This circuit was found in a 1964 documentation. It shows how to achieve automatic gain control for an oscillator. The transistors are of the time and the circuit controls signals from 2.6 to 3.1 kHz.
Although there is an enormous amount of 12 V voltage regulator integrated circuits, it may be that...
This circuit is from an old Mullard (Philips) manual with applications using the 555. Choosing...
This quick response game was found in a Popular Electronics from the 80s. It uses only discrete analog...