This bargraph circuit was found in the January 1986 issue of Radio Electronics magazine. It is based on the well-known LM3914 and has two of them in cascade driving a good number of LEDs.
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...