| 摘要 |
Core-less current sensor comprises two parallel conductors carrying equal currents in the same direction. The magnetic field in mid location of the two parallel conductors carrying equal currents in the same direction for all current magnitudes is zero in absence of an external magnetic interference. Sum of magnetic fields in two points equidistant from the mid location on both the sides is zero as magnetic fields at these points are equal in magnitude and opposite in polarity for all current magnitudes and for equal amount of currents flowing through both conductors in same direction in absence of an external magnetic interference. Two sensing elements can be arranged between the two parallel conductors for sensing the magnetic field due to currents flowing through them for the purpose of current measurement. Sensor output is the difference between two outputs measured by the sensing elements. Outputs of sensing elements can vary due to external interference. As variation in the outputs of sensing elements due to external interference gets cancelled in sensor output, automatic external field compensation can be achieved.
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