Fuse Element Segmentation for High Overcurrent Response
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior art fuses exhibit unsatisfactory operation times at high overcurrent values, with melting times remaining constant and not decreasing as overcurrent values increase, failing to ensure low melting times across a range of current values.
Innovation Solution
A fuse design featuring two electric contacts and a fuse element with a first section of minimum width and a second section connected in series, where the second section has a narrowed part with a width ranging from 20% to 50% of the first section, ensuring shorter operation times at high overcurrents by allowing the second fuse to melt instead of the first.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a conventional fuse element design is used, then the melting time remains within ISO limits at low overcurrent values (1.35-6 times rated current), but the melting time becomes asymptotic and does not decrease at high overcurrent values (8-10 times rated current)
Solution Approach 1:
The fuse element is divided into two distinct sections: a first section with a minimum width and a second section with a narrowed width (20-50% of the first section). This segmentation allows each section to serve different functions - the first section handles low overcurrent values while the second section is designed to melt at high overcurrent values, eliminating the asymptotic behavior and ensuring continuously decreasing melting times across all overcurrent ranges.
Solution Approach 2:
Different portions of the fuse element are given different cross-sectional dimensions to optimize performance at different current levels. The narrowed second section (20-50% width of the first section) creates a localized weak point that melts preferentially at high overcurrents, while the first section maintains appropriate dimensions for low overcurrent protection. This local quality variation resolves the contradiction between meeting ISO standards at low currents and achieving fast response at high currents.
2Ease of manufacture
If the fuse element has uniform cross-section, then the manufacturing is simple, but the melting time does not continuously decrease at high overcurrent values
Solution Approach 1:
The fuse element is segmented into two sections with different cross-sectional dimensions. The first section has a minimum width while the second section has a narrowed width (20-50% of the first section). This segmentation can be implemented through conventional manufacturing techniques such as rolling or drawing processes that can create width variations along the length of the element, maintaining ease of manufacture while achieving the desired non-uniform geometry for improved high overcurrent response.
Solution Approach 2:
The cross-sectional dimension parameter of the fuse element is changed along its length, creating a narrowed second section. This parameter change allows the fuse to exhibit different melting characteristics at different current levels. The narrowed section reduces the melting time at high overcurrents while the first section ensures proper operation at low overcurrents, resolving the contradiction between manufacturing simplicity and performance optimization.
3Device complexity
If a single fuse section is used, then the device complexity is low, but the operation time cannot be optimized for both low and high overcurrent values
Solution Approach 1:
The fuse element is divided into two sections with different cross-sectional dimensions - a first section with minimum width and a second narrowed section (20-50% of the first section width). This segmentation enables the fuse to optimize operation times at both low and high overcurrent values. The additional complexity is minimal and can be achieved through simple manufacturing processes, making it a practical solution that significantly improves performance across the full current range.
Solution Approach 2:
The fuse element incorporates local quality variations through the narrowed second section, which creates a preferential melting point at high overcurrents. This local modification allows the fuse to achieve continuously decreasing melting times across all overcurrent values while maintaining overall structural simplicity. The local quality change is sufficient to resolve the performance contradiction without requiring complex multi-component designs.
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 maintains appropriate melting times at low overcurrents and significantly reduces operation times at high overcurrents, addressing the asymptotic behavior of prior fuses by ensuring continuously decreasing melting times as overcurrent values increase.
Implementation Method 1
When one of the electric contacts receives a current value exceeding a preset fusing current threshold, the fuse element melts and stops power supply to the power consuming unit connected to the other electric contact, thereby protecting it from current peaks.
Data Source
AI summary
A fuse comprises two electric contacts with a contact width, a fuse element disposed between two opposed fuse ends and comprising a first fuse having a minimum-section part with a first width and a first section. The fuse element further comprises at least one second fuse disposed between the first fuse and one of said two fuse ends. The second fuse comprises a narrowed part with a second width smaller than the first width and the contact width and with a second section ranging from 20% to 50% of the first section.