Abstract: A wide range current flow fault detector comprising a current sensor and a selective interrogator are disclosed. Current flow, or the lack thereof, between a power supply (e.g., capacitor bank) and a load (e.g, the hammer coils of a line printer) is sensed by a current sensor connected to detect the voltages at spaced points along a selected length of the supply conductor connecting the power supply to the load. A differential amplifier forming a part of the current sensor produces an output voltage related to the voltage difference between the selected points. The output voltage of the differential amplifier is compared, in a comparator, with a preset voltage. Any time the output voltage of the differential amplifier is above the preset voltage, the output of the comparator changes from a first state (e.g., low) to a second state (e.g., high). At all other times, the output of the comparator remains in the first state.