This circuit for incandescent lamps was found in the February 1972 Radio Electronics magazine. The triac is rated according to the lamp power and the sensitivity adjustment is made in R1.
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...