INDUCTION ENERGY TRANSMISSION SYSTEM

An induction energy transmission system includes a supply unit having a supply induction element to inductively provide energy in an operating state. A receiving unit receives at least part of the energy provided by the supply induction element in the operating state. A sensor unit detects a measurement variable and a first information channel transmits a first signal between the receiving unit and the supply unit, with the first signal coding the measurement variable. A second information channel which differs from the first information channel transmits a second signal between the receiving unit and the supply unit, with the second signal coding the measurement variable.

The invention relates to an induction energy transmission system, in particular an induction cooking system, as claimed in the preamble of claim1, as well as a method for operating an induction energy transmission system, in particular an induction cooking system, as claimed in the preamble of claim13.

An induction energy transmission system, which has a supply unit which is configured as a cooktop and a receiving unit which is configured as a positioning unit, is already known from the prior art. Positioning units which have an item of cookware and a support unit which are arranged in an operating state between the item of cookware and a positioning plate, which is configured in particular as a cooktop plate, are known. In this case, components of the positioning unit, such as for example a transmitting unit, are integrated in the support unit. Alternatively, positioning units having in each case a housing unit, which forms an external housing and which defines a receiving space for receiving food, are known. In this case, components of the positioning unit are integrated in the housing unit. In an operating state, the supply unit transmits energy inductively to the receiving unit by means of a supply induction element. The receiving unit has a transmitting unit which in the operating state transmits a signal to the supply unit. In this case the signal characterizes an identification parameter, whereby in the operating state the receiving unit is identified as a function of the signal of the transmitting unit and, in particular, an association between a supply induction element of the supply unit and the receiving unit is possible.

The object of the invention, in particular, is to provide a system of the generic type having improved characteristics in terms of safety. The object is achieved according to the invention by the features of claims1and13, while advantageous embodiments and developments of the invention may be derived from the subclaims.

The invention is based on an induction energy transmission system, in particular an induction cooking system, and advantageously an induction cooktop system, having at least one supply unit which has at least one supply induction element which inductively provides energy in at least one operating state, having at least one receiving unit which receives at least part of the energy provided by the supply induction element in the operating state, having at least one sensor unit for detecting at least one measurement variable, and having a first information channel for transmitting at least one first signal between the receiving unit and the supply unit, which first signal codes the measurement variable.

It is proposed that the induction energy transmission system has at least one second information channel, which differs from the first information channel, for transmitting at least one second signal between the receiving unit and the supply unit, which second signal codes the measurement variable. By means of the embodiment according to the invention a high degree of safety may be achieved, in particular for a user. In particular, information transmitted via the first information channel by means of a first signal may be transmitted again and/or in parallel by a second signal via the second information channel and verified thereby. As a result, in particular, a correct transmission of a measurement variable detected by means of the sensor unit may be ensured, whereby in particular malfunctions and risks potentially associated therewith for a user may be reduced. Additionally, a high degree of functionality and thus a high degree of user convenience and/or a simple and/or convenient usability may be permitted and a user satisfaction may be increased.

An “induction energy transmission system”, in particular an “induction cooking system” and advantageously an “induction cooktop system”, is intended to be understood to mean, in particular, a system which has at least one supply unit, in particular at least one induction cooking appliance and advantageously at least one induction cooktop, and which has a main functionality in the form of transmitting energy. For example, the induction energy transmission system could be configured as an induction hand-held power tool system. In particular, the supply unit and/or the receiving unit could be configured as a hand-held power tool, such as for example a drill and/or an electric screwdriver and/or a hammer drill and/or a saw. Alternatively or additionally, the supply unit and/or the receiving unit could be configured as a transformer. The induction energy transmission system could be provided, in particular, for at least one self-propelled implement and/or for at least one remote controller and/or for at least one remote control. In particular, the receiving unit could be configured as a self-propelled implement and/or as a remote controller and/or as a remote control. The self-propelled implement could be configured, for example, as a self-propelled mower and/or as a self-propelled vacuum cleaner. The remote controller and/or the remote control could be provided, in particular, for an operation and/or for a control of at least one blind and/or at least one electrical appliance, in particular at least one household electrical appliance, and/or at least one model object, such as for example a model automobile and/or a model aircraft and/or a model boat. Moreover, the receiving unit of the induction energy transmission system could be configured as a means of transportation, in particular as an electric motor vehicle or as a hybrid motor vehicle or as an electric bicycle or as an electric scooter or as another fully or partially electrically operated means of transportation. Preferably, the induction energy transmission system is configured as an induction cooking system. For example, the induction energy transmission system could be configured as an induction oven system and/or as an induction grill system. In particular, the supply unit and/or the receiving unit could be configured as an induction oven and/or as an induction grill. Advantageously, the induction energy transmission system is configured as an induction cooktop system. The supply unit and/or the receiving unit is then configured, in particular, as an induction cooktop.

