Patent ID: 7205757
Filing Date: 2007-04-17
Classification: G01R

Abstract:
1. A current sensor for measuring an electric current flowing through a current bus bar comprising: a magnetic core with an opening, through which the current bus bar passes with a predetermined interval; a first magnetic sensor for detecting magnetic flux density in the magnetic core, the magnetic flux density generated by the electric current passing through the current bus bar, wherein the magnetic core has a first gap and a second gap, the first magnetic sensor is disposed in the first gap, and the second gap is capable of preventing magnetic saturation of the magnetic core; a second magnetic sensor for detecting magnetic flux density in the magnetic core, the magnetic flux density generated by the electric current passing through the current bus; and a current detection circuit coupled to the first and the second magnetic sensors, wherein the second magnetic sensor is disposed in the second gap, and the current detection circuit compensates for an effect of residual flux density in the magnetic core on the basis of outputs of the first and the second magnetic sensors.