Shunt Resistor Slit Structure for Accurate Current Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shunt resistors face challenges in accurately determining current values due to interference from resistance values of current and coupling regions, leading to power loss and weak mechanical strength, while also being difficult to downsize.
Innovation Solution
A shunt resistor design with conductors separated by insulating resin-filled slits, ensuring accurate resistance values between voltage regions and mechanical strength without increasing size, achieved by open ends of slits on inner conductor faces and strategic slit placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the slit extends from the outer end face toward the inner end face and terminates midway, then the conductor is separated into current and voltage regions, but the resistance value between voltage regions is affected by current region and coupling region resistance making accurate current detection difficult
Solution Approach 1:
The conductor is divided into current regions and voltage regions by slits that extend from the outer end face to the inner end face, completely separating the current path from the voltage detection path. This segmentation eliminates the coupling region that causes measurement errors, allowing the voltage difference between voltage regions to accurately reflect only the resistance of the resistive element.
Solution Approach 2:
The harmful coupling region is eliminated by extending the slits to the inner end face where they connect to the resistive element. This extraction removes the source of measurement error (the coupling region resistance) from the measurement path, ensuring that only the resistive element's resistance contributes to the voltage difference used for current detection.
2Device complexity
If the slit is open on the outer end face with free ends, then the conductor structure is simplified, but the mechanical strength against external stress becomes weak
Solution Approach 1:
The slits are designed to terminate at the inner end face rather than extending beyond it, providing a natural stop that prevents stress concentration at free ends. The connection of slit ends to the resistive element provides structural support, cushioning against external stress before it can cause damage to the conductor structure.
3Reliability
If the slit has a certain degree of width to prevent current passage, then electrical insulation between current and voltage regions is achieved, but downsizing becomes difficult
Solution Approach 1:
An insulating layer is introduced as an intermediary substance filling the slits to prevent current passage between current and voltage regions. This allows the slits to be made very narrow (improving downsizing) while still achieving reliable electrical insulation through the insulating material that lines the slit walls.
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 design ensures precise resistance measurement and improved mechanical strength by isolating current and voltage regions, reducing power loss and enabling efficient manufacturing.
Implementation Method 1
a first insulating resin filling the first slit; a second insulating resin filling the second slit
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3
AI summary
In a shunt resistor of the present invention, a first slit (40(1)-40D(1); 70(1): 80(1)) filled with a first in□sulating resin (50(1)) separates a first conductor (20(1)) into a first current region (30(1)) and a first voltage region (35(1)), and a second slit (40(2)-40D(2); 70(2); 80(2)) filled with a second insulating resin (50(2)) separates a second conductor (20(2)) into a second current region (30(2)) and a second voltage region (35(2)). The first slit (40(1)-40D(1); 70(1); 80(1)) has a first end (41(1); 71(1); 81(1)) open on an inner end face (21(1)), which is joined to a first joint face (11(1)) of a resistive element (10), so that the first current region (30(1)) and the first voltage region (35(1)) both have a region joined to the first joint face (11(1)), and the second slit (40(2)-40D(2); 70(2); 80(2)) has a first end (41(2); 71(2); 81(2)) open on an inner end face (21(2)), which is joined to a second joint face (11(2)) of the resistive element (10), so that the sec□ond current region (30(2)) and the second voltage region (35(2)) both have a region joined to the second joint face (11(2)).