The most simple and most basic type of power supply filter is a single shunt capacitor filter, as shown in Figure 3. We saw in the previous lab that the full-wave rectifier produces a full-wave output waveform which is twice that of the frequency of the input supply frequency. We can increase its average DC output level even higher by connecting a suitable filter or smoothing capacitor across the output of the bridge circuit as shown in Figure3.
Figure 3. Full-wave bridge rectifier with a capacitor filter
The filter capacitor converts the full-wave rippled output of the rectifier into a smoother DC output voltage. Generally for DC power supply circuits the filter capacitor is an aluminium electrolytic type that has a capacitance value of 100 uF or more with repeated DC vatage pulses fron the rectifier charging up the capacitor to peak voltage. However, there are two important paraneters to consider when choosing a suitable filter capacitor and these are its Working Voltage, which determines the amount of ripple that will a