A “supply unit” is intended to be understood to mean, in particular, a unit which in at least one operating state inductively provides energy and which, in particular, has a main functionality in the form of providing energy. For providing energy, the supply unit has, in particular, at least one supply induction element which, in particular, has at least one coil, in particular at least one primary coil, and which provides energy inductively, in particular in the operating state.

An “induction element” is intended to be understood to mean, in particular, an element which in at least one operating state provides and/or receives energy, in particular for the purpose of transmitting energy inductively. In particular, in the operating state an induction element which is configured as a supply induction element provides energy, in particular, for the purpose of transmitting energy inductively. The supply induction element could have, in particular, at least one coil, in particular at least one primary coil, which could be provided, in particular, for transmitting energy inductively to at least one secondary coil. The secondary coil, for example, could be part of the receiving unit, in particular at least of a receiving induction element of the receiving unit. In particular, in the operating state an induction element which is configured as a receiving induction element receives energy, in particular for the purpose of transmitting energy inductively, and namely, in particular, from the supply induction element. The receiving induction element could have, in particular, at least one coil, in particular at least one secondary coil, which can be provided in particular for receiving energy inductively from the supply induction element.

The supply induction element could be configured, for example, as a transformer element. Alternatively or additionally, the supply induction element could be configured, in particular, as an induction heating element and could be provided, in particular, for transmitting energy to at least one receiving unit which is configured as a positioning unit, in particular for the purpose of heating the positioning unit. In at least one operating state, the supply induction element could provide, in particular, an alternating field, in particular an electromagnetic alternating field, with a frequency of at least 1 Hz, in particular of at least 2 Hz, advantageously of at least 5 Hz and preferably of at least 10 Hz. In particular, in at least one operating state the supply induction element could provide, in particular, an alternating field, in particular an electromagnetic alternating field, with a frequency of a maximum of 150 kHz, in particular of a maximum of 120 kHz, advantageously of a maximum of 100 kHz and preferably of a maximum of 80 kHz. A supply induction element which is configured, in particular, as an induction heating element could provide in at least one operating state, in particular, a high-frequency alternating field, in particular a high-frequency electromagnetic alternating field, with a frequency of at least 15 kHz and in particular of a maximum of 100 kHz.

For example, the supply unit could have exactly one supply induction element. The supply unit could however also have at least two, in particular at least three, advantageously at least four, particularly advantageously at least five, preferably at least eight and particularly preferably a plurality of supply induction elements which could provide, in particular in the operating state, in each case energy inductively and namely in particular to a single receiving unit, in particular, or to at least two or more receiving units. In particular, any one of the supply induction elements could be arranged, in particular, in the vicinity of at least one other of the supply induction elements. At least some of the supply induction elements could be arranged, for example, in a row and/or in the form of a matrix.

A “receiving unit” is intended to be understood to mean, in particular, a unit which in at least one operating state receives energy, in particular inductively, and which in particular has at least one main function. The receiving unit could have, for example, at least one consumer which in the operating state, in particular, could consume energy. The receiving unit could be, for example, a hand-held power tool, such as for example a drill and/or an electric screwdriver and/or a hammer drill and/or a saw, and/or an automobile and/or a mobile device, such as for example a laptop and/or a tablet and/or a mobile telephone, and/or a remote controller and/or a remote control and/or a self-propelled implement. Moreover, the receiving unit could be configured as a means of transportation, in particular as an electric motor vehicle or as a hybrid motor vehicle or as an electric bicycle or as an electric scooter or as another fully or partially electrically operated means of transportation. A main function of the receiving unit could include, for example, drilling and/or hammering and/or sawing and/or screwing and/or data processing and/or telephoning and/or traveling. In the case of an induction energy transmission system configured as an induction cooking system, a main function of the receiving unit is, in particular, receiving energy. For example, the energy received by the receiving unit in the operating state, in particular, could be converted directly into at least one further energy type, such as for example into heat. In particular, the receiving unit could be free of receiving induction elements. Preferably, the receiving unit has at least one receiving induction element for receiving inductive energy. The receiving induction element could have, for example, at least one coil, in particular at least one secondary coil.

