The movement of the LEDs in this circuit mimics the back-and-forth movement of a pendulum, making it suitable for clock projects. The circuit is from a Radio Electronics magazine from May 1978.
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...