In a method for operating an induction hob including a controller and including a cooking point including an induction heating coil, a relationship between a cooking vessel temperature and a heating power of the induction heating coil is stored in the controller as area power which results in a constant cooking vessel temperature during long-term operation. By monitoring whether the cooking vessel temperature remains constant, increases or drops when a first relatively low heating power is set after a heating time at a high heating power, it is possible to set a target temperature, which corresponds to the first relatively low heating power, for frying processes.

The objective of the present invention is to enable accurate detection of a mismatch during electric resistance welding. This operation monitoring device for high-frequency resistance welding and induction heated welding of an electric resistance welded steel pipe, in which a strip-shaped metal sheet is continuously formed into a cylindrical shape by means of a group of rollers while being conveyed from an upstream side to a downstream side, and in which the two edge portions, in the circumferential direction, of the metal sheet, which are caused to converge into a V-shape, are caused to melt by the application of heat and are caused to abut one another, is characterized by being provided with a means for detecting a mismatch by recognizing a non-uniformity between light-emitting regions of a metal part, on both sides, in the circumferential direction, of the abutting position on an outer surface or an inner surface of the metal plate, on the basis of an image of a region including a V-convergence location, which is a location at which the two edge portions in the circumferential direction converge into said V-shape, and said metal part which is caused to flow out onto the surface of the metal plate by means of an electromagnetic force downstream of the V-convergence location, wherein said image is captured by means of an image capturing device from an outer surface side or an inner surface side of the metal plate that has been formed into said cylindrical shape.

The objective of the present invention is to enable accurate detection of a mismatch during electric resistance welding. This operation monitoring device for high-frequency resistance welding and induction heated welding of an electric resistance welded steel pipe, in which a strip-shaped metal sheet is continuously formed into a cylindrical shape by means of a group of rollers while being conveyed from an upstream side to a downstream side, and in which the two edge portions, in the circumferential direction, of the metal sheet, which are caused to converge into a V-shape, are caused to melt by the application of heat and are caused to abut one another, is characterized by being provided with a means for detecting a mismatch by recognizing a non-uniformity between light-emitting regions of a metal part, on both sides, in the circumferential direction, of the abutting position on an outer surface or an inner surface of the metal plate, on the basis of an image of a region including a V-convergence location, which is a location at which the two edge portions in the circumferential direction converge into said V-shape, and said metal part which is caused to flow out onto the surface of the metal plate by means of an electromagnetic force downstream of the V-convergence location, wherein said image is captured by means of an image capturing device from an outer surface side or an inner surface side of the metal plate that has been formed into said cylindrical shape.

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

Provided is a welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured. This welding monitoring apparatus includes an image capturing unit that captures images of a region including the V-convergence region in time series; and an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.

Provided is a welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured. This welding monitoring apparatus includes an image capturing unit that captures images of a region including the V-convergence region in time series; and an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.

An automatically flushing water heater maintenance system may be provided, the system including a water heater and a water heater controller. The water heater may include an inlet, an outlet, and a flush outlet having a first control valve in flow communication therewith. The first control valve may be configured to control a flow of water and sediment through the flush outlet out of the water heater. The water heater controller may be configured to communicate with the first control valve by transmitting a first control signal to the first control valve, the first control signal configured to cause the first control valve to open or close as part of an automatic flushing process. As a result of the flushing, the useful life of the water heater may be extended, and/or water heater leakage alleviated. Insurance discounts may be provided based upon using the automatic water heater flushing functionality.

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.

High frequency electrical heating system is provided for heating electrically conductive parts as they are advanced, either for annealing or welding processes, and in which the electrical heating current is supplied by a solid state DC to AC inverter through a load matching and frequency control circuit that maintains the desired load current and frequency with changes in the load impedance caused by the electrically conductive parts as they are advanced. Load matching is achieved with high frequency variable reactors having 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 reactor pair.

High frequency electrical heating system is provided for heating electrically conductive parts as they are advanced, either for annealing or welding processes, and in which the electrical heating current is supplied by a solid state DC to AC inverter through a load matching and frequency control circuit that maintains the desired load current and frequency with changes in the load impedance caused by the electrically conductive parts as they are advanced. Load matching is achieved with high frequency variable reactors having 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 reactor pair.