A “sensor unit” is intended to be understood to mean, in particular, a unit which in at least one operating state detects and processes at least one measurement variable. The sensor unit has at least one sensor element. The sensor unit could also have, in particular, a plurality of sensor elements. A “sensor element” is intended to be understood to mean in this context, in particular, an element which is assigned to the sensor unit and which may be configured, in particular, as a sensor and in at least one operating state detects quantitatively and/or qualitatively at least one measurement variable and/or at least one physical and/or chemical characteristic in the environment thereof and converts it into an electrical signal for further processing, wherein the detection may take place actively, such as in particular by generating and emitting an electrical measurement signal, and/or passively, such as in particular by detecting characteristic changes of a sensor component. A sensor element could be configured, for example, as a temperature sensor or as a weight sensor or as a volume sensor or as a humidity sensor. Various other sensor elements which appear expedient to the person skilled in the art are conceivable.

A “measurement variable” is intended to be understood to mean, in particular, a measurable physical variable. A measurement variable could be, for example, a temperature and/or a mass and/or a volume and/or a material quantity and/or a power and/or a time and/or a pressure and/or a relative and/or absolute humidity and/or a material composition. Alternatively or additionally, a measurement variable could be a qualitative variable which describes a state, for example an operating state or a cooking state or a charging state. In principle, all measurement variables which appear expedient to the person skilled in the art are conceivable.

“Coded” is intended to be understood to mean, in particular, converted and/or translated into a specific format and, in particular, a format which is suitable for an efficient transmission and/or storage. In particular, a coding may include a process of a conversion from analog to digital and/or from digital to analog. It is conceivable that a coding also comprises a step of encryption in order to block, for example, an unauthorized access to information coded in a signal.

An “information channel” is intended to be understood to mean, in particular, the entirety of all units, elements and transmission paths which are involved in a transmission of at least one signal from at least one transmitter to at least one receiver. In particular, an information channel comprises at least one part of the supply unit and at least one part of the receiving unit. A “transmission path” is intended to be understood to mean, in particular, a path via which a signal to be transmitted may be transmitted from at least one transmitter to at least one receiver. A transmission path in this case may be wired, wherein a transmission medium in this case may be an electrically conductive metal cable and/or a line or an optical waveguide consisting, for example, of glass, quartz or synthetic fibers. Preferably, a transmission path inside an information channel is wireless and comprises at least one electromagnetic wave, wherein in this case a transmission medium of the information channel could be air, for example.

The supply unit could be configured, for example, as an energy charging device, in particular as an induction energy charging device and could be provided, in particular, to transmit energy by means of the supply induction element to at least one receiving unit which could be configured, in particular, as a mobile device, such as for example a laptop and/or a tablet and/or a mobile telephone, and/or as a hand-held power tool and/or as a self-propelled implement and/or as a remote controller and/or as a remote control. Moreover, the receiving unit could be configured as a means of transportation, such as for example as an electric motor vehicle and/or a hybrid motor vehicle and/or as an electric bicycle and/or as an electric scooter and/or as another fully or partially electrically driven means of transportation, wherein in these cases the supply unit could be configured as a charging station or charging pole, or the like and, for example, could be integrated on or in a parking facility. Preferably, the supply unit is configured as a cooking appliance, in particular as an induction cooking appliance, such as for example as a cooktop, in particular as an induction cooktop and/or as an oven, in particular as an induction oven and/or as a grill, in particular as an induction grill. In particular, by means of the energy provided by the supply induction element, the supply unit heats at least one part of the receiving unit, in particular at least one receiving space of the receiving unit. As a result, the receiving unit may be supplied, in particular, with the energy provided for the receiving unit, whereby in particular optimal cooking results and/or a reliable operational efficiency of electrical and/or electronic units integrated in the receiving unit are/is achieved.

A “receiving space” is intended to be understood to mean, in particular, a spatial region which, in the operating state in which the supply unit, in particular, transmits energy to the receiving unit, is defined at least to a large part by the receiving unit and in which, in particular, food may be arranged in the operating state. The food could be arranged, in particular, in fluid form, in particular in liquid form and/or at least to a large part in liquid form, and/or in solid form in the receiving space. Food may be cooked, in particular, in a particularly efficient and/or targeted manner thereby, since in particular an energy required for a cooking may be accurately transmitted.

