This circuit shows how to simulate a high-performance diode with two diodes. The circuit is from a 1960s RCA documentation. Modern general-purpose transistors can be used.
Using components from the era, this 90's EDN circuit is used in analog to digital conversion...
Found in an American publication from the 90s, this circuit allows the supply of 3, 6 and 9 V...
We found this circuit in an old Popular Electronics. The circuit is experimental, driving an LED...