EP3556181B1 - Domestic appliance - Google Patents

Description

The invention relates to a household appliance device, in particular a cooking device device according to the preamble of claim 1.

A household appliance device with at least one inverter unit in a half-bridge or full-bridge circuit for operating a plurality of inductors by means of a multiplexer is already known from the prior art.

the EP 1 206 164 A2 discloses a device that comprises a plurality of heating cells (resistors) for determining the installation location of cooking appliances on a hob, which are distributed in a matrix arrangement below a heat-resistant surface on which the cooking appliance can be set up as desired, based on the determination of the installation location , Shape and dimensions [of the cooking device], energy is applied to those heating cells which are below the cooking device, the same heating cells also being used individually for the determination.

the EP 0 862 714 B1 shows a household appliance device according to the preamble of claim 1.

The object of the invention is in particular to provide a device of the generic type with improved properties with regard to efficiency. The object is achieved according to the invention by the features of claim 1, while advantageous configurations and developments of the invention can be found in the subclaims.

A household appliance device, in particular a cooking device device and preferably a hob device, is proposed with at least a number N of row switching elements, with at least a number M of column switching elements and with at least one heating matrix which has at least one, in particular exactly one, number NxM of heating matrix elements, where for any i from 1 to N and any j from 1 to M with a total number N + M of column switching elements and row switching elements greater than 2, the i, j-th heating matrix element is at least one, preferably comprises exactly one, i, j-th inductor and is connected to both the i-th row switching element and the j-th column switching element.

In this context, a “household appliance device” should be understood to mean in particular at least a part, preferably at least one subassembly, of a household appliance. In particular, the household appliance device can also include the entire household appliance. The household appliance is in particular as a cooking device, preferably as a microwave, an oven and / or a, in particular variable, hob, in particular a matrix hob, and particularly preferably as an inductive cooking device, such as in particular an induction oven and / or preferably an induction hob, in particular a Matrix induction hob, formed. A “cooking appliance device” is to be understood in particular as a household appliance device which at least partially forms a cooking appliance. A "variable hob" is to be understood in this context in particular as a hob in which inductors are arranged, in particular in a regular spatial arrangement, in particular under a hob plate of the household appliance device, and at least partially form at least one heating zone, preferably several variable heating zones, which preferably comprises an area of the hob plate of at least 10%, preferably of at least 30% and particularly advantageously of at least 40% of a total area of the hob plate. In particular, the inductors are provided for the purpose of forming the heating zone and adapting it to the cooking utensil as a function of a position of cooking utensils positioned on the hob plate. “Provided” is to be understood in particular as specifically programmed, designed and / or equipped. The fact that an object is provided for a specific function should be understood in particular to mean that the object fulfills and / or executes this specific function in at least one application and / or operating state. In this context, a “number” should be understood to mean any number from the set of natural numbers. In particular, it should always apply that the total number N + M of column switching elements and row switching elements is greater than 2 if the number N of row switching elements and / or the number M of column switching elements is greater than 1. In this context, a “row switching element” and / or a “column switching element” should be understood to mean, in particular, switching elements which rows and / or columns of a grid are assigned to and / or define a circuit diagram arrangement. The circuit arrangement is in particular different from a spatial arrangement in which the column switching elements and row switching elements can be arranged in a particularly compact arrangement preferred by a person skilled in the art. The row switching elements are connected in particular to a reference potential common to the row switching elements. The reference potential common to the line switching elements is in particular an operating potential of an operating voltage with which the household appliance device is operated. The reference potential common to the line switching elements is in particular a ground potential. The column switching elements are in particular connected to a further reference potential common to the column switching elements. The further reference potential common to the column switching elements is in particular a further operating potential of the operating voltage. The further reference potential common to the column switching elements is in particular of one Different ground potential. In particular, an operating voltage is applied between the reference potential common to the row switching elements and the further reference potential common to the column switching elements. In this context, a "switching element" should be understood to mean in particular an element which is provided to connect a first connection to at least one second connection in an electrically conductive manner in at least one first switching state and the first connection to the second connection in at least one second switching state to separate. In particular, the switching element has at least one control connection via which the switching state of the switching element can be controlled. The switching element is provided in particular to change over from one of the switching states to the other switching state in a switching process. The switching element can be designed as any switching element, preferably a semiconductor switching element, that appears sensible to a person skilled in the art, such as a transistor, preferably an FET, a MOSFET and / or an IGBT, preferably an RC-IGBT and particularly preferably a HEMT Transistor. A “HEMT transistor” is to be understood in particular as a high electron mobility transistor, in particular with a particularly high electron mobility, which is particularly preferred ^{at 25 ° C., in particular at least 400 cm 2} V ^-1 s ^-1 is at least 600 cm ² V ^-1 s ^-1 , more preferably at least 800 cm ² V ^-1 s ^-1 and particularly preferably at least 1000 cm ² V ^-1 s ^-1 . Furthermore, modulation doped field effect transistors (MODFET), two-dimensional electron gas field effect transistors (TEGFET), selectively doped heterojunction transistors (SDHT) and / or heterojunction field effect transistors should also be used (HFET) can be understood as HEMT transistors. In particular, the switching element has at least one first connection, which is preferably a source connection, a second connection, which is preferably a drain connection, and / or a control connection, which is in particular a gate connection. In particular, at least one diode, in particular a feedback diode, and / or at least one capacitance, in particular a damping capacitance, of the household appliance device can be connected in parallel with the switching element. At least one i-th row switching element and at least one j-th column switching element, which are connected in particular in a full-bridge topology or preferably in a half-bridge topology, serve in particular as inverter switching elements and together form at least partially, preferably completely, an i, j-th inverter unit of the Household appliance device. The household appliance device comprises, in particular, a number N × M of inverter units. An "i, j-th inverter unit" is to be understood as meaning, in particular, a unit which is provided to supply a high-frequency heating current, preferably with a frequency of at least 1 kHz, in particular of at least 10 kHz and advantageously of at least 20 kHz, in particular at a Operation of the i, j-th inductor, to provide and / or to generate. The household appliance device has a control unit which is provided for controlling the row switching elements and the column switching elements. A “control unit” is to be understood in particular as an electronic unit which is preferably at least partially integrated in a control and / or regulating unit of a household appliance. The control unit preferably comprises a computing unit and, in particular, in addition to the computing unit, a memory unit with a control and / or regulating program stored therein, which is provided to be executed by the computing unit. The control unit is particularly advantageously provided to control the row switching elements and the column switching elements as inverter switching elements, in particular in such a way that a smooth switching process occurs between at least a first switching state and a second switching state of the switching elements. A "soft switching process" is to be understood in particular as a switching process with a negligibly low power loss, which occurs in particular when the switching process is in particular at least substantially current-free and / or preferably at least substantially voltage-free. An "at least substantially current-free switching process", which is also known in particular by the English term "zero current switching (ZCS)", is to be understood in particular as a soft switching process in which a current, which in particular immediately before a switching process in the i , j-th heating matrix element and in particular flows in the i, j-th inductor, is at least substantially negligibly small, in particular substantially zero. In particular, the control unit is provided to switch the switching elements during an at least substantially current-free switching process with a switching frequency which is less than or equal to a resonance frequency of the i, j-th heating matrix element. An "at least substantially voltage-free switching process", which is also known by the English designation "zero voltage switching (ZVS)", is to be understood in particular as a soft switching process in which a voltage that, in particular, immediately before a switching process at the i, j-th heating matrix element and in particular is applied to the i, j-th inductor and / or falls, is at least essentially vanishingly small, in particular essentially zero. In particular, the control unit provided to switch the switching elements in an at least substantially voltage-free switching process with a switching frequency which is greater than a resonance frequency of the i, j-th heating matrix element. A "vanishingly low value" is to be understood in particular as a value which is in particular at least a factor of 10, preferably at least a factor 50, preferably at least a factor 100 and particularly preferably at least a factor 500 lower than a maximum operating value. A “heating matrix” is to be understood in particular as a grid of a circuit diagram arrangement of i, j-th heating matrix elements. The i, j-th heating matrix element is in particular connected at least indirectly and preferably directly to both the i-th row switching element and the j-th column switching element. The fact that “at least two electrical components are directly connected to one another” should in particular be understood in this context to mean that a connection between the electrical components is free of at least one further electrical component which is a phase between a current and a voltage and / or preferably changes a current and / or a voltage itself. Particularly preferably, the i, j-th inductor has at least one, in particular exactly one i, j-th connection, which is connected both to the i-th row switching element, in particular to a first connection of the i-th row switching element, and to the j- th column switching element, in particular with a second connection of the j-th column switching element, is connected. An "inductor" is to be understood in particular as an electrical component which, in at least one cooking mode, is provided to inductively heat at least one cookware that is positioned on the hob plate of the household appliance device. The inductor comprises at least one, preferably in the form of a circular disk, wound electrical conductor through which a high-frequency heating current flows in at least the cooking operating state. The inductor is preferably provided to convert electrical energy into an alternating magnetic field in order to cause eddy currents and / or magnetic reversal effects in the cookware, which are converted into heat.

