DC power generation:Thyristor-controlled rectifier

Thyristor-controlled rectifier

An alternative to the transistor, a thyristor (Figure 15.4) may be used as the regulating device for a power supply. A thyristor is triggered into conduc- tion by a positive voltage applied to its gate, provided that its anode is

positive with respect to the cathode. When fed with an a.c. voltage, the thyristor can only conduct during the positive half cycle. The conduction period is determined by the timing of the trigger pulse to the gate. The output level may thus be controlled by switching the thyristor for longer or shorter periods of time as shown in Figure 15.5.