Current Sensor Tilting to Reject Parasitic Magnetic Fields
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing current sensor arrangements face challenges with increasing miniaturization, as parasitic magnetic fields from connecting webs and feed lines can cause errors in current measurement due to interference with the magnetization of magnetic field-sensitive layers, leading to inaccurate readings.
Innovation Solution
The solution involves strategically positioning magnetic field-sensitive sensor elements on current-measuring active conductor sections while aligning them to minimize the impact of parasitic magnetic fields from current-measuring-parasitic conductor sections through tilting, offsetting, or using magnetic field compensation, ensuring that only the magnetic fields from the active conductor sections cause significant sensor value changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor element is positioned close to the current-measuring-active conductor section to improve measurement sensitivity, then measurement precision is improved, but parasitic magnetic fields from connecting webs and feed lines increase causing measurement errors
Solution Approach 1:
The sensor element is tilted relative to the conductor element, changing the spatial orientation from a planar arrangement to a three-dimensional configuration. This angular arrangement in another dimension allows the sensor to detect magnetic fields perpendicular to the parasitic field directions while maintaining sensitivity to the measurement current's magnetic field.
Solution Approach 2:
The sensor element is positioned at specific locations on the conductor legs and tilted at specific angles, creating localized optimal measurement zones. This local optimization ensures that each sensor element experiences maximum signal from the measurement current while minimum interference from parasitic fields in its specific spatial position.
2Measurement precision
If the length of the U-shaped conductor legs is increased to reduce inhomogeneous interference fields, then measurement precision is improved, but device complexity and space requirements increase
Solution Approach 1:
Instead of increasing the planar dimensions of the conductor legs, the solution introduces a third dimension by tilting the sensor element. This angular arrangement in the vertical dimension provides interference rejection without requiring longer conductor legs, thus avoiding increased device complexity and space requirements.
3Object-affected harmful factors
If the sensor element is tilted relative to the conductor element to reduce parasitic field influence, then parasitic field rejection is improved, but manufacturing precision requirements increase
Solution Approach 1:
The fastening element is pre-formed with an integrated tilt angle during manufacturing, establishing the correct angular orientation before the sensor element is mounted. This preliminary preparation of the mounting structure eliminates the need for precise angular adjustment during assembly, reducing the actual manufacturing precision requirements during the assembly process.
Solution Approach 2:
The fastening element acts as an intermediary component that provides the tilt function. Instead of requiring the sensor element itself to be precisely tilted, the fastening element mediates the angular relationship between the sensor and conductor, making the system more tolerant to manufacturing variations in the sensor element's orientation.
4Volume of moving object
If miniaturization of the sensor arrangement is increased to reduce device size, then device complexity is reduced, but parasitic field interference increases due to closer proximity of conducting elements
Solution Approach 1:
The tilt arrangement introduces a vertical dimension to the sensor-conductor geometry, allowing miniaturization in the horizontal plane while maintaining parasitic field rejection through the angular orientation. The sensor can be positioned closer to the conductor in the planar direction while the tilt angle ensures that parasitic fields from connecting webs and feed lines do not couple into the sensor's sensitive axis.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a linear and accurate current measurement by isolating parasitic magnetic fields from the sensor elements, reducing errors and maintaining sensitivity only to the magnetic fields generated by the current-measuring active conductor sections.
Implementation Method 1
an arrangement for indirectly measuring a current in a conductor by detecting the magnetic field surrounding the current-carrying conductor
Implementation Method 2
sensors that utilize the anisotropic magnetoresistive effect (AMR effect), auxiliary magnets are present in the vicinity of the magnetic field-sensitive layers, which ensure stabilization or basic magnetization of the magnetic field-sensitive layers on the sensor chip
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to an arrangement for measuring electrical currents, the measurement being based on magnetic fields. By means of at least one sensor element (10) which is sensitive to magnetic fields, the current is measured in a bent, particularly U-shaped, conductor element (2) comprising at least one conductor section (4, 30) which is active in terms of current measurement and at least one conductor section (5, 32) which is parasitic in terms of current measurement. In the region of the conductor section (4, 30) which is active in terms of current measurement, the sensor element (10) is oriented, particularly twisted with respect to the conductor section (5, 32) which is parasitic in terms of current measurement, tilted with respect to the conductor section (5, 32) which is parasitic in terms of current measurement and/or height-adjusted with respect to the conductor section (5, 32) which is parasitic in terms of current measurement, such that the magnetic field of the conductor section (4, 30) which is active in terms of current measurement is oriented substantially in the direction of sensitivity (70) and the magnetic field of the conductor section (5, 32) which is parasitic in terms of current measurement is oriented substantially not in the direction of sensitivity (70), particularly perpendicular to the direction of sensitivity (70).