A household appliance device with improved properties in terms of efficiency, in particular cost efficiency and / or energy efficiency, can advantageously be provided by means of a corresponding configuration. In particular, a number of switching elements can be reduced, since switching elements partially operate several inductors, whereby component costs can be saved. Can be further advantageous different inductors of the heating matrix can be controlled individually, as a result of which energy consumption can be lowered and, in particular, an electrical stray field can be reduced. The above-mentioned arrangement particularly advantageously enables the switching elements to be switched softly, in particular in particular at least substantially without current or at least substantially without voltage, as a result of which switching losses can be reduced. Furthermore, an advantageous detection of cookware can be made possible, with additional components, such as sensor elements, being able to be avoided.

In order to reduce the installation space required for the inductors and in particular to achieve an efficient spatial arrangement of the inductors for a cooking operation of cooking utensils, it is further proposed that the inductors are spatially arranged in an inductor matrix which, with respect to a proximity ratio of at least two of the inductors, is is different to one another from the heating matrix in which the inductors are arranged in a circuit diagram. An "inductor matrix" is to be understood in particular as a grid of a spatial arrangement of the inductors below a hob plate of the household appliance device. A “different proximity ratio” is to be understood in particular to mean that nearest neighbors of i, j-th inductors in the inductor matrix are not nearest neighbors of i, j-th inductors in the heating matrix.

In a preferred embodiment of the invention, it is proposed that the inductors are spatially arranged in the inductor matrix such that at least one i, j-th inductor, for which i = j applies in the heating matrix, is adjacent to at least one i, j-th inductor is for which i ≠ j in the heating matrix. An “i, j-th inductor for which i = j applies in the heating matrix” is to be understood in particular as a diagonal inductor which is arranged on a diagonal of the heating matrix. An “i, j-th inductor for which i ≠ j applies in the heating matrix” is to be understood in particular as an off-diagonal inductor which is arranged outside a diagonal of the heating matrix. Preferably, between at least two i, j-th inductors, for which i = j applies in the heating matrix, at least one i, j-th inductor, for which i ≠ j applies in the heating matrix, is arranged. Particularly preferred is an i, j-th inductor for which i = j in the heating matrix applies, of several, in particular of at least three, preferably of at least four and particularly preferably of at least five i, j-th inductors, for which i ≠ j in the heating matrix, surrounded, preferably surrounded in a ring. Alternatively, it is conceivable that the heating matrix is free of i, j-th heating matrix elements and in particular i, j-th inductors, for which i = j applies in the heating matrix. In this way, control of the household appliance device can be further simplified, since, in particular, simultaneous operation of diagonal inductors can be avoided.

In a particularly preferred embodiment of the invention, it is proposed that in the inductor matrix i, j-th inductors of the same i or the same j are adjacent to one another and preferably directly adjacent to one another. In particular, the i, j-th inductors of the same i or the same j are arranged in the same row or column of the heating matrix. In particular, i, j-th inductors of the same i or j are arranged grouped with one another and in particular form at least partially, preferably at least to a large extent and particularly preferably completely at least one heating zone for a cookware. More preferably, i, j-th inductors of different i or j form at least partially different heating zones. As a result, control of the household appliance device can be further simplified since, in particular, simultaneous operation of at least two i, j-th inductors, for which i = j applies in the heating matrix, can particularly advantageously be avoided.

