Magnetic Field Sensor Switching Network for Directional Bridge Sensing
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Solution Overview
Problem
Magnetic field sensors face challenges in effectively differentiating and responding to magnetic fields with different directions, leading to limitations in accurately detecting and distinguishing between directly coupled and reflected magnetic fields, which affects their sensitivity and accuracy in various applications.
Innovation Solution
The implementation of a switching network that couples magnetic field sensing elements to form multiple bridge circuits, allowing them to respond differently to magnetic fields with varying directions, thereby enhancing the sensor's ability to distinguish between directly coupled and reflected fields through selective connection configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If magnetic field sensing elements are coupled in a single bridge arrangement, then the circuit structure is simple, but the sensor cannot effectively differentiate and respond to magnetic fields with different directions
Solution Approach 1:
The patent employs a switching network that dynamically reconfigures the bridge circuit arrangements based on the direction of the magnetic field being measured. The switching network allows the sensing elements to be connected in different bridge configurations (first bridge arrangement for directly coupled fields, second bridge arrangement for reflected fields), enabling the sensor to adapt its response characteristics to different field directions without requiring multiple fixed circuit boards.
2Measurement precision
If multiple bridge circuits are formed to detect different magnetic field directions, then the sensor accuracy and sensitivity improve, but the device complexity increases
Solution Approach 1:
The patent implements a universal switching network that can configure the same set of magnetic field sensing elements into multiple different bridge circuit arrangements. This switching network serves multiple functions: it creates first bridge circuits for detecting directly coupled magnetic fields, second bridge circuits for detecting reflected magnetic fields, and can selectively activate appropriate configurations based on the measurement requirements, thereby achieving multi-functionality with a single set of sensing elements.
Solution Approach 2:
The switching network dynamically reconfigures the bridge circuits based on the magnetic field direction being measured. For directly coupled fields, it forms first bridge arrangements; for reflected fields, it forms second bridge arrangements. This dynamic reconfiguration allows the sensor to optimize its measurement precision for different field directions without requiring physically separate circuit boards for each function.
3Adaptability or versatility
If the sensor uses a fixed bridge arrangement, then the circuit is simpler, but the sensor cannot provide both differential and common mode signals for different field types
Solution Approach 1:
The switching network dynamically configures the bridge circuits to provide different signal output modes. When measuring directly coupled magnetic fields, it forms first bridge arrangements that provide differential signals. When measuring reflected magnetic fields, it forms second bridge arrangements that provide common mode signals. This dynamic switching capability allows a single sensor to provide both differential and common mode signals as needed, eliminating the need for separate fixed circuit boards for each signal type.
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 improves the sensor's accuracy and sensitivity by providing differential and common mode signals that are responsive to specific changes in magnetic fields, allowing for precise detection of target position and movement, while being independent of temperature and stray field variations.
Implementation Method 1
a first coil supported by the substrate and configured to carry a first current in a first direction to generate a first magnetic field
Implementation Method 2
a second coil supported by the substrate and nested within the first coil to form a gap between the first and second coils, the second coil configured to carry a second current in a second, opposite direction to generate a second magnetic field
Implementation Method 3
A plurality of magnetic field sensing elements is configured to detect the first and second magnetic fields
Implementation Method 4
The switching network is coupled to the plurality of magnetic field sensing elements and configured to connect the plurality of magnetic field sensing elements to form a first bridge circuit having a first arrangement of the magnetic field sensing elements and a second bridge circuit having a second arrangement of the magnetic field sensing elements
Data Source
AI summary
A magnetic field sensor comprises a substrate, a first coil supported by the substrate and configured to carry a first current in a first direction to generate a first magnetic field, and a second coil supported by the substrate and nested within the first coil to form a gap between the first and second coils, the second coil configured to carry a second current in a second, opposite direction to generate a second magnetic field. A plurality of magnetic field sensing elements is configured to detect the first and second magnetic fields. A switching network is coupled to the plurality of magnetic field sensing elements and configured to connect the plurality of magnetic field sensing elements to form a first bridge circuit having a first arrangement of the magnetic field sensing elements and a second bridge circuit having a second arrangement of the magnetic field sensing elements.