We found this circuit in a 1969 General Electric documentation. The circuit uses transistors of the time and the diodes in the dotted board must be mounted on the output transistor heatsinks.
This current sensing circuit for applications up to 10 A has been found in a Linear Technology...
High Current Through Hole Inductors for Vishay's 5A Series IHXL-2000VZ-5A Series Power Supply are...
We find in a Radio Electronics of the 90s this low noise amplifier that makes use of an uncommon...