It is conceivable that the total number N + M of column switching elements and row switching elements is less than or equal to the number N × M of heating matrix elements. In order to operate a number N × M of heating matrix elements with the lowest possible total number N + M of column switching elements and row switching elements and advantageously reduce component costs, it is proposed that the number N of column switching elements is equal to the number M of row switching elements. In particular, the heating matrix is then designed as a square matrix.

In order to exclude unintentional activation of at least two diagonal inductors, it is proposed that the total number N + M of column switching elements and row switching elements is one greater than the number N × M of heating matrix elements. For this case, the heating matrix is designed in particular as a vector, preferably a row vector, in particular if the number N of row switching elements is 1, or as a column vector, in particular if the number M of column switching elements is 1.

Furthermore, it is proposed that the i, j-th heating matrix element have at least one i, j-th diode, by means of which the i, j-th inductor is connected at least to the i-th row switching element. In particular, the i, j-th diode is connected to the i, j-th connection between the i, j-th inductor and the i-th row switching element. The i, j-th diode allows in particular a current flow in the direction of the i-th row switching element and preferably blocks a current flow in the direction of the i, j-th inductor. In particular in the event that the number of row switching elements is equal to 1, the i, j-th diode can be dispensed with. In addition, in particular a flyback diode and / or a damping capacitor of the household appliance device could be connected in parallel with the j-th column switching element. The i, j-th heating matrix element further advantageously has at least one i, j-th further diode, by means of which the i, j-th inductor is connected at least to the j-th column switching element. In particular, the i, j-th further diode is connected to the i, j-th connection between the i, j-th inductor and the j-th column switching element. The i, j-th diode in particular allows a current flow in the direction of the i, j-th inductor and preferably blocks a current flow in the direction of the j-th column switching element. Furthermore, in the event that the number M of column switching elements is equal to 1, the further i, j-th diode can be dispensed with. In addition, in particular a flyback diode and / or a damping capacitor could be connected in parallel to the i-th row switching element. In this way, in particular, an uncontrolled flow of current, in particular between a plurality of heating matrix elements, can be avoided.

It is further proposed that the i, j-th heating matrix element have at least one i, j-th capacitance, by means of which the i, j-th inductor is connected to at least one reference potential common to the heating matrix elements. The reference potential common to the heating matrix elements is in particular the operating potential. Furthermore, the i, j-th heating matrix element has in particular at least one i, j-th further capacitance, by means of which the i, j-th inductor is connected to at least one further reference potential common to the heating matrix elements. The further reference potential common to the heating matrix elements is in particular the further operating potential. The i, j-th capacitance comprises at least one capacitor. The capacitance can preferably comprise a plurality of capacitors, in particular a capacitor network, which preferably consists of capacitors connected at least partially in series and / or in parallel with one another. Furthermore, the capacitance can in particular be adjustable. The i, j-th inductor in particular has at least one i, j-th further connection, which is connected to both the i, j-th capacitance and the i, j-th further capacitance. In this way, a natural frequency of an oscillating circuit of the household appliance device can advantageously be matched to the area of application by a corresponding selection of the capacities.

It is further proposed that the heating matrix comprises a number N of row diodes, the i-th row diode connecting at least the i-th row switching element to at least one further reference potential common to the row switching elements, in particular the further operating potential. It is further proposed that the heating matrix comprises a number M of column diodes, the jth column diode connecting at least the jth column switching element to at least one reference potential common to the column switching elements, in particular the operating potential. This enables a particularly smooth shifting process to be achieved.

In at least one cooking utensil recognition mode, the control unit is provided to determine at least one electrical parameter occurring at at least one of the inductors when an operating voltage assumes an at least essentially negligibly low value. The electrical parameter is preferably correlated with an electromagnetic coupling of the inductor with a cookware, in particular with a degree of coverage and / or a material of the cookware. In particular, the control unit can infer the electromagnetic coupling of the inductor to the cookware at least on the basis of the electrical parameter and preferably determine this. The electrical parameter corresponds in particular to a direct control variable. The electrical parameter is advantageously an electrical signal and / or electronic signal, in particular measured by a sensor unit of the household appliance device. The electrical parameter is preferably a frequency, amplitude and / or phase of a voltage that is applied to the inductor and / or of a current that flows through the inductor. This can improve the flexibility of the household appliance device, since cooking utensils can be detected.

In the cooking utensil detection mode, the control unit is provided to charge the inductor first and then when an operating voltage has an at least substantially negligible value assumes to discharge again. The control unit is advantageous in the cookware recognition mode provided to detect a characteristic curve of a discharge process of the inductor and to determine the electrical parameter by means of this characteristic curve. The characteristic curve is, in particular, a time profile of the electrical parameter. In particular, the control unit is provided to determine the electrical characteristic value by adapting a comparison characteristic curve to the characteristic curve, in particular based on parameters for generating the comparison characteristic curve. In this way, the inductor can be discharged in a simple manner, it being possible to avoid a short circuit with other electrical components.

The household appliance device should in particular not be restricted to the application and embodiment described above. In particular, the household appliance device can have a number of individual elements, components and units that differs from a number of individual elements, components and units mentioned herein in order to fulfill a mode of operation described herein. In the case of the value ranges specified in this disclosure, values lying within the stated limits should preferably also be regarded as disclosed and can be used as desired

Further advantages emerge from the following description of the drawings. Several exemplary embodiments of the invention are shown in the drawing. The drawing, the description and the claims contain numerous features in combination.

Fig. 1

ein Haushaltsgerät mit einer Haushaltsgerätevorrichtung in einer schematischen Draufsicht,

Fig. 2

ein schematisches Schaltbild eines Teils der Haushaltsgerätevorrichtung mit einer Heizmatrix,

Fig. 3

einen Teil der Haushaltsgerätevorrichtung mit einer Induktormatrix in einer schematischen Draufsicht,

Fig. 4

einen schematischen Ablaufplan eines Verfahrens zum Betrieb der Haushaltsgerätevorrichtung mit einem Gargeschirrerkennungsmodus,

Fig. 5 a-b

verschiedene Schaubilder mit typischen Strom- und/oder Spannungsverläufen bei einem Betrieb der Haushaltsgerätevorrichtung,

Fig. 6 a, b

verschiedene Schaubilder mit typischen Strom- und/oder Spannungsverläufen bei einem Betrieb der Haushaltsgerätevorrichtung,

Fig. 7

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung,

Fig. 8

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung,

Fig. 9

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung,

Fig. 10

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung,

Fig. 11

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung,

Fig. 12

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung,

Fig. 13

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung,

Fig. 14

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung,

Fig. 15

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung und

Fig. 16

eine weitere Haushaltsgerätevorrichtung in einer schaltbildlichen Darstellung.

