At A, the output of a half-wave rectifier. At B, the output of a fullwave rectifier. Note the difference in how the effective (eff ) voltages compare with the peak voltages.
Another way to get full-wave rectification is the full-wave bridge rectifier, often called simply a bridge. It is diagrammed in above figure C. The output waveform is similar to that of the full-wave center- tap circuit (above figure B).
The effective output voltage from a power supply that uses a full-wave bridge rectifier is somewhat less than the peak transformer output voltage, as shown in above figure B. The peak voltage across the diodes in the reverse direction is about 1.4 times the applied rms ac voltage. Therefore, each diode needs to have a PIV rating of at least 1.4 × 1.5, or 2.1, times the rms ac voltage that appears at the transformer secondary.
The bridge circuit does not require a center-tapped transformer secondary. It uses the entire secondary winding on both halves of the wave cycle, so it makes even more efficient use of the transformer than the full-wave center-tap circuit. The bridge is also easier on the diodes than half-wave or full-wave center-tap circuits.