Systems, methods, and apparatus to weld by preheating welding wire and inductively heating a workpiece are disclosed. An example welding system includes: a welding current source configured to provide welding current to a welding circuit, the welding circuit comprising an electrode wire and a first contact tip of a welding torch; an electrode preheating circuit configured to provide preheating current through a first portion of the electrode wire via a second contact tip of the welding torch; and at least one induction heating coil configured to apply induction heat to a workpiece, the welding current source, the electrode preheating circuit, and the induction heating coil configured to perform a preheating operation and a welding operation on the workpiece.

Systems, methods, and apparatus to weld by preheating welding wire and inductively heating a workpiece are disclosed. An example welding system includes: a welding current source configured to provide welding current to a welding circuit, the welding circuit comprising an electrode wire and a first contact tip of a welding torch; an electrode preheating circuit configured to provide preheating current through a first portion of the electrode wire via a second contact tip of the welding torch; and at least one induction heating coil configured to apply induction heat to a workpiece, the welding current source, the electrode preheating circuit, and the induction heating coil configured to perform a preheating operation and a welding operation on the workpiece.

An example apparatus to monitor a welding-type system includes: a test signal generator configured to output a test signal to a monitored circuit; and a lock-in amplifier configured to: receive a reference signal based on the test signal; measure a leakage current in the monitored circuit based on the reference signal; and generate an output signal representative of the leakage current.

An example apparatus to monitor a welding-type system includes: a test signal generator configured to output a test signal to a monitored circuit; and a lock-in amplifier configured to: receive a reference signal based on the test signal; measure a leakage current in the monitored circuit based on the reference signal; and generate an output signal representative of the leakage current.

A method of controlling highly regulated power and frequency from a high frequency power supply system to provide a highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactor pairs with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and a split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.

A method of controlling highly regulated power and frequency from a high frequency power supply system to provide a highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactor pairs with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and a split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.

Apparatuses, systems, and/or methods for providing an induction heating system are disclosed. The induction heating system includes an induction power supply and an induction heating tool configured to receive induction-type power from the induction power supply through one or more ports. The ports may be part of the induction power supply and/or an associated junction box. The induction heating tool may include a heating coil attached to one or more plugs via one or more cables. The ports of the induction power supply and/or junction box are configured to receive the plugs of the induction heating tool. A communication device may be positioned adjacent the ports. The communication device may be configured to read data from one or more memory devices of the induction heating tool (e.g., in/on the plugs) via close proximity communication.

An example system for controlling heating of a workpiece includes: an interface configured to receive a target temperature (T.sub.T) for the workpiece; a processor configured to: select a current temperature (T.sub.S) for the workpiece based on monitoring one or more temperature sensors; and set a control temperature (T.sub.C) based on the received target temperature and T.sub.S; and a control system configured to: control heating of the workpiece via a heating device until the workpiece reaches T.sub.C as measured by at least one of the one or more temperature sensors, and controlling the heating device to stop heating the workpiece in response to the workpiece reaching T.sub.C; wherein: the processor is configured to characterize a temperature ramp rate based on a measured temperature overshoot at the workpiece after turning off the heating device; and the control system is configured to control heating of the workpiece to T.sub.T by controlling the heating device based on the temperature ramp rate.

An example system for controlling heating of a workpiece includes: an interface configured to receive a target temperature (T.sub.T) for the workpiece; a processor configured to: select a current temperature (T.sub.S) for the workpiece based on monitoring one or more temperature sensors; and set a control temperature (T.sub.C) based on the received target temperature and T.sub.S; and a control system configured to: control heating of the workpiece via a heating device until the workpiece reaches T.sub.C as measured by at least one of the one or more temperature sensors, and controlling the heating device to stop heating the workpiece in response to the workpiece reaching T.sub.C; wherein: the processor is configured to characterize a temperature ramp rate based on a measured temperature overshoot at the workpiece after turning off the heating device; and the control system is configured to control heating of the workpiece to T.sub.T by controlling the heating device based on the temperature ramp rate.

A system for controlled induction welding of at least one weld seam area (A) of at least two surfaces of at least one workpiece is provided. The system comprises an inductor configured to be arranged in conjunction with the at least one workpiece, a processing means configured to generate an electromagnetic field by applying an alternating voltage to the inductor so as to inductively heat at least one of the surfaces so that the weld seam area (A) is welded together, simultaneously measure at least one parameter (P) of the at least one workpiece at least based on the generated electromagnetic field, detect a change of the at least one parameter (P), and determine a temperature estimation of the at least one workpiece based on said detected change.