor, or electrolytic capacitor, provides the corresponding smoothing. The residual voltage variation is referred to as ripple and directly affects the power system noise rejection ratio( PSRR).
For further smoothing, the values of the time constants can be increased or several filter circuits can be connected in series. The smoothing effect depends on the size of the electrolytic capacitor, the inductance and the frequency.