Power source for electric arc welding

• US 9,751,150 B2
• Filed: 08/10/2012
• Issued: 09/05/2017
• Est. Priority Date: 07/13/2004
• Status: Active Grant

• Current Assignee: Lincoln Global Incorporated (Lincoln Electric Holdings Incorporated)
• Original Assignee: Lincoln Global Incorporated (Lincoln Electric Holdings Incorporated)
• Inventors: Daniel, Joseph A., Kooken, Todd E., Luo, Lifeng
• Primary Examiner(s): PAIK, SANG YEOP
• Application Number:
  US13/572,354
• Publication Number:
  US 20120305535A1
• Time in Patent Office: 1,852 Days
• Field of Search: 2191301, 21913051, 219137 PS, 21913021
• CPC Class Codes: B23K 9/09 Arrangements or circuits for arc welding with pulsed current or voltage
• CPC Class Codes: B23K 9/1006 Power supply

Abstract

A power source for an electric arc welding process, wherein the power source comprises an input stage having an AC input and a first DC output signal; a second stage in the form of an unregulated DC to DC converter having an input connected to the first DC output signal and an output in the form of a second DC output signal electrically isolated from the first DC output signal and with a magnitude of a given ratio to the first DC output signal; and, a third stage to convert the second DC output signal to a welding output for the welding process.

Claims

1. A power source comprising:

an input rectifier for receipt of an AC input signal to output a rectified DC signal;

a power factor correcting converter connected to said input rectifier to convert said rectified DC signal to a first fixed DC voltage signal having a first magnitude to define a first DC bus;

DC to DC inverter connected to said first DC bus to convert said first fixed DC signal to a second fixed DC voltage signal having a second magnitude to define a second DC bus, where said second magnitude is lower than said first magnitude; and

a regulated output converter coupled to said second DC bus to convert said second fixed DC signal to an output signal for a welding process, said output converter being regulated by a feedback signal from said welding process.

2. The power source of claim 1, wherein the DC to DC inverter is unregulated so as to not to be adjusted by a real time signal from said welding process.

3. The power source of claim 1, wherein the input rectifier and power factor correcting converter define a preregulator, the power source comprising a first controller coupled to the preregulator and a first power supply converter coupled to the first DC bus and first controller to define a first feedback switching network and control circuit.

4. The power source of claim 1, wherein the power source comprises a second controller coupled to the output converter and a second power supply converter coupled to the output signal and second controller to define a second feedback switching network and control circuit.

5. The power source of claim 1, wherein said power factor correcting converter is one of:

buck converter, a boost converter, a buck+boost converter.

6. The power source of claim 1, wherein said DC to DC inverter comprises:

a network of switches to convert said first fixed DC voltage signal to a first AC signal;

an isolation transformer with a primary winding and a secondary winding for transforming said first AC signal into a second internal AC signal different than said first AC signal; and

a rectifier and capacitor to convert said second internal AC signal into said second fixed DC voltage signal.

7. The power source of claim 1, wherein said regulated output converter is a chopper.