TV receiver reference voltage switching circuit - turns on phase comparator transistor when level exceeded by signal from sawtooth voltage of thyristor horizontal deflection circuit

摘要

The reference voltage circuit turns on the transistor in a phase comparator when the reference level is exceeded by a signal derived from the sawtooth deflection voltge of a ty receiver's thyristor horizontal deflection circuit and alters the triggering angle of the regulating thyristor. The circuit is simplified by connecting the zener diode (5) is series with the transistor's (4) emitter. (The signal derived from the sawtooth is applied to the transistor's base). The transistor's collector is coupled to the stage (19) that drives the regulating thyristor. The zener diode is shunted by a capacitor (17).