Show it:

Fig. 1

a household appliance with a household appliance device in a schematic top view,

Fig. 2

a schematic circuit diagram of part of the household appliance device with a heating matrix,

Fig. 3

a part of the household appliance device with an inductor matrix in a schematic plan view,

Fig. 4

a schematic flow chart of a method for operating the household appliance device with a cooking utensil detection mode,

Fig. 5

various diagrams with typical current and / or voltage curves when the household appliance device is in operation,

Fig. 6 a, b

various diagrams with typical current and / or voltage curves when the household appliance device is in operation,

Fig. 7

another household appliance device in a circuit diagram,

Fig. 8

another household appliance device in a circuit diagram,

Fig. 9

another household appliance device in a circuit diagram,

Fig. 10

another household appliance device in a circuit diagram,

Fig. 11

another household appliance device in a circuit diagram,

Fig. 12

another household appliance device in a circuit diagram,

Fig. 13

another household appliance device in a circuit diagram,

Fig. 14

another household appliance device in a circuit diagram,

Fig. 15

another household appliance device in a circuit diagram and

Fig. 16

another household appliance device in a circuit diagram.

Fig. 1 shows a household appliance 48a with a household appliance device in a schematic plan view. In the present case, the household appliance 48a is designed as a cooking appliance. The household appliance 48a is a hob, in particular a variable induction hob. Alternatively, the household appliance 48a can be designed as any household appliance 48a, in particular a cooking appliance, that is different from a hob and in particular appears to be advantageous to a person skilled in the art, such as a microwave or an induction oven.

The household appliance device has a hob plate 50a. The household appliance device is provided to at least one cooking utensil, which on any Position is arranged on the hob plate 50a to operate. The hob plate 50a comprises preferred heating zone positions 52a, which indicate preferred positions for cooking utensils. In the present case, the hob plate 50a has six preferred heating zone positions 52a. For a better overview, only one of the preferred heating zone positions 52a is provided with a reference number. The hob plate 50a can in particular have any number of preferred heating zone positions 52a or even no preferred heating zone positions 52a.

Fig. 2 shows a schematic circuit diagram of part of the household appliance device. The household appliance device comprises at least a number N of row switching elements 10a. Furthermore, the household appliance device comprises at least a number M of column switching elements 12a. The household appliance device comprises at least one heating matrix 14a. The heating matrix 14a has at least one i, j-th heating matrix element 16a for any i from 1 to N and any j from 1 to M. The heating matrix 14a has a number N × M of heating matrix elements 16a. A total number N + M of row switching elements 10a and column switching elements 12a is greater than 2. The total number N + M of row switching elements 10a and column switching elements 12a is less than or equal to the number N × M of heating matrix elements 16a. In the present case, the household appliance device has a number of N = 8 line switching elements 10a. In the present case, the household appliance device has a number of N = 3 column switching elements 12a. In addition, the household appliance device has a number of N × M = 24 heating matrix elements 16a. However, it is also conceivable that N and / or M can be any other natural number that is considered to be particularly advantageous by a person skilled in the art. Alternatively or additionally, a number N can be selected to be equal to a number M or such that the total number N + M is one greater than the number N × M.

In the following, an arrangement of the electrical components of the household appliance device, in particular a circuit diagram, is explained by way of example using i-th, j-ter and i, j-th electrical components of the household appliance device. The following explanations can be applied to other equivalent electrical components.

The i-th row switch element 10a is designed as a transistor. The i-th row switch element 10a has a first connection. The first connection is a source connection. The first connection of the i-th row switch element 10a is connected to the i, j-th heating matrix element 16a. The i-th row switch element 10a has a second Connection on. The second connection is a drain connection. The second connection of the i-th row switch element 10a is connected to a reference potential 30a common to the row switch elements 10a. The reference potential 30a common to the row switching elements 10a is an operating potential of an operating voltage, specifically preferably a ground potential. The household appliance device has, in particular, a rectifier which at least partially converts a line voltage into the operating voltage. The operating voltage is the voltage which is present between the reference potential 30a common to the row switching elements 10a and a further reference potential 32a common to the column switching elements 12a. The i-th row switch element 10a has a control connection. The control connection is a gate connection. The control connection is connected to a control unit 38a of the household appliance device.

The j-th column switching element 12a is formed as a transistor. The j-th column switching element 12a has a first connection. The first connection is a source connection. The first connection of the j-th column switching element 12a is connected to the further reference potential 32a common to the column switching elements 12a. The further reference potential 32a common to the column switching elements 12a is the further operating potential. The j-th column switching element 12a has a second terminal. The second connection is a drain connection. The second terminal of the j-th column switching element 12a is connected to the i, j-th heating matrix element 16a. The j-th column switching element 12a has a control connection. The control connection is a gate connection. The control connection is connected to the control unit 38a of the household appliance device.

The i-th row switch element 10a and the j-th column switch element 12a are arranged in a half-bridge topology. It is conceivable that the household appliance device comprises i-th further row switching elements 10a and j-th further column switching elements 12a, so that i-th row switching elements 10a, i-th further row switching elements 10a, j-th column switching elements 12a and j-th further column switching elements 12a can be arranged in a full bridge topology.

The i-th row switching element 10a and the j-th column switching element 12a serve as inverter switching elements. The i-th row switching element 10a and the j-th column switching element 12a together form at least one i, j-th inverter unit 54a of FIG Household appliance device. The household appliance device comprises, in particular, a number of N × M inverter units 54a. The control unit 38a is provided to control the i-th row switching element 10a and the j-th column switching element 12a as inverter switching elements. The control unit 38a controls the i-th row switching element 10a and the j-th column switching element 12a in such a way that a soft switching process occurs between at least a first switching state and a second switching state of the i-th row switching element 10a and the j-th column switching element 12a.

