The presented circuit was found in the National Semiconductor FET Databook. The setting applies to other operational amplifiers and other FETs. 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...