Welding-type power supplies with adjustable AC current commutation thresholds

Patent metadata

Field	Value
Publication number	US-12263545-B2
Application number	US-201715670168-A
Country	US
Kind code	B2
Filing date	Aug 7, 2017
Priority date	Aug 16, 2016
Publication date	Apr 1, 2025
Grant date	Apr 1, 2025

Abstract

Welding-type power supplies with adjustable AC current commutation thresholds are disclosed. An example welding-type power supply includes an interface device to receive a commutation selection input, a power converter to convert input power to welding-type power, a commutator circuit to output alternating current (AC) welding-type power and to control a polarity of the AC welding-type power, and a control circuit. The control circuit determines a threshold output current based on the commutation selection input, determines an output current and a polarity of the AC welding-type power and, when the output current is less than the threshold output current, controls the commutator circuit to change the polarity of the AC welding-type power.

First claim

What is claimed is:

1. A welding-type power supply, comprising:
an interface device configured to receive a commutation current threshold selection input;
a power converter configured to convert input power to welding-type power;
a commutator circuit configured to output alternating current (AC) welding-type power and to control a polarity of the AC welding-type power; and
a control circuit configured to:
set a commutation current threshold based on the commutation current threshold selection input, wherein the commutation current threshold selection input comprises a selection of a percentage of a peak current amplitude, and the control circuit is configured to determine the commutation current threshold based on multiplying the commutation current threshold selection input by a positive peak current setpoint or a negative peak current setpoint;
determine an output current of the AC welding-type power and the polarity of the AC welding-type power; and
when the output current traverses the commutation current threshold, control the commutator circuit to change the polarity of the AC welding-type power.

2. The welding-type power supply as defined in claim 1 , wherein the control circuit is configured to set the commutation current threshold equal to a value received via the commutation current threshold selection input.

3. The welding-type power supply as defined in claim 1 , wherein the commutation current threshold is a same value for a positive current or a negative current with respect to a reference current.

4. The welding-type power supply as defined in claim 1 , wherein the commutation current threshold is a different value for a positive current or a negative current with respect to a reference current.

5. The welding-type power supply as defined in claim 1 , wherein the different arc characteristics comprise characteristics of a harder or softer arc.

Assignees

• Illinois Tool Works

Inventors

• Kadlec Mark S
• Henry Andrew Joseph

Classifications

• B23K9/0953

  using computing means · CPC title

• B23K9/092

  characterised by the shape of the pulses produced · CPC title

• B23K9/067

  Starting the arc · CPC title

• B23K9/1006

  Power supply · CPC title

• B23K9/0731 Primary

  Stabilising of the arc tension · CPC title