Patent ID: 7148675

Claim:
A ring type current sensor for a conductor comprising: a C-shaped core for enclosing the conductor, wherein the C-shaped core has end faces, which face in a circumferential direction of the C-shaped core, and a gap is formed between the end faces, and wherein the core is formed by a stack of C-shaped core plates that are stacked in an axial direction of the core, which is perpendicular to the circumferential direction, and the thickness of each core plate, which is measured in the axial direction, is uniform over the entire circumferential extent of each core plate, and the circumferential lengths of the core plates vary, such that a cross-sectional area of the core perpendicular to the circumferential direction gradually increases from the end faces to an intermediate portion opposite to the gap in a diametrical direction of the core; and a magnetic sensor disposed in the gap.