While Hall-effect sensors are most frequently used to detect the proximity, position, or speed of mechanical targets, they are also useful for sensing electrical current. This is done indirectly, by measuring the magnetic field associated with current flow. Before getting into magnetic current sensing, let’s talk about the more commonly used technique of resistive current sensing.
Resistive current sensing exploits the voltage drop associated with an electrical current flowing through a resistor, as shown in Figure 7-1.
Figure 7-1 Current sensing with a resistor.
The voltage ...