This circuit was found in a RE Experimenter Handbook from the 90's. The components are of the time, rare nowadays, except the 555 and 4017.
This 1965 General Electric circuit uses a "Thyrector" that is a suppressor of the time. The...
We found this circuit in documentation from the 1970s; The circuit uses Japanese transistors of...
The output voltage depends on the zener diode. Zener in the range between 1.2 to 12 V rated to 1 W...