This circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms and excites a load of 16 ohms. The integrated circuit of the time is the PA237.
This circuit that can only be used with simple resistive and inductive loads (never electronic) was...
This digital instrument input circuit was found in the September 1989 issue of Radio Electronics...
This circuit was found in an 80s documentation. The integrated circuit used is from that time,...