Method for controlling a cooking appliance

The present invention relates generally to the field of cooking appliances. More specifically, the present invention relates to a method for controlling a cooking appliance which provides au tomatic temperature control without user interaction.

BACKGROUND OF THE INVENTION

Cooking appliances, specifically cooking appliances based on in duction technology are known in prior art.

In known cooking appliances, the user has to change the power settings manually in order to maintain a constant or essentially constant temperature of the cookware item, which may be, for ex ample a pan or a pot.

Disadvantageously, such manual temperature control is imprecise and time-consuming.

SUMMARY OF THE INVENTION

It is an objective of the embodiments of the invention to pro- vide a method for controlling a cooking appliance which allows a more precise and user-friendly temperature control. The objec tive is solved by the features of the independent claims. Pre ferred embodiments are given in the dependent claims. If not ex plicitly indicated otherwise, embodiments of the invention can be freely combined with each other.

It is known in the art that household cooking hobs or cooking appliances usually are provided for conducting at least one cooking process comprising heating and/or cooling step, respec tively. Such cooking process preferably at least comprises a heating step, e.g. frying, boiling, simmering or pouching of a foodstuff or a cooking liquid, respectively. For supporting the foodstuff or cookware item, it is particularly known to provide a cooking support, for example in the form of a cooking surface. Such cooking surface usually provides a support for the cookware items, for example, provided in the form of a plate element, particularly a glass or glass ceramic plate.

Preferably, the cooking hob comprises, preferably consists of, a cooking support and a lower casing. Thereby it is preferred that an open top side of the lower casing is covered by at least a part of the cooking support. The cooking support may be provided particularly as at least one panel, wherein preferably the panel is a glass ceramic panel. Preferably, at least one or more heat ing power transferring elements are arranged beneath the panel.

The lower casing may be manufactured from different material comprising plastics or metal, e.g. aluminum.

In particular, such casing may include a bottom wall and at least one sidewall. It is preferred that said casing is made of metal, e.g. aluminium or steel, and/or plastics, wherein prefer- ably the casing made of metal is grounded.

Advantageously said lower casing may comprise at least one heat ing power energy unit, particularly arranged in a respective heating power energy unit housing, the heating power transfer- ring elements, heating power transferring element carrier or heating power transferring element support. In other words, the lower casing and the cooking support may form a closed unit com prising all essential parts of the cooking hob. Thereby the lower casing may comprise fastening means for fastening and/or arranging the cooking hob on top of or in a cutout of a work plate .

Thereby, preferably, a power transferring element may be ar- ranged below a cooking support. Preferably, the one or more heating power transferring elements are arranged in an upper portion of the lower casing of the cooking hob. A power trans ferring element may be arranged and supported by one or more heating power transferring element carrier or heating power transferring element support, preferably the power transferring element attached and/or arranged on said carrier or support. A housing comprising an energy power unit may be arranged below one or more heating power transferring element carrier or heat ing power transferring element supports. Thereby, preferably a heating power transferring element carrier or heating power transferring element support with the supported heating power transferring element may advantageously be arranged on top of and/or attached to such housing of an energy power unit. For conducting the cooking process, particularly a heating step, a cooking appliance, particularly the lower casing, comprises at least one heating power-transferring element. Said heating power-transferring element is provided for transferring heating power to the foodstuff or cooking liquid, preferably contained in a cookware item.

Preferably, the at least one heating power transferring element is an electric heating element, in particular an induction heat ing element, particularly induction coil, and/or radiant heating element. The heating power provided by a heating power-transfer- ring element may be preferably provided electrically. Prefera bly, the heating power may be provided by a heat-generating mag netic field, more particularly an induction field. Accordingly, the cooking hob of the present invention preferably is an induc tion hob.

Preferably, a heating power-transferring element in the form of an induction coil comprises a planar conductive winding wire, particularly a copper wire. Preferably, an induction coil com prises at least one magnetic field supporting element, e.g. a ferrite element. Preferably, said at least one magnetic field supporting element, particularly at least one ferrite element, is arranged below the plane of the conductive winding wire. Said at least one magnetic field supporting element, particularly ferrite element, is advantageous in establishing and/or support ing the high frequent alternating magnetic field of the induc tion coil. Said magnetic field supporting element, particularly if arranged below the conductive winding wire, may be glued to or supported by ferrite support elements, e.g. snap fit connect ors or the like.