The i, j-th heating matrix element 16a has at least one i, j-th inductor 18a. The i, j-th inductor 18a is connected both to the i-th row switching element 10a and to the j-th column switching element 12a. The i, j-th inductor 18a has at least one i, j-th connection 20a. The i, j-th connection 20a is connected both to the i-th row switch element 10a, in particular the first connection of the i-th row switch element 10a, and to the j-th column switch element 12a, in particular to the second connection of the j-th column switch element 12a , connected. A total of N × M inductors 18a are arranged in a circuit diagram in the heating matrix 14a.

The i, j-th heating matrix element 16a has at least one i, j-th diode 24a. The i, j-th inductor 18a is connected to at least the i-th row switching element 10a by means of the i, j-th diode 24a. A first connection of the i, j-th diode 24a is connected to the i, j-th connection 20a of the i, j-th inductor 18a. A second connection of the i, j-th diode 24a is connected to a first connection of the i-th row switch element 10a. The i, j-th diode 24a allows a current to flow in the direction of the i-th row switching element 10a. The i, j-th diode 24a blocks a current flow in the direction of the i, j-th inductor 18a.

The i, j-th heating matrix element 16a has at least one i, j-th further diode 26a. The i, j-th inductor 18a is connected to at least the j-th column switching element 12a by means of the i, j-th further diode 26a. A first connection of the i, j-th further diode 26a is connected to the i, j-th connection of the i, j-th inductor 18a. A second connection of the i, j-th further diode 26a is connected to the second connection of the j-th column switching element 12a. The i, j-th further diode 26a allows a current to flow in the direction of the i, j-th inductor 18a. The i, j-th further diode 26a blocks a current flow in the direction of the j-th column switching element 12a.

The i, j-th heating matrix element 16a has at least one i, j-th capacitance 28a. The i, j-th capacitance 28a is a capacitor. By means of the i, j-th capacitance 28a, the i, j-th inductor 18a is connected to at least one reference potential 30a common to the heating matrix elements 16a. The reference potential 30a common to the heating matrix elements 16a is the operating potential. A first connection of the i, j-th capacitance 28a is connected to an i, j-th further connection 42a of the i, j-th inductor 18a. A second connection of the i, j-th capacitance 28a is connected to the common reference potential 30a.

In Fig. 3 a plan view of part of the household appliance device with an inductor matrix 22a is shown. In the present case, i, j-th inductors 18a are the same i in FIG Fig. 3 provided with the same hatching. Inductors 18a, for which i = j applies in the heating matrix 14a, are additionally marked with a point. The i, j-th inductors 18a are spatially arranged in the inductor matrix 22a. The inductor matrix 22a is different from the heating matrix 14a with respect to the proximity relationships of at least two of the i, j-th inductors 18a relative to one another. In the inductor matrix 22a, i, j-th inductors 18a of the same i or j are adjacent to one another. In the inductor matrix 22a, the i, j-th inductors 18a are spatially arranged such that at least one i, j-th inductor 18a, for which i = j applies in the heating matrix 14a, is adjacent to at least one i, j-th inductor 18a is, for which i ≠ j in the heating matrix 14a applies. An i, j-th inductor 18a, for which i = j applies in the heating matrix 14a, is one of several, in particular of at least three, preferably of at least four and particularly preferably of at least five, i, j-th inductors 18a, for which i ≠ j in the heating matrix 14a applies, surrounded, preferably surrounded in a ring shape.

Fig. 4 shows a method for controlling the household appliance device. In the present case, the method is described on the basis of an exemplary operation of the electrical components with the indices i = 1 and i = 2, as well as the electrical components with the indices j = 1 and j = 2. The method can be transferred equivalently to any further i-th electrical components and j-th electrical components.

The method includes an operating step 56a. In operating step 56a, the control unit 38a controls the 2nd row switching element 10a and the 1st column switching element 12a as inverter switching elements. The 2nd row switching element 10a and the 1st column switching element 12a alternately change from a first switching state to a second switching state through a switching process. The 2nd row switching element 10a and the 1st column switching element 12a connect the 2,1th heating matrix element 16a, in particular the 2.1-th inductor 18a, alternating with the reference potential 30a common to the row switching elements 10a and the further reference potential 32a common to the column switching elements 12a. The 2nd row switching element 10a and the 1st column switching element 12a generate a supply voltage with which the 2.1th heating matrix element 16a, in particular the 2.1th inductor 18a, is operated. A heating current flows through the 2.1th heating matrix element 16a, in particular the 2.1th inductor 18a.

The method includes a cookware recognition mode 40a. The cooking utensil detection mode 40a runs at the same time as the operating step 56a. Alternatively, the cooking utensil detection mode 40a can take place independently of the operating step 56a. The cookware detection mode 40a comprises a loading step 58a. In the loading step 58a, the control unit 38a controls the 1st column switching element 12a in such a way that it changes to a first switching state. The 1,1th heating matrix element 16a, in particular the 1,1th capacitance 28a, is charged by means of the 1st column switching element 12a to the further reference potential 32a common to the column switching elements 12a. The control unit 38a controls the 1st row switching element 10a in such a way that it is in a second switching state and thus does not establish a conductive connection to the reference potential 30a common to the row switching elements 10a. No current flows, which means that the charged voltage is retained. In the same way, the 2.2th heating matrix element 16a, in particular the 2.2th capacitance 28a, is charged with the reference potential 30a made available by the 2nd row switching element 10a and common to the row switching elements 10a. In the loading step 58a, the control unit 38a controls the 2nd line switching element 10a, so that it changes to a second switching state. The 2.2th heating matrix element 16a, in particular the 2.2th capacitance 28a, is charged to the reference potential 30a common to the row switching elements 10a. The control unit 38a controls the 2nd column switching element 12a in such a way that it is in the second switching state and thus no conductive connection to the further reference potential 32a common to the column switching elements 12a is established. No current flows, which means that the charged voltage is retained.

