This setting applies to virtually any photo transistor and any operational amplifier. The power supply must be symmetrical, and the gain is determined by the relationship between R2 and R1.
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...