Abstract: Apparatus, devices, and methods for providing a voltage reduction capability in a welding power source for safety purposes. The resistive load and the output voltage of the welding power source output are monitored and compared to predefined or preselected threshold values to generate a load condition signal and an output voltage condition signal (e.g., logic signals). The load condition signal and the output voltage condition signal serve as inputs to a voltage reduction device control logic which generates control signals to enable and disable the input and output of the welding power source according to the defined control logic. As a result, an extra measure of safety in preventing electrical shock is provided to users of the welding power source during hazardous operating conditions.

Abstract: A method and apparatus for welding is disclosed. The output is preferably a cyclical CV MIG output, and each cycle is divided into segments. An output parameter is sampled a plurality of times within one or more of the segments. The CV output is controlled within the at least one segment in response to the sampling. The parameter is output power, a resistance of the load, an output current, an output voltage, or functions thereof in various embodiments. The control loop is preferably a PI or PID loop. The loop may be applied only within a window. The set point may be taught or fixed. The system can be used to weld with a controlled arc length.

Abstract: A welding power supply including power conversion circuitry adapted to receive a primary source of power, to utilize one or more power semiconductor switches to chop the primary source of power, and to convert the chopped power to a welding output is provided. The provided welding power supply includes a pulse width modulated (PWM) digital controller including gate drive circuitry that generates a PWM output signal that controls the switching of the one or more power semiconductor switches. The PWM output signal includes a duty cycle term corrected for one or more sources of error in the welding system.

Abstract: A method and system to start and use a combination wire feed and energy source system for any of brazing, cladding, building up, filling, and hard-facing overlaying applications. High intensity energy is applied onto a workpiece to heat the workpiece. One or more resistive filler wires are fed toward the workpiece at or just in front of the applied high intensity energy. Sensing of when a distal end of the one or more resistive filler wires makes contact with the workpiece at or near the applied high intensity energy is accomplished. Electric heating current to the one or more resistive filler wires is controlled based on whether or not the distal end of the one or more resistive filler wires is in contact with the workpiece. The applied high intensity energy and the one or more resistive filler wires are moved in a same direction along the workpiece in a fixed relation to each other.

Abstract: A constant voltage (CV) welding process power supply including a controller that implements a variable minimum current is provided. The controller is configured to periodically compute a running current value during a welding operation. The controller is also configured to periodically compute a minimum current value based on a difference between the running current value and a preset offset value, wherein the preset offset value remains constant throughout the welding operation.

Abstract: A control method for an arc welding apparatus having a function of prohibiting detection of neck based on a change amount of welding voltage and an arc welding apparatus using the method. Thus, since neck determination can be carried out accurately by preventing wrong detection of neck, it is possible to reduce the occurrence of spatter.

Abstract: A welding system and method includes a main torch including a main electrode configured to form a first arc with a base metal; a first bypass torch including a first bypass electrode configured to form a second arc with the main electrode; and a second bypass torch including a second bypass electrode configured to form a third arc with the main electrode.

Abstract: Apparatus and method for controlling blanket gas flow in an electrical welding facility, wherein welding is performed using a welding electrode in electrical connection with a welding machine unit. The apparatus includes an electric measuring device having a current sensor for determining the magnitude of an electrical welding current carried in a circuit incorporating the welding electrode and having a current sensor output adapted to provide a I signal indicating the current magnitude, and a voltage sensor for determining the magnitude of electrical voltage applied to the welding electrode and having a voltage sensor output for providing a U signal indicating the voltage magnitude, and a control device having inputs connected to the current sensor output and the voltage sensor output, respectively, and a control signal output for providing a control signal to a blanket gas flow controller.

Abstract: A system and method of starting a welding operation is provided where an electrode is advanced towards a work piece in a pulsed fashion and having a voltage level which will provide a first current when contact between the electrode and the work piece is made. After contact the electrode is retracted so that a welding arc is established and after the welding arc is established the current and wire feed speed is increased to a welding level.

