Rectification and smoothing

Half-wave rectification shows only the positive (or negative) half of the AC signal, resulting in a pulsating DC with large gaps. Full-wave rectification inverts the negative half of the AC signal to become positive, resulting in a pulsating DC with smaller gaps.

A single diode allows current to flow in only one direction. In half-wave rectification, the diode blocks the negative half-cycles of the AC input, allowing only the positive half-cycles to pass through as pulsating DC.

A bridge rectifier uses four diodes to convert AC to full-wave DC. During each half-cycle of the AC input, two diodes conduct, allowing the current to flow through the load resistor in the same direction regardless of the input polarity, effectively inverting the negative half-cycles.

A capacitor stores charge during the peaks of the rectified voltage and discharges it during the troughs, reducing the voltage ripple and providing a smoother DC output. It acts as a temporary energy reservoir.

Increasing the capacitance value increases the amount of charge stored and the time it takes for the capacitor to discharge. This leads to a smaller voltage ripple and a smoother DC output.

Increasing the load resistance decreases the rate at which the capacitor discharges. This also leads to a smaller voltage ripple and a smoother DC output because less current is drawn from the capacitor.