Preferably, an induction coil comprises a shielding element, e.g. a mica sheet. The shielding element preferably is adapted to the form of the planar conductive winding wire or the form of at least two planar conductive winding wires of at least two ad jacently arranged coils. The shielding element preferably is provided above the at least one magnetic field supporting ele- ment, particularly at least one ferrite element. The shielding element preferably in its main function is a support for the planar conductive wire windings of the coil. However, addition ally the shielding element, particularly mica sheet, may also shield temperature radiated from the above, e.g. resulting from a heated up pot bottom.

In the cooking hob of the present invention the at least one heating power transferring element is preferably arranged and/or mounted on a heating power transferring element carrier or heat ing power transferring element support, particularly comprised in the lower casing. It is particularly preferred that a carrier made of aluminum sheet metal supports the heating power-trans- ferring element. Particularly, the cooking hob of the present invention may comprise power transferring element carrier or heating power transferring element support to support one heat ing power transferring element, however, it is also considered herein that one power transferring element carrier or heating power transferring element support is provided to support more than one heating power transferring element.

In a preferred embodiment of the present invention, two heating power transferring elements are arranged on and supported by one common heating power transferring element carrier. Particularly at least two induction coils are arranged on and supported by one common induction coil carrier plate.

The heating power transferring element carrier or heating power transferring element support may be advantageously supported by or on a housing of the heating energy power unit.

Particularly, at least one of, preferably all of, the heating power transferring elements of an cooking hob of the invention, more particularly an induction coil of an induction hob, may be arranged below a cooking support, particularly a cooking surface in form of a plate element, and particularly within the lower casing, in order to provide the heat for a heating step to a heating zone of the cooking support and to the bottom side of a cookware item and foodstuff, respectively, when placed on said heating zone.

A cooking support of a cooking hob of the invention, particu larly of an induction hob of the invention, preferably comprises at least one heating zone. Such heating zone as referred to herein, preferably refers to a portion of the cooking support, particularly cooking surface, which is associated with one heat ing power transferring element, e.g. a radiant heating element or an induction coil, which is arranged at, preferably below, the cooking support, e.g. the glass ceramic plate. Particularly, in an embodiment according to which the cooking hob of the pre sent invention is an induction hob, it is preferred that such heating zone refers to a portion of the cooking support, which is associated with at least one induction coil. Thereby, the heating power transferring elements associated with a heating zone are preferably configured such that the same heating power of the associated heating power transferring elements is trans ferred to the heating zone. Preferably, the heating zone thus refers to a portion of the cooking support to which the same heating power of the associated at least one heating power transferring element is transferred.

In addition, the cooking hob of the present invention, may par- ticularly be configured such that in one operation mode one or more than one heating zones form one cooking zone and/or are combined to one cooking zone, respectively. A cooking zone may be particularly provided as at least a portion of the cooking surface. Particularly, such cooking zone is associated with at least one heating zone. Additionally, or alternatively, a cook ing zone may be associated with more than one heating zone. Par ticularly, a cooking zone may be associated with an even number, particularly two, four, six, eight or ten, more particularly two, heating zones. Alternatively, a cooking zone may be associ- ated with an uneven number, particularly three, five, seven or nine, more particularly three, heating zones.

Preferably, the cooking hob of the present invention is config ured such that a cooking zone comprises one or more than one heating zones, which can be driven with the same or different power, frequency or heating level.

In the present invention, it is preferred that in at least one operation mode of the cooking hob according to the present in vention is configured such that a cooking zone comprises at least two, preferably two, heating zones, driven by the same power, frequency or heating level. Particularly, such cooking zone comprises or is associated with at least two, preferably two, heating power-transferring elements.

Additionally, or alternatively, the cooking hob of the present invention may be configured such that the number of heating zones associated with one cooking zone may vary and/or may be adjustable dependent on the needs of the cook and/or the size, form or kind of cookware placed on the cooking surface.

