LITERATURE REVIEW

JOURNAL 3

SMOOTHING 

Smoothing is performed by a large value electrolytic capacitor connected across the DC supply to act as a reservoir, supplying current to the output when the varying DC voltage from the rectifier is falling. The diagram shows the unsmoothed varying DC (dotted line) and the smoothed DC (solid line). The capacitor charges quickly near the peak of the varying DC, and then discharges as it supplies current to the output.

Note that smoothing significantly increases the average DC voltage to almost the peak value. Smoothing is not perfect due to the capacitor voltage falling a little as it discharges, giving a small ripple voltage. A larger capacitor will give less ripple. The capacitor value must be doubled when smoothing half-wave DC.