In an advantageous embodiment of the present invention, it is proposed that the receiving unit is configured as an item of cookware, in particular as an item of induction cookware. The receiving unit which is configured as an item of cookware advantageously has at least one receiving induction element which is configured as a secondary coil. The receiving induction element supplies at least one electrical heating element, preferably an electrical resistance heating element, with a part of the energy received by the supply induction element. As a result, advantageously at least one food to be cooked, which is arranged during a cooking process in the receiving space of the item of cookware, may be accurately supplied with the energy provided for one respective cooking process, whereby in particular optimal cooking results may be achieved. Alternatively or additionally, the receiving unit which is configured as an item of cookware could have at least one, in particular ferromagnetic, base plate which is arranged below the receiving space and in which eddy currents are induced by the energy inductively provided by the supply induction element, which eddy currents heat the base plate for heating a food to be cooked located in the receiving space.

In an advantageous alternative embodiment of the present invention, it is proposed that the receiving unit may be configured as a support unit for positioning an item of cookware. For example, a receiving unit which is configured as a support unit could consist of at least one magnetic, in particular at least one ferromagnetic, material and as a result advantageously said receiving unit may permit, in particular, a heating of an item of cookware which is not suitable for induction and/or which is non-magnetic, in particular which is non-ferromagnetic, by means of the energy provided by the supply induction element. Moreover, advantageously a transmission of heat from the item of cookware to a positioning plate may be at least substantially prevented thereby.

It might be conceivable, for example, that the first information channel has a wired transmission unit and a wired reception unit for an electrical and/or optical transmission of a first signal. Alternatively or additionally, it is conceivable that the first information channel has at least two radio transmitters and at least two radio receivers and could be suitable for a bidirectional signal transmission. Advantageously, however, the first information channel has at least one radio transmitter and at least one radio receiver. As a result, a cost-effective wireless transmission of a first signal may advantageously take place between the supply unit and the receiving unit. Moreover, in particular, advantageously a user convenience may be increased thereby.

It is further proposed that a transmission of the first signal takes place between the radio transmitter and the radio receiver according to the Bluetooth standard. As a result, in particular, a reliable transmission of the first signal may advantageously take place between the supply unit and the receiving unit. Alternatively or additionally, it might be conceivable that a transmission of the first signal between the radio transmitter and the radio receiver takes place according to a different radio standard, for example according to the wireless LAN standard or the Z-wave standard or the Zig-Bee standard or a different radio standard which appears expedient to a person skilled in the art for a transmission of the first signal.

It is further proposed that the second information channel comprises the supply induction element and at least one receiving induction element of the receiving unit which is configured as a reception induction element. As a result, advantageously a second signal which codes the measurement variable may be transmitted between the supply unit and the receiving unit. In particular, as a result, a second signal may be transmitted between the supply unit and the receiving unit by means of an energy transmission signal. As a result, advantageously an embodiment which is compact and/or which has a reduced number of components may be achieved. A “reception induction element” is intended to be understood to mean, in particular, an induction element which in at least one operating state receives an electromagnetic signal, in particular for the purpose of an inductive signal transmission. The reception induction element could, in particular, comprise at least one coil, in particular at least one secondary coil, which could be provided in particular for inductively receiving an electromagnetic signal provided by the supply induction element. The reception induction element may be a receiving induction element, which implements as a main function a reception of the energy provided by the supply induction element and additionally fulfills the function of a reception of a further signal which is different from an energy transmission signal, in particular of a second and/or third signal. Alternatively, a reception induction element may be configured differently from a receiving induction element and exclusively fulfill a function of a further signal which is different from an energy transmission signal, in particular of a second and/or a third signal. The receiving unit may have a plurality of reception induction elements.

For example, the signal could be modulated to an energy transmission signal of the supply unit and/or could be identical to the energy transmission signal of the supply unit. In particular, an energy transmission signal of the supply unit and the second signal could have the same frequency and/or multiples of the same frequency. As a result, in particular, an embodiment which is compact and/or which has a reduced number of components may be achieved, whereby in particular low costs may be achieved.

It is further proposed that the second signal is frequency modulated and/or amplitude modulated and/or duty cycle modulated. In particular, at least one piece of information which is coded in the second signal and/or a third signal and/or may be transmitted by means of the second signal and/or the third signal is modulated by at least one frequency and/or at least one amplitude and/or at least one duty cycle, in particular, to an energy transmission signal of the supply unit. The second signal and/or the third signal could correspond, in particular, to a harmonic of an energy transmission signal of the supply unit.

