Found in American documentation from the 1990s, this circuit can generate signals of up to a few tens of megahertz. The transistor must be suitable for high frequencies.
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...