Particularly, a cooking hob according to the present invention, preferably an electric hob, such as an induction hob, may com- prise at least one heating power energy unit. A heating power energy unit as used herein, preferably provides energy to at least one of, preferable a number of, the heating power trans ferring elements such that the heating power transferring ele ment is capable of transferring heating power for heating up the foodstuff or cooking liquid. A heating power energy unit of an induction hob, for example, may provide energy in the form of a high frequency alternating current to a heating power-transfer- ring element in the form of an induction coil, which transfers heating power in the form of a magnetic field to a suitable cookware item. For such purpose, a heating power energy unit may comprise at least one associated power circuit mounted and/or arranged on at least one printed circuit board. Preferably, a heating power energy unit is supported and arranged in a hous ing, preferably a plastic housing, preferably arrangable in and adapted to the lower casing. This allows easy manufacturing and modularization .

Particularly, the housing may comprise supporting elements for supporting the heating power transferring element carrier or heating power transferring element support. Particularly, such supporting elements may comprise elastic means, e.g. springs or silicon elements, for elastically supporting the heating power transferring element carrier or heating power transferring ele- ment support, and particularly advantageous in pressing a heat ing power-transferring element onto the bottom surface of the cooking support plate, which particularly is a glass ceramic plate . Particularly, the heating power energy unit, and particularly the associated power circuit, may be configured to be connected to at least one, preferably two phases of a mains supply. A cooking hob according to the present invention thereby comprises at least one, preferably two or three heating power energy units, connected to one or two, preferably one phases of the mains supply each.

Preferably, a heating power energy unit may comprise at least - one associated power circuit, particularly in the form of an at least one heating power generator, for generating heating power and supplying heating power-transferring elements with heating power, particularly for providing heating power to the at least one heating zone. Thereby the power circuit particularly may be provided in the form of a half-bridge configuration or a quasi- resonant configuration.

It will be immediately understood that the heating power energy unit may thus comprise one heating power generator for providing heating power to more than one heating zone, each associated with at least one heating power transferring element.

Furthermore, the heating power energy unit may comprise one heating power generator comprising a single or pair of high fre quency switching elements, in the following also referred to as power transistor.

In particular, the high frequency switching element is provided in the form of a semiconductor-switching element, particularly an IGBT element.

In case the heating power energy unit may comprise one heating power generator comprising a single high frequency switching el- ement, the single switching element preferably forms part of as sociated power circuit, provided in the form of a or a part of a Quasi Resonant circuit.

In case that the heating power energy unit may comprise one heating generator comprises a pair of high frequency switching elements, said pair of high frequency switching elements prefer ably forms part of an associated power circuit, provided in the form of a or a part of a half-bridge circuit. A person skilled in the art will immediately understand that the heat, generated by and/or radiated from particularly the heating power transferring elements, the heating power energy unit and/or the cookware item, particularly the bottom thereof, may have also disadvantageous effects, particularly regarding safety and proper functioning. Particularly, the heating power energy unit, more particularly power circuits comprising switching ele ments, may generate a significant amount of heat being disad vantage for the safety and proper functioning of the cooking hob. For this reason, the cooking hob comprises at least one cooling means. Particularly, said cooling means is adapted for cooling down the electric and/or electronic elements. Particu larly, the heating power energy unit may comprise such cooling means. Such cooling means may comprise at least one of a fan, a cooling channel, a cooling body, preferably from a metal, par ticularly aluminium, cooling air-guiding means, cooling air de flection means and the like. Particularly, the cooking hob of the present invention may comprise such cooling means for cool ing at least one heating power generator or a part thereof, par- ticularly to at least one single or pair of high frequency switching elements. More particularly, such cooling means may comprise a cooling body, preferably arranged in the air path of a cooling fan, and thermally connected to at least one heating power generator or a part thereof, particularly to at least one single or pair of high frequency switching elements. Thereby it is preferred that the cooling means comprises at least one fan for generating an air stream through the cooling channel. Pref erably, the cooling channel and/or cooling body extends horizon tally through the cooking hob. For example, the cooling channel and/or cooling body extends over a substantial part of the hori zontal width of the cooking hob.

The cooking hob according to the present invention preferably further comprises a control unit. Such control unit is prefera- bly operatively connected with the heating power energy unit to control at least one operational parameter of the cooking hob, particularly an operational parameter of the heating power en ergy unit. Furthermore, the control unit comprises a user inter face at least for receiving a command input of a user. This ad- vantageously allows the user to control at least one operational parameter of the cooking hob, particularly an operational param eter of the heating power energy unit. Moreover, the control unit, and particularly a user interface if present, may be oper- atively connected to other appliances or interfaces, e.g. a suc tion hood, a voice control device, a server, a remote interface, a cloud-computing source or the like. Accordingly, the household cooking hob according to the present invention comprises at least one electric and/or electronic ele ment. Particularly, said at least one electric and/or electronic element comprises a heating power energy unit and/or control unit or parts thereof.

