Welding Power Supply Output Conditioning for Open-Circuit Voltage Control

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Solution Overview

Problem

Power supplies struggle to maintain output levels within predefined limits, particularly when transitioning between connected and disconnected loads, which can lead to open circuit voltage conditions exceeding industrial standards.

Innovation Solution

A welding-type system with a controller that monitors voltage feedback signals to adjust the output of a switched mode power supply, ensuring compliance with industrial standards by pulsing the output signal and maintaining it within threshold limits, even during load changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the power supply provides continuous high voltage output, then the wire feeder can be reliably activated, but the open circuit voltage may exceed industrial standards when the load is disconnected

Engineering Contradiction:
Improvewire feeder activationVSAvoidopen circuit voltage exceeding standards
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The power supply output is converted from continuous to pulsed operation. The controller generates pulsed width modulated (PWM) signals that periodically switch the power supply on and off, maintaining the average voltage within industrial standards while providing sufficient peak voltage to activate the wire feeder during the on-periods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts the output characteristics based on load conditions. The controller monitors the circuit state and modifies the PWM duty cycle and frequency in real-time, transitioning between continuous output mode (when load is connected) and pulsed output mode (when load is disconnected) to maintain compliance with voltage standards.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If the power supply output is reduced to meet voltage standards, then open circuit voltage compliance is achieved, but the wire feeder may not receive sufficient power for reliable operation

Engineering Contradiction:
Improveopen circuit voltage complianceVSAvoidwire feeder operation
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

By using pulsed output with high peak voltage followed by zero-voltage intervals, the system maintains voltage compliance during the off-periods while delivering sufficient power during the on-periods to ensure reliable wire feeder activation and operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The controller changes the temporal parameters of the voltage output (duty cycle, frequency, peak voltage) rather than reducing the maximum voltage capability. This allows the power supply to maintain high voltage potential when needed while complying with standards during measurement intervals.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the power supply continuously monitors voltage feedback, then open circuit conditions are detected, but the system complexity increases

Engineering Contradiction:
Improveopen circuit detectionVSAvoidmonitoring system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system implements a feedback loop where the controller continuously monitors the output voltage and circuit current. Based on this feedback, the controller automatically detects open circuit conditions and adjusts the output mode accordingly, providing intelligent control without requiring complex external monitoring hardware.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4159351B1System for conditioning an output of a welding type power supply
Publication Date: 2025.12.17 ILLINOIS TOOL WORKS INC
  • EP4159351B1 patent drawingFigure 1
  • EP4159351B1 patent drawingFigure 2A
  • EP4159351B1 patent drawingFigure 2B

AI summary

A welding-type system comprising a wire feeder to provide an electrode wire to a welding-type torch and a welding-type power supply to provide power to one or both of the welding-type torch or the wire feeder. The welding-type power supply comprising a controller configured to: control a sense voltage circuit to provide a sense voltage to an output of the power supply for the wire feeder; monitor a voltage feedback signal associated with the sense voltage; determine whether the wire feeder is activated or deactivated based on a change in the voltage feedback signal; control a switched mode power supply of the power supply to provide a first power output to operate the wire feeder in response to a determination that the wire feeder is activated; control the switched mode power supply of the power supply to provide a second pulsed power output in response to a determination that the wire feeder is deactivated, the first pulsed power output being greater than the second pulsed power output; and control the sense voltage circuit to provide the sense voltage and continue to monitor the sense voltage signal in response to the determination that the wire feeder is deactivated.