Abstract: If a short circuit does not occur during deceleration of a wire feed speed in forward feed of a welding wire before the wire feed speed reaches a predetermined wire feed speed, a cyclic change is stopped and the wire feed speed is constantly controlled at the first feed speed. If a short circuit occurs during forward feed at the first feed speed, deceleration from the first feed speed starts, and the cyclic change is resumed for welding. This achieves uniform weld bead without increasing spatters even if any external disturbance such as change of distance between a tip and base material occurs.

Abstract: A method and apparatus for short circuit welding includes providing welding power suitable for short circuit welding, sensing the stick out length, and adjusting the welding speed, such as wire feed speed or travel speed, adjusting a welding parameter, or adjusting the gas mixture in response thereto. Stick out is preferably determined by measuring a welding parameter, and performing an FFT on the parameter, and then calculating stick out, in one embodiment. Stick out can be either CTTWD or CPTPD. The system can determine when a short is about to clear by calculating a value Vc defined by Vc=d/dt(k1*dp/dt), and comparing Vc to a Vthreshold, which varies in response to welding cycle history.

Abstract: A method of automatically setting a welding parameter for MIG/MAG welding including the following steps:—initiating (S1) a parameter setting welding operation;—measuring (S12) a welding voltage and retrieving (S13) a parameter representing a wire feed speed during said parameter setting welding operation; and—identifying (S14) a second function mapping said welding current to said welding voltage from said measured welding voltage and said retrieved parameter.

Abstract: A welding power supply including power conversion circuitry adapted to receive a primary source of power, to utilize one or more power semiconductor switches to chop the primary source of power, and to convert the chopped power to a welding output is provided. The provided welding power supply includes a pulse width modulated (PWM) digital controller including gate drive circuitry that generates a PWM output signal that controls the switching of the one or more power semiconductor switches. The PWM output signal includes a duty cycle term corrected for one or more sources of error in the welding system.

Abstract: A electric welding machine having an auxiliary power output, and a method for controlling the auxiliary power output on a welding machine is provided. In one embodiment, the system includes a main transformer having a first secondary winding in circuit communication with a welder power output and a second secondary winding in circuit communication with an auxiliary power supply having an auxiliary power output. The auxiliary power supply includes an input for monitoring the welder power output to determine if the welder power output is on; circuitry for determining whether a surge or spike in demand is present at the auxiliary power output; and circuitry for limiting the available power to the auxiliary power output if certain conditions are satisfied.

Abstract: Various embodiments of a method for monitoring a machine condition are provided. An embodiment of the present invention provides a method of monitoring a machine condition, comprising the following steps: modeling a normal signal model performed by detecting a signal for monitoring condition of a normal machine and converting the detected signal to a normal signal model in time domain using a hidden Markov model (HMM) algorithm; calculating a probability value data of the monitoring signal at a subject machine performed by detecting a signal for monitoring condition of the subject machine in real-time and converting the detected signal to the probability value data relative to the normal state signal model using the HMM algorithm; and determining a section having deficiency where the probability value data of the monitoring signal at the subject machinery is not maintained constantly relative to the normal signal model.

Abstract: A capacitor discharge (CD) fastener welding circuit including: an input voltage source; a rectifier bridge of diodes receiving the input voltage source; at least two capacitor charge switches linked with the rectifier bridge; at least one capacitor linked with the at least two capacitor charge switches; and at least two capacitor discharge switches linked with the capacitor and to welding output terminals.

Abstract: Methods and apparatus to characterize a welding output circuit path. A welding output circuit path is characterized in real time with respect to at least one of a true energy and true power input to the welding output circuit path.

Abstract: The invention relates to a welding method for implementing and monitoring a welding process, whereby a power source (2) and a feeding device (10) for the welding rod (11) are controlled by means of a control device (4), and whereby at least one control variable is measured or calculated from characteristic variables of the arc during the welding process.

