We found this circuit in a Poptronics from the 90's. Equivalent operational amplifiers can be used. The circuit must be supplied by a symmetrical source.
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...