This 5 V power supply was found in the January 1992 issue of Radio Electronics magazine. The integrated circuit must be equipped with a heat sink and the current is 1 A.
In the figure we have the way to implement a 5 to 45 V zener diode with 50 mA of maximum current...
This circuit is from a Radio Electronics magazine from December 1958. The indicator instrument is analog...
These integrated ones consist of class B amplifiers with gain fixed 24 internally for better...