Plug-in Connector With Soldered Litz Wire for High-Frequency Current

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Solution Overview

Problem

Existing connector systems are inadequate for simplifying cable laying in high-frequency, high-current applications as they either cater to low-current technology or low-frequency operations, leading to inefficiencies and limitations in medium-frequency energy transmission.

Innovation Solution

A connector system comprising a metallic contact part with a soldered connection to HF litz wire, allowing for reliable electrical contact and efficient transmission of medium-frequency currents, along with a feed device that enables contactless energy transmission using a primary conductor with HF stranded wire, reducing skin effect and enabling high current intensities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional connectors are used for high-frequency applications, then low-current technology or low-frequency operations are supported, but medium-frequency energy transmission with high current intensities cannot be achieved

Engineering Contradiction:
Improvefrequency rangeVSAvoidcurrent transmission capability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the electrical parameters of the connector system by using Litz wire instead of conventional solid conductors. This parameter change enables the connector to handle medium-frequency currents (10-100 kHz) with high current intensities (up to 100A) by reducing the skin effect, which is significant at these frequencies. The Litz wire construction with multiple insulated strands allows for better current distribution and reduced AC resistance.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If HF stranded wire is used for medium-frequency current transmission, then skin effect is reduced, but reliable electrical contact and connection stability become challenging

Engineering Contradiction:
Improveskin effectVSAvoidelectrical contact reliability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent employs a composite connection structure combining Litz wire (multiple insulated strands) with a metallic contact part. The Litz wire maintains low AC resistance through its stranded construction, while the metallic contact part provides stable mechanical and electrical contact. The insulating body integrates these components, creating a composite connector that simultaneously achieves low energy loss and high reliability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The connector is segmented into distinct functional parts: the Litz wire for current transmission with reduced skin effect, the metallic contact part for reliable electrical contact, and the insulating body for structural integrity and isolation. This segmentation allows each component to optimize its specific function while working together as a unified system.

Inventive Principle:
Principle #1Segmentation

3Reliability

If soldered connection is used to connect contact part to HF litz wire, then reliable electrical contact is achieved, but manufacturing complexity increases

Engineering Contradiction:
Improveelectrical contactVSAvoidconnector assembly
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the connection functions into an integrated assembly process where the Litz wire is inserted into a recess of the contact part and soldered in place. The insulating body is designed to hold all components in their correct positions during assembly. This merging of connection and positioning functions into a single integrated structure simplifies the overall manufacturing process despite the soldering step.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of operation

If connector system is designed for tight plug connection with high degree of protection, then decentralized installation is enabled, but device complexity increases

Engineering Contradiction:
Improveinstallation flexibilityVSAvoidconnector structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The connector system is designed with universal features that serve multiple functions: the insulating body provides both structural support and protection, the metallic contact part ensures both electrical connection and mechanical stability, and the recess design facilitates both alignment and sealing. This multi-functionality reduces the need for additional specialized components, thereby limiting complexity growth despite enhanced protection features.

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

The solution facilitates efficient, reliable, and easy-to-manufacture plug connections for high-frequency, high-current applications, reducing thermal stress and enabling decentralized installation with minimal losses, thus simplifying cable laying and enhancing system performance.

Implementation Method 1

the first contact part at its first axial end area is cohesively connected to stranded wires of an HF stranded wire, in particular by means of a soldered connection

Methodology Applied
Scientific EffectSoldering: Soldering

Implementation Method 2

the primary conductor to be plugged in in a contactless energy transmission system that operates at medium frequency, even though the primary conductor is made of HF stranded wire

Methodology Applied
Scientific EffectSkin effect: Skin Effect

Data Source

PatentEP1949497B1Plug-in connector system and feed-in device
Publication Date: 2012.06.20 SEW EURODRIVE GMBH & CO KG
  • EP1949497B1 patent drawingFigure 1
  • EP1949497B1 patent drawingFigure 2
  • EP1949497B1 patent drawingFigure 3a~3b

AI summary

Plug-in connector system and feed-in device, in particular for a system operating at a mid-frequency for contactless energy transmission, comprising a plug-in connector part and a mating plug-in connector part, wherein the plug-in connector part comprises a metallic contact part, which has a soldered joint with RF braided wire at its first axial end region, and is connected in an insulating body.