Particularly, the at least one electric and/or electronic ele ment of the household cooking hob of the present invention may be part of an at least one heating energy power unit, preferably mounted and/or arranged on a power board and/or a power generat- ing circuit mounted on a printed circuit board (PCB) .

Such at least one electric and/or electronic element may be, for example, selected from the group comprising a heating power gen erator, filter coils, EMC filters, rectifier, switching ele- ments, like IGBTs, relays, or the like.

According to an aspect, the invention refers to a method for controlling a cooking appliance with a temperature sensor. The cooking appliance comprises at least one heating power transfer- ring element for heating a cookware item placed on a cooking support .

The method comprises the following steps: Gathering temperature information related to the cookware item or its content with the temperature sensor at or in the cookware item. Optionally, after a heat-up process, information regarding a power reduction action initiated by a user input is gathered. In other words, a control unit of the cooking appliance monitors if a user input is received which lowers the heating power, respec- tively, the provision of power to one or more heating power transferring elements associated with a cooking zone.

Furthermore, temperature information provided by the temperature sensor is evaluated, said temperature information being corre- lated with the temperature of the cookware item or the cookware item content. The temperature sensor may be a temperature sensor which indirectly measures the temperature of the cookware item. Therefore, temperature information may comprise an offset or de lay with respect to the "real" temperature of the cookware item.

Temperature lock information is provided to the user if the var iation of the temperature of the cookware item or the cookware item content is equal or lower than a certain temperature varia tion value. In other words, it is monitored if the temperature variation over time decayed such that the temperature variation in a given period of time is lower than a temperature variation threshold value.

After providing temperature lock information, a temperature lock confirmation is received. Said temperature lock confirmation may be initiated by a user input at a user interface. The tempera ture hold information may be to an information to hold the cur rent temperature or to adjust the current temperature by a pre determined value, for example lower or increase the temperature by 2 °C.

After receiving said temperature lock confirmation, the provi sion of heat energy to the cookware item is controlled based on temperature information provided by the temperature sensor such that the temperature of the cookware item or the cookware item content is maintained within a given temperature range. Said provision of heat energy to the cookware item is controlled au tomatically without any manual control of the user.

Said method is advantageous because the temperature of the cook ing process can be controlled in a comfortable and user-friendly way . According to an embodiment, the temperature information at the point of time at which the temperature lock information is re ceived is used as temperature control target value. In other words, the temperature information is determined when tempera ture lock information is received and the temperature of the cookware item is controlled based on said temperature infor mation. Or in other words the user may choose to hold the cur rent temperature or optimize the temperature by lower or in crease the temperature by a predetermined value. According to an embodiment, the provision of heat energy to the cookware item is controlled such that the temperature infor mation provided by the temperature sensor is kept in a tempera ture range provided around the temperature control target value. For example, said temperature range may comprise an upper bound- ary and a lower boundary. Said upper boundary may be, for exam ple, 1 - 10°C, more specifically 3 - 7°C, especially 5°C above and said lower boundary may be, for example, 1 - 10°C, more spe cifically 3 - 7°C, especially 5°C below said temperature control target value. Thereby, the temperature of the cookware item can be stabilized around the temperature control target value.

According to an embodiment, temperature lock information is vis ual information provided at a user interface. For example, tem perature lock information may be provided by a LED or another light source. Thereby, the user can visually recognize when a constant or essentially constant temperature state of the cookware item is reached. According to an embodiment, the temperature sensor comprises a resistor changing its resistance value depending on the tempera ture. Said temperature sensor may indirectly measure the temper ature information of the cookware item through the cooking sup port .

According to an embodiment, the temperature sensor is an NTC- thermistor. Also other temperature measurement means may be pos sible . According to an embodiment, temperature information is derived by sampling an electrical value provided by the temperature sen sor. More specifically, temperature information may be derived by periodic sampling a voltage value provided at the temperature sensor .

