Found in a 1991 PE Hobbyst Handbook, this circuit activates an oscillator that deactivates at the end of the programmed time. Transistors are commonly used.
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...