This circuit was obtained in a 1977 documentation. Two operational amplifiers 741 provide an input impedance of 200 Megohms. The supply must be symmetrical and the two operational make the null point adjustment.
This circuit was obtained in a 1977 documentation. Two operational amplifiers 741 provide an input impedance of 200 Megohms. The supply must be symmetrical and the two operational make the null point adjustment.