# US 2018/0021872 A1 · Welding power supplies having adjustable current ramping rates > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0021872 A1 - Document ID: US20180021872A1 - Status: Published application - Kind: A1 - Application number: 15/582,972 - Filed: 2017-05-01 - Published: 2018-01-25 - Earliest claimed: 2016-07-22 - Assignees: Illinois Tool Works Inc. - Applicants: Illinois Tool Works Inc. - Inventors: Alan F. Smith; Cody J. Bowman - Web page: https://patentgrep.com/patent/US20180021872A1 ## CPC - B23K 9/0956: {using sensing means, e.g. optical} - B23K 9/0732: {Stabilising of the arc current} - B23K 9/0953: {using computing means} - B23K 9/1006: {Power supply} - B23K 9/1043: {characterised by the electric circuit (B23K9/1012 takes precedence)} - B23K 9/1062: {with computing means} - H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters - H02M 1/0003: {Details of control, feedback or regulation circuits} - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract Welding power supplies having adjustable current ramping rates are disclosed. An example welding power supply, comprising: a switched mode power supply to convert primary power to welding-type power having an output current based on a current control loop; a voltage sensing circuit to measure a weld voltage; a voltage comparator to determine whether the weld voltage corresponds to a welding arc condition or a short circuit condition; and a control circuit to: select a current ramping rate; and execute the current control loop to control the output current, the control circuit configured to, while the weld voltage corresponds to the short circuit condition, increase the output current at the current ramping rate. ## Claims ### Claim 1 A welding power supply, comprising: a switched mode power supply to convert primary power to welding-type power having an output current based on a current control loop; a voltage sensing circuit to measure a weld voltage; a voltage comparator to determine whether the weld voltage corresponds to a welding arc condition or a short circuit condition; and a control circuit to: select a current ramping rate; and execute the current control loop to control the output current, the control circuit configured to, while the weld voltage corresponds to the short circuit condition, increase the output current at the current ramping rate. ### Claim 2 (depends on 1) The welding power supply as defined in claim 1, further comprising a user input device to receive a current ramping rate input, the control circuit configured to select the current ramping rate based on the current ramping rate input. ### Claim 3 (depends on 2) The welding power supply as defined in claim 2, further comprising a second user input device to receive an output current setpoint, the control circuit configured to, when the weld voltage corresponds to a welding arc, control the output current based on the output current setpoint. ### Claim 4 (depends on 2) The welding power supply as defined in claim 2, wherein a ratio of a maximum value of the current ramping rate input and a minimum value of the current ramping rate input is between 5:1 and 500:1. ### Claim 5 (depends on 1) The welding power supply as defined in claim 1, wherein the control circuit is configured to control the switched mode power supply to increase the output current at the current ramping rate to an upper current limit of the switched mode power supply while the weld voltage corresponds to the short circuit condition. ### Claim 6 (depends on 5) The welding power supply as defined in claim 5, further comprising receiving a value of the upper current limit via an input device. ### Claim 7 (depends on 1) The welding power supply as defined in claim 1, wherein the voltage sensing circuit is configured to measure the weld voltage at an output of the welding power supply. ### Claim 8 (depends on 1) The welding power supply as defined in claim 1, wherein the control circuit is configured to execute the current control loop by, in response to determining that the weld voltage corresponds to the short circuit condition: calculating a voltage error based on a difference between a reference voltage and the weld voltage; multiplying the voltage error by a value proportional to the current ramping rate to determine a current adjustment; scaling the current adjustment to determine a scaled current adjustment; integrating the scaled current adjustment into a prior value of the scaled current adjustment to determine an updated scaled current adjustment; and adding the updated scaled current adjustment to a commanded output current to determine the output current. ### Claim 9 (depends on 1) The welding power supply as defined in claim 1, wherein the control circuit is configured to increase the output current by iteratively adding current to the output current at each execution of the current control loop. ### Claim 10 (depends on 9) The welding power supply as defined in claim 9, wherein the current ramping rate is linear, and the control circuit is configured to add a same amount of current to the output current at each execution of the current control loop. ### Claim 11 (depends on 9) The welding power supply as defined in claim 9, wherein the current ramping rate is non-linear, and the control circuit is configured to add a variable amount of current to the output current at each execution of the current control loop based on at least one of the output current, a time duration of the short circuit condition, a current ramping rate input, or the weld voltage. ### Claim 12 (depends on 1) The welding power supply as defined in claim 1, wherein the control circuit is configured to increase the output current at the current ramping rate when the weld voltage corresponds to the short circuit condition for at least a threshold time period. ### Claim 13 (depends on 1) The welding power supply as defined in claim 1, wherein the current ramping rate is between 4 amps per millisecond and 40 amps per millisecond. ### Claim 14 (depends on 1) The welding power supply as defined in claim 1, wherein the current ramping rate is between 1 amp per millisecond and 500 amps per millisecond. ### Claim 15 (depends on 1) The welding power supply as defined in claim 1, wherein the control circuit is configured to identify welding data corresponding to at least one of the output current, the weld voltage, a weld parameter input to the control circuit, an electrode size, or an electrode type, the control circuit being configured to select the current ramping rate based on the welding data. ### Claim 16 (depends on 1) The welding power supply as defined in claim 1, wherein the control circuit is configured to store weld data corresponding to a welding operation, the control circuit being configured to select the current ramping rate based on a prior welding operation. ### Claim 17 (depends on 17) The welding power supply as defined in claim 17, wherein the control circuit is configured to select the current ramping rate based on determining a short circuit rate from the weld data. ### Claim 18 (depends on 1) The welding power supply as defined in claim 1, wherein the voltage comparator determines that the weld voltage corresponds to the short circuit condition when the weld voltage is less than a threshold voltage. ### Claim 19 A non-transitory machine readable medium comprising machine readable instructions which, when executed by a processor, cause the processor to: execute a current control loop to control a switched mode power supply to convert primary power to welding-type power having an output current; determine whether a measured weld voltage corresponds to a welding arc condition or a short circuit condition; select a current ramping rate; execute the current control loop to control the output current; and in response to determining that the measured weld voltage corresponds to the short circuit condition, increase the output current at the current ramping rate. ### Claim 20 (depends on 19) The machine readable medium as defined in claim 19, wherein the instructions cause the processor to access a current ramping rate input received from a user input device.