Shunt Resistor Terminal Layout for Temperature-Accurate Current Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current detection apparatuses using shunt resistors face accuracy issues due to temperature fluctuations, as the resistance value of the shunt resistor changes with temperature, affecting the accuracy of current measurement.
Innovation Solution
A shunt resistor design with specific voltage detection terminals positioned to have different temperature coefficients of resistance, combined with a current detector that corrects or calculates the current using a correction coefficient or formula to minimize the temperature effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a shunt resistor is used for current detection, then current measurement is enabled, but measurement accuracy deteriorates due to temperature-induced resistance changes
Solution Approach 1:
The shunt resistor is divided into multiple resistance elements (first resistance element, second resistance element, third resistance element) with different temperature coefficients of resistance. Each element is positioned at different locations on the shunt resistor body, allowing the system to segment the temperature compensation function across multiple components with distinct characteristics.
Solution Approach 2:
Different resistance elements are assigned different temperature coefficients of resistance based on their local positions. The first resistance element has a first temperature coefficient, the second has a second temperature coefficient, and the third has a third temperature coefficient. This local differentiation allows each element to contribute differently to temperature compensation, improving overall measurement accuracy under varying temperature conditions.
2Stability of the object's composition
If alloy materials like Manganin are used to reduce TCR, then temperature stability improves, but material cost and manufacturing complexity increase
Solution Approach 1:
The shunt resistor employs a composite structure consisting of multiple resistance elements made from different materials or with different properties. By combining resistance elements with different temperature coefficients of resistance, the system achieves temperature compensation without relying on a single expensive alloy material, thereby reducing manufacturing complexity and cost while maintaining resistance stability.
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
Accurately determines the current flowing through the shunt resistor by minimizing the impact of temperature changes, ensuring high measurement accuracy across a wide range of currents.
Implementation Method 1
The current detection board detects the current by measuring a voltage drop at a voltage measurement position of the shunt resistor
Implementation Method 2
the resistance value of the shunt resistor changes depending on the temperature. In other words, even if the current flowing through the shunt resistor is constant, the detected voltage can change depending on the temperature
Data Source
AI summary
The present invention relates to a shunt resistor and a current detection apparatus. A current detector (2) includes voltage detection terminals (8A, 8B) provided at first characteristic positions of the electrodes (6, 7) where a temperature coefficient of resistance of a shunt resistor (1) has a first coefficient, and voltage detection terminals (8C, 8D) provided at second characteristic positions of the electrodes (6, 7) where a temperature coefficient of resistance of the shunt resistor (1) has a second coefficient. The first coefficient and the second coefficient have different numerical values.