Patent Description:
Welding is a process that has increasingly become ubiquitous in all industries. Welding is, at its core, simply a way of bonding two pieces of metal. A wide range of welding systems and welding control regimes have been implemented for various purposes. In continuous welding operations, metal inert gas (MIG) welding and submerged arc welding (SAW) techniques allow for formation of a continuing weld bead by feeding welding electrode wire shielded by inert gas from a welding torch and/or by flux. Such wire feeding systems are available for other welding systems, such as tungsten inert gas (TIG) welding. Electrical power is applied to the welding wire and a circuit is completed through the workpiece to sustain a welding arc that melts the electrode wire and the workpiece to form the desired weld.

Prior patent document <CIT> (describing the preamble of claim <NUM>) discloses an example of an AC TIG welding apparatus using a hot wire. In the apparatus, an unconsumable electrode is arranged in opposedly spaced relationship with a base metal to be welded. An AC arc welding power supply is connected between the base metal and the unconsumable electrode. A filler wire is fed toward an arc-generated part between the base metal and the unconsumable electrode. The apparatus comprises a wire-heating power supply for producing a pulsed current. The wire heating power supply heats the filler wire by supplying thereto a pulsed current in accordance with a synchronous signal from the AC arc welding power supply or a detection signal of an arc current or an arc voltage of the AC arc power supply.

According to the present invention, a welding power supply is defined in claim <NUM>.

Methods and apparatus to provide welding-type power and preheating power are disclosed, substantially as illustrated by and described in connection with at least one of the figures, as set forth more completely in the appended claims.

For the purpose of promoting an understanding of the principles of the present invention, reference will be now made to the examples illustrated in the drawings and specific language will be used to describe the same.

For an electrode wire of given material properties (e.g., resistivity, density, specific heat capacity, etc.), a relationship can be defined between final preheat temperature and heating energy input. This relationship can be determined using the target wire temperature, process parameters, and material properties, and/or can be determined empirically by measuring the wire temperature through contact methods and/or reliable non-contact methods. An additional relationship exists between the final preheat temperature preheat current, wire feed speed, and wire area squared. This relationship will compensate for changes in wire diameter, wire feed speed, and/or preheating distance, because the heating energy input is a function that includes mass to be heated, resistance of the segment of wire to be heated, and preheating time.

Disclosed example welding power supplies use a temperature model involving the relationships discussed above to preheat electrode wire to a target temperature, without measuring the temperature of the preheated wire. Because temperature measurements of preheated wire within a welding torch are difficult due to the construction and/or geometries of welding torches, as well as the proximity of the preheated wire to a welding arc, disclosed example systems and methods permit accurate and reliable preheating temperature control without changes to the welding torch. Additionally, disclosed examples can be easily adapted to many different types of preheating welding systems, including different torches and/or power supplies.

Disclosed example welding power supplies enable a welding process developer to accurately target a defined preheat temperature without having to determine the corresponding preheating process parameters, which can shorten development time of the welding process. Welding process developers can use disclosed systems and methods to more quickly understand the manipulation of balance between preheat and welding energy for applications such as welding hot-rolled material, reduce heat input, reduce diffusible hydrogen in the resulting weld with cored wires (e.g., flux-cored wire, metal-cored wire), and/or manipulate fume generation rates.

Disclosed example welding power supplies use the temperature model (e.g., including the relationships discussed above) to define the process parameters, such as wire feed speed, preheating distance, preheating current, and/or preheating voltage, for controlling of the preheating process during welding. Some examples integrate the temperature model into the preheating and/or welding control system(s) to control the preheat process to preheat to a target temperature that is defined by the system and/or by the user.

As utilized herein the terms "circuits" and "circuitry" refer to physical electronic components (i.e. hardware) and any software and/or firmware (code) that may configure the hardware, be executed by the hardware, and/or otherwise be associated with the hardware. As used herein, for example, a particular processor and memory may comprise a first "circuit" when executing a first set of one or more lines of code and may comprise a second "circuit" when executing a second set of one or more lines of code. In other words, "x and/or y" means "one or both of x and y. " As another example, "x, y, and/or z" means any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, "x, y, and/or z" means "one or more of x, y and z". As utilized herein, the terms "e.g." and "for example" set off lists of one or more non-limiting examples, instances, or illustrations. As utilized herein, circuitry is "operable" to perform a function whenever the circuitry comprises the necessary hardware and code (if any is necessary) to perform the function, regardless of whether performance of the function is disabled or not enabled (e.g., by an operator-configurable setting, factory trim, etc.).

As used herein, a wire-fed welding-type system refers to a system capable of performing welding (e.g., gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), submerged arc welding (SAW), etc.), brazing, cladding, hardfacing, and/or other processes, in which a filler metal is provided by a wire that is fed to a work location, such as an arc or weld puddle.

As used herein, a welding-type power source refers to any device capable of, when power is applied thereto, supplying welding, cladding, plasma cutting, induction heating, laser (including laser welding and laser cladding), carbon arc cutting or gouging and/or resistive preheating, including but not limited to transformer-rectifiers, inverters, converters, resonant power supplies, quasi-resonant power supplies, switch-mode power supplies, etc., as well as control circuitry and other ancillary circuitry associated therewith. The terms "power source" and "power supply" are used interchangeably herein.

As used herein, preheating refers to heating the electrode wire prior to a welding arc and/or deposition in the travel path of the electrode wire.

Some disclosed examples describe electric currents being conducted "from" and/or "to" locations in circuits and/or power supplies. Similarly, some disclosed examples describe "providing" electric current via one or more paths, which may include one or more conductive or partially conductive elements. The terms "from," "to," and "providing," as used to describe conduction of electric current, do not necessitate the direction or polarity of the current. Instead, these electric currents may be conducted in either direction or have either polarity for a given circuit, even if an example current polarity or direction is provided or illustrated.

<FIG> illustrates an example welding system <NUM>, including a welding power supply <NUM> configured to convert input power to welding power and preheating power. The example welding system <NUM> of <FIG> includes the welding power supply <NUM> and a preheating welding torch <NUM>. The welding torch <NUM> may be a torch configured for any wire-fed welding process, such as gas metal arc welding (GMAW), flux cored arc welding (FCAW), self-shielded FCAW, and/or submerged arc welding (SAW), based on the desired welding application.

The welding power supply <NUM> converts the input power from a source of primary power <NUM> to one or both of output welding power and/or preheating power, which are output to the welding torch <NUM>. In the example of <FIG>, the welding power source also supplies the filler metal to a welding torch <NUM> configured for GMAW welding, FCAW welding, or SAW welding.

The welding power supply <NUM> is coupled to, or includes, the source of primary power <NUM>, such as an electrical grid or engine-driven generator that supplies primary power, which may be single-phase or three-phase AC power. For example, the welding power supply <NUM> may be an engine-driven welding power source that includes the engine and generator that provides the primary power <NUM> within the welding power supply <NUM>. The welding power supply <NUM> may process the primary power <NUM> to output welding-type power for output to the welding torch <NUM> via an torch cable <NUM>.

