Back to results
US RE29,441 EGranted
Direct current power supply for manual arc welding
AssigneeElektriska Svetsningsaktiebolaget
InventorRolf Ericsson
Life of this patent
Estimating the term…
Abstract
A direct current power supply for manual arc welding having a steeply drooping, adjustable characteristic, comprising a polyphase transformer and a polyphase rectifier system including triggered rectifier means and a control system therefor providing both welding current and welding voltage feed-back. The welding current feed-back is substantially fixed. The welding voltage feed-back is adjustable for adjustment of the slope of the characteristic.
Claims3
A direct current power supply for manual arc welding having a steeply drooping, adjustable volt-ampere characteristic comprising
- a polyphase transformer having a plurality of secondary output leads carrying mutually phase displaced voltages, a polyphase rectifier system connecting said secondary output leads to a pair of D.C. welding current conductors, said rectifier system comprising a set of triggered rectifier valves connected one in series with each of said secondary output leads, said triggered rectifier valves having each a trigger terminal for initiating current flow through the valve,
- means for periodically supplying igniting pulses to each of said trigger terminals, including means for causing the angular position of said pulses to vary in response to a direct current control signal, and,
- means for producing said direct current control signal comprising the following means, to wit,
- a. means for producing an adjustable direct current reference signal,
- b. means including a welding current sensing means for producing a welding current feed-back direct current signal bearing a substantially fixed proportion to the welding current carried by the pair of welding current conductors,
- c. means including a welding voltage sensing means for producing a welding voltage feed-back direct current signal proportional to the welding voltage between said welding current conductors,
- d. summing means for combining said reference signal, said welding current feed-back signal and said welding voltage feed-back signal into a compound signal constituting the control signal aforementioned, both of said feed-back signals being supplied to said summing means in opposing relationship to said reference signal, said means for producing a welding voltage feed-back signal including means for adjustment of the slope of the volt-ampere characteristic of the power supply through adjustment of the ratio of said welding voltage feed-back signal to the welding voltage independently of the ratio of the welding current feed-back signal to the welding current.
4 more elements
A direct power supply having a steeply drooping volt-ampere characteristic for manual arc welding comprising
- a polyphase transformer having a plurality of secondary output leads carrying mutually phase displaced voltages, a polyphase rectifier system connecting said secondary output leads to a pair of D. C. welding current conductors, said rectifier system comprising a set of triggered rectifier valves connected one in series with each of said secondary output leads, said triggered rectifier valves having each a trigger terminal for initiating current flow through the valve,
- means for periodically supplying igniting pulses to each of said trigger terminals, including means for causing the angular position of said pulses to vary in response to a direct current control signal, and, means for producing said direct current control signal comprising the following means, to wit,
- a. means for producing an adjustable direct current reference signal,
- b. means including a welding current sensing means for producing a welding current feed-back direct current signal bearing a substantially fixed proportion to the welding current carried by the pair of welding current conductors,
- c. means including a welding voltage sensing means for producing a welding voltage feed-back direct current signal proportional to the welding voltage between said pair of welding current conductors,
- d. summing means for combining said reference signal, said welding current feed-back signal and said welding voltage feed-back signal into a compound signal constituting the control signal aforementioned, both of said feed-back signals acting in opposition to said reference signal in said summing means,
- said means for producing a welding current feed-back signal, said summing means, said means for controlling the firing angle of the triggered rectifier valves and said rectifier system constituting a welding current feed-back loop arranged to provide a welding current feed-back factor not less than 1.5 volts per ampere, and
- said means for producing a welding voltage feed-back signal including means for adjustment of the ratio of said welding voltage feed-back signal to the welding voltage independently of the ratio of the welding current feed-back signal to the welding current to provide a selected, steep slope of the volt-ampere characteristic of the power supply.
5 more elements
Dependencies are inferred from the claim text.