The cookware detection mode 40a comprises an unloading step 60a. The unloading step 60a is performed during the operating step 56a. The operating voltage which is applied between the 2nd row switching element 10a and the 1st column switching element 12a is applied varies with time. If the operating voltage assumes an at least essentially negligibly low value, the discharging step 60a is carried out. The control unit 38a discharges the 1,1-th heating matrix element 16a. For this purpose, the control unit 38a switches the 1st line switching element 10a to the first switching state. The 1st row switching element 10a connects the 1.1th heating matrix element 16a, in particular the 1.1th capacitance 28a, to the reference potential 30a common to the row switching elements 10a. The heating matrix element 16a, in particular the 1.1-th capacitance 28a, discharges. A characteristic curve 46a of the discharging process is recorded. Another characteristic curve 47a of the discharging process is recorded.

The cookware detection mode 40a comprises a determination step 62a. In the determination step 62a, a comparison characteristic curve is adapted to the characteristic curve 46a detected in the discharging step 60a and in particular to the further characteristic curve 47a. A quality of an electromagnetic coupling is determined from parameters of the comparison characteristic. From the quality of the electromagnetic coupling, a degree of overlap between the 1,1th inductor 18a and a cookware coupled to the 1,1th inductor 18a and / or a material of the cookware is determined.

Figure 5a FIG. 13 shows a diagram of the method for controlling the home appliance device. A time is plotted on an abscissa axis 64a. A voltage is plotted on an ordinate axis 66a. A first voltage curve 68a shows a time profile of the supply voltage which is applied to the 2,1-th heating matrix element 16a. A second voltage curve 70a shows a time profile of a voltage which is applied to the 1,1th heating matrix element 16a. A third voltage curve 72a shows a time profile of a voltage which is applied to the 1,2-th heating matrix element 16a. A fourth voltage curve 74a shows a time profile of a voltage which is applied to the 2,2th heating matrix element 16a. A fifth voltage curve 76a shows a time profile of the operating voltage. In Figure 5b the curves 68a, 70a, 72a, 74a, 76a are shown again. In Figure 5b is an area of the graph of Figure 5a is shown at a point in time T at which the operating voltage assumes an at least essentially negligibly low value. In Fig.5b the abscissa axis 64a has a finer scaling than in FIG Figure 5a .

Figure 6a FIG. 13 shows a diagram of the method for controlling the home appliance device. A time is plotted on an abscissa axis 64a. On an ordinate axis 66a applied a stream. A first current curve 80a shows a time profile of the heating current which flows through the 2.1th heating matrix element 16a. A second current curve 82a shows a time profile of a current which flows through the 1,1-th heating matrix element 16a. A third current curve 84a shows a current which flows through the 1,2-th heating matrix element 16a. A fourth current curve 86a shows a current which flows through the 2,2-th heating matrix element 16a. In Figure 6b is an area of the graph of Figure 6a is shown at a point in time T at which the operating voltage assumes an at least essentially negligibly low value. In Fig.6b the abscissa axis 64a has a finer scaling than in FIG Figure 6a .

The second current curve 82a and the second voltage curve 70a show the charging step 58a of the 1,1-th heating matrix element 16a. In the charging step 58a, the 1,1th heating matrix element 16a is charged with the further reference potential 32a common to the column switching elements 12a. In the discharging step 60a, as soon as the operating voltage, the fifth voltage curve 76a, assumes an at least substantially zero value, the 1,1th heating matrix element 16a is discharged. A current flows which corresponds to the second current curve 82a. The second voltage curve 70a is recorded. The second voltage characteristic serves as a characteristic 46a for determining the electrical characteristic. The second current curve 82a is recorded. The second current curve 82a serves as a further characteristic curve 47a for determining the electrical parameter.

In the Figures 7 to 16 further embodiments of the invention are shown. The following description and the drawings are essentially limited to the differences between the exemplary embodiments, whereby with regard to components with the same designation, in particular with regard to components with the same reference numerals, in principle also to the drawing and / or the description of the other exemplary embodiments, in particular the Figures 1 to 6 , can be referenced. To distinguish the exemplary embodiments, the letter a is the reference number of the exemplary embodiment in FIG Figures 1 to 6 re-enacted. In the embodiments of Fig. 7 to 16 the letter a is replaced by the letters b to h, k, p and q.

Fig. 7 shows a circuit diagram of a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to a number N and a number M. In the present case, a number N of row switching elements 10b is equal to the number M of column switching elements 12b. Furthermore, the total number N + M of row switching elements 10b and column switching elements 12b is less than or equal to the number N × M of heating matrix elements 16b. In the present case the number N = 4 and the number M = 4. In the present case, at least the i-th row switching element 10b, in particular all row switching elements 10b, and / or at least the j-th column switching element 12b, in particular all column switching elements 12b, are designed as switches, preferably relays. The household appliance device also has an additional inverter unit 54b. The inverter unit 54b has a first inverter element 88b. The inverter unit 54b also has a second inverter element 89b. The inverter elements 88b, 89b are designed as transistors. The inverter element 88b connects the row switch elements 10b to a reference potential 30b common to the row switch elements 10b. The further inverter element 89b connects the column switching elements 12b to a further reference potential 32b common to the column switching elements 12b.

Fig. 8 shows a circuit diagram of a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to a number N and M. A total number N + M of row switching elements 10c and column switching elements 12c is one greater than a number N × M of heating matrix elements 16c. In the present case the number N = 2 and the number M = 1. A heating matrix 14c forms a circuit diagram vector, in particular a column vector. In an embodiment for which it applies that the total number N + M is one greater than the number N, i, 1st diodes can be dispensed with. A first connection of the i-th row switching element 10c is connected to an i, 1-th connection 20c of an i, 1-th inductor 18c.

Fig. 9 shows a circuit diagram of a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to a number N and M. A total number N + M of row switching elements 10d and column switching elements 12d is one greater than a number N × M of heating matrix elements 16d. In the present case, the number N = 1 and the number M = 2. A heating matrix 14d forms a circuit diagram vector, in particular a line vector. In an embodiment for which it applies that the total number N + M is one greater than the number N, 1, j-th diodes can be dispensed with. A first Terminal of the j-th row switching element 12d is connected to a 1, j-th terminal 20d of a 1, j-th inductor 18d.

