We found this circuit in a 90's EDN. The circuit is based on a control integrated that is still common in these types of applications. The circuit uses a PROM.
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...