Current-Sensing Resistor Incisions for Temperature Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional current measuring resistors in motor vehicle electrical systems face challenges in temperature stability due to the higher temperature coefficient of copper connection parts compared to the resistance material, affecting the accuracy of voltage drop measurements.
Innovation Solution
Incorporating transverse incisions in the copper connection parts of the current measuring resistor to reduce temperature dependence, ensuring equipotential lines reach the resistance element's edges, thus isolating the voltage measurement from the conductor material's influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper connection parts are used in the current measuring resistor, then electrical conductivity is improved, but temperature coefficient increases affecting measurement accuracy
Solution Approach 1:
The connection parts are segmented by introducing incisions that divide the copper plates into separate regions. This segmentation creates distinct current flow paths and voltage measurement paths, isolating the voltage measurement from the temperature-sensitive copper material's influence while maintaining good electrical conductivity for current flow.
Solution Approach 2:
Different regions of the connection parts are given different functional qualities through the incisions. The areas near the incisions are designed to carry current while the areas away from incisions serve as voltage measurement points. This local differentiation ensures that voltage measurements are taken from regions less affected by copper's temperature coefficient.
2Reliability
If incisions are made in connection parts, then temperature dependence is reduced, but structural integrity may be compromised
Solution Approach 1:
The incisions are designed to extend only partially through the connection parts, not completely separating them. This partial action is sufficient to create the desired current and voltage path separation for temperature compensation while maintaining the structural integrity and mechanical strength of the connection parts.
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 design significantly reduces the temperature coefficient of the entire current measuring resistor by up to 60%, enhancing the accuracy and stability of current measurements.
Implementation Method 1
the current to be measured being conducted through the resistance element via the plate-shaped connection parts
Implementation Method 2
According to Ohm's law, the voltage drop across the resistance element is then a measure of the electrical current to be measured
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5B
AI summary
The invention relates to a current-sensing resistor (1) for measuring an electric current, in particular also for measuring a battery current in a vehicle power supply, having a plate-shaped first connecting part (3) for introducing the electrical current to be measured, wherein the plate-shaped first connecting part (3) consists of an electrically conductive conductor material; a plate-shaped second connecting part (2) for conducting away the electrical current to be measured, wherein the plate-shaped second connecting part (2) consists of an electrically conductive conductor material; and a plate-shaped resistance element (4), which is connected in the current path between the two connecting parts and through which the electrical current to be measured flows, wherein the resistance element (4) consists of a comparatively high-impedance resistance material. According to the invention an incision (10, 11) is arranged in the plate-shaped first connecting part (3) and/or in the plate-shaped second connecting part (2) in order to reduce the temperature dependency of the measurement and to eliminate the influence of the plate-shaped connecting parts (usually copper or aluminium).