This circuit was found in the 1969 RCA thyristor manual. The circuit has a limiter (clipping) with two 12 V zener diodes in opposition to cut power grid pulses that may influence the trigger.
This circuit, from the 90's, is intended for operation with vinyl record players of the time, as...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime...