Shape Memory Fuse Element for Thermal Fault Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrical devices with safety devices, such as fuses and pyrotechnic systems, are limited in detecting non-electrical faults and require manual reset after a fault, with pyrotechnic devices being disposable and only addressing short circuits and earth faults.

Innovation Solution

Incorporating a shape memory material fuse element that bridges or short-circuits electrical conductors in error-free operation, assuming a fault-detecting shape only when a predetermined temperature is exceeded, such as in a fire, to prevent further damage and allow for reproducible operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional fuses or FI switches are used as safety devices, then electrical faults such as short circuits and earth faults can be detected, but manual reset is required after fault elimination and only electrical faults are detected

Engineering Contradiction:
Improvefault detection capabilityVSAvoidmanual reset requirement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The safety device automatically detects faults and interrupts the electrical conductor without requiring manual intervention. The shape memory material fuse element self-actuates by changing its shape in response to temperature increase, thereby opening the circuit automatically when a fault is detected.

Inventive Principle:
Principle #25Self-service

2Reliability

If pyrotechnic safety devices are used to separate power supply in accident cases, then sparks that could cause further damage are avoided, but the device must be completely replaced after triggering and cannot be reused

Engineering Contradiction:
Improvesafety function in accidentVSAvoiddisposable nature
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

Instead of being completely discarded after use like pyrotechnic devices, the shape memory material fuse element can recover its original shape after deformation through heating. This allows the safety device to be reset and reused, eliminating the need for complete replacement after triggering.

Inventive Principle:
Principle #34Discarding and recovering

3Extent of automation

If a shape memory material fuse element is used to bridge an interrupted electrical conductor, then the conductor is restored in fault-free operation and automatically interrupted when temperature exceeds a predetermined value, but the device complexity increases compared to traditional fuses

Engineering Contradiction:
Improveautomatic fault responseVSAvoidshape memory material integration
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The fuse element utilizes temperature as a critical parameter to trigger its shape change. When the temperature exceeds a predetermined value indicative of a fault, the shape memory material undergoes a phase transformation that changes its shape, thereby automatically opening the electrical circuit without requiring additional sensing or control components.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If existing safety devices are used, then electrical faults are detected, but other fault cases such as fire or intense heat exposure cannot be taken into account

Engineering Contradiction:
Improveelectrical fault detectionVSAvoiddetection of non-electrical faults
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The shape memory material fuse element serves multiple functions: it acts as both the electrical conductor bridge in normal operation and the fault detection sensor. By responding to temperature changes regardless of their source (electrical fault, fire, or intense heat exposure), the device achieves multi-functional safety coverage for both electrical and non-electrical faults.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Effectively detects and prevents damage from temperature-related faults, such as fires, by interrupting current or signal transmission only when necessary, and allows for automatic fault detection and prevention without manual intervention.

Implementation Method 1

the interruption is performed in the event of a fault that the electrically conductive and consisting of a shape memory material fuse element assumes its originally trained shape

Methodology Applied
Scientific EffectShape memory effect: Shape Memory Alloy

Data Source

PatentEP2705573B1Different variants of an electrical appliance with a safety device
Publication Date: 2016.08.24 HIRSCHMANN AUTOMOTIVE GMBH
  • EP2705573B1 patent drawingFigure 1~2

AI summary

The invention relates to, inter alia, an electrical appliance with a safety device, wherein the appliance has at least one electric conductor (1), wherein the invention provides that the electrical conductor (1) is interrupted and the interruption is bridged, during fault-free operation of the appliance, by a fuse element (3), wherein, in the event of a fault, the interruption is produced by virtue of the fact that the electrically conductive fuse element (3), which consists of a shape memory material, assumes its originally trained shape.