This circuit that draws 1 out of 8 LEDs was found in an 80's American documentation. The circuit can also work with an astable using the 555 instead of the 4046 which is not a common component today.
This circuit was found in Electronics Now. With it the dialing signals of a telephone are...
This circuit switches the brightness of the LED. We found it in an English documentation....
This circuit already explored in several diagrams in this section was found in a 90’s Popular...