Power conversion circuitry <NUM> converts the primary power (e.g., AC power) to welding-type power as either direct current (DC) or AC, and to preheating power. Example preheating power may include DC and/or AC electrical current that provides resistive, or Joule, heating when conducted through a portion of the electrode wire <NUM>. Additional examples of preheating power disclosed herein may include high frequency AC current that provides inductive heating within the electrode wire <NUM>, and/or power suitable for hotwire techniques, arc-based preheating in which an electrical arc is used to apply heat to the wire prior to the welding arc, laser-based preheating, radiant heating, convective heating, and/or any other forms of wire heating. The power conversion circuitry <NUM> may include circuit elements such as transformers, switches, boost converters, inverters, buck converters, half-bridge converters, full-bridge converters, forward converters, flyback converters, an internal bus, bus capacitor, voltage and current sensors, and/or any other topologies and/or circuitry to convert the input power to the welding power and the preheating power, and to output the welding power and the preheating power to the torch <NUM>. Example implementations of the power conversion circuitry <NUM> are disclosed below in more detail.

The first and second portions of the input power may be divided by time (e.g., the first portion is used at a first time and the second portion is used at a second time) and/or as portions of the total delivered power at a given time. The power conversion circuitry <NUM> outputs the welding power to a weld circuit, and outputs the preheating power to a preheating circuit or other preheater. The weld circuit and the preheating circuit may be implemented using any combination of the welding torch <NUM>, a weld accessory, and/or the power supply <NUM>.

The power conversion circuitry <NUM> may include circuit elements such as boost converters. In some examples, the primary power <NUM> received by the power conversion circuitry <NUM> is an AC voltage between approximately 110V and 575V, between approximately 110V and 480V, or between approximately 110V and 240V. As used in reference to the input power, the term approximately may mean within <NUM> volts or within <NUM> percent of the desired voltage.

The power conversion circuitry <NUM> may be configured to convert the input power to any conventional and/or future welding-type output. The example power conversion circuitry <NUM> may implement one or more controlled voltage control loop(s), one or more controlled current control loop(s), one or more controlled power control loops, one or more controlled enthalpy control loops, and/or one or more controlled resistance control loops to control the voltage and/or current output to the welding circuit and/or to the preheating circuit. As described in more detail below, the power conversion circuitry <NUM> may be implemented using one or more converter circuits, such as multiple converter circuits in which each of the welding-type output and the preheating output is produced using separate ones of the converter circuits.

In some examples, the power conversion circuitry <NUM> is configured to convert the input power to a controlled waveform welding output, such as a pulsed welding process or a short circuit welding process (e.g., regulated metal deposition (RMD™)). For example, the RMD™ welding process utilizes a controlled waveform welding output having a current waveform that varies at specific points in time over a short circuit cycle.

The welding power supply <NUM> includes control circuitry <NUM> and an user interface <NUM>. The control circuitry <NUM> controls the operations of the welding power supply <NUM> and may receive input from the user interface <NUM> through which an operator may choose a welding process (e.g., GMAW, FCAW, SAW) and input desired parameters of the input power (e.g., voltages, currents, particular pulsed or non-pulsed welding regimes, and so forth). The control circuitry <NUM> may be configured to receive and process a plurality of inputs regarding the performance and demands of the system <NUM>.

The control circuitry <NUM> includes one or more controller(s) and/or processor(s) <NUM> that controls the operations of the power supply <NUM>. The control circuitry <NUM> receives and processes multiple inputs associated with the performance and demands of the system. The processor(s) <NUM> may include one or more microprocessors, such as one or more "general-purpose" microprocessors, one or more special-purpose microprocessors and/or ASICS, one or more microcontrollers, and/or any other type of processing and/or logic device. For example, the control circuitry <NUM> may include one or more digital signal processors (DSPs). The control circuitry <NUM> may include circuitry such as relay circuitry, voltage and current sensing circuitry, power storage circuitry, and/or other circuitry, and is configured to sense the primary power <NUM> received by the power supply <NUM>.

The example control circuitry <NUM> includes one or more memory device(s) <NUM>. The memory device(s) <NUM> may include volatile and/or nonvolatile memory and/or storage devices, such as random access memory (RAM), read only memory (ROM), flash memory, hard drives, solid state storage, and/or any other suitable optical, magnetic, and/or solid-state storage mediums. The memory device(s) <NUM> store data (e.g., data corresponding to a welding application), instructions (e.g., software or firmware to perform welding processes), and/or any other appropriate data. Examples of stored data for a welding application include an attitude (e.g., orientation) of a welding torch, a distance between the contact tip and a workpiece, a voltage, a current, welding device settings, and so forth. The memory device <NUM> may store machine executable instructions (e.g., firmware or software) for execution by the processor(s) <NUM>. Additionally or alternatively, one or more control schemes for various welding processes, along with associated settings and parameters, may be stored in the memory device(s) <NUM>, along with machine executable instructions configured to provide a specific output (e.g., initiate wire feed, enable gas flow, capture welding current data, detect short circuit parameters, determine amount of spatter) during operation.

The example user interface <NUM> enables control or adjustment of parameters of the welding system <NUM>. The user interface <NUM> is coupled to the control circuitry <NUM> for operator selection and adjustment of the welding process (e.g., pulsed, short-circuit, FCAW) through selection of the wire size, wire type, material, and gas parameters. The user interface <NUM> is coupled to the control circuitry <NUM> for control of the voltage, amperage, power, enthalpy, resistance, wire feed speed, and arc length for a welding application. The user interface <NUM> may receive inputs using any input device, such as via a keypad, keyboard, buttons, touch screen, voice activation system, wireless device, etc..

The user interface <NUM> may receive inputs specifying wire material (e.g., steel, aluminum), wire type (e.g., solid, cored), wire diameter, gas type, and/or any other parameters. Upon receiving the input, the control circuitry <NUM> determines the welding output for the welding application. For example, the control circuitry <NUM> may determine weld voltage, weld current, wire feed speed, inductance, weld pulse width, relative pulse amplitude, wave shape, preheating voltage, preheating current, preheating pulse, preheating resistance, preheating energy input, and/or any other welding and/or preheating parameters for a welding process based at least in part on the input received through the user interface <NUM>.

In some examples, the welding power supply <NUM> may include polarity reversing circuitry. Polarity reversing circuitry reverses the polarity of the output welding-type power when directed by the control circuitry <NUM>. For example, some welding processes, such as TIG welding, may enable a desired weld when the electrode has a negative polarity, known as DC electrode negative (DCEN). Other welding processes, such as stick or GMAW welding, may enable a desired weld when the electrode has a positive polarity, known as DC electrode positive (DCEP). When switching between a TIG welding process and a GMAW welding process, the polarity reversing circuitry may be configured to reverse the polarity from DCEN to DCEP.

