This amplifier for instrumentation with very high input impedance was found in a manual of JFET circuits. The operational ones used are current and the power supply must be symmetrical.
This circuit was found in an 80's Electronic Engineering. The circuit uses operatives of the time...
This circuit was obtained in a 90’s American documentation. The FET can be replaced by a modern...
This unregulated low voltage source was found in the July 1962 Radio Electronics magazine....