According to an embodiment, the heating procedure is recorded in a recording mode and information regarding the heating procedure is stored in order to reuse said information for a further heat ing procedure. Information regarding the heating procedure may be the heating level, respectively, the heating power, the dura tion of using a certain heating level, the total heating dura tion etc.

According to an embodiment, the cooking appliance is an induc- tion cooking appliance. However, the control method can also be used in other types of cooking appliances.

According to an embodiment, the temperature of the cookware item is estimated with an algorithm using power board parameters, in particular power consumption and/or switching frequency, as in put values.

According to a further aspect, the invention relates to a cook- ing system comprising a temperature sensor and a cooking appli ance, the cooking appliance comprising at least one heating power transferring element for heating a cookware item placed on a cooking support and a user interface at least for receiving a command input of a user. . The temperature sensor is configured to provide information regarding a temperature correlated with the cookware item or the cookware content. The cooking appliance further comprises:

- a control unit configured to gather information regard ing a power reduction action initiated by a user input after a heat-up process;

- a control unit configured to evaluate temperature infor mation provided by the temperature sensor, said tempera ture information being correlated with the temperature of the cookware item or the cookware content;

- a control unit configured to provide temperature lock information to the user if the variation of the tempera ture of the cookware item or the cookware content is equal or lower than a certain temperature variation value ;

- a control unit configured to receive temperature lock confirmation after providing temperature lock infor mation;

- a control unit configured to control, after receiving temperature lock confirmation, the provision of heat en- ergy to the cookware item or the cookware content based on temperature information provided by the temperature sensor such that the temperature of the cookware item is maintained within a given temperature range. The term "control unit", as mentioned before, may refer to a single control unit which handles all tasks mentioned before or may refer to multiple control units, i.e. said tasks are handled by multiple control units in a shared manner. The control unit is in particular configured to perform the method according to at least one, in particular all, above described embodiments.

The cooking system may comprise a cooking appliance according to the embodiments specified below. In particular, the temperature sensor may be part of the cooking appliance. In an embodiment the temperature sensor is provided below the cooking support.

According to an embodiment of the cooking appliance, a control unit is configured to control the provision of heat energy to the cookware item such that temperature information provided by the temperature sensor is kept in a temperature range provided around a temperature control target value, said temperature con trol target value being temperature information provided by the temperature sensor at the point of time at which said tempera ture lock information is receipt.

According to an embodiment of the cooking appliance, the cooking appliance comprises a user interface configured to provide tem- perature lock information. For example, temperature lock infor mation may be provided by a LED or another light source.

Thereby, the user can visually recognize when a constant or es sentially constant temperature state of the cookware item is reached .

According to an embodiment of the cooking appliance, the temper ature sensor comprises a resistor with a temperature-dependent resistance value. According to a preferred embodiment, the tem perature sensor is an NTC-thermistor . According to an embodiment of the cooking appliance, the cooking appliance comprises a storage configured to store information regarding a heating procedure in a recording mode. The cooking appliance is further configured to reuse stored information for a further heating procedure. Said reuse may read stored infor mation from the storage and perform a heating procedure accord ing to said information. According to an embodiment of the cooking system the temperature sensor may be part of a cookware item or configured to be placed into the cookware item.

According to an embodiment of the cooking system, the tempera- ture sensor is a food sensor, in particular wirelessly coupled with the control unit and/or the internet. Known short range communication technics as Bluetooth or SAW (surface acoustic wave) may be used for the coupling. According to a further embodiment the food sensor may be a food spit or meat probe.

According to an embodiment of the cooking system the tempera tures sensor is combined with an algorithm for estimating the cookware temperature. In particular, the algorithm may use con trol parameters of the appliance, in particular parameters used by the control unit for controlling the temperature of the cookware item, as input. Additionally or alternatively parame ters of a power board of the cooking appliance, like power con- sumption or frequency of the power or switching frequency may be used as input parameters for the algorithm. In particular the control unit may be configured to execute the algorithm and to adapt provision of the heat energy based on an output of the al gorithm or to provide the predetermined value. According to an embodiment of the cooking appliance, the cooking appliance is an induction cooking appliance. The term "temperature information provided by the temperature sensor, said temperature information being correlated with the temperature of the cookware item" as used in the present disclo sure may refer to any thermal coupling between the temperature sensor and the cookware item due to an indirect temperature measurement. Therefore, the temperature information provided by the temperature sensor may follow the temperature of the

cookware item with a certain delay and/or with a certain offset.