Additionally or alternatively, the operator may simply connect the torch <NUM> to the power supply <NUM> without knowledge of the polarity, such as when the torch is located a substantial distance from the power supply <NUM>. The control circuitry <NUM> may direct the polarity reversing circuitry to reverse the polarity in response to signals received through communications circuitry, and/or based on a selected or determined welding process.

In some examples, the power supply <NUM> includes communications circuitry. For example, communications circuitry may be configured to communicate with the welding torch <NUM>, accessories, and/or other device(s) coupled to power cables and/or a communications port. The communications circuitry sends and receives command and/or feedback signals over welding power cables used to supply the welding-type power. Additionally or alternatively, the communications circuitry may communicate wirelessly with the welding torch <NUM> and/or other device(s).

For some welding processes (e.g., GMAW), a shielding gas is utilized during welding. In the example of <FIG>, the welding power supply <NUM> includes one or more gas control valves <NUM> configured to control a gas flow from a gas source <NUM>. The control circuitry <NUM> controls the gas control valves <NUM>. The welding power supply <NUM> may be coupled to one or multiple gas sources <NUM> because, for example, some welding processes may utilize different shielding gases than others. In some examples, the welding power supply <NUM> is configured to supply the gas with the welding power and/or the preheating power to the torch <NUM> via a combined torch cable <NUM>. In other examples, the gas control valves <NUM> and gas source <NUM> may be separate from the welding power supply <NUM>. For example, the gas control valves <NUM> may be disposed connected to the combined torch cable <NUM> via a connector.

The example power supply <NUM> includes a wire feed assembly <NUM> that supplies electrode wire <NUM> to the welding torch <NUM> for the welding operation. The wire feed assembly <NUM> includes elements such as a wire spool <NUM> and a wire feed drive configured to power drive rolls <NUM>. The wire feed assembly <NUM> feeds the electrode wire <NUM> to the welding torch <NUM> along the torch cable <NUM>. The welding output may be supplied through the torch cable <NUM> coupled to the welding torch <NUM> and/or the work cable <NUM> coupled to the workpiece <NUM>. As disclosed in more detail below, the preheating output may be supplied to the welding torch <NUM> (or another via a connection in the wire feed assembly <NUM>), supplied to the welding torch <NUM> via one or more preheating power terminals, and/or supplied to a preheater within the wire feed assembly <NUM> or otherwise within a housing <NUM> of the welding power supply <NUM>.

The example power supply <NUM> is coupled to a preheating GMAW torch <NUM> configured to supply the gas, electrode wire <NUM>, and electrical power to the welding application. As discussed in more detail below, the welding power supply <NUM> is configured to receive input power, convert a first portion of the input power to welding power and output the welding power to a weld circuit, and to convert a second portion of the input power to preheating power and output the preheating power to a preheating circuit or other preheater.

The example torch <NUM> includes a first contact tip <NUM> and a second contact tip <NUM>. The electrode wire <NUM> is fed from the wire feed assembly <NUM> to the torch <NUM> and through the contact tips <NUM>, <NUM>, to produce a welding arc <NUM> between the electrode wire <NUM> and the workpiece <NUM>. The preheating circuit includes the first contact tip <NUM>, the second contact tip <NUM>, and a portion <NUM> of the electrode wire <NUM> that is located between the first contact tip <NUM> and a second contact tip <NUM>. The example power supply <NUM> is further coupled to the work cable <NUM> that is coupled to the workpiece <NUM>.

In operation, the electrode wire <NUM> passes through the second contact tip <NUM> and the first contact tip <NUM>, between which the power conversion circuitry <NUM> outputs a preheating current to heat the electrode wire <NUM>. Specifically, in the configuration shown in <FIG>, the preheating current enters the electrode wire <NUM> via the second contact tip <NUM> and exits via the first contact tip <NUM>. However, the preheating current may be conducted in the opposite direction, using AC, and/or a combination of AC and DC. At the first contact tip <NUM>, a welding current may also enter (or exit) the electrode wire <NUM>.

The welding current is output by the power conversion circuitry <NUM>, which derives the preheating power and the welding power from the primary power <NUM>. The welding current flows between the electrode wire <NUM> and the workpiece <NUM>, which in turn generates the welding arc <NUM>. When the electrode wire <NUM> makes contact with the workpiece <NUM>, or when an arc exists between the electrode wire <NUM> and the workpiece <NUM>, an electrical circuit is completed and the welding current flows through the electrode wire <NUM>, across the arc <NUM>, across the metal work piece(s) <NUM>, and returns to the power conversion circuitry <NUM> via a work cable <NUM>. The welding current causes the electrode wire <NUM> and the parent metal of the work piece(s) <NUM> to melt, thereby joining the work pieces as the melt solidifies. By preheating the electrode wire <NUM>, the welding arc <NUM> may be generated with drastically reduced arc energy. Generally speaking, the preheating current is proportional to the distance between the contact tips <NUM>, <NUM> and the electrode wire <NUM> size.

During operation, the power conversion circuitry <NUM> establishes a preheating circuit to conduct preheating current through a section <NUM> of the electrode wire <NUM>. The preheating current flows from the power conversion circuitry <NUM> to the second contact tip <NUM> via a first conductor <NUM>, through the section <NUM> of the electrode wire <NUM> to the first contact tip <NUM>, and returns to the power conversion circuitry <NUM> via a second conductor <NUM> connecting the power conversion circuitry <NUM> to the first contact tip <NUM>. Either, both, or neither of the conductors <NUM>, <NUM> may be combined with other cables and/or conduits. For example, the conductor <NUM> and/or the conductor <NUM> may be part of the cable <NUM>. In other examples, the conductor <NUM> is included within the cable <NUM>, and the conductor <NUM> is routed separately to the torch <NUM>. To this end, the power supply <NUM> may include between one and three terminals to which one or more cables can be physically connected to establish the preheating, welding, and work connections. For example, multiple connections can be implemented into a single terminal using appropriate insulation between different connections.

In the illustrated example of <FIG>, the power supply <NUM> includes two terminals <NUM>, <NUM> configured to output the welding power to the contact tip <NUM> and the work cable <NUM>. The conductor <NUM> couples the terminal <NUM> to the torch <NUM>, which provides the power from the conductor <NUM> to the contact tip <NUM>. The work cable <NUM> couples the terminal <NUM> to the workpiece <NUM>. The example terminals <NUM>, <NUM> may have designated polarities, or may have reversible polarities.

Because the preheating current path is superimposed with the welding current path over the connection between the first contact tip <NUM> and the power conversion circuitry <NUM> (e.g., via conductor <NUM>), the cable <NUM> may enable a more cost-effective single connection between the first contact tip <NUM> and the power conversion circuitry <NUM> (e.g., a single cable) than providing separate connections for the welding current to the first contact tip <NUM> and for the preheating current to the first contact tip <NUM>.

The example power supply <NUM> includes a housing <NUM>, within which the control circuitry <NUM>, the power conversion circuitry <NUM>, the wire feed assembly <NUM>, the user interface <NUM>, and/or the gas control valving <NUM> are enclosed. In examples in which the power conversion circuitry <NUM> includes multiple power conversion circuits (e.g., a preheating power conversion circuit and a welding power conversion circuit), all of the power conversion circuits are included within the housing <NUM>.

<FIG> illustrates another example welding system <NUM> including a welding power supply <NUM> configured to convert input power to welding power and a preheating power supply <NUM> configured to convert input power to preheating power. The welding system <NUM> includes the example torch <NUM> having the contact tips <NUM>, <NUM>. The system <NUM> further includes the electrode wire <NUM> fed from a wire spool <NUM>, a preheating power supply <NUM>, and a welding power supply <NUM>. The system <NUM> is illustrated in operation as producing the welding arc <NUM> between the electrode wire <NUM> and a workpiece <NUM>.

In the example of <FIG>, the system <NUM> includes separate power supplies <NUM>, <NUM> to provide the welding power and the preheating power to the torch <NUM>, instead of the single power supply <NUM> in the example of <FIG>.

In operation, the electrode wire <NUM> passes from the wire spool <NUM> through the second contact tip <NUM> and the first contact tip <NUM>, between which the preheating power supply <NUM> generates a preheating current to heat the electrode wire <NUM>. Specifically, in the configuration shown in <FIG>, the preheating current enters the electrode wire <NUM> via the second contact tip <NUM> and exits via the first contact tip <NUM>. The example preheating power supply <NUM> may implement a controlled voltage control loop or a controlled current control loop to control the voltage and/or current output to the preheating circuit.

At the first contact tip <NUM>, a welding current may also enter the electrode wire <NUM>. The welding current is generated, or otherwise provided by, the welding power supply <NUM>. The welding current flows between the electrode wire <NUM> and the workpiece <NUM>, which in turn generates the welding arc <NUM>. When the electrode wire <NUM> makes contact with a target metal workpiece <NUM>, or when an arc exists between the electrode wire <NUM> and the workpiece <NUM>, an electrical circuit is completed and the welding current flows through the electrode wire <NUM>, across the arc <NUM>, across the metal work piece(s) <NUM>, and returns to the welding power supply <NUM>. The welding current causes the electrode wire <NUM> and the parent metal of the work piece(s) <NUM> to melt, thereby joining the work pieces as the melt solidifies. By preheating the electrode wire <NUM>, a welding arc <NUM> may be generated with drastically reduced arc energy. Generally speaking, the preheating current is proportional to the distance between the contact tips <NUM>, <NUM> and the electrode wire <NUM> size.

The welding current is generated, or otherwise provided by, a welding power supply <NUM>, while the preheating current is generated, or otherwise provided by, the preheating power supply <NUM>. The preheating power supply <NUM> and the welding power supply <NUM> may ultimately share a common power source (e.g., a common generator or line current connection), but the current from the common power source is converted, inverted, and/or regulated to yield the two separate currents - the preheating current and the welding current. For instance, the preheat operation may be facilitated with a single power source and associated converter circuitry, in which case three leads may extend from a single power source.

During operation, the system <NUM> establishes a welding circuit to conduct welding current from the welding power supply <NUM> to the first contact tip <NUM>, and returns to the power supply <NUM> via the welding arc <NUM>, the workpiece <NUM>, and a work lead <NUM>. To enable connection between the welding power supply <NUM> and the first contact tip <NUM> and the workpiece <NUM>, the welding power supply <NUM> includes terminals <NUM>, <NUM> (e.g., a positive terminal and a negative terminal).

During operation, the preheating power supply establishes a preheating circuit to conduct preheating current through a section <NUM> of the electrode wire <NUM>. To enable connection between the preheating power supply <NUM> and the contact tips <NUM>, <NUM>, the preheating power supply <NUM> includes terminals <NUM>, <NUM>. The preheating current flows from the preheating power supply <NUM> to the second contact tip <NUM>, the section <NUM> of the electrode wire <NUM>, the first contact tip <NUM>, and returns to the preheating power supply <NUM> via a cable <NUM> connecting the terminal <NUM> of the welding power supply <NUM> to the terminal <NUM> of the preheating power supply <NUM>.

Because the preheating current path is superimposed with the welding current path over the connection between the first contact tip <NUM> and the power supplies <NUM>, <NUM>, the cable <NUM> may enable a more cost-effective single connection between the first contact tip <NUM> and the power supplies <NUM>, <NUM> (e.g., a single cable) than providing separate connections for the welding current to the first contact tip <NUM> and for the preheating current to the first contact tip <NUM>. In other examples, the terminal <NUM> of the preheating power supply <NUM> is connected to the first contact tip <NUM> via a separate path than the path between the first contact tip <NUM> and the welding power supply <NUM>.

As illustrated in <FIG>, the example system <NUM> includes a wire feeder <NUM> that feeds the electrode wire <NUM> to the torch <NUM> using a wire drive <NUM>. The electrode wire <NUM> exits the wire feeder <NUM> and travels through a wire liner <NUM>.

<FIG> is a block diagram of an example implementation of the power supplies <NUM>, <NUM> of <FIG>. The example power supply <NUM>, <NUM> powers, controls, and supplies consumables to a welding application. In some examples, the power supply <NUM>, <NUM> directly supplies input power to the welding torch <NUM>. In the illustrated example, the power supply <NUM>, <NUM> is configured to supply power to welding operations and/or preheating operations. The example power supply <NUM>, <NUM> also provides power to a wire feeder to supply the electrode wire <NUM> to the welding torch <NUM> for various welding applications (e.g., GMAW welding, flux core arc welding (FCAW), SAW).

The power supply <NUM>, <NUM> receives primary power <NUM> (e.g., from the AC power grid, an engine/generator set, a battery, or other energy generating or storage devices, or a combination thereof), conditions the primary power, and provides an output power to one or more welding devices and/or preheating devices in accordance with demands of the system. The primary power <NUM> may be supplied from an offsite location (e.g., the primary power may originate from the power grid). The power supply <NUM>, <NUM> includes a power conversion circuitry <NUM>, which may include transformers, rectifiers, switches, and so forth, capable of converting the AC input power to AC and/or DC output power as dictated by the demands of the system (e.g., particular welding processes and regimes). The power conversion circuitry <NUM> converts input power (e.g., the primary power <NUM>) to welding-type power based on a weld voltage setpoint and outputs the welding-type power via a weld circuit.