Abstract: A method for determination of electrical variables of a welding circuit which is connected to an electrical power supply device and operable to provide either a welding current or a lesser pilot current, the method including the steps of (a) determining the resistance of the welding circuit and (b) determining the inductance of the welding circuit.

Abstract: A control method for AC pulse arc welding performed upon application of cyclic AC welding current is provided. The welding current has a cycle including an electrode negative polarity period and an electrode positive polarity period subsequent to the electrode negative polarity period. In the control method, an electrode negative polarity base current and a subsequent electrode negative polarity peak current are applied during the electrode negative polarity period. The electrode negative polarity base current has an absolute value smaller than a first critical value, and the electrode negative polarity peak current has an absolute value greater than the first critical value. Then, an electrode positive polarity peak current is applied during the electrode positive polarity period. The electrode positive polarity peak current has a value greater than a second critical value.

Abstract: An electric arc welder includes a short detecting circuit for creating a short signal upon occurrence of a short circuit between an advancing electrode and a workpiece, and a boost circuit to create a plasma boost pulse after the short circuit is cleared during the time period when the welder is not outputting a peak pulse current.

Abstract: A welding control apparatus includes an integrator for starting calculation of a voltage error integral value Sv2 when a first pulse period ends and a second pulse period starts in a pulse cycle, based on various data. The apparatus also includes a comparator for comparatively determining whether a value of the voltage error integral value Sv2 provided as the calculation result has become 0, and a waveform generator for terminating the relevant pulse cycle and starting a next pulse cycle when the value of the voltage error integral value Sv2 is 0. Where Sv2=?{Ks(Io2?Is2)+Vs2?Vo2}dt??(1).

Abstract: An electric arc device and methods to build up, clad, join, or overlay an alloyed metal onto a parent metal with minimal admixture. The methods employed in the electric arc device provide a high frequency waveform with a high amplitude pulse, a low amplitude background current, and a special shorting routine, to alleviate the problem of generating too much ad-mixture. A fast transition from a peak current level to a background current level along with a shorting response and a plasma boost pulse reduces the droplet size and reduces the heat input required to achieve good welding performance.

Abstract: If arc interruption occurs during AC arc welding, a first AC frequency predetermined for normal welding is switched to a second AC frequency higher than the first AC frequency. This allows the arc to be reignited without applying a high frequency high voltage, thereby preventing the damage of the surface of the weld bead or communication failure due to the high frequency high voltage.

Abstract: An arc welding method relates to consumable electrode arc welding in which a welding wire feeding rate suitable for a welding current is determined as an average feeding rate, and the short circuit state and the arc generation state are alternately generated by changing the wire feeding periodically and repeatedly between the forward feeding and the reverse feeding. The method offers arc welding with the average feeding rate according to a welding current, a predetermined frequency, and a predetermined velocity amplitude. In the method, at least any one of the frequency and the velocity amplitude is set to a value suitable for the welding current.

Abstract: A method of testing a fusion weld for a shaft includes producing two shaft subsections, wherein the shaft subsections are symmetrical and faun a cylinder coaxially along the axis of rotation. Core regions of each shaft subsection are removed in order to produce open recesses in the cylinder within remaining tubular webs. The two shaft subsections are positioned coaxially one on top of the other, wherein the two remaining webs are mutually adjacent and the two open recesses form a hollow space. A first tubular ring seam is produced by narrow-gap arc welding and in one of the two shaft subsections a passage from outside into the hollow space is produced. Further, a quality of the first tubular ring seam within the hollow space during and/or after the welding operation is evaluated by a detection device or radiation source which is introduced through the passage into the hollow space.

Abstract: A welding system including a welding power source including power conversion circuitry adapted to receive primary power and to convert the primary power to a weld power output for use in a welding operation and a controller communicatively coupled to the welding power source are provided. The controller is adapted to determine a statistical signature of at least one parameter of a welding process and to utilize the statistical signature to determine at least one of an electrode type, an electrode diameter, and a shielding gas type during the welding operation.

