Vehicle Ethernet Cable Drain Wire Grounding for EMC
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Solution Overview
Problem
Existing data transmission systems in motor vehicles, such as Ethernet and BroadR-Reach, are complex and expensive due to the need for intricate shielding and connectors, which are not well-suited for the electromagnetic compatibility (EMC) demands of modern vehicle electrical systems.
Innovation Solution
A data transmission system with a cable having three cores and a stranded drain wire, where the drain wire contacts the shielding and provides ground, eliminating the need for complex braided shields and allowing for a cost-effective foil shield, and using a standard connector with a plastic housing to maintain mechanical stability without electrical functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If standard HSD cables with complex braided shields and intricate connectors are used, then electromagnetic compatibility (EMC) protection is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the essential grounding function from the complex braided shield structure and implements it through a simple drain wire that contacts the foil shield at discrete points. This removes unnecessary complexity while retaining the core EMC protection capability through proper grounding of the shield.
Solution Approach 2:
The patent employs a foil shield (thin film) instead of a complex braided shield structure. The foil shield is simpler to manufacture and integrate, and when combined with the drain wire grounding system, provides adequate EMC protection without the complexity of traditional braided shields.
2Object-affected harmful factors
If complex braided shields and intricate connectors are used, then shielding effectiveness is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive braided shield structures with a simpler foil shield construction combined with a drain wire. This cost-effective approach achieves the necessary shielding effectiveness for vehicle applications without the high manufacturing costs associated with complex braided shields and intricate connectors.
Solution Approach 2:
The use of a foil shield (thin film) instead of a complex braided shield significantly reduces manufacturing cost while maintaining adequate shielding effectiveness. The foil shield is easier and cheaper to produce, and the drain wire provides the necessary grounding function.
3Reliability
If a drain wire with larger diameter than core wires is used, then grounding effectiveness is improved, but connector balance and symmetry deteriorate
Solution Approach 1:
The patent intentionally uses an asymmetric drain wire design where the drain wire has a different diameter than the core wires. This asymmetry is acceptable because the drain wire serves a specific grounding function and does not need to match the core wire dimensions. The connector is designed to accommodate this asymmetry without compromising overall system performance.
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 solution simplifies the construction and assembly of data transmission systems, reduces costs, and maintains data transmission integrity and signal quality, while allowing for the use of existing connectors and assembly machinery.
Implementation Method 1
the drain wire making contact with the shielding at least in sections and being in contact with a wire connection contact of the plug
Data Source
Figure 1~3
Figure 4~5
Figure 6
AI summary
The invention relates to a vehicle electrical system component (20) for a data transmission system in a motor vehicle, in particular for an Ethernet transmission system, comprising a cable (1) having wires (2-4) and a plug (13) having wire connection contacts (16) for contacting the wires (2-4), wherein the wires (2-4) have an electrical insulation (7), wherein a common shielding (6) is arranged around the wires (2-4) which is enclosed by a common cable sheath (9), wherein the cable (1) has at least three wires (2-4) and an electrically conductive drain wire (5), wherein the drain wire (5) contacts the shielding (6) at least in sections and is contacted to a wire connection contact (16) of the plug (13).