Sense automobile high-side current with discrete components.

The article explains how to easily build a circuit that could be as accurate as the new integrated circuits (ICs) that sense current. It notes that the setup works with an analog input to the microprocessor and that two zener diodes protect the circuit from the automobile electrical systems. It provides a diagram that shows how the temperature compensation amplifier keeps the first current amplifier collector voltage constant no matter what the temperature does to the circuit.