Current Sensing Module with Partial Path Frame
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Solution Overview
Problem
Existing current sensing modules are unable to accurately measure current due to large size and high cost, and often fail to sense current effectively when only a part of the current path is encapsulated.
Innovation Solution
A current sensing module comprising a conductive substrate with terminals and slots, a frame with side and bottom portions surrounding a partial current path, and a magnetic sensor located between the frame's side portions to enhance magnetic flux and reduce external interference, utilizing a Permalloy frame with specific grain size to minimize remanence errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the frame encapsulates the whole current path, then the current sensing accuracy is improved, but the device size and manufacturing cost increase
Solution Approach 1:
The frame is designed to encapsulate only a partial path of the current instead of the entire current path. The frame includes two side portions and a bottom portion that surround a portion of the conductive substrate, thereby reducing the device size while maintaining sufficient magnetic flux for accurate current sensing.
Solution Approach 2:
The magnetic sensor is positioned at a specific location between the two side portions of the frame where the magnetic flux is most concentrated. This localized positioning optimizes the sensing accuracy without requiring the frame to enclose the entire current path, thus reducing overall device size.
2Measurement precision
If the frame encapsulates the whole current path, then the current sensing accuracy is improved, but the manufacturing cost increases
Solution Approach 1:
The frame structure is segmented to enclose only the necessary portion of the current path rather than the entire path. This reduction in frame size and material usage directly lowers manufacturing costs while preserving the essential magnetic flux concentration needed for accurate sensing.
3Volume of stationary object
If only a part of the current path is encapsulated, then the device size is reduced, but the current sensing accuracy deteriorates
Solution Approach 1:
The magnetic sensor is strategically positioned between the two side portions of the frame at a location where the magnetic flux from the partial current path is most concentrated. This optimized positioning ensures that even though only a portion of the current path is enclosed, the sensor still receives sufficient magnetic flux for accurate current measurement.
Solution Approach 2:
The frame encapsulates a partial path of the current rather than the complete path. This partial enclosure is sufficient to generate adequate magnetic flux for accurate sensing while significantly reducing the device size compared to full encapsulation.
4Device complexity
If the magnetic sensor is located in the gap between the two side portions, then the device complexity is reduced, but the current sensing accuracy deteriorates
Solution Approach 1:
The magnetic sensor is positioned at a specific optimal location between the two side portions where the magnetic flux is most concentrated. This precise positioning maximizes the magnetic flux received by the sensor, ensuring high sensing accuracy while keeping the overall structure simple and the device complexity low.
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 module provides accurate current measurement by increasing magnetic flux, stabilizing the magnetic field, and reducing external interference, while maintaining a compact size and reducing costs, thereby enhancing reliability and safety in applications such as vehicle systems.
Implementation Method 1
a magnetic sensor, wherein the magnetic sensor senses the current and generates a first current sensing signal correspondingly
Implementation Method 2
The frame is made of Permalloy with grain size between 350 μm and 600 μm. The current passes through a space between the two opposite surfaces to generate a magnetic flux
Data Source
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AI summary
A current sensing module (1, 1') for measuring a current includes a conductive substrate (10), a frame (12), a circuit board (14) and a magnetic sensor (16). The conductive substrate (10) has two terminals (100a, 100b) and at least one slot (102). The frame (12) has two side portions (120) and a bottom portion (122), wherein the bottom portion (122) connects the two side portions (120) to form an opening ring-shape. At least one of the two side portions (120) is disposed in the at least one slot (102), such that the two side portions (120) surround a partial path of the current. A gap exists between two ends of the two side portions (120). The circuit board (14) is disposed with respect to the conductive substrate (10). The magnetic sensor (16) is connected to the circuit board (14) and located in a space between the two side portions (120) rather than in the gap. The magnetic sensor (16) senses the current and generates a first current sensing signal correspondingly.