This circuit is from an American manual from 1975. The transistors are types of the time, but equivalents can be used, as well as the relay that can be according to the supply voltage.
This circuit was found in a 1999 publication. Its purpose is to flash two LEDs according to the...
This circuit is based on the well-known digital module ICL7107 feeding 4 displays with...
This configuration can be found in other articles in this section. This was obtained in a 2000...