Abstract: A control method for an arc welding apparatus having a function of prohibiting detection of neck based on a change amount of welding voltage and an arc welding apparatus using the method. Thus, since neck determination can be carried out accurately by preventing wrong detection of neck, it is possible to reduce the occurrence of spatter.

Abstract: A electric welding machine having an auxiliary power output, and a method for controlling the auxiliary power output on a welding machine is provided. In one embodiment, the system includes a main transformer having a first secondary winding in circuit communication with a welder power output and a second secondary winding in circuit communication with an auxiliary power supply having an auxiliary power output. The auxiliary power supply includes an input for monitoring the welder power output to determine if the welder power output is on; circuitry for determining whether a surge or spike in demand is present at the auxiliary power output; and circuitry for limiting the available power to the auxiliary power output if certain conditions are satisfied.

Abstract: A weld data acquisition system collects data from the weld controller according to user selected collection parameters. The weld data acquisition system is able to transmit the data at high frequency to a weld data software utility that provides a user interface.

Abstract: A control method for an arc welding apparatus having a function of prohibiting detection of neck based on a change amount of welding voltage and an arc welding apparatus using the method. Thus, since neck determination can be carried out accurately by preventing wrong detection of neck, it is possible to reduce the occurrence of spatter.

Abstract: Methods and systems for clearing short circuits during a MIG welding process are disclosed. A method may include detecting a short circuit and increasing output current of a power source at a first ramp rate to clear the short circuit. The method further includes increasing output current at a second ramp rate after the output current reaches a threshold. Power sources and systems implementing the method are also provided.

Abstract: Methods and apparatus to characterize a welding output circuit path. A welding output circuit path is characterized in real time with respect to a true energy and/or true power input to the welding output circuit path. A welding output circuit path is also characterized with respect to an inductance of the welding output circuit path. A welding output circuit path is further characterized with respect to a welding output waveform.

Abstract: A method monitors a weld signature of a welding apparatus by processing the signature through a neural network to recognize a pattern, and by classifying the weld signature in response to the pattern. The method determines if the weld signature is sufficiently different from training weld signatures stored in a database, and records the weld signature in the database when sufficiently different. The method tests a weld joint to determine values of different weld joint properties, and then correlates the signature with the weld data to validate the database. An apparatus monitors a weld signature during a welding process to predict welding joint quality, and includes a welding gun, a power supply, and a sensor for detecting welding voltage, current, and wire feed speed (WFS). A neural network receives the welding process values and classifies the signature into different weld classifications each corresponding to a predicted welding joint quality.

Abstract: A method controls a welding apparatus by using a neural network to recognize an acceptable weld signature. The neural network recognizes a pattern presented by the instantaneous weld signature, and modifies the instantaneous weld signature when the pattern is not acceptable. The method measures a welding voltage, current, and wire feed speed (WFS), and trains the neural network using the instantaneous weld signature when the instantaneous weld signature is different from each of the different training weld signatures. A welding apparatus for controlling a welding process includes a welding gun, a power supply for supplying a welding voltage and current, and a sensor for detecting values of a plurality of different welding process variables. A controller of the apparatus has a neural network for receiving the welding process variables and for recognizing a pattern in the weld signature. The controller modifies the weld signature when the pattern is not recognized.

Abstract: A system, in one embodiment, may include a portable welder having a welding output, a charging output, a welding circuit coupled to the welding output; and a charging circuit coupled to the charging output. The charging circuit may be configured to automatically adjust power to the charging output based on a feedback associated with charging a battery.

