Suggested by a 1968 Motorola power semiconductor manual, this circuit uses a special transformer and transistors from the era. The frequency is 60 Hz.
The operational amplifier taken as an example is uncommon today, but the configuration can be made...
The integrated circuit used in this regulator is not easy to obtain, since the publication is from...
This configuration was obtained in a 1977 FET Databook. The circuit can be practically any JFET...