Variable resistance phase shift trigger circuit cd

Figure 16-3 (a) is a unidirectional thyristor; Figure 16-3 (c) is a bidirectional thyristor.
    Circuit features: ① Simple, phase shift range <90. [Figure 16-3 (a)], phase shift range <180. [Figure 16-3(c)];
② It is greatly affected by temperature (referring to phase shift accuracy), and is suitable for low power and low-demand situations.