We found this touch control on a Popular Electronics from 1970. The circuit makes use of an integrated of the time. It can be adapted to use modern equivalent components.
This simple metronome, from 1985 documentation uses only transistors and has two settings. For...
This circuit is suitable for modulating AM transmitters. The circuit is from a 1977 radio amateur...
This flasher was found in an old Hands On, but uses common components. The optocoupler can be...