Device and method for starting electric arc of a welder
AssigneeThe Lincoln Electric Company
InventorElliott K. Stava
Life of this patent
Estimating the term…
Abstract
A method and apparatus for starting the electric arc of a welder by applying a high frequency, high voltage starting signal across the spark gap between the electrode and workpiece of the welder. This device and method comprises a series resonant circuit having a capacitive reactance element and an inductive reactance element combining to establish a resonant frequency for the series circuit, electrical drive means for energizing the series circuit at a driving frequency near a harmonic of the resonant frequency and means for converting the voltage developed across at least a portion of a designated one of the elements, generally the inductive reactance, into the starting signal.
Claims50
A device for starting the electric arc of a welder including an arc gap between an electrode and a workpiece, said device comprising a series resonant circuit including an inductor, a portion of which is a transformer primary winding, and a capacitor, said series circuit having a given resonant frequency;
- electrical means for driving said series circuit with an electrical signal pulsating at a driving frequency near only one of the harmonics of said resonant frequency;
- a transformer with a secondary winding and means for coupling said secondary winding to said primary winding;
- and, means for applying the voltage developed across said secondary winding across said arc gap.
A device for starting the electric arc of a welder by applying a high frequency, high voltage starting signal across the arc gap between an electrode and the workpiece, said device comprising a series resonant circuit having a capacitive reactance element and inductive reactance element combining to establish a resonant frequency for said series circuit;
- electrical driving means for energizing said series circuit at a driving frequency near only one the harmonics of said resonant frequency;
- and, means for converting the voltage developed across at least a portion of a designated one of said elements into said starting signal.
A method of starting the electric arc of a welder including an arc gap between an electrode and a workpiece, said method comprising the steps of:
- (a) providing a series resonant circuit including an inductor, a portion of which is a transformer primary winding, and a capacitor, said series circuit having a given resonant frequency;
- (b) driving said series circuit with an electrical signal pulsating at a driving frequency near only one of the harmonics of said resonant frequency;
- (c) providing a transformer with a secondary winding;
- (d) coupling said secondary winding to said primary winding;
- and,
- (e) applying the voltage developed across said secondary winding across said arc gap.
A method of starting the electric arc of a welder by applying a high frequency, high voltage starting signal across the arc gap between an electrode and the workpiece, said method comprising the steps of:
- (a) providing a series resonant circuit having a capacitive reactance element and inductive reactance element combining to establish a resonant frequency for said series circuit;
- (b) energizing said series circuit at a driving frequency near only said resonant frequency;
- and,
- (c) converting the voltage developed across at least a portion of a designated one of said elements into said starting signal.
A device for starting the electric arc of a welder by applying a high frequency, high voltage starting signal across the arc gap between an electrode and the workpiece, said device comprising a resonant circuit having a capacitive reactance element and an inductive reactance element combining to establish a resonant frequency for said resonant circuit;
- electrical driving means for energizing said resonant circuit at a driving frequency near only said resonant frequency;
- and, means for converting the voltage developed across at least a portion of a designated one of said elements into said starting signal.
Dependencies are inferred from the claim text.