As a result, in particular, a simple and/or reliable transmission of the second signal and/or the third signal may be ensured. Alternatively or additionally, it might be conceivable that the second signal and/or the third signal correspond/corresponds to the energy transmission signal of the supply unit. A “frequency modulation” is intended to be understood to mean, in particular, a modulation method in which a carrier frequency, for example a frequency of an energy transmission signal or a network frequency is changed in order to transmit a further signal. An “amplitude modulation” is intended to be understood to mean, in particular, a modulation method in which an amplitude of a carrier signal, for example an amplitude of an energy transmission signal is changed in order to transmit a further signal. A “duty cycle modulation” is intended to be understood to mean, in particular, a modulation method in which a duty cycle, i.e. a ratio of a pulse duration of a carrier signal to a period duration of a carrier signal, for example of an energy transmission signal, is changed in order to transmit a further signal.

It is further proposed that the sensor unit has at least one sensor element which is integrated in the supply unit. As a result, for example, advantageously a high level of convenience for a user may be provided. Alternatively or additionally, it might be conceivable that the sensor unit may have an external sensor element which may be connected, for example, via a cable or wirelessly, for example to the supply unit.

It is further proposed that the sensor unit has at least one sensor element, in particular a further sensor element, which is integrated in the receiving unit. By means of such an embodiment, advantageously at least one measurement variable may be determined in an environment and, in particular, inside the receiving space of the receiving unit. As a result, in particular, an embodiment which is compact and/or which has a reduced number of components may be advantageously achieved and a number of components may be reduced. Alternatively or additionally, it might be conceivable that the sensor unit has an external sensor element which, for example, may be fixed and/or attached and/or positioned on the receiving unit and/or connected in a different expedient manner to the receiving unit.

It is further proposed that the sensor unit has at least one temperature sensor.

Advantageously, at least one sensor element of the sensor unit is configured as a temperature sensor. As a result, advantageously a temperature, for example a temperature of a food to be cooked, may be determined by the sensor unit as a measurement variable and, for example, processed for an output to a user and/or for an, in particular automatic, adaptation of an energy provided by the supply unit. Alternatively or additionally, it is conceivable that at least one sensor element of the sensor unit is configured as a sensor which is different from a temperature sensor. It might be conceivable, for example, that at least one sensor element of the sensor unit is configured, for example, as a weight sensor or as a volume sensor or as a pressure sensor or as a humidity sensor or as a motion sensor or as a further sensor which appears expedient to a person skilled in the art for a use of an induction energy transmission system. It is also conceivable that at least one further sensor element of the sensor unit is configured as a further temperature sensor.

According to a further advantageous embodiment of the present invention, it is proposed that the induction energy transmission system comprises at least one third information channel for transmitting at least one third signal between the receiving unit and the supply unit, which third signal codes a further measurement variable. The third information channel, in particular, may have common units with the second information channel, in particular a common supply induction element and a common reception induction element. The third information channel differs from the second information channel, in particular, by the third signal which is different from the second signal. A carrier frequency of the third signal could, in particular, be a further frequency, which is different from a carrier frequency of the second signal, of an electromagnetic alternating field provided by the supply induction element, for example a network frequency. The third signal, for example, could be modulated in particular by a frequency modulation and/or an amplitude modulation and/or a duty cycle modulation to the further carrier frequency. Alternatively or additionally, for example, it might be conceivable that the second signal is transmitted by a first modulation, for example by frequency modulation of a carrier frequency, and the third signal is transmitted via a second additional modulation, for example via an amplitude modulation of the same carrier frequency. As a result, in particular, a further measurement variable may be advantageously transmitted between the receiving unit and the supply unit. As a result, in particular, an error-free transmission of a further measurement variable between the supply unit and the receiving unit may be ensured. Moreover, in particular, a high level of convenience for a user may be advantageously provided.

The invention is further based on a method for operating an induction energy transmission system, in particular an induction cooking system, having at least one supply unit which has at least one supply induction element, and having at least one receiving unit, wherein energy is inductively provided by the supply induction element in at least one operating state, which energy is at least partially received by the receiving unit, and at least one measurement variable is detected, which measurement variable is coded in a first signal and is transmitted by a first information channel between the supply unit and the receiving unit.

