Welding type power supply for TIG starts
AssigneeIllinois Tool Works Inc.
InventorsQuinn W. Schartner, Bernard J. Vogel, Andrew D. Nelson
Life of this patent
Estimating the term…
Abstract
A method and apparatus for TIG welding and starting a TIG welding process includes limiting the pulse width of a power circuit when a TIG start is being performed, and monitoring for the creation of a welding arc. After the welding arc has been detected the limiting of the pulse width is ended.
Claims18
A welding type power supply, comprising a switched power circuit disposed to receive input power and to provide welding type power to a welding output, and a control input, and further comprising a controller, wherein the controller comprises:
- a control output connected to the control input such that the switched power circuit is responsive to the control output;
- feedback input, connected to receive feedback indicative of the presence or absence of an arc;
- a pwm module connected to the control output and configured to control a pulse width of the switched power circuit based on calculating the pulse width for a target welding output, wherein a smaller pulse width controls the switched power circuit to reduce the welding output;
- a pulse width limiting module configured to:
- activate in response to feedback indicative of the absence of an arc at a start of a welding operation;
- while activated, limit a pulse width output by the pwm module to less than the pulse width calculated for the presence of an arc;
- and
- deactivate after establishment of the arc to permit the pwm module to control the pulse width of the switched power circuit based on the pulse width calculated for the presence of an arc.
A welding type power supply, comprising a switched power circuit disposed to receive input power and to provide welding type power to a welding output, and a control input, and further comprising a controller, wherein the controller comprises:
- a control output connected to the control input;
- feedback input, connected to receive feedback indicative of the absence of an arc;
- a pwm module comprising circuitry configured to control a pulse width of the switched power circuit and via the control output based on calculating the pulse width for a target welding output, wherein a smaller pulse width controls the switched power circuit to reduce the welding output;
- a pulse width limiting module comprising circuitry configured to:
- activate in response to the feedback indicative of the absence of the arc at a start of a welding operation;
- while activated, limit the pulse width of the switched power circuit via the pwm module responsive to the feedback input;
- and
- deactivate after establishment of the arc to permit the pwm module to control the pulse width of the switched power circuit based on the pulse width calculated for the presence of an arc.
Dependencies are inferred from the claim text.