In some examples, the power conversion circuitry <NUM> is configured to convert the primary power <NUM> to both welding-type power and auxiliary power outputs. However, in other examples, the power conversion circuitry <NUM> is adapted to convert primary power only to a weld power output, and a separate auxiliary converter is provided to convert primary power to auxiliary power. In some other examples, the power supply <NUM>, <NUM> receives a converted auxiliary power output directly from a wall outlet. Any suitable power conversion system or mechanism may be employed by the power supply <NUM>, <NUM> to generate and supply both weld and auxiliary power.

The power supply <NUM>, <NUM> includes a control circuitry <NUM> to control the operation of the power supply <NUM>, <NUM>. The power supply <NUM>, <NUM> also includes a user interface <NUM>. The control circuitry <NUM> receives input from the user interface <NUM>, through which a user may choose a process and/or input desired parameters (e.g., voltages, currents, particular pulsed or non-pulsed welding regimes, and so forth). The user interface <NUM> may receive inputs using any input device, such as via a keypad, keyboard, buttons, touch screen, voice activation system, wireless device, etc. Furthermore, the control circuitry <NUM> controls operating parameters based on input by the user as well as based on other current operating parameters. Specifically, the user interface <NUM> may include a display <NUM> for presenting, showing, or indicating, information to an operator. The control circuitry <NUM> may also include interface circuitry for communicating data to other devices in the system, such as the wire feeder. For example, in some situations, the power supply <NUM>, <NUM> wirelessly communicates with other welding devices within the welding system. Further, in some situations, the power supply <NUM>, <NUM> communicates with other welding devices using a wired connection, such as by using a network interface controller (NIC) to communicate data via a network (e.g., ETHERNET, 10baseT, 10base100, etc.). In the example of <FIG>, the control circuitry <NUM> communicates with the wire feeder via the weld circuit via a communications transceiver <NUM>.

The control circuitry <NUM> includes at least one controller or processor <NUM> that controls the operations of the welding power supply <NUM>, <NUM>. The control circuitry <NUM> receives and processes multiple inputs associated with the performance and demands of the system. The processor <NUM> may include one or more microprocessors, such as one or more "general-purpose" microprocessors, one or more special-purpose microprocessors and/or ASICS, and/or any other type of processing device. For example, the processor <NUM> may include one or more digital signal processors (DSPs).

The example control circuitry <NUM> includes one or more storage device(s) <NUM> and one or more memory device(s) <NUM>. The storage device(s) <NUM> (e.g., nonvolatile storage) may include ROM, flash memory, a hard drive, and/or any other suitable optical, magnetic, and/or solid-state storage medium, and/or a combination thereof. The storage device <NUM> stores data (e.g., data corresponding to a welding application), instructions (e.g., software or firmware to perform welding processes), and/or any other appropriate data. Examples of stored data for a welding application include an attitude (e.g., orientation) of a welding torch, a distance between the contact tip and a workpiece, a voltage, a current, welding device settings, and so forth.

The memory device <NUM> may include a volatile memory, such as random access memory (RAM), and/or a nonvolatile memory, such as read-only memory (ROM). The memory device <NUM> and/or the storage device(s) <NUM> may store a variety of information and may be used for various purposes. For example, the memory device <NUM> and/or the storage device(s) <NUM> may store processor executable instructions <NUM> (e.g., firmware or software) for the processor <NUM> to execute. In addition, one or more control regimes for various welding processes, along with associated settings and parameters, may be stored in the storage device <NUM> and/or memory device <NUM>, along with code configured to provide a specific output (e.g., initiate wire feed, enable gas flow, capture welding current data, detect short circuit parameters, determine amount of spatter) during operation.

In some examples, the welding power flows from the power conversion circuitry <NUM> through a weld cable <NUM>. The example weld cable <NUM> is attachable and detachable from weld studs at each of the power supply <NUM>, <NUM> (e.g., to enable ease of replacement of the weld cable <NUM> in case of wear or damage). Furthermore, in some examples, welding data is provided with the weld cable <NUM> such that welding power and weld data are provided and transmitted together over the weld cable <NUM>. The communications transceiver <NUM> is communicatively coupled to the weld cable <NUM> to communicate (e.g., send/receive) data over the weld cable <NUM>. The communications transceiver <NUM> may be implemented based on various types of power line communications methods and techniques. For example, the communications transceiver <NUM> may utilize IEEE standard P1901. <NUM> to provide data communications over the weld cable <NUM>. In this manner, the weld cable <NUM> may be utilized to provide welding power from the power supply <NUM>, <NUM> to the wire feeder <NUM> and the welding torch <NUM>. Additionally or alternatively, the weld cable <NUM> may be used to transmit and/or receive data communications to/from the wire feeder <NUM> and the welding torch <NUM>. The communications transceiver <NUM> is communicatively coupled to the weld cable <NUM>, for example, via cable data couplers <NUM>, to characterize the weld cable <NUM>, as described in more detail below. The cable data coupler <NUM> may be, for example, a voltage or current sensor.

In some examples, the power supply <NUM>, <NUM> includes or is implemented in a wire feeder.

The example communications transceiver <NUM> includes a receiver circuit <NUM> and a transmitter circuit <NUM>. Generally, the receiver circuit <NUM> receives data transmitted by the wire feeder via the weld cable <NUM> and the transmitter circuit <NUM> transmits data to the wire feeder via the weld cable <NUM>. As described in more detail below, the communications transceiver <NUM> enables remote configuration of the power supply <NUM>, <NUM> from the location of the wire feeder and/or compensation of weld voltages by the power supply <NUM>, <NUM> using weld voltage feedback information transmitted by the wire feeder <NUM>. In some examples, the receiver circuit <NUM> receives communication(s) via the weld circuit while weld current is flowing through the weld circuit (e.g., during a welding-type operation) and/or after the weld current has stopped flowing through the weld circuit (e.g., after a welding-type operation). Examples of such communications include weld voltage feedback information measured at a device that is remote from the power supply <NUM>, <NUM> (e.g., the wire feeder) while the weld current is flowing through the weld circuit.

Example implementations of the communications transceiver <NUM> are described in <CIT>. However, other implementations of the communications transceiver <NUM> may be used.

The example wire feeder <NUM> also includes a communications transceiver <NUM>, which may be similar or identical in construction and/or function as the communications transceiver <NUM>.

In some examples, a gas supply <NUM> provides shielding gases, such as argon, helium, carbon dioxide, and so forth, depending upon the welding application. The shielding gas flows to a valve <NUM>, which controls the flow of gas, and if desired, may be selected to allow for modulating or regulating the amount of gas supplied to a welding application. The valve <NUM> may be opened, closed, or otherwise operated by the control circuitry <NUM> to enable, inhibit, or control gas flow (e.g., shielding gas) through the valve <NUM>. Shielding gas exits the valve <NUM> and flows through a cable <NUM> (which in some implementations may be packaged with the welding power output) to the wire feeder which provides the shielding gas to the welding application. In some examples, the power supply <NUM>, <NUM> does not include the gas supply <NUM>, the valve <NUM>, and/or the cable <NUM>.

