Pulse welder and method utilizing a plasma boost
AssigneeLincoln Global, Inc.
InventorsBruce E. Fulmer, James E. Hearn, Christopher Hsu, Steven R. Peters
Life of this patent
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Abstract
An electric arc welder includes a short detecting circuit for creating a short signal upon occurrence of a short circuit between an advancing electrode and a workpiece, and a boost circuit to create a plasma boost pulse after the short circuit is cleared during the time period when the welder is not outputting a peak pulse current.
Claims32
An electric arc welder for performing a pulse welding process between an advancing electrode and a workpiece at a voltage of between approximately 17-22 volts with a waveform including a welding current with a succession of pulses each pulse of said succession of pulses having a peak current and a background current, said electric arc welder comprising:
- a circuit to reduce said welding current during creation of a short circuit,
- a short detecting circuit creating a signal upon occurrence of said short circuit between said advancing electrode and said workpiece for initializing a short circuit clearing routine, said clearing routine comprising increasing a value of said welding current from an initial first value at a short circuit detection time to a higher second value at a short circuit clear time, and
- a boost circuit to create a plasma boost pulse immediately after creation of said short circuit clearing routine, said boost circuit continuously increasing said welding current from at least said higher second value at said short circuit clear time to a third higher value at an end of said boost circuit peak portion, and resulting in a gap between said advancing electrode and said workpiece, said electric arc welder further comprising:
- a first timer for starting said succession of pulses at a given time and
- a second timer for creating said plasma boost pulse at a given position between said succession of pulses.
The electric arc welder of 17, wherein
- a waveform profile of said plasma boost pulse is processed by said welder during said interrupt from said interrupt circuit.
The electric arc welder of 19, further comprising
- a circuit to sense a voltage of a welding arc during said plasma boost pulse and
- a circuit to adjust said background segment based upon said sensed arc voltage.
A method of pulse welding between an advancing electrode and a workpiece at a voltage of between 17-22 volts with a welding current including a succession of pulses each having a peak current and a background current, said method comprising:
- (a) reducing said welding current during creation of a short circuit;
- (b) creating a signal upon detecting a short circuit;
- (c) clearing said short circuit upon creation of said signal;
- said signal increasing a value of said welding current from an initial first value at detection of said short circuit to a higher second value at a short circuit clear time;
- and,
- (d) creating a plasma boost pulse immediately after said short circuit has been cleared, a boost circuit continuously increasing said welding current from at least said higher second value at said short circuit clear time to a third higher value at an end of said boost circuit peak portion, and results in a gap between said advancing electrode and said workpiece.
Dependencies are inferred from the claim text.