This circuit was suggested by National Semiconductor in one of its manuals. The LM108 integrated circuit, uncommon nowadays, can be replaced by an equivalent. The power supply must be symmetrical.
The integrated circuit used in this project is not common today, but it can be implemented with more...
Found in an American publication from 1969, this circuit can be adapted to be used as a shield....
This current meter with many scales was found in a 80s American documentation. The operational amplifier...