It serves as a reference, since today we can have simpler and more compact solutions. This circuit is from an Electronics Experimenter Handbook from 1992. The integrated circuits are from that time.
We found this circuit in a 1980s documentation. The circuit uses general purpose transistors,...
This simple circuit for experimental LED sequencing is based on a multivibrator with transistors....
This circuit is from an American documentation from 1975. The circuit uses components of the time...