The term "essentially" or "approximately" as used in the inven- tion means deviations from the exact value by +/- 10%, prefera bly by +/- 5% and/or deviations in the form of changes that are insignificant for the function.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which :

Fig. 1 shows an example top view on a cooking appliance com prising multiple heating zones;

Fig. 2 shows a schematic illustration of a cooking appliance with a cookware item placed on a cooking support; and Fig. 3 shows a pair of temperature curves wherein a first tem perature curve illustrates the temperature profile of the temperature at the cookware over time and the sec ond temperature curve illustrates the temperature pro file of the temperature at a temperature sensor over time .

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The present invention will now be described more fully with ref erence to the accompanying drawings, in which example embodi ments are shown. The embodiments in the figures may relate to preferred embodiments, while all elements and features described in connection with embodiments may be used, as far as appropri- ate, in combination with any other embodiment and feature as discussed herein, in particular related to any other embodiment discussed further above. However, this invention should not be construed as limited to the embodiments set forth herein.

Throughout the following description similar reference numerals have been used to denote similar elements, parts, items or fea tures, when applicable.

The features of the present invention disclosed in the specifi cation, the claims, examples and/or the figures may both sepa- rately and in any combination thereof be material for realizing the invention in various forms thereof.

Fig. 1 illustrates a schematic diagram of an electric cooking appliance 1, specifically an induction hob. The induction hob 1 comprises multiple heating zones 1.1, 1.2. Each heating zone 1.1, 1.2 may be, for example, associated with one or more heating power transferring elements 2, specifically, one or more induction coils. In the present embodiment, each heating zone 1.1, 1.2 is associated with a single heating power transferring element 2. However, according to other embodiments, a heating zone 1.1, 1.2 may be associated with multiple heating power transferring elements 2.

In addition, the cooking appliance 1 comprises a user interface 4, based on which a user may control the cooking appliance 1.

For example, based on the user interface 7, the user may control the power level of the heating zones 1.1, 1.2. Fig. 2 a-c show schematic side sectional views of a cooking sys tem with a cooking appliance 1 on which a cookware item 3 is placed. The cooking appliance 1 comprises a cooking support 4 on which the cookware item can be placed. Below the cooking support 4, a heating power transfer element 2 is provided. The heating power transfer element 2 may be, for example, an induction coil. The heating power transfer element 2 is coupled with a heating power energy unit 9. In order to determine the temperature of the cookware item 3, a temperature sensor 5 is provided either with the appliance or separately. Said temperature sensor 5 may be arranged below the cooking support 4 as shown in Fig. 2a. Thus, the temperature sensor 5 may be adapted to indirectly measure the temperature of the cookware item 3 based on the heat transmitted by the

cookware item 3 through the cooking support 4. Alternatively, the temperature sensor 5 may be provided with the cookware item 3 as shown in Fig. 2b or may be a food sensor placeable in the cookware item 3 as shown in Fig. 2c.

The temperature sensor 5 may comprise a thermal resistor, i.e. a resistor which changes the resistance value depending on its temperature. Specifically, the temperature sensor 5 may be an NTC-thermistor (NTC: negative temperature coefficient).

The temperature sensor 5 may be coupled with a control unit 8.

This coupling may be a wired coupling or a wireless coupling with a known wireless short range technology. The control unit 8 may be configured to receive temperature information from the temperature sensor 5 and provide temperature control based on said temperature information. The control unit 8 may be a cen tral control unit. The control unit 8 may also be coupled with the heating power energy unit 9 in order to control the provi- sion of heat to the cookware item 3.

In order to support the user of the cooking appliance 1 in keep ing the temperature of the cookware item 3 constant or essen tially constant, the cooking system and/or cooking appliance 1 is configured to perform a temperature control method.

Fig. 3 shows a diagram indicating the temperature of the

cookware T _CO okware over time. In addition, the diagram includes a temperature curve indicating the temperature information T _sen sor measured by the temperature sensor 5 over time.

The temperature curves regarding T _CO okware and T _se nsor refer to a heating procedure, in which a cookware item 3 is heated up in a heat-up phase theat u _P · During said heat-up phase, the temperature of the cookware item 3 may rise from a start temperature T _sta rt·

After reaching a certain temperature T _peak/ which may be, for ex ample the boiling temperature, the user may lower the heating power provided to the cookware item 3 (point of time tl) . Said lowering of heating power may be performed due to an input of the user at the user interface 7.

