Differential Magnetic Current Sensing Against Field Interference
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Solution Overview
Problem
Traditional contact current measurement methods are complex and costly, while magnetic sensing methods suffer from accuracy issues due to environmental magnetic field interference.
Innovation Solution
A current detection apparatus utilizing a magnetic sensor with distinct first and second sensing portions that differ in magnetic field direction and strength, generating differential electrical signals to isolate current measurements from environmental interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional contact current measurement method using a resistor and sampling circuit is employed, then current measurement can be achieved, but the overall device framework becomes complex and cost increases
Solution Approach 1:
The patent replaces the traditional mechanical/electrical contact measurement system (resistor, sampling circuit, isolation chip) with a magnetic field-based non-contact sensing system. The magnetic sensor detects the magnetic field generated by current flow through the conductor, converting it directly into a measurement signal without physical contact or complex circuitry.
Solution Approach 2:
The patent extracts only the essential measurement function by using a magnetic sensor to directly sense the magnetic field around the conductor. This eliminates unnecessary components such as the resistor, sampling circuit, and isolation chip, retaining only what is needed for accurate current measurement.
2Ease of manufacture
If a magnetic sensing method is used to detect current, then cost is reduced, but detection accuracy is affected by environmental magnetic field interference
Solution Approach 1:
The patent divides the magnetic sensor into multiple sensing portions (first sensing portion and second sensing portion) with different sensing directions. This segmentation allows the system to differentiate between the magnetic field generated by the conductor and environmental magnetic field interference, enabling accurate current measurement despite the presence of external magnetic fields.
Solution Approach 2:
The patent assigns different sensing directions to different portions of the magnetic sensor. The first sensing portion senses in one direction while the second sensing portion senses in another direction, allowing each portion to capture specific components of the magnetic field. This local differentiation in sensing quality enables the system to isolate the conductor's magnetic field from environmental interference.
3Device complexity
If a single magnetic sensor is used for current detection, then device complexity is reduced, but ability to distinguish signal magnetic field from environmental magnetic field is insufficient
Solution Approach 1:
The patent introduces asymmetry in the magnetic sensor configuration by creating sensing portions with different sensing directions. This asymmetric arrangement allows the sensor to differentiate between magnetic fields based on their directional characteristics, enabling the system to distinguish the conductor's signal magnetic field from environmental magnetic field interference while maintaining relatively simple device structure.
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
Enhances current detection accuracy by filtering out environmental magnetic field interference, simplifying the device framework, and reducing costs.
Implementation Method 1
a first signal magnetic field is generated when a current passes through the conductor... The magnetic sensor is configured to generate a sensing electrical signal according to the first signal magnetic field
Data Source
AI summary
A current detection apparatus having a substrate, at least one magnetic sensor arranged on the substrate, and a processing circuit. The magnetic sensor includes a first sensing portion and a second sensing portion which are different in a direction of a magnetic field component of the first signal magnetic field. The magnetic sensor is configured to generate a sensing electrical signal according to the first signal magnetic field. The processing circuit is connected to the magnetic sensor and is configured to determine, according to the sensing electrical signal, a value of the current flowing through the conductor.