Fig. 10 shows a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to further electrical components of the household appliance device. The household appliance device has a number M of column diodes 36e. The j-th column diode 36e connects at least one j-th column switching element 12e to at least one reference potential 30e common to the column switching elements 12e. The reference potential 30e common to the column switching elements 12e is equal to a reference potential 30e common to the row switching elements 10e. A first connection of the j-th column switching element 12e is connected to a further reference potential 32e common to the column switching elements 12e. A second connection of the j-th column switching element 12e is connected to a first connection of a j-th column diode 36e. The j-th column diode 36e blocks a current in the direction of the reference potential 30e common to the column switching elements 12e. The j-th column diode 36e allows a current from the direction of the reference potential 30e common to the column switching elements 12e.

The household appliance device has a number N of row diodes 34e. The i-th row diode 34e connects at least one i-th row switching element 10e to at least one further reference potential 32e common to the row switching elements 10e. The further reference potential 32e common to the row switching elements 10e is a further operating voltage. The further reference potential 32e common to the row switching elements 10e is the same as the further reference potential 32e common to the column switching elements 12e. A first connection of the i-th row diode 34e is connected to a first connection of the i-th row switching element 10e. A second connection of the i-th row diode 34e is connected to the further reference potential 32e common to the row switching elements 10e. The i-th row diode 34e blocks a current from the direction of the further reference potential 32e common to the row switching elements 10e. The i-th row diode 34e permits a current from the direction of the further reference potential 32e common to the row switching elements 10e.

An i, j-th heating matrix element 16e has at least one i, j-th further capacitance 29e. The i, j-th further capacitance 29e is a capacitor. By means of the further i, j-th capacity 29e, an i, j-th inductor 18e is connected to at least one further reference potential 32e common to the heating matrix elements 16e. The further reference potential 32e common to the heating matrix elements 16e is a further operating voltage. A first connection of the i, j-th further capacitance 28e is connected to an i, j-th further connection 42e of the i, j-th inductor 18e. A second connection of the i, j-th capacitance 28e is connected to the further reference potential 32e common to the heating matrix elements 16a. Alternatively or additionally, the i, j-th capacitance 28e can be designed as a capacitor network which comprises a plurality of capacitors in series and / or capacitors connected in parallel.

Fig.11 shows a further embodiment of the invention. The further embodiment differs from the previous embodiment at least essentially with regard to a number N and a number M. The total number N + M of row switching elements 10f and column switching elements 12f is one greater than the number NxM of heating matrix elements 16f. In the present case the number N = 2 and the number M = 1. The heating matrix 14f forms a circuit diagram vector, in particular a column vector. In an embodiment for which it applies that the total number N + M is one greater than the number N, i, 1st diodes can be dispensed with.

Fig.12 shows a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to a number N and a number M. The total number N + M of row switching elements 10g and column switching elements 12g is one greater than the number N × M of heating matrix elements 16g. In the present case the number N = 2 and the number M = 1. The heating matrix 14g forms a circuit diagram vector, in particular a column vector. In an embodiment for which it applies that the total number N + M is one greater than the number N. It is possible to dispense with i, 1st diodes. The household appliance device has a number of N return diodes 90g. The i-th flyback diode 90g is connected to the i-th row switching element 10g. The i-th flyback diode 90g is connected in parallel to the i-th row switching element 10g. A first connection of the flyback diode 90g is connected to a first connection of the i-th row switching element 10g. A second connection of the i-th flyback diode 90g is connected to a second connection of the i-th row switching element 10g. The i-th flyback diode 90g blocks a current flow in the direction of the reference potential common to the row switching elements 10g 30g. The i-th flyback diode 90g allows a current to flow from the direction of the reference potential 30g common to the row switching elements 10g. Alternatively or additionally, the household appliance device can have a number of further return diodes 90g. A j-th further flyback diode 90g could be connected in parallel with a j-th column switching element 12g. Furthermore, a column diode can be dispensed with in the present case.

Fig. 13 shows a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to a number of additional electrical components. The present exemplary embodiment differs in a circuit of row diodes 34h. In the present case, the i-th row diode 34h is connected to an i, j-th terminal 20h of an i, j-th inductor 18h. A first connection of the i-th row diode 34h is connected to the i, j-th connection 20h. A second connection of the i-th row diode 34h is connected to a further reference potential 32h common to the row switching elements 10h. The i-th row diode 34h blocks a current from the direction of the further reference potential 32h common to the row switching elements 10h. The i-th row diode 34h allows a current to pass from the direction of the further reference potential 32h common to the row switching elements 10h.

Fig. 14 shows a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to a number of additional electrical components. The household appliance device has a number N of line capacities 92k. The i-th row capacitance 92k is connected in parallel to an i-th row switching element 10k. Furthermore, the i-th row capacitance 92k is connected in parallel to an i-th flyback diode 90k. A first connection of the i-th row capacitance 92k is connected to a first connection of the i-th row switching element 10k. A second connection of the i-th row capacitance 92k is connected to a second connection of the i-th row switching element 10k. Furthermore, a column diode can be dispensed with in the present case.

Fig.15 shows a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to a number N and a number M. The total number N + M of row switching elements 10p and column switching elements 12p is one greater than the number NxM of heating matrix elements 16p. In the present case, the number N = 1 and the number M = 2. The heating matrix 14p forms a circuit diagram vector, in particular a line vector. In an embodiment for which the total number N + M is one greater than the number N, j, 1st further diodes can be dispensed with. The household appliance device has a number of M further return diodes 91p. The j-th further flyback diode 91p is connected to the j-th column switching element 12p. The j-th further flyback diode 91p is connected in parallel to the j-th column switching element 12p. A first connection of the further flyback diode 91p is connected to a first connection of the j-th column switching element 12p. A second connection of the j-th further flyback diode 91p is connected to a second connection of the j-th column switching element 12p. The j-th further flyback diode 91p allows a current to flow in the direction of the reference potential 32p common to the column switching elements 12p. The jth further flyback diode 91p blocks a current flow from the direction of the reference potential 32 common to the column switching elements 12p. Alternatively or additionally, the household appliance device can have a number of flyback diodes 90p. An i-th flyback diode 90p could be connected in parallel with an i-th row switching element 10p. Furthermore, a row diode can be dispensed with in the present case. Furthermore, an i-th row diode can be dispensed with.

