Current Sensor With Magnetoresistance Selection Circuit
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Solution Overview
Problem
Current smart meters require high-resolution current sensors with a broad dynamic range and low power consumption, which is challenging due to the increasing current-induced magnetic field that leads to higher power consumption in existing magnetic balance systems.
Innovation Solution
A current sensor comprising multiple magnetoresistance elements with different magnetic field sensitivities, where a selection circuit chooses the optimal element to measure current-induced magnetic fields, reducing power consumption by adjusting magnetic field sensitivity using linear response magnetic bodies or magnetic flux guides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic balance system with high-sensitivity magnetoresistance element is used to achieve high resolution, then measurement precision is improved, but power consumption increases proportionately with the magnitude of the current-to-be-measured
Solution Approach 1:
The patent divides the measurement range into multiple segments by providing multiple magnetoresistance elements with different sensitivity characteristics. Each element is optimized for a specific current range, allowing the system to segment the overall measurement task into manageable portions that each operate within their optimal efficiency zones.
Solution Approach 2:
The patent implements dynamic selection of magnetoresistance elements based on the magnitude of the current being measured. The selection circuit dynamically switches between different elements depending on the operating conditions, optimizing the balance between measurement precision and power consumption for each specific measurement scenario.
2Adaptability or versatility
If multiple magnetoresistance elements with different sensitivities are used to cover broad dynamic range, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent makes each magnetoresistance element serve multiple purposes: they all function as current sensors but with different sensitivity ranges. This multi-functionality allows a single set of elements to cover the entire broad dynamic range required, reducing the need for completely separate measurement systems for different current levels.
Solution Approach 2:
The patent changes the sensitivity parameter of the magnetoresistance elements to create a family of sensors with different characteristics. By varying this key parameter across multiple elements, the system achieves broad adaptability while maintaining a consistent and manageable structural design that can be systematically organized and controlled.
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
Enables high-precision current measurement across a wide range with reduced power consumption, maintaining accuracy and efficiency even at high current levels.
Implementation Method 1
a magnetoresistance element whose resistance value changes by application of an current-induced magnetic field from a current-to-be-measured
Data Source
AI summary
A current sensor comprises: a plurality of magnetoresistance elements whose resistance value changes by application of an current-induced magnetic field from a current-to-be-measured; and a selection circuit that selects one magnetoresistance element from these plurality of magnetoresistance elements and outputs a signal of a selected magnetoresistance element. In the plurality of magnetoresistance elements, relationships between a magnitude of the applied current-induced magnetic field and the resistance value are different from each other.