DC output generated by a rectifier circuit, not a wave of pure DC, but the waveform up and down or pulsing. These waves can not be used to distribute electronic circuits.

Process of flattening the pulsing waves of rectifier circuit, it can be done by connecting in parallel a large value of filter capacitor to output DC, as in the circuit below

filter capacitor to output DC
The capacitor used is usually electrolytic capacitors (elco) and has a capacitance value of 1000 μF or more. DC pulses from rectifier circuit are generated continuously and will fill capacitor immediately, until the voltage reaches maximum value.

When the load draw current of the circuit, the voltage on capacitor bit by bit away from maximum value, but the voltage will be immediately returned to maximum value by the next pulse. The result is a DC waveform with a little wave ripple.

DC waveform with a little wave ripple
DC waveform with a little wave ripple like picture above, can use to supply or distribute electronic circuit. It's almost a wave of pure DC.


Current output generated by half-wave rectifier circuit, is only worth half input cycle. This means that half of the input power is wasted.

Rectifier would be better, when using two diodes in series. Consider the circuit below

On positive cycle and negative cycle of the AC waveform, given a forward bias diode. Current flows through two diodes to the load and returned to the transformer through the ct (center tap). So that the circuit can be considered to consist of two half-wave rectifier circuit that works in turn.

Waveform at the output of which is at the end of RL load is shown in the picture below

Rectifier circuit is still generating output during the second half-wave cycles (cycles of positive and negative). So this series 100% efficient, because there is no input power is wasted. The circuit is called a full wave rectifier circuit.