What are the different types of rectifier circuits?

Rectifiers convert AC to DC. Single-phase types include: half-wave (one diode, 50% output, high ripple), full-wave center-tap (two diodes, requires center-tapped transformer), and full-wave bridge (four diodes, most common). Three-phase rectifiers include: six-pulse bridge (six diodes, standard industrial), twelve-pulse (two bridges with 30-degree phase shift, lower harmonics). Controlled rectifiers use thyristors instead of diodes to adjust DC output voltage by controlling firing angle.