US 9,308,598 B2 · Systems and methods for efficient provision of arc welding power source

Abstract

Methods and systems for creating and controlling an AC output for welding, plasma cutting or heating are provided. One embodiment of the present disclosure achieves a desired square wave AC output and reduces the number of circuit components needed by combining components of a buck converter and a full bridge inverter. Current flow paths through a power control circuit that are generated via switching of transistors in the circuit on and off are provided. In one embodiment, a pulse width modulation leg, which controls the level of current flow through an inductor, is provided. Certain embodiments include a bidirectional buck converter that converts an unregulated DC flow to a regulated DC flow through an inductor. In one embodiment, a steering leg is provided, which controls a direction of current flow through the inductor. Additionally, an output clamp circuit, which suppresses the parasitic load inductance during polarity reversal is provided.

Claims10

Dependent claims

A welding or cutting system, comprising:

a circuit, comprising:
an input leg comprising a capacitor and a diode arranged in series;
a pulse width modulation leg arranged in parallel with the input leg, wherein the pulse width modulation leg is configured to convert DC voltage from the capacitor to current in an inductor of the pulse width modulation leg, and wherein the pulse width modulation leg is configured to function as a bidirectional buck converter;
a steering leg arranged in parallel with the input leg, wherein the steering leg is configured to determine a direction of current flow through the inductor and an output, the output arranged between the pulse width modulation leg and the steering leg;
and
an output clamp leg arranged in parallel with the input leg, wherein the output clamp leg is configured to suppress inductance of the circuit during reversal of current flow through the output.

3 more elements

A method of controlling current flow through an output load of a welding circuit, comprising:

pulse width modulating voltage from a primary capacitor and a blocking diode by switching one of a pair of modulation transistors to provide a level of current through an inductor and an output of the welding circuit, wherein the pair of modulation transistors are arranged in series relative to one another along a pulse width modulation leg, and the inductor extends from between the pair of modulation transistors to the output of the welding circuit;
controlling a direction of current through the inductor and the output of the welding circuit by switching a first of a pair of steering transistors to an on configuration such that the current passes through the first of the pair of steering transistors in the on configuration and returns to the primary capacitor;
and
suppressing inductance of the welding circuit during reversal of current flow through an output of the welding circuit.

1 more element

Dependencies are inferred from the claim text.

Systems and methods for efficient provision of arc welding power source

Life of this patent

Systems and methods for efficient provision of arc welding power source

Life of this patent

Abstract

Claims10