This circuit was found in an American documentation from the 90's. What it does is provide at the output a voltage that is the average of the voltages set for the inputs.
This circuit for cars with mechanical ignition systems was found in the Electronics Experimenter handbook...
This code practice circuit was found in a 1990s issue of Radio Amaterur Today magazine. It...
The circuit presented was found in the Linear Applications Handbook of the National Semiconductoir of 1994....