Abstract: A consumable electrode arc-welding machine comprising an arc resistance calculating part that calculates an arc resistance from a welding current and a welding voltage to develop an arc resistance signal, wherein the welding current and welding voltage are controlled by a short-circuit waveform control signal and an arc waveform control signal that vary in accordance with the arc resistance signal. In this way, the spatter control and the arc stability can be achieved. During an arc period, if the arc resistance signal exhibits a level greater than a predetermined level for a predetermined period, a constant current control signal is developed to perform a constant current control of the welding current by use of a predetermined current value that is higher than the current value developed during the development of the arc waveform control signal, thereby preventing the arc from going off.

Abstract: Provided is a switching power supply unit which uses a multilayer board or a stack of planar conductors as the windings of transformers so as to reduce the volume of the transformers and to have high efficiency, small size and small noise. The switching power supply unit is formed by connecting a plurality of capacitors (23), (24), (25) and (26) connected in series with each other to input terminals (22a) and (22b) of a plurality of switching power supplies having switching elements (27), (28), (29) and (30), transformers (31) and (32), and rectifiers (33), (34), (37) and (38). The switching power supply unit inputs the voltages of capacitors (23)-(26), and outputs the respective voltages developed by the plurality of switching power supplies together to common output terminals (40a) and (40b). The transformers (31) and (32) are each composed of windings made up of a stack of planar conductor coils.

Abstract: A method and apparatus for providing welding-type power includes an input circuit, a switched circuit connected to the input circuit, and an output circuit connected to the switched circuit. A controller controls the system output in response to a setpoint and an output feedback signal. A first gain is used to control the output at start up, and a second gain is used to control the output during steady-state welding. The first gain is greater than the second gain.

Abstract: Systems and methods are provided for pulse welding, in which a welding signal is provided to an electrode in series of pulse welding cycles, where the amount of energy applied to the electrode in each cycle is determined and a pulse is provided to initiate a transfer condition of each cycle based at least partially on the energy applied in the cycle.

Abstract: An operating system is provided for an electric arc welder including a high switching speed inverter power source for creating an arc voltage and arc current between an electrode and a workpiece. This operating system regulating the arc voltage to provide a voltage with a slope by using an error circuit to create an error output and having a first input with a signal representing the set voltage and a second input representing the sum of the actual arc voltage and the actual arc current multiplied by a slope constant. A DSP program reduces the error output by adjusting the voltage output of the inverter power source to change the actual arc voltage. The slope constant is in the range of 0–10%.

Abstract: An electric arc welder operated to perform a short circuit welding process between an electrode and a workpiece, where the process comprises a succession of alternate short circuit conditions and arc conditions, with a first current waveform during the short circuit condition and a second voltage waveform during the arc condition. A first waveform generator constructs the first waveform from a series of current pulses controlled by a pulse wave modulator operated at a rate greater than 18 kHz and a second waveform generator constructs the second waveform from a series of current pulses controlled by a pulse wave modulator operated at a rate greater than 18 kHz. The second waveform generator has a circuit to generate the second waveform with a generally constant arc parameter, generally voltage.

Abstract: A power supply connectable to a source of AC line voltage for AC electric arc welding by an AC arc current across a welding gap between an electrode and a workpiece, the power supply comprises a high capacity transformer that converts said line voltage to an AC output voltage, and a rectifier that converts the AC output voltage to a DC voltage between a positive terminal and a common terminal at generally zero volts and a negative terminal and the common terminal. The power supply has a first switch that connects the positive terminal to the common terminal across the gap when a gate signal is applied to the first switch, a second switch for connecting the negative terminal to the common terminal across the gap when a gate signal is applied to the second switch and a pulse width modulator operated for generating pulses at a frequency of at least about 18 kHz.

