Multi-gap Ferromagnetic Core Current Sensor for Wide Range Detection
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Solution Overview
Problem
Current current sensors with ferromagnetic cores are inadequate for sensing multiple current level ranges, as they require multiple sensors, which are costly and space-consuming, and existing designs fail to efficiently detect a wide range of currents due to limited magnetic field concentration capabilities.
Innovation Solution
A current sensor design featuring a ferromagnetic core with multiple gap portions of varying spacings, each optimized for different current level ranges, utilizing multiple magnetic field sensing elements with calibrated circuit portions to generate distinct magnetic field signals for precise current detection across multiple ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single current sensor with a ferromagnetic core is used, then the device complexity is reduced and cost is lowered, but the measurement precision across multiple current level ranges is insufficient
Solution Approach 1:
The ferromagnetic core is segmented into multiple gap portions (first gap portion, second gap portion, etc.), each with different gap spacings. This segmentation allows the single sensor to detect multiple current level ranges by utilizing the magnetic field concentration differences across the segmented gaps, thereby maintaining measurement precision across various current ranges while using only one sensor.
Solution Approach 2:
Different gap portions are assigned different local qualities through varying their gap spacings. The first gap portion has a first gap spacing optimized for lower current detection, while the second gap portion has a second gap spacing optimized for higher current detection. This local quality differentiation enables each gap portion to excel at detecting specific current levels, achieving high measurement precision across the full range without requiring multiple sensors.
2Measurement precision
If multiple current sensors are used to detect different current level ranges, then the measurement precision across ranges is improved, but the device complexity and space requirements increase
Solution Approach 1:
Multiple gap portions that would traditionally require separate sensors are merged into a single ferromagnetic core structure. The first gap portion, second gap portion, and additional gap portions are integrated within the same core, sharing common magnetic circuit elements. This merging allows the sensor to detect multiple current level ranges simultaneously in a compact footprint, reducing the total space occupation while maintaining measurement precision across all ranges.
Solution Approach 2:
The single current sensor achieves multi-functionality by incorporating multiple gap portions with different spacings, enabling it to detect both low current levels (using the first gap portion) and high current levels (using the second gap portion) within the same device. This universal design eliminates the need for multiple specialized sensors, reducing space requirements while maintaining the ability to accurately measure across the full current range.
3Measurement precision
If multiple current sensors are used to detect different current level ranges, then the measurement precision across ranges is improved, but the material costs and manufacturing complexity increase
Solution Approach 1:
The ferromagnetic core is segmented into multiple gap portions (first gap portion, second gap portion, etc.), each with different gap spacings. This segmentation allows the single sensor to detect multiple current level ranges by utilizing the magnetic field concentration differences across the segmented gaps, thereby maintaining measurement precision across various current ranges while using only one sensor.
Solution Approach 2:
Different gap portions are assigned different local qualities through varying their gap spacings. The first gap portion has a first gap spacing optimized for lower current detection, while the second gap portion has a second gap spacing optimized for higher current detection. This local quality differentiation enables each gap portion to excel at detecting specific current levels, achieving high measurement precision across the full range without requiring multiple sensors.
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 design allows for efficient detection of currents across a wide range, from low to high levels, using a single sensor, reducing material and space costs while maintaining high accuracy through tailored gap spacings and sensing element configurations.
Implementation Method 1
at least one first magnetic field sensing element disposed in a first one of the gap portions and configured to generate a respective first magnetic field signal in response to a first magnetic field generated in the first gap portion
Implementation Method 2
magnetic field sensing elements, such as Hall effect elements and/or magnetoresistance elements
Implementation Method 3
A ferromagnetic core can be used to concentrate the magnetic field for detection by the magnetic field sensing element
Implementation Method 4
The first magnetic field has a magnitude greater than the second magnetic field
Data Source
Figure 1
Figure 2~2A
Figure 2B~2C
AI summary
A current sensor includes a ferromagnetic core having a substantially central opening for receiving a current conductor and at least two gaps portions, each of the gap portions having an associated gap spacing. A detector of the current sensor includes at least one first sensing element disposed in a first one of the gap portions and configured to generate a respective first magnetic field signal in response to a first magnetic field generated in the first gap portion in response to a current through the current conductor. The detector also includes at least one second sensing element disposed in a second one of the gap portions and configured to generate a respective second magnetic field signal in response to a second magnetic field generated in the second gap portion in response to the current through the conductor. A method of sensing a current through a current conductor is also provided.