Modular power source for electric ARC welding and output chopper

Patent metadata

Field	Value
Publication number	US-9956639-B2
Application number	US-5119605-A
Country	US
Kind code	B2
Filing date	Feb 7, 2005
Priority date	Feb 7, 2005
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A three stage power source for an electric arc welding process comprising 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, a network of switches switched at a high frequency with a given duty cycle to convert the input into a first internal AC signal, an isolation transformer with a primary winding driven by the first internal high frequency AC signal and a secondary winding for creating a second internal high frequency AC signal and a rectifier to convert the second internal AC signal into a second DC output signal of the second stage; with a magnitude related to the duty cycle of the switches and, a third stage to convert the second DC output signal to a welding output for welding wherein the input stage and the second stage are assembled into a first module and the third stage is assembled into a second module connectable to the first module.

First claim

Having thus defined the invention, the following is claimed:

1. A power source for an electric arc welding process, said power source comprising:
a first module including:
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, unregulated by a feedback signal from the electric arc welding process, having an input configured to receive said first DC output signal, a controller configured to operate a network of switches at a frequency greater than 18 kHz with a duty cycle to convert said received first DC output signal into a first internal AC signal, an isolation transformer with a primary winding driven by said first internal AC signal and a secondary winding for creating a second internal AC signal, and a rectifier to convert said second internal AC signal into a second DC output signal of said second stage, with a magnitude related to said duty cycle of said switches; and
a second module including a third stage to convert said second DC output signal to a welding output for welding in said process, said input stage and said second stage being assembled into said first module and said third stage being assembled into said second module so as to be releasably connectable to said first module.

2. The power source as defined in claim 1 wherein said input stage includes a rectifier and a power factor correcting converter.

3. The power source as defined in claim 2 wherein said power factor correcting converter is a boost converter.

4. The power source as defined in claim 2 wherein said power factor converter is a buck converter.

5. The power source as defined in claim 4 wherein said third stage of said second module is a chopper with a power switch operated at a given frequency.

6. The power source as defined in claim 5 wherein said power switch has a soft switching circuit.

7. The power source as defined in claim 6 wherein said soft switching circuit is passive.

8. The power source as defined in claim 5 wherein said chopper is a dual mode chopper with a first polarity path with a first power switch and a first polarity switch and a second polarity path with a second power switch and a second polarity switch.

9. The power source as defined in claim 8 including a second controller with a first mode alternately operating said chopper between said first and second polarity paths and a second mode operating said chopper in only one of said polarity paths.

10. The power source as defined in claim 9 wherein said first and second polarity switches each have a soft switching circuit.

11. The power source as defined in claim 10 wherein said soft switching circuits are passive.

12. The power source as defined in claim 8 wherein said first and second power switches each have a soft switching circuit.

13. The power source as defined in claim 12 wherein said soft switching circuits are passive.

14. The power source as defined in claim 3 wherein said third stage of said second module is a chopper with a power switch operated at a given frequency.

15. The power source as defined in claim 14 wherein said power switch has a soft switching circuit.

16. The power source as defined in claim 15 wherein said soft switching circuit is passive.

17. The power source as defined in claim 14 wherein said chopper is a dual mode chopper with a first polarity path with a first modulating switch and a first polarity switch and a second polarity path with a second modulating switch and a second polarity switch.

18. The power source as defined in claim 17 including a second controller with a first mode alternately operating said chopper between said first and second polarity paths and a second mode operating said chopper in only one of said polarity paths.

19. The power source as defined in claim 18 wherein said first and second modulating switches each have a soft switching circuit.

20. The power source as defined in claim 19 wherein said soft switching circuits are passive.

21. The power source as defined in claim 17 wherein said first and second modulating switches each have a soft switching circuit.

22. The power source as defined in claim 21 wherein said soft switching circuits are passive.

23. The power source as defined in claim 2 wherein said third stage of said second module is a chopper with a power switch operated at a given frequency.

24. The power source as defined in claim 23 wherein said power switch has a soft switching circuit.

25. The power source as defined in claim 24 wherein said soft switching circuit is passive.

26. The power source as defined in claim 23 wherein said chopper is a dual mode chopper with a first polarity path with a first modulating switch and a first polarity switch and a second polarity path with a second modulating switch and a second polarity switch.

27. The power source as defined in claim 26 including a controller with a first mode alternately operating said chopper between said first and second polarity paths and a second mode operating said chopper in only one of said polarity paths.

28. The power source as defined in claim 27 wherein said first and second polarity switches each have a soft switching circuit.

29. The power source as defined in claim 28 wherein said soft switching circuits are passive.

30. The power source as defined in claim 26 wherein said first and second modulating switches each have a soft switching circuit.

31. The power source as defined in claim 30 wherein said soft switching circuits are passive.

32. The power source as defined in claim 1 wherein said third stage of said second module is a chopper with a power switch operated at a given frequency.

33. The power source as defined in claim 32 wherein said power switch has a soft switching circuit.

34. The power source as defined in claim 33 wherein said soft switching circuit is passive.

35. The power source as defined in claim 32 wherein said chopper is a dual mode chopper with a first polarity path with a first modulating switch and a first polarity switch and a second polarity path with a second modulating switch and a second polarity switch.

36. The power source as defined in claim 35 including a second controller with a first mode alternately operating said chopper between said first and second polarity paths and a second mode operating said chopper in only one of said polarity paths.

37. The power source as defined in claim 36 wherein said first and second polarity switches each have a soft switching circuit.

38. The power source as defined in claim 37 wherein said soft switching circuits are passive.

39. The power source as defined in claim 35 wherein said first and second modulating switches each have a soft switching circuit.

40. The power source as defined in claim 39 wherein said soft switching circuits are passive.

41. The power source as defined in claim 1 wherein said third stage of said second module is a circuit with a power switch to perform an STT welding process.

42. The power source as defined in claim 41 wherein said power switch has a soft switching circuit.

Assignees

• Kooken Todd E
• Luo Lifeng
• Lincoln Global Inc

Inventors

• Kooken Todd E
• Luo Lifeng

Classifications

• B23K9/1043

  characterised by the electric circuit (B23K9/1012 takes precedence) · CPC title

• B23K9/09

  Arrangements or circuits for arc welding with pulsed current or voltage · CPC title

• B23K9/1075

  Parallel power supply, i.e. multiple power supplies or multiple inverters supplying a single arc or welding current · CPC title

• B23K9/173 Primary

  and of a consumable electrode · CPC title

• H02M1/4225

  using a non-isolated boost converter · CPC title