This circuit was suggested by Signetics in 1980s documentation. The circuit makes use of the hard-to-obtain component of our day. It is for reference only.
Texas Instruments' low power operational amplifiers OPAx196 can be found on Mouser Electronics....
This variable power supply uses common components and can supply a current up to 1 A. The...
This circuit was fond in an old publication of the years 1950. The transistors are germanium types and...