The purpose of this circuit is to find two resistors with very close values for critical projects. The circuit was found in the November 1995 issue of Electronics Now magazine.
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...