Using the CA3140 in the figure we have a comparator that goes low in the window voltage space. The circuit was found in June 1986 Radio Electronics magazine.
This configuration can be found in other articles on this site. This is from European...
This simple voltage regulator with FET was found in American documentation from the 1980s....
This fourth-order filter was obtained in a 1977 technical documentation and can be implemented with other...