Galvanically Isolated Welding Data Line for HF Ignition Decoupling

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Solution Overview

Problem

In welding processes, high-frequency (HF) ignition energy often leaks through electrical paths other than the intended welding electrode, reducing the energy available for arc ignition and posing safety concerns due to limited permissible HF ignition energy.

Innovation Solution

The implementation of a galvanic separation of the data line, including the shielding, to prevent HF leakage paths and reduce the flow of HF ignition energy, along with separate power supplies for coupling members to ensure no HF energy flows through the power supply, effectively decouples HF voltage from the data line without using blocking throttles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If blocking chokes are used in welding cables to prevent HF ignition energy leakage, then HF energy is directed to the welding electrode, but the chokes also undesirably attenuate or block high-frequency signals

Engineering Contradiction:
ImproveHF ignition energy leakageVSAvoidhigh-frequency signal transmission
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent introduces an intermediary device (HF decoupling device with capacitors and diodes) that selectively blocks HF ignition energy while allowing data signals to pass through the data line, resolving the contradiction between preventing energy leakage and maintaining signal transmission

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the electrical paths by providing separate power supplies for the welding torch and control electronics, with the HF decoupling device creating distinct zones: one for HF ignition energy containment and another for clean data signal transmission

Inventive Principle:
Principle #1Segmentation

2Reliability

If the HF ignition voltage is increased to compensate for energy losses, then arc ignition reliability improves, but safety limits defined by standards are exceeded

Engineering Contradiction:
Improvearc ignition reliabilityVSAvoidexcessive HF ignition energy
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the potentially harmful HF ignition energy that would leak through the data line into a beneficial effect by using the HF decoupling device to contain and direct it exclusively to the welding electrode, thereby improving ignition reliability without exceeding safety limits

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The HF decoupling device provides preliminary anti-action by preemptively blocking HF ignition energy from entering the data line and control electronics, preventing energy losses before they occur and ensuring all HF energy reaches the welding electrode within safe limits

Inventive Principle:
Principle #9Preliminary anti-action

3Device complexity

If shared power supplies are used for welding torch and control electronics, then device complexity is reduced, but HF ignition energy can flow through the power supply to the control electronics

Engineering Contradiction:
Improvepower supply configurationVSAvoidHF energy flow to control electronics
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces separate power supplies as intermediary components that electrically isolate the control electronics from the HF ignition energy path, eliminating the harmful effect while maintaining reasonable system complexity through modular design

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach effectively reduces HF ignition energy drainage via unintended paths, ensuring more energy is directed to arc ignition, while maintaining stable data communication and avoiding the limitations and impracticalities of using blocking throttles.

Implementation Method 1

The implementation of a galvanic separation of the data line, including the shielding, to prevent HF leakage paths and reduce the flow of HF ignition energy

Methodology Applied
Scientific EffectGalvanic separation: Electrical Resistance

Implementation Method 2

a high-frequency, high-voltage current is applied to the electrode to ionize the gas space between the electrode and the workpiece surface, making it electrically conductive

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 3

it is already known to install a blocking choke in the welding cable between the power section of a welding machine and the high-frequency generator for producing the RF ignition voltage

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4301537B1Welding apparatus with a decoupling device for hf voltage on a data line
Publication Date: 2025.04.02 FRONIUS INT GMBH
  • EP4301537B1 patent drawingFigure 1
  • EP4301537B1 patent drawingFigure 2~3
  • EP4301537B1 patent drawingFigure 4

AI summary

The aim of the invention is to reduce the draining of HF ignition energy via a data line (20) for data transmission between a welding device (2) and another part of a welding assembly (1). The aim is achieved in that a decoupling apparatus (35) is provided, in which a first data line portion (20a) of the data line (20) is connected to a first coupling element (21a) and a second data line portion (20b) of the data line (20) is connected to a second coupling element (21b), wherein the first coupling element (21a) and the second coupling element (21b) are interconnected via a wireless coupling section (23) for galvanic isolation of the data line (20), and a separate power supply (22a, 22b) is provided for each of the first coupling element (21a) and the second coupling element (21b), and wherein the power supplies (22a, 22b) of the first coupling element (21a) and the second coupling element (21b) are decoupled from one another for a HF voltage on the data line (20) as a result of the HF ignition voltage (uz).