Distortion free arc welding voltage measurement
First Claim
1. An apparatus, comprising:
- a first feedback circuit configured to provide a head voltage of an arc welding apparatus to a power supply of the arc welding apparatus;
a first measurement wire coupled to a head of the arc welding apparatus and to a first input of the first feedback circuit to provide the head voltage and noise induced on the first measurement wire to the first feedback circuit; and
a first reference wire coupled to a first reference node of the arc welding apparatus and to a second input of the first feedback circuit to provide noise induced on the first reference wire to the feedback circuit, wherein the first reference node is proximate to and electrically isolated from the head of the arc welding apparatus, and wherein the first reference wire and the first measurement wire are arranged adjacent to one another along a path to the first feedback circuitry circuit such that the noise induced on the first reference wire is equal to noise induced on the first measurement wire;
wherein the first feedback circuit includes a transformer and a resistor and is configured to determine the head voltage as a difference between (i) a sum of the head voltage and the noise induced on the first measurement wire and (ii) the noise induced on the first reference wire.
1 Assignment
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Accused Products
Abstract
Methods and systems to reduce distortions induced in a voltage measurement wire. In an embodiment, a measurement wire is coupled to a head of an arc welding apparatus and to a feedback circuit to provide a head voltage and noise induced on the measurement wire to the feedback circuit. A reference wire is coupled to a reference node and to the feedback circuit to provide noise induced on the reference wire to the feedback circuit. The reference node may be proximate to and electrically isolated from the head, and the measurement wire and the reference wire may be arranged adjacent to one another (e.g., as a twisted pair), so that the similar distortions are induced in the measurement wire and the reference wire. The feedback circuit determines the head voltage as a difference between noise of the reference wire and the head voltage and noise of the first measurement wire.
0 Citations
17 Claims
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1. An apparatus, comprising:
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a first feedback circuit configured to provide a head voltage of an arc welding apparatus to a power supply of the arc welding apparatus; a first measurement wire coupled to a head of the arc welding apparatus and to a first input of the first feedback circuit to provide the head voltage and noise induced on the first measurement wire to the first feedback circuit; and a first reference wire coupled to a first reference node of the arc welding apparatus and to a second input of the first feedback circuit to provide noise induced on the first reference wire to the feedback circuit, wherein the first reference node is proximate to and electrically isolated from the head of the arc welding apparatus, and wherein the first reference wire and the first measurement wire are arranged adjacent to one another along a path to the first feedback circuitry circuit such that the noise induced on the first reference wire is equal to noise induced on the first measurement wire; wherein the first feedback circuit includes a transformer and a resistor and is configured to determine the head voltage as a difference between (i) a sum of the head voltage and the noise induced on the first measurement wire and (ii) the noise induced on the first reference wire. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An arc welding apparatus, comprising:
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an arc welding head; a boom to support the arc welding head; a column to support the boom; a power supply to provide a voltage between the arc welding head and a workpiece; a first feedback circuit configured to provide a head voltage to the power supply; a first measurement wire coupled to the arc welding head and to a first input of the first feedback circuit to provide the head voltage and noise induced on the first measurement wire to the first feedback circuit; and a first reference wire coupled to a first reference node of the arc welding apparatus and to a second input of the first feedback circuit to provide noise induced on the first reference wire to the feedback circuit first, wherein the first reference node is proximate to and electrically isolated from the arc welding head, and wherein the first reference wire and the first measurement wire are arranged adjacent to one another along a path to the first feedback circuit such that the noise induced on the first reference wire is equal to noise induced on the first measurement wire; wherein the first feedback circuit includes a transformer and a resistor and is configured to determine the head voltage as a difference between (i) a sum of the head voltage and the noise induced on the first measurement wire and (ii) the noise induced on the first reference wire. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A method for removing noise on a head voltage measurement wire, comprising:
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inverting noise induced on a reference wire to obtain an inverted noise signal, wherein the reference wire is coupled to a node proximate to and electrically isolated from a head of an arc welding apparatus, and wherein a path of the reference wire is adjacent to a path of a head voltage measurement wire of the arc welding apparatus such that the noise induced on the reference wire is equal to noise induced on the head voltage measurement wire; summing the inverted noise signal with a head voltage received over the head voltage measurement wire, and with the noise induced on the head voltage measurement wire, to generate a noiseless head voltage signal; and controlling a power supply of the arc welding apparatus based on the noiseless head voltage signal, wherein the inverting includes applying the noise induced on the reference wire to a primary winding of a transformer to induce the inverted noise signal at a node of a secondary winding of the transformer, and wherein a resistor is connected across the secondary winding of the transformer. - View Dependent Claims (16, 17)
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Specification