It is proposed that the at least one measurement variable is coded in a second signal and is transmitted between the supply unit and the receiving unit by at least one second information channel which is different from the first information channel. As a result, an operating reliability may be increased.

The induction energy transmission system in this case is not intended to be limited to the above-described use and embodiment. In particular, for fulfilling a mode of operation described herein the induction energy transmission system may have a number of individual elements, components and units which is different from a number mentioned herein.

FIG.1shows a plan view of an induction energy transmission system10awhich is configured as an induction cooking system.FIGS.2and3show lateral views of the induction energy transmission system10a, partially in sectional view.

In the present exemplary embodiment, the induction energy transmission system10ais configured as an induction cooktop system. The induction energy transmission system10ahas a supply unit12awhich is configured as an induction supply unit. The supply unit12ais configured as a cooking appliance38a, in particular as a cooktop and namely as an induction cooktop. In the present exemplary embodiment the supply unit12ahas a positioning plate24a.

In a mounted state, the positioning plate24aforms a visible surface which in a mounted state is arranged, in particular, facing a user. The positioning plate24ais provided for positioning a receiving unit16aof the induction energy transmission system10a, and namely an item of cookware40afor heating. In the present exemplary embodiment, the positioning plate24ais configured as a cooktop plate. The receiving unit16awhich is configured as an item of cookware40ahas at least one receiving space42aand at least one base plate100a. In at least one operating state, food is located in the receiving space42a, said food being cooked in a particularly efficient and/or targeted manner by the energy provided by a supply induction element14aand received by the receiving unit16a.

The supply unit12ahas a user interface26afor an input and/or selection of operating parameters, for example a heating power and/or a heating power density and/or a heating zone. The user interface26ais provided for an output of a value of an operating parameter to a user.

The supply unit12ahas a control unit28a. The control unit28ais provided to perform actions and/or to change settings as a function of operating parameters input by means of the user interface26a. In an operating state, the control unit28acontrols an energy supply to at least one supply induction element14aof the supply unit12a.

Preferably, the supply unit12ahas a plurality of supply induction elements14a. In the present exemplary embodiment, the supply induction elements14aare arranged in the form of a matrix (not shown). Alternatively, the supply unit12acould have a different number of supply induction elements14a. The supply induction elements14acould be arranged, for example, in a manner which is different from an arrangement in the form of a matrix. Only one of the supply induction elements14ais shown in the figures. Hereinafter only one of the supply induction elements14ais described.

The supply induction element14ais provided to heat the receiving unit16awhich is positioned on the positioning plate24aabove the supply induction element14a. The supply induction element14ais configured as an induction heating element. The supply induction element14ais arranged in an installed position below the positioning plate24a(seeFIG.2).

In the operating state, the supply induction element14aprovides energy inductively. In the operating state, the supply induction element14aprovides energy inductively for heating at least one part of the receiving unit16a. The receiving unit16ahas at least one receiving induction element18a. The receiving induction element18aof the receiving unit16ais configured as a secondary coil and in the operating state receives a part of the energy provided by the supply induction element14a. The receiving unit16acomprises at least one electrical heating element (not shown) which is operated with a part of the energy received by the receiving induction element18aand is provided for heating at least one food to be cooked which is located in the receiving space42a. With a further part of the energy received by the supply induction element14a, the receiving induction element18asupplies at least one further unit, in particular a sensor unit20a. In the present exemplary embodiment, the receiving induction element18ais additionally configured as a reception induction element50aand also receives in at least one operating state, in addition to the part of the energy provided by the supply induction element14a, at least one piece of information which is coded, in particular, in a second signal36aand/or in a third signal92a.

The induction energy transmission system10ahas the sensor unit20a. The sensor unit20aserves for detecting at least one measurement variable22a. The sensor unit20ahas at least one first sensor element52a. The first sensor element52ais configured as a temperature sensor56aand is part of the receiving unit16a(seeFIG.3). The temperature sensor56ameasures a temperature inside the receiving space42a, for example in order to be able to set an optimal heating power for cooking a food to be cooked which is located in the receiving space42a. In the present exemplary embodiment, the sensor unit20ahas at least one second sensor element54a. The second sensor element54ais part of the supply unit12aand is integrated in the positioning plate24a. The second sensor element54ais configured as a further temperature sensor. The second sensor element54ameasures a temperature of a surface of the positioning plate24afacing a user, for example in order to warn the user of a possible risk of burning due to a high temperature of the positioning plate24a.

