The circuit shown in the figure can be designed with more modern operational amplifiers, as it is from 1994 documentation by National Semiconductor. The power supply must be symmetrical.
This 1995 circuit uses interruption sensors or NC connected in series in any quantity. With the...
This circuit, suggested by a 1975 documentation, detects an electrical discharge in a storm by...
Found in an old Electronic Design, this circuit provides an output voltage that is the absolute...