Arrangement for measuring alternate current or direct current

摘要

A current passing through a conductor (1) produces a magnetic field in a yoke (2) which has an air gap (3). A sensor (4) located in the air gap detects when the field is annulled by a winding (7) supplied from a measuring circuit (6). A second sensor (10) is placed to detect a parasitic field (9) in a similar way to the first sensor (4) in the main field and signals a correction (Vc) to the measuring circuit (6) through an amplifier (12).