The induction energy transmission system10ahas at least one first information channel30a. The first information channel30aserves for transmitting a first signal32abetween the receiving unit16aand the supply unit12a. The first signal32acodes the measurement variable22a. The induction energy transmission system10aalso has at least one second information channel34awhich is different from the first information channel30aand which is provided for transmitting a second signal36abetween the receiving unit16aand the supply unit12a. In this case the second signal36aalso codes the measurement variable22a.

The induction energy transmission system10ahas at least one radio transmitter46aand at least one radio receiver48awhich are assigned to the first information channel30a. The radio transmitter46atransmits the first signal32a, which is configured as a radio signal, to the radio receiver48a. A transmission of the first signal32atakes place between the radio transmitter46aand the radio receiver48aaccording to the Bluetooth standard.

The second information channel34acomprises the supply induction element14aand at least the receiving induction element18aof the receiving unit16awhich is configured as the reception induction element50a. The supply induction element14atransmits the second signal36ato the reception induction element50aof the receiving unit16a.

In the present exemplary embodiment, the second signal36ais a harmonic of an energy transmission signal which is transmitted in the operating state from the supply induction element14ato the receiving induction element18aof the receiving unit16awhich is configured as the reception induction element50a. In the present exemplary embodiment, the second signal36ais frequency modulated (seeFIG.4). Additionally, in the present exemplary embodiment the second signal36ais amplitude modulated. Alternatively or additionally, the second signal36acould be duty cycle modulated.

FIG.4shows an overall view of four diagrams. The second signal36ais plotted on an ordinate axis58aof a first diagram. A time is plotted on an abscissa axis60aof the first diagram. An amplitude96aof the second signal36ais plotted on an ordinate axis62aof a second diagram. A time is plotted on an abscissa axis64aof the second diagram. A frequency98aof the second signal36ais plotted on an ordinate axis66aof a third diagram. A time is plotted on an abscissa axis68aof the third diagram. The measurement variable22ais plotted in the form of a measurement variable characteristic curve76aon an ordinate axis72aof a fourth diagram. A time is plotted on an abscissa axis74aof the fourth diagram.

The second signal36ahas a specific duration and/or a specific number of oscillations. In particular, the second signal36ahas a minimum duration70awhich the second signal36ain particular should at least adopt. For example, the minimum duration70acould result from an inertia in a transmission of energy and/or advantageously a transmission of the second signal36a.

During the minimum duration70a, the amplitude96aand the frequency98aof the second signal36ain each case remain constant and code a first measurement variable value84aof the measurement variable22a.

It may be derived fromFIG.4that in the present exemplary embodiment after a minimum duration70ais exceeded, the second signal36achanges over a further progression of the time plotted on the abscissa axis60aand that the measurement variable characteristic curve76achanges over a progression of the time plotted on the abscissa axis74a. During a first time period which in the present case corresponds to the minimum duration70a, the measurement variable characteristic curve76ahas a constant progression and represents the first measurement variable value84aof the measurement variable22awhich is plotted on the ordinate axis72a. After the minimum duration70ahas elapsed, the second signal36ahas changed due to a change in the modulation of the amplitude96aand the frequency98a. During a second time period which corresponds at least to the minimum duration70a, the amplitude96aand the frequency98aof the second signal36aonce again remain constant and code a second measurement variable value86aof the measurement variable22a. During this second time period, the progression of the measurement variable characteristic curve76aalso remains constant and thus represents the second measurement variable value86awhich is plotted on the ordinate axis72a. After the second time period has elapsed, the second signal36ahas changed again due to a further change in the modulation of the amplitude96aand the frequency98a. During a third time period which corresponds at least to the minimum duration70a, the amplitude96aand the frequency98aof the second signal36aonce again remain constant and thus code a third measurement variable value88aof the measurement variable22awhich is plotted on the ordinate axis72a.

The measurement variable characteristic curve76ashown inFIG.4could be, for example, a temperature characteristic curve of a temperature progression inside the receiving unit16adetected by the temperature sensor56aof the sensor unit20. In this case, the first measurement variable value84awould correspond to a first temperature inside the receiving unit16adetected within a first time period78aby the temperature sensor56a. The second measurement variable value86awould in this case correspond to a second temperature within a subsequent second time period80adetected by the temperature sensor56aof the sensor unit20.