In either of the example systems of <FIG> and/or 1B, the preheating power supply (e.g., the power conversion circuitry <NUM>, the preheating power supply <NUM>) may be configured to preheat the electrode wire <NUM> to a target temperature, without using a temperature sensor to measure the temperature of the preheated wire. For example, the preheating power supplies may use a temperature model (e.g., a predetermined relationship) to preheat the electrode wire <NUM> by identifying the material properties of the electrode wire <NUM>, determining or receiving a target preheat temperature, and controlling the preheating output to result in preheating the electrode wire <NUM> to the target temperature using the temperature model.

The example temperature model may relate the final preheat temperature of the electrode wire <NUM> to the heating energy input (e.g., in Joules), relate a given electrode wire to a set of one or more material properties for controlling preheat process parameters, relate the material properties of a given electrode wire formulation to the target temperature, and/or relate the target temperature and welding conditions (e.g., wire feed speed) to corresponding preheat parameters. In some examples, the temperature model is selected or adapted based on the type of the electrode wire <NUM>. For example, electrode wires may have different structures (e.g., solid wire, flux cored, metal cored, etc.), diameters (e.g., cross-sectional areas), and/or compositions (e.g., different solid metal alloys, sheath alloys, flux compositions, metal filler compositions, lubricant compositions, etc.), which affect the resistivity and/or specific heat capacity of the resulting electrode wire <NUM>.

In some examples, the temperature model may be adapted using constants that control for the different material properties of different electrode wires. The constants can be derived based on, for example, the target wire temperature, process parameters, and/or material properties. Additionally or alternatively, constants and/or compensation factors may be determined empirically by measuring the wire temperature through contact methods and/or reliable non-contact methods.

During operation, the example control circuitry (e.g., the control circuitry <NUM>, the control circuitry <NUM>) determines material properties of the electrode wire <NUM> to be preheated via the wire preheating power (e.g., using the temperature model).

<FIG> illustrates an example user interface <NUM> that may be used to input electrode wire properties for determining a target temperature. The example user interface <NUM> may implement the user interface <NUM> of <FIG> and/or the user interface <NUM> of <FIG>. For example, the user interface <NUM> may be a touchscreen, a display and input devices (e.g., buttons, mouse and cursor, etc.), and/or any other type of input and/or output devices.

The example user interface <NUM> enables a user to select a wire type <NUM> (e.g., from a selection of multiple wire types), a wire diameter <NUM>, a target preheat temperature <NUM>, a material thickness <NUM> of the workpiece <NUM>, a material type <NUM> of the workpiece <NUM>, and/or a gas type <NUM>. The example user interface <NUM> may further enable the operator to select or refine weld and/or preheat parameters, such as weld voltage, wire feed speed, weld current, preheat voltage, preheat current, and/or any other desired weld parameters and/or preheat parameters. To this end, the user interface <NUM> includes example buttons <NUM>, <NUM>, <NUM>, <NUM> to navigate the user interface <NUM>, to select properties and/or parameters, and/or to specify values for the properties and/or parameters. However, other input devices, such as a touchscreen, a knob, buttons, and/or other input devices may be used.

In some examples, a preheat target temperature may be input (e.g., the target preheat temperature <NUM> via the user interface <NUM>, and/or via a communications device) and/or determined by the control circuitry <NUM>, <NUM> based on an upper preheat temperature limit of the particular electrode wire. For example, different electrode wires may have different temperatures at which column strength is lost and/or melting occurs. <FIG> is a table representative of an example database <NUM> storing target temperatures <NUM> and/or resistivities <NUM> associated with different wire types <NUM>. In the example of <FIG>, the wire types are assigned index numbers, which may correspond to wire formulations, commercial electrode wires, and/or any other identification of electrode wire types. For each of the example wire types <NUM>, the control circuitry <NUM>, <NUM> may access a corresponding target temperature <NUM> and/or the resistivity <NUM>. However, the database <NUM> may store other parameters, compensation factors, constants, and/or any other information about the stored electrode wires <NUM> to implement at least a portion of the temperature model.

The example control circuitry <NUM>, <NUM> may retrieve or access the upper preheat temperature limit based on the determined or input electrode type, and determine the target preheat temperature based on a percentage reduction or constant offset reduction from the upper preheat temperature limit.

In some examples, a default preheat target temperature may be selected by the control circuitry <NUM>, <NUM> based on the electrode type and/or material properties, and an operator may be permitted to adjust the preheat target temperature via the user interface <NUM>. For example, reducing the preheat target temperature may cause an increase in the welding power output by the welding power conversion circuitry and increase the penetration of the weld. Conversely, increasing the preheat target temperature may cause a decrease in the welding power output and decrease the penetration of the weld.

The control circuitry <NUM>, <NUM> determines one or more preheat process parameter(s) to heat the electrode wire <NUM> to the target preheat temperature based on the material properties and the temperature model (e.g., a predetermined relationship) between the target temperature, the material properties, and the preheat process parameter(s). Example preheat process parameters include a preheat voltage, preheat current, a wire resistance, a preheat power, a preheat enthalpy, a wire feed speed, and/or a preheat length.

The control circuitry <NUM>, <NUM> may use the temperature model to relate the final preheat temperature to the initial temperature of the electrode wire <NUM>, the material properties of the electrode wire <NUM> and/or a configuration of the preheating circuit, the diameter and/or cross-sectional area of the electrode wire <NUM>, and the wire feed speed. The initial temperature of the electrode wire <NUM> may be determined using, for example, a temperature sensor <NUM> configured to measure an ambient temperature and/or a temperature of the electrode wire <NUM> at the spool <NUM>. Additionally or alternatively, a temperature input via the user interface <NUM> (e.g., a user input of the ambient temperature via the user interface <NUM>), retrieving ambient temperature information from a remote source via communications circuitry (e.g., a network source of temperature, a wireless ambient temperature sensor), and/or any other source.

Additionally or alternatively, when sequences of welds are performed, a portion of the electrode wire <NUM> may be preheated from a prior weld, in which case the temperature input may not be accurate. The example control circuitry <NUM>, <NUM> may further model the temperature of the electrode wire <NUM> based on a time since the most recent weld to determine the initial temperature for a first portion of the subsequent weld, and adjust an initial wire temperature (and corresponding preheating current and/or preheating voltage parameters) during an initial preheating period for the subsequent weld.

The temperature model involves a second-order polynomial relating wire temperature to material properties and a plurality of preheat process parameters, such as wire feed speed, a preheat current, a preheat voltage, preheat power, preheat enthalpy, and/or preheat length. Equations <NUM> and <NUM> below illustrate another example relationship that may be used by the control circuitry <NUM>, <NUM> to determine the preheat current for a given temperature. <MAT><MAT>.