Abstract: The present invention relates to an arc welding method in which generation of spatters can be suppressed while the use quantity of gas to be supplied to a welding portion can be decreased. A welding wire 8 is brought into contact with a work W while applying a voltage between the welding wire 8 and the work W, so that the end of the welding wire 8 is caused to be fixingly welded to the work W. At this time, an electric resistance between the welding wire 8 and the work W is continuously obtained during the contact between the welding wire 8 and the work W, and thus, a minimum of the electric resistance is detected. When the current is temporarily reduced after the detection of the minimum of the electric resistance, the tip of the welding wire 8 hardly bursts, thus suppressing the expelling of molten particles, which may cause spatters, from the welding wire 8. The minimum value is also used for the torch-to-workpiece distance control.

Abstract: An apparatus for brazing a connecting piece of electrically conducting material such as metal, to a metal surface by means of a new type of temperature-controlled brazing whereby for certain types of material a brazing is obtained that is free of martensite formation underneath the brazed joint in, for example, railway track and/or pipework. The apparatus has an electrode and processing circuitry by which a voltage applied in electrical circuit with the electrode causes an electric arc to be struck between the electrode and an adjacent workpiece to generate the heat necessary for brazing.

Abstract: A power supply connectable to a source of AC line voltage for AC electric arc welding by an AC arc current across a welding gap between an electrode and a workpiece, the power supply comprises a high capacity transformer that converts said line voltage to an AC output voltage, and a rectifier that converts the AC output voltage to a DC voltage between a positive terminal and a common terminal at generally zero volts and a negative terminal and the common terminal. The power supply has a first switch that connects the positive terminal to the common terminal across the gap when a gate signal is applied to the first switch, a second switch for connecting the negative terminal to the common terminal across the gap when a gate signal is applied to the second switch and a pulse width modulator operated for generating pulses at a frequency of at least about 18 kHz.

Abstract: The invention relates a method for gas-shielded metal-arc welding during the re-strike during the welding process. It is object of the invention to provide a gas-shielded metal-arc welding method to permit as low an energy intake as possible in the short-circuit phase for the arc welding. According to the invention, this object is solved by a method, characterized in that at the beginning of a short-circuit, a control is activated and remains active for the duration of the short-circuit, which increases an energy intake (phase A) when a characteristic threshold value S1 is fallen short of, and terminates the energy intake when a threshold value S2 is reached, and than lowers the energy intake (phase B).

Abstract: An arc welding apparatus (10) for performing a waveform-controlled arc welding process includes an arc welding torch (14) that interacts with an associated weld. A power supply (12) applies a selected waveform-controlled power to the welding load via the arc welding torch (14) and a grounding cable over a process interval (Tweld). The power supply (12) includes a sampling circuit (34) for sampling instantaneous current and voltage values of the power during a snip portion (Tsnip) of the process interval (Tweld). A processor (40) is designed to (i) compute a true heat over the snip portion (Tsnip) of the process interval (Tweld), and (ii) extrapolate a true heat over the process interval (Tweld) based thereon.

Abstract: A stud welder utilizing a frequency inverter which is capable of delivering in access of 1000 A for a short duration of about 1 second using double-sided cooled power semiconductors. The inverter can deliver constant power to the stud circuit or the arc, sense the progress of the stud process, and stop the process if the forecast for an acceptable stud will not be achieved, and detected sufficiently early that the current has not created a stud that can not be removed and repeated. The stud welder also has a circuit capable of delivering a high voltage pulse capable of penetrating paint covering the base metal, and thereby enabling better stud welding to painted material. The stud welder and method also monitor the ending energy delivered and adjust it to the energy required. The stud welder further has a battery or capacitor storage device to reduce the fuse size used by storing the energy needed when a stud is formed by charging the storage device when no power is needed.

Abstract: An apparatus and process for determining whether a fault has occurred in a welding process while the process is under way. The invention is applicable to welding and cutting processes where there is an arc plasma, such as gas-metal arc welding, tungsten-inert gas welding, pulsed welding, resistance welding and submerged welding. It involves sampling welding voltage and welding current to provide first and second signals, generating artificial third signals from these dependent on values of the first and second signals through generalised discrete point convolution operations, identifying corresponding values as triplets and collecting triplets of values into groups or regions.