| 摘要 |
PROBLEM TO BE SOLVED: To provide a current detector capable of reproducing a state that a current is conducted through a current line to be measured, in a flux gate type current sensor, and to provide a current detector capable of detecting a current to be measured with high accuracy by correcting sensor sensitivity, even in a situation where the working environment temperature of the sensor changes.SOLUTION: A current detector comprises: a flux gate type current sensor 51 having a magnetic substance core 2 forming a closed magnetic circuit, an excitation coil 3 wound around the magnetic substance core 2, and a detection coil 4 wound around the magnetic substance core 2, a current line 1 to be measured passing through the magnetic substance core 2; an excitation processing unit 61 for generating an excitation magnetic field by conducting an AC excitation signal 38 through the excitation coil 3; a detection processing unit 62 for extracting only a second harmonic component of the excitation magnetic field from an output voltage waveform of the detection coil 4 and performing signal processing on it; and an offset control circuit 22 or the like for superposing an offset signal on the AC excitation signal 38 at a predetermined timing. |
