A current measurement system includes a magnetic core having an inside area through which a conductor carrying current to be measured extends. A measurement winding is wound on the magnetic core. A voltage source couples to the measurement winding to generate current through the measurement winding. A gap of low permeability material is disposed in the magnetic core. A sensing device is positioned in the gap, wherein the sensing device generates a control signal having one of a first state and a second state based on a strength and a direction of a magnetic field in the gap.