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center-tapped, high-voltage secondary. Because of the center tap, the output of the rectifier is limited to
one-half of the input voltage of the high-voltage secondary.
BRIDGE RECTIFIERS are full-wave rectifiers that do not use a center-tapped, high-voltage
secondary. Because of this, their dc output voltage is equal to the input voltage from the high-voltage
secondary of the power transformer. Bridge rectifiers use four diodes connected in a bridge network.
Diodes conduct in diagonal pairs to give a full-wave pulsating dc output.
FILTER CIRCUITS are designed to smooth, or filter, the ripple voltage present on the pulsating dc
output of the rectifier. This is done by an electrical device that has the ability to store energy and to
release the stored energy.
CAPACITANCE FILTERS are nothing more than large capacitors placed across the output of the
rectifier section. Because of the large size of the capacitors, fast charge paths, and slow discharge paths,
the capacitor will charge to average value, which will keep the pulsating dc output from reaching zero
volts.
