This Intersil circuit was found in a 1980s documentation. Operational are of the time, but current equivalents can be experienced. The graph with the circuit performance is given next to the diagram.
This automatic volume control for audio signals was found in American documentation from the 90s....
This electronic voltmeter circuit was found in a documentation from the 50's. The sensitivity is...
Found in a Popular Electronics from the 90s, this game can be seen in other configurations on this site. The...