Due to said lowering of heating power, the temperature of the cookware T _CO okware may lower and approximate to a constant tempera- ture value.

As can be seen in fig. 3, due to the indirect temperature meas urement performed by the temperature sensor 5, temperature in formation Tsensor follows the temperature of the cookware T _CO okware with a certain offset and/or a certain delay. However, also tem perature information T _sen sor approaches to a constant temperature value . In order to support the user in keeping the temperature of the cookware T _CO okware constant or essentially constant over time, the control unit 8 may monitor if the heating power is lowered by means of a certain input at the user interface 7. If such lowering action is recognized, the control unit 8 is configured to monitor the decay of temperature information

T _sensor · More specifically, the control unit 8 may monitor if the variation of the temperature information T _sen sor stays within a given temperature variation range. Even more specifically, the control unit 8 may monitor if the variation of the temperature information T _sen sor stays within the temperature variation range in a certain period of time. Said monitoring may be performed by sampling the electrical signal provided by the temperature sen sor 8 and processing said sampled information by the control unit 8.

For example, after recognizing a lowering of heating power by a user input, the control unit 8 may constantly or at certain in tervals check if the variation of temperature information T _sen sor within a certain period of time is equal or lower than a certain temperature variation value. Said temperature variation value may be the difference between an upper and a lower temperature boundary . If the variation of temperature information T _sen sor within a cer tain period of time is equal or lower than a certain temperature variation value (point of time t2), the control unit 8 may pro- vide temperature lock information. Said temperature lock infor mation may be indicative for the user that the cookware tempera ture has reached a constant or essentially constant value. The temperature lock information may be visually recognizable information and/or audible information. The temperature lock in formation may be provided at or via the user interface 7. For example, the temperature lock information may be a light signal provided at the user interface 7.

After the provision of temperature lock information, the user is able to activate a temperature lock mode. Said activation may be performed, for example, by a certain user input. The control unit 8 may receive a temperature lock confirmation. After re- ceiving said temperature lock confirmation, the automatic tem perature control may be started.

The control unit 8 may use the present temperature information as a target value for the automatic temperature control. The control unit 8 may control the provision of heating power pro vided to the heating power transferring element 2 such that the temperature information provided by the temperature sensor 5 is kept within the a given temperature range 6. Said temperature range 6 is schematically illustrated in Fig. 3. Thereby the tem- perature of the cookware item 3 is kept constant or essentially constant without user interaction.

According to an embodiment, the cooking appliance 1 may be con figured to perform a recording mode, in which information re- garding the heating procedure is gathered and stored. Thus, the cooking appliance 1 may comprise a storage for storing gathered information. In addition, the cooking appliance 1 may provide, for example, at the user interface 7 a cooking procedure menu, which can be used for defining a certain entry for a certain cooking procedure. An example for such cooking procedure may be, for example, a cooking procedure for boiling pasta in a certain cookware item. So, for example, the user can define a new entry or folder in said cooking procedure menu which is associated with certain cooking procedure information. Said entry or folder can be selected later on in order to reuse stored cooking proce dure information for the cooking procedure.

More in detail, the cooking appliance 1 is configured to store a certain cooking procedure. Said storing can be initiated before starting the cooking process. Alternatively, the cooking appli ance 1 may be adapted to buffer cooking procedure information during a cooking procedure and storing of said cooking procedure information can be initiated during the cooking procedure or af- ter finishing the cooking procedure.

Said cooking procedure information may, for example, comprise information regarding the heating power provided to the cookware item 3, regarding the period of time in which said heating power is provided to the cookware item 3, changes of heating power, the duration of the heating process etc.

After storing said cooking procedure information, the user is able to reuse cooking procedure information later on for a simi- lar or identical cooking procedure.

It should be noted that the description and drawings merely il lustrate the principles of the proposed invention. Those skilled in the art will be able to implement various arrangements that, although not explicitly described or shown herein, embody the principles of the invention. List of reference numerals

1 cooking appliance

1.1 heating zone

1.2 heating zone

2 heating power transferring element

3 cookware item

4 cooking support

5 temperature sensor

6 temperature range

7 user interface

8 control unit

9 heating power energy unit