This 10-minute timer was found in the July 1994 Radio Electronics magazine. The relay must be sensitive to the supply voltage used. The capacitors determine time ranges.
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...