Fig. 16 shows a further embodiment of the invention. The further exemplary embodiment differs from the previous exemplary embodiment at least essentially with regard to a number of additional electrical components. The household appliance device has a number M of column capacities 93q. The j-th column capacitance 93q is connected in parallel to a j-th column switching element 12q. The j-th column capacitance 93q is connected in parallel to a j-th further flyback diode 91q. A first connection of the j-th column capacitances 93q is connected to a first connection of the j-th column switching element 12q. A second connection of the j-th column capacitances 93q is connected to a second connection of the j-th column switching element 12q. Furthermore, an i-th row diode can be dispensed with.

Reference number

10

Line switch element

12th

Column switching element

14th

Heating matrix

16

Heating matrix element

18th

Inductor

20th

connection

22nd

Inductor matrix

24

diode

26th

Another diode

28

capacity

29

capacity

30th

Reference potential

32

Another reference potential

34

Line diode

36

Column diode

38

Control unit

40

Cookware detection mode

42

Another connection

46

curve

47

curve

48

Home appliance

50

Hob plate

52

Heating zone position

54

Inverter unit

56

Operational step

58

Loading step

60

Unloading step

62

Determination step

64

Abscissa axis

66

Ordinate axis

68

First tension curve

70

Second voltage curve

72

Third voltage curve

74

Fourth voltage curve

76

Fifth voltage curve

80

First current curve

82

Second current curve

84

Third current curve

86

Fourth current curve

88

Inverter element

89

Inverter element

90

Flyback diode

91

Another flyback diode

92

Line capacity

93

Column capacity

T

time

Claims (15)

1. Household appliance device, in particular a cooking appliance device, with at least a number N of row switching elements (10a-q), with at least a number M of column switching elements (12a-q), with at least one heating matrix (14a-q), which has at least a number NxM of heating matrix elements (16a-q),
   wherein for any i from 1 to N and any j from 1 to M with a total number N+M of row switching elements (10a-q) and column switching elements (12a-q) greater than 2, the heating matrix element (16a-q) at position i,j comprises at least one inductor (18a-q) at position i,j and is connected to both the i-th row switching element (10a-q) and the j-th column switching element (12a-q), and a control unit (38a-q), which is provided to activate the row switching elements (10a-q) and the column switching elements (12a-q). characterised in that in at least one cookware detection mode (40a), when the operating voltage has an at least essentially vanishingly low value, the control unit (38a-q) is provided to determine at least one electrical characteristic variable occurring at at least one of the inductors (18a-q), wherein in cookware detection mode (40a) the control unit (38a-q) is provided first to charge the inductor (18a-q) at position i,j and then, when an operating voltage has an at least essentially vanishingly low value, to discharge it again.
2. Household appliance device according to claim 1, characterised in that the inductor (18a-q) at position i,j has at least one connection (20a-q) at position i,j, which is connected to both the i-th row switching element (10a-q) and the j-th column switching element (12a-q).
3. Household appliance device according to claim 1 or 2, characterised in that the inductors (18a-q) are arranged spatially in an inductor matrix (22a) which differs, in respect of proximity relationships of at least two of the inductors (18a-q) relative to one another, from the heating matrix (14a-q) in which the inductors (18a-q) are arranged in a schematic circuit.
4. Household appliance device according to in claim 3, characterised in that in the inductor matrix (22a) the inductors (18a-q) are arranged spatially such that at least one inductor (18a-q) at position i,j, for which i=j in the heating matrix (14a-q), is adjacent to at least one inductor (18a-q) at position i,j, for which i≠j in the heating matrix (14a-q).
5. Household appliance device according to claim 3 or 4, characterised in that in the inductor matrix (22a) inductors (18a-q) at position i,j of identical i or identical j are adjacent to one another.
6. Household appliance device according to one of the preceding claims, characterised in that the number N of row switching elements (10b) is equal to the number M of column switching elements (12b).
7. Household appliance device according to one of claims 1 to 5, characterised in that the total number N+M of row switching elements (10c; 10d; 10f-q) and column switching elements (12c; 12d; 12f-q) is one greater than the number NxM of heating matrix elements (16c; 16d; 16f-q).
8. Household appliance device according to one of the preceding claims, characterised in that the heating matrix element (16a; 16b; 16d; 16e; 16p, 16q) at position i,j has at least one diode (24a; 24b; 24d; 24e; 24p; 24q) at position i,j, by means of which the inductor (18a; 18b; 18d; 18e; 18p; 18q) at position i,j is connected at least to the i-th row switching element (10a; 10b; 10d; 10e; 19p; 10q).
9. Household appliance device according to one of the preceding claims, characterised in that the heating matrix element (16a-c; 16e-k) at position i,j has at least one further diode (26ac; 26e-k) at position i,j, by means of which the inductor (18a-c; 18e-k) at position i,j is connected at least to the j-th column switching element (12a-e; 12e-k).
10. Household appliance device according to one of the preceding claims, characterised in that the heating matrix element (16a-q) at position i,j has at least one capacitance (28a-q) at position i,j, by means of which the inductor (18a-q) at position i,j is connected at least to at least one reference potential (30a-q) common to the heating matrix elements (16a-q).
11. Household appliance device according to one of the preceding claims, characterised by a number M of column diodes (36e; 36f; 36h; 36p; 36q), wherein the j-th column diode (36e; 36f; 36h; 36p; 36q) connects at least the j-th column switching element (12e; 12f; 12h; 12p; 12q) to at least one reference potential (30e; 30f; 30h; 30p; 30q) common to the column switching elements (12e; 12f; 12h; 12p; 12q).
12. Household appliance device according to one of the preceding claims, characterised by a number N of row diodes (34e-k), wherein the i-th row diode (34e-k) connects at least the i-th row switching element (10e-k) to at least one further reference potential (32e-k) common to the row switching elements (10e-k).
13. Household appliance device according to one of the preceding claims, characterised in that the control unit (38a-fq) is provided to activate the row switching elements (10a-q) and the column switching elements (12a-q) as inverter switching elements.
14. Household appliance device according to one of the preceding claims, characterised in that in cookware detection mode (40a) the control unit (38a-q) is provided to acquire a characteristic line (46a, 47a) of a discharging operation of the inductor (18a-q) at position i,j and to use this to determine the electrical characteristic variable.
15. Household appliance (48a), in particular a cooking appliance, with a household appliance device according to one of the preceding claims.

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