Noncontact Current Sensor Using an Amorphous-Core Multivibrator

Use of a zero-magnetostriction amorphous wire two core multivibrator magnetometer in the noncontact sensing of line currents was studied. In the range ±30 percent the nonlinearity is less than 1 percent FS, indicating good linearity. The maximum value of the current to be detected can be adjusted over a wide extent by adjusting the distance between the object wire and each core. A 100 A current can be detected when the distance from the wire to the core is set to approximately 2 cm, and drift and noise are less than 0.01 percent FS.