FIG.5shows a transmission of the first signal32aand the second signal36aschematically in a block diagram. At least the measurement variable22ais initially detected by means of the first sensor element52a, converted into an electrical signal and processed by the sensor unit20a. The sensor unit20atransmits the measurement variable22ato the radio transmitter46a. The radio transmitter46atransmits the first signal32a, which codes the measurement variable22a, to the radio receiver48a. In the present exemplary embodiment, the first signal32ais a radio signal and, in particular, a Bluetooth signal. The radio receiver48aconverts the first signal32areceived from the radio transmitter46ainto an electrical signal and transmits it to a data processing unit82a. In the present exemplary embodiment, the radio transmitter46a, the first signal32aand the radio receiver48aform the first information channel30a. The sensor unit20aalso transmits the measurement variable22ato the supply induction element14aof the supply unit12a. The supply induction element14atransmits the second signal36a, which codes the measurement variable22a, to the reception induction element50aof the receiving unit16a. In the present exemplary embodiment, the second signal36ais an induction signal. The reception induction element50aconverts the second signal36ainto an electrical signal and transmits it to the data processing unit82a. In the present exemplary embodiment, the supply induction element14aof the supply unit12a, the reception induction element50aof the receiving unit16aand the second signal36aform the second information channel34a. The data processing unit82acompares information transmitted by means of the first information channel30arelative to the measurement variable22awith information transmitted by means of the second information channel34arelative to the measurement variable22a.

FIG.6shows a variant of the present exemplary embodiment for a transmission of the second signal36aand for an additional transmission of the third signal92a, schematically in a further block diagram. The first measurement variable22ais initially detected by means of the first sensor element52a, converted into an electrical signal and processed by the sensor unit20a. A further measurement variable94ais detected by means of the second sensor element54aand processed by the sensor unit20a. The sensor unit20atransmits the measurement variable22aand the further measurement variable94to the supply unit12a. The measurement variable22ais coded by the second signal36aand transmitted via the second information channel34ato the receiving unit16a. The further measurement variable94ais coded by the third signal92aand transmitted via a third information channel90ato the receiving unit16a. The receiving unit16atransmits the measurement variable22aand the further measurement variable94ato the data processing unit82a.

The third information channel90acomprises at least part of the receiving unit16a, at least part of the supply unit12aand the third signal92a. In the present exemplary embodiment, the second signal36aand the third signal92ain each case are modulated to the energy transmission signal which the supply induction element14atransmits in the operating state to the receiving induction element18aof the receiving unit16aconfigured as the reception induction element50a. The third signal92ain this case is a further harmonic of the energy transmission signal in a frequency range which is different from the second signal36a. In the present exemplary embodiment, the third signal92ais frequency modulated and amplitude modulated. The modulation of the frequency98aand the amplitude96a, shown schematically inFIG.4for the second signal36a, may also expediently apply to the third signal92a. Alternatively or additionally, the third signal92acould be duty cycle modulated. In a method for an operation of the induction energy transmission system10a, in the operating state energy is inductively provided by means of the supply induction element14a. In the operating state, a part of the energy provided by the supply induction element14ais received by the receiving unit16a. At least the measurement variable22ais detected by means of the sensor element52aof the sensor unit20a, coded in the first signal32aand transmitted by the first information channel30abetween the supply unit12aand the receiving unit16a. The at least one measurement variable22ais coded in the second signal36aand transmitted via the second information channel34abetween the supply unit12aand the receiving unit16a(seeFIG.5).

A further exemplary embodiment of the invention is shown inFIG.7. The following description is substantially limited to the differences between the exemplary embodiments, wherein relative to components, features and functions which remain the same, reference is made to the description of the exemplary embodiment ofFIGS.1to6. For differentiating between the exemplary embodiments the letter a in the reference numerals of the exemplary embodiment inFIGS.1to6is replaced by the letter b in the reference numerals of the exemplary embodiment ofFIG.7. Relative to components denoted the same, in particular relative to components with the same reference numerals, in principle reference may also be made to the drawings and/or the description of the exemplary embodiment ofFIGS.1to6.

FIG.7shows a receiving unit16bof an alternative induction energy transmission system10b. The receiving unit16bis configured as a support unit44bfor positioning an item of cookware40b. Apart from an inductive heating, the receiving unit16bhas the functionality of the receiving unit16aof the previous exemplary embodiment. In the present case, the inductive heating takes place directly in a cookware base of the item of cookware40b.

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