Magnetic Sensor Array Layout for Wide-Range Current Sensing
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Solution Overview
Problem
Magnetic sensors have a limited dynamic range, making them ineffective for measuring both small and large currents, and are susceptible to external magnetic fields unrelated to the current flow.
Innovation Solution
A sensing apparatus using an array of magnetic sensors with varying sensitivity levels, positioned at different distances and orientations, and combined with processing circuitry to select and process relevant information, providing a wide dynamic range for current characterization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single magnetic sensor is used to measure current, then the sensor provides electrical isolation and accurate readings for currents within its dynamic range, but the sensor cannot effectively measure both small and large currents due to limited dynamic range
Solution Approach 1:
The patent divides the measurement system into multiple magnetic sensors, each optimized for different current ranges. The sensor array includes sensors with varying sensitivities that can individually measure specific current segments, collectively covering a wide dynamic range from small to large currents.
Solution Approach 2:
The patent varies the sensitivity parameter of different magnetic sensors in the array to match different current measurement ranges. By adjusting sensor sensitivity through positioning and orientation, the system can accurately measure both small and large currents without saturation or loss of precision.
2Measurement precision
If magnetic sensors are positioned close to the conductor for high sensitivity, then small currents can be detected, but the sensors become susceptible to external magnetic fields unrelated to current flow
Solution Approach 1:
The patent positions magnetic sensors asymmetrically at specific angles (e.g., 45 degrees) relative to the conductor rather than symmetrically at 0 or 90 degrees. This asymmetric positioning optimizes the balance between sensitivity to current-generated magnetic fields and rejection of external magnetic field interference.
Solution Approach 2:
The patent uses external magnetic field interference as a reference signal. By measuring the field at multiple positions and using signal processing, the system identifies and subtracts the external field component, converting the harmful interference into useful information for rejection.
3Adaptability or versatility
If multiple magnetic sensors with varying sensitivity are used to expand dynamic range, then both small and large currents can be measured, but the device complexity increases
Solution Approach 1:
The patent designs the sensor array and processing circuitry to perform multiple functions: individual sensors measure different current ranges, the system provides electrical isolation, rejects external fields, and maintains a wide dynamic range. This multi-functionality reduces the need for additional separate systems.
Solution Approach 2:
The patent combines multiple magnetic sensors, processing circuitry, and control logic into an integrated current measurement system. By merging these components into a unified apparatus, the patent reduces overall system complexity compared to using separate measurement systems for different current ranges.
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
The apparatus effectively characterizes currents across a wide range, accurately measuring both small and large currents while rejecting external magnetic interference.
Implementation Method 1
magnetic sensors measure current based on the principles of Maxwell's equations, which provide that the magnitude of a magnetic field generated by the flow of current through, e.g., a conductor
Implementation Method 2
Magnetic sensors measure current based on the principles of Maxwell's equations
Data Source
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AI summary
A sensing apparatus for characterizing current flow through a conductor includes a plurality of magnetic sensors. In some embodiments, the sensors are grouped in pairs to achieve common mode rejection of signals generated in response to magnetic fields not resulting from current flow through the conductor. Sensors having different levels of sensitivity are used to collect information regarding the magnetic field generated by the current flowing through the conductor, where such information is processed in order to characterize the magnetic field. In some cases the sensors are included on or in flexible material that can be wrapped around the conductor.