In Equations <NUM> and <NUM>, I is the preheat current, temp is the target preheat temperature, b is the initial temperature of the electrode wire, m is a constant based on the material properties (e.g., resistivity, specific heat capacity) of the electrode wire <NUM> and/or a configuration of the preheating circuit (e.g., preheat length), A is the cross-sectional area of the electrode wire <NUM>, and v is a wire feed speed of the electrode wire <NUM>.

In some examples, the control circuitry <NUM>, <NUM> further determines additional preheat parameters from the determined preheat current I. For example, in a voltage-controlled preheat control loop, the control circuitry <NUM>, <NUM> may determine a preheat voltage based on the preheat current, the actual or estimated resistance of the wire over the preheat length, and/or the preheat length.

During the weld operation, the control circuitry <NUM>, <NUM> controls the power conversion circuitry (e.g., the power conversion circuitry <NUM>, <NUM>) to output the wire preheating power based on the preheat process parameter(s) to heat the electrode wire <NUM> to the target temperature. For example, the control circuitry <NUM>, <NUM> may control the power conversion circuitry <NUM>, <NUM> to output the determined preheat voltage and/or the determined preheat current to achieve the target preheat temperature of the wire. The control circuitry <NUM>, <NUM> monitors the preheat voltage, the preheat current, preheat power, preheat enthalpy, the wire resistance, and/or the wire feed speed, and controls the preheat voltage and/or preheat current to preheat the electrode wire <NUM> to the target temperature.

If the wire feed speed or other weld variable changes, the example control circuitry <NUM> may recalculate the preheat current and/or the preheat voltage based on the temperature model.

<FIG> is a flowchart representative of example machine readable instructions <NUM> which may be executed by the example power supplies of <FIG>, <FIG>, and/or <NUM> (e.g., via the control circuitry <NUM>, <NUM>) to output welding power and preheating power. The example instructions <NUM> are described below with reference to the control circuitry <NUM>.

At block <NUM>, the control circuitry <NUM> determines material properties of an electrode wire <NUM> to be preheated in a welding operation. For example, the control circuitry <NUM> may look up material properties based on identification of an electrode type and/or receive the material properties from the user interface <NUM>. Example material properties include an initial temperature of the electrode wire <NUM>, a cross-sectional area of the electrode wire <NUM>, a resistivity of the electrode wire <NUM>, a density of the electrode wire <NUM>, and/or a specific heat capacity of the electrode wire <NUM>. An example implementation of block <NUM> is described below with reference to <FIG>.

At block <NUM>, the control circuitry <NUM> determines a target temperature for the preheated electrode wire <NUM>. For example, the control circuitry <NUM> may determine the target temperature based on the material properties of the electrode wire <NUM> and/or the wire feed speed, and/or by looking up a target temperature for an electrode type in a database. In some examples, the target temperature may be input and/or adjusted via the user interface <NUM>.

At block <NUM>, the control circuitry <NUM> determines preheat process parameter(s) to heat the electrode wire <NUM> to the target temperature. For example, the control circuitry <NUM> may determine a preheat current, a preheat voltage, a preheat wire resistance, and/or any other process parameters. An example implementation of block <NUM> is described below with reference to <FIG>.

At block <NUM>, the control circuitry <NUM> determines whether welding is active. If welding is active (block <NUM>), at block <NUM>, the control circuitry <NUM> controls power conversion circuitry (e.g., the power conversion circuitry <NUM>) to output wire preheating power based on the preheat process parameters to heat the electrode wire <NUM> to the target temperature. An example implementation of block <NUM> is described below with reference to <FIG>.

If welding is not active (block <NUM>), control returns to block <NUM> to determine whether the material properties of the electrode wire <NUM> have changed. In other examples, the control circuitry <NUM> may iterate block <NUM> until welding is active and/or until changes to the electrode wire <NUM> are made.

In some examples, block <NUM> may also be iterated during welding to monitor and control the preheat process parameters. For example, the control circuitry <NUM> may apply the temperature model to recalculate the preheat process parameter(s) in response to changes or variations in wire feed speed and/or initial wire temperature.

<FIG> is a flowchart representative of example machine readable instructions <NUM> which may be executed by the example power supplies <NUM>, <NUM> of <FIG>, <FIG>, and/or <NUM> to determine material properties of an electrode wire to be preheated. The example instruction <NUM> may be executed by the control circuitry <NUM> of <FIG> and/or the control circuitry <NUM> of <FIG> to implement block <NUM> of <FIG> to determine material properties of an electrode wire <NUM> to be preheated in a welding operation.

At block <NUM>, the example control circuitry <NUM> determines whether a wire type input is received via a user interface (e.g., the wire type <NUM> of the user interface <NUM>). If the wire type input has been received via the user interface (block <NUM>), at block <NUM> the control circuitry <NUM> retrieves material properties including one or more of a cross-sectional area of the electrode wire <NUM>, a resistivity of the electrode wire <NUM>, a density of the electrode wire <NUM>, or a specific heat capacity of the electrode wire <NUM>, from a database (e.g., the database <NUM> of <FIG>) based on the received wire type.

If a wire type input is not received via the user interface (block <NUM>), at block <NUM> the control circuitry <NUM> determines whether a wire type input has been received via a scanning device. For example, a spool or other package of electrode wire may have a barcode, QR code, RFID tag, and/or other device that may supply information associated with the electrode wire <NUM>. The example user interface <NUM> may include a scanner, such as an RFID reader or barcode scanner, to access wire identification information and/or material properties from the wire package. If the user interface <NUM> receives wire identification information via the scanning device (block <NUM>), at block <NUM> the control circuitry <NUM> accesses a database based on the received wire type (e.g., identification information) to retrieve material properties corresponding to the wire type.

If the wire type is not received via the scanning device (block <NUM>), at block <NUM> the control circuitry <NUM> determines whether material properties have been received via a user interface (e.g., the user interface <NUM>). For example, the user interface <NUM> may enable a user to directly enter material properties of the wire if the wire information is not stored in the database.

If material properties have been received via a user interface (block <NUM>), at block <NUM> the control circuitry <NUM> sets the material properties based on the material property information received via the user interface <NUM>.

After setting the material properties (block <NUM>), if material properties have not been received via a user interface (block <NUM>), after retrieving the material properties from the database (block <NUM>, block <NUM>), the example instructions <NUM> end and return control to block <NUM> of <FIG>.

<FIG> is a flowchart representative of example machine readable instructions <NUM> which may be executed by the example power supplies <NUM>, <NUM> of <FIG>, <FIG>, and/or <NUM> to determine preheat process parameter(s) to heat the electrode wire to a target temperature. The example instructions <NUM> may be performed by the control circuitry <NUM> of <FIG> and/or the control circuitry <NUM> of <FIG> to implement block <NUM> of <FIG>.

