This circuit of an Electronics Hobbyists Handbook uses a different configuration for a triac. The circuit uses an integrated frequency divider and a coupler with a fotodiac.
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...