Magnetic Field Guide Layer Permeability Control for Sensor Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic detection devices face issues with sensitivity variation and detection noise due to high magnetic permeability in soft magnetic materials, leading to unwanted detection of horizontal magnetic field components and offset in vertical detection outputs when exposed to strong external fields.
Innovation Solution
A magnetic detection device is designed with a magnetic field guide layer having varying permeability, where the portion facing the sensor has lower permeability to minimize horizontal field detection and higher permeability elsewhere to maintain soft magnetic characteristics, preventing residual magnetization and sensitivity variation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the magnetic permeability of the magnetic field guide layer is increased to improve magnetic field guiding capability, then the sensitivity varies with respect to horizontal magnetic field components, but if the magnetic permeability is decreased to reduce horizontal field detection, then the soft magnetic characteristics are deteriorated and residual magnetization occurs under strong external fields
Solution Approach 1:
The magnetic field guide layer is divided into a first portion and a second portion with different magnetic permeabilities. The first portion has lower magnetic permeability to reduce horizontal field detection and detection noise, while the second portion has higher magnetic permeability to maintain soft magnetic characteristics and prevent residual magnetization under strong external fields.
Solution Approach 2:
The magnetic field guide layer is segmented into multiple portions (first portion and second portion) with different magnetic permeability characteristics. This segmentation allows each portion to perform its specific function: the first portion suppresses horizontal field interference while the second portion maintains overall soft magnetic properties.
2Reliability
If the magnetic permeability is high to guide vertical magnetic field effectively, then horizontal magnetic field components are drawn to the magnetic body causing sensitivity variation, but if the magnetic permeability is low to avoid horizontal field interference, then the magnetic body retains magnetization under strong external fields
Solution Approach 1:
The magnetic field guide layer employs local quality differentiation where the first portion has lower magnetic permeability to prevent horizontal field interference and maintain detection stability, while the second portion has higher magnetic permeability to ensure proper magnetic field guidance and prevent residual magnetization effects.
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 configuration reduces detection noise from unwanted magnetic field components and maintains sensitivity stability even under strong external fields, preventing offset and sensitivity variation in the original detection direction.
Implementation Method 1
a magnetic permeability of the first portion is lower than that of the second portion
Implementation Method 2
a magnetic sensor located on a virtual surface facing an end portion of the magnetic field guide layer, the magnetic sensor having a sensitivity axis in a second direction perpendicular to the first direction
Data Source
AI summary
A magnetic field component in a Z direction is guided by a magnetic field guide layer and applied to a magnetic sensor in an X direction that is the same as a sensitivity axis direction thereof, and a detection output is obtained. A bridge circuit is formed with a plurality of magnetic sensors and configured such that an output is not provided for a magnetic field component in the X direction. However, when an external magnetic field in the X direction is drawn to the magnetic field guide layer, variation of sensitivity for the X direction may occur. Thus, soft magnetic characteristics of a first portion of the magnetic field guide layer are deteriorated to decrease the magnetic permeability of the first portion.