At block <NUM>, the control circuitry <NUM> determines a preheat current to achieve a target preheat temperature of the electrode wire <NUM> based on an initial temperature of the electrode wire <NUM> and material properties of the electrode wire <NUM>. For example, the control circuitry <NUM> may use the example Equation <NUM> above to determine the preheat current based on the material properties determined in block <NUM> of <FIG> (e.g., via the instructions <NUM> of <FIG>), a measured initial temperature of the electrode wire <NUM>, and the determined target preheat temperature (e.g., determined in block <NUM>).

The initial temperature may be determined using, for example, a temperature measurement of an ambient temperature (e.g., an environment around the wire feeder or wire package), a temperature measurement of the wire package (e.g., a spool <NUM> or other source of the electrode wire <NUM>) via the temperature sensor <NUM>, a temperature measurement of one or more elements of the torch <NUM> via the temperature sensor <NUM>, a temperature measurement of a torch coolant via the temperature sensor <NUM>, a temperature input via the user interface <NUM> (e.g., a user input of the ambient temperature via the user interface <NUM>), retrieving ambient temperature information from a remote source via communications circuitry (e.g., a network source of temperature, a wireless ambient temperature sensor), and/or any other source.

Additionally or alternatively, when sequences of welds are performed, a portion of the electrode wire <NUM> may be preheated from a prior weld, in which case the temperature input may not be accurate. The example control circuitry <NUM> may further model the temperature of the electrode wire <NUM> based on a time since the most recent weld to determine the initial temperature for a first portion of the subsequent weld, and adjust an initial wire temperature (and corresponding preheating current and/or preheating voltage parameters) during an initial preheating period for the subsequent weld.

At block <NUM>, the control circuitry <NUM> determines a voltage corresponding to the determined current. For example, in a voltage-controlled preheat control loop, the control circuitry <NUM> may control the power conversion circuitry <NUM> to output the preheat power based on a target voltage. Additionally or alternatively, the control circuitry <NUM> may monitor and/or control a resistance of the electrode wire <NUM> to a target resistance (which may correspond to a target temperature) by monitoring the voltage across the preheating section <NUM> and the current through the preheating section <NUM>.

The example instructions <NUM> may then end and return control to block <NUM> of <FIG>.

<FIG> is a flowchart representative of example machine readable instructions <NUM> which may be executed by the example power supplies <NUM>, <NUM> of <FIG>, <FIG>, and/or <NUM> to control the power conversion circuitry <NUM>, <NUM> to output wire preheat power. The example instructions <NUM> may be performed by the control circuitry <NUM> of <FIG> and/or the control circuitry <NUM> of <FIG> to implement block <NUM> of <FIG>.

At block <NUM>, the power conversion circuitry <NUM> receives the power input (e.g., the primary power <NUM> of <FIG>). At block <NUM>, the control circuitry <NUM> determines whether a welding output is enabled (e.g., based on welding process parameters). If the welding output is enabled (block <NUM>), at block <NUM> the control circuitry <NUM> controls the power conversion circuitry <NUM> to convert the input power <NUM> to a welding power output based on a determined welding power output.

At block <NUM>, the power conversion circuitry <NUM> outputs the welding output to the weld torch <NUM>. For example, the welding output is conducted to the contact tip <NUM> and the work cable <NUM> for generation of the arc <NUM>.

After outputting the welding-type power (block <NUM>), or if the welding output is disabled (block <NUM>), at block <NUM> the control circuitry <NUM> determines whether preheating is enabled (e.g., based on the preheating process parameters). For example, the control circuitry <NUM> may selectively enable the power conversion circuitry <NUM> to provide a preheating output (e.g., to the contact tips <NUM>, <NUM>) and selectively disable the power conversion circuitry <NUM> to stop the preheating output. The control circuitry <NUM> may enable and/or disable the preheating based on, for example, a user input via the user interface <NUM>, and/or an input from the power source, a remote control, and/or the welding torch <NUM>.

If the preheating output is enabled (block <NUM>), at block <NUM> the power conversion circuitry <NUM> converts at least a portion of the input power to a preheating power output based on the determined preheating power output. For example, the control circuitry <NUM> may control the power conversion circuitry <NUM>, <NUM> to convert the primary power <NUM> to the preheating output.

At block <NUM>, the power conversion circuitry <NUM> outputs the welding-type power to the weld torch <NUM>. For example, the preheating output is conducted to the contact tip <NUM> and the contact tip <NUM> via the conductors <NUM>, <NUM>.

After outputting the preheating power (block <NUM>), or if the preheating is disabled (block <NUM>), the example instructions <NUM> end and control returns to block <NUM> of <FIG>. The example instructions <NUM> may iterate via blocks <NUM>, <NUM>.

The present devices and/or methods may be realized in hardware, software, or a combination of hardware and software. The present methods and/or systems may be realized in a centralized fashion in at least one computing system, processors, and/or other logic circuits, or in a distributed fashion where different elements are spread across several interconnected computing systems, processors, and/or other logic circuits. A typical combination of hardware and software may be a processing system integrated into a welding power supply with a program or other code that, when being loaded and executed, controls the welding power supply such that it carries out the methods described herein. Another typical implementation may comprise an application specific integrated circuit or chip such as field programmable gate arrays (FPGAs), a programmable logic device (PLD) or complex programmable logic device (CPLD), and/or a system-on-a-chip (SoC). Some implementations may comprise a non-transitory machine-readable (e.g., computer readable) medium (e.g., FLASH memory, optical disk, magnetic storage disk, or the like) having stored thereon one or more lines of code executable by a machine, thereby causing the machine to perform processes as described herein. As used herein, the term "non-transitory machine readable medium" is defined to include all types of machine readable storage media and to exclude propagating signals.

An example control circuit implementation may be a microcontroller, a field programmable logic circuit and/or any other control or logic circuit capable of executing instructions that executes weld control software. The control circuit could also be implemented in analog circuits and/or a combination of digital and analog circuitry.

Claim 1:
A welding power supply (<NUM>; <NUM>, <NUM>), comprising:
power conversion circuitry (<NUM>; <NUM>) configured to convert input power to wire preheating power, and to output the wire preheating power to a preheating system (<NUM>); and
control circuitry (<NUM>; <NUM>) configured to control the power conversion circuitry;
characterised in that the control circuitry (<NUM>; <NUM>) is configured to control the power conversion circuitry (<NUM>; <NUM>) based on the output of a temperature model to preheat an electrode wire (<NUM>) to a target temperature via the preheating system (<NUM>); and
wherein the temperature model comprises a second-order polynomial relating wire temperature to a plurality of preheat process parameters, wherein the preheat process parameters comprise two or more of a wire feed speed, a preheat current, a preheat voltage, a preheat power, a preheat resistance, a preheat enthalpy, or a preheat length.