Induction cooking appliance device, induction cooking appliance, and method for operating an induction cooking appliance device
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- BSH HAUSGERATE GMBH
- Filing Date
- 2024-08-28
- Publication Date
- 2026-07-08
Smart Images
Figure EP2024074084_06032025_PF_FP_ABST
Abstract
Description
[0001] Induction cooking device, induction cooking device and method for operating an induction cooking device
[0002] State of the art
[0003] The invention relates to an induction cooking device.
[0004] Full bridge circuits in particular are known from the state of the art.
[0005] The object of the invention is, in particular but not limited to, to provide a generic device with improved properties with regard to design requirements and / or operational control. This object is achieved according to the invention by the features of claim 1, while advantageous embodiments and further developments of the invention can be found in the subclaims.
[0006] Advantages of the invention
[0007] An induction cooking appliance device is proposed with a first switching unit which has a first high-side switching element and a first low-side switching element connected in series therewith, between which a first center tap is formed, with at least one second switching unit which has a second high-side switching element and a second low-side switching element connected in series therewith, between which a second center tap is formed, and with at least one induction heating unit which is arranged in terms of circuitry between the first center tap and the second center tap, wherein connections of the high-side switching elements which are facing away from the center taps are not connected to one another.
[0008] An induction cooking device with improved power control can be realized. Advantageously, particularly simple control of the induction cooking device can be achieved. Advantageously, the output power can be adjusted particularly flexibly. Advantageously, the induction cooking device can be operated at a fixed frequency. A notch EMC filter can be used with the induction cooking device. Advantageously, the use of resonance capacitors can be dispensed with.
[0009] The induction cooking appliance is preferably designed as an induction hob. An "induction cooking appliance," in particular an "induction hob," is understood to mean at least one part, in particular a subassembly, of an induction cooking appliance, advantageously an induction hob. Accessory units for the induction cooking appliance, preferably the induction hob, may also be included, such as, for example, a sensor unit for externally measuring the temperature of a cooking utensil and / or a food item. In particular, the induction hob may also comprise the entire induction hob. The induction cooking appliance could, for example, be designed as an oven, a microwave, a grill, a steamer, a combination of these, or the like.
[0010] The induction cooking device is, in particular, an electronic circuit, preferably for the induction cooking device. The induction cooking device is preferably intended for connection to a voltage source, in particular to an alternating voltage source, preferably to a mains voltage. The induction cooking device is preferably connected to the voltage source, preferably to the alternating voltage source, at least in one operating state.
[0011] The induction heating unit is intended, in particular, for heating a cooking utensil. The cooking utensil is designed, for example, as a pot, a pan, a roasting pan, or any other cooking utensil deemed appropriate by a person skilled in the art. Preferably, when placed on a support plate, in particular a hob plate, of the induction hob, in particular of the induction hob device, the cooking utensil can be supplied with energy, at least partially, preferably inductively, at least for heating, in particular by means of the induction heating unit. The induction heating unit is arranged, in particular, below the support plate.
[0012] In this document, position designations such as “below” or “above” preferably refer to an installation position, in particular the mounted state, of the induction cooking appliance, preferably the
[0013] Induction cooking appliance, unless explicitly stated otherwise.
[0014] The induction cooking device preferably comprises a rectifier unit. The rectifier unit is preferably connected upstream of the first switching unit. The rectifier unit is in particular connected downstream of the voltage source, preferably arranged between the voltage source and the first switching unit in terms of circuitry. The first switching unit is preferably arranged between the second switching unit and the rectifier unit in terms of circuitry. The rectifier unit is in particular intended to convert an AC voltage from the voltage source into a DC voltage. It is conceivable for the rectifier unit to be designed as an uncontrolled rectifier or as a controllable rectifier. For example, the rectifier unit comprises a half-wave rectifier, a center-wave rectifier, a bridge rectifier circuit, or the like.
[0015] "Intended" should be understood as specifically configured, specifically designed, and / or specifically equipped. The fact that an object is intended for a specific function should be understood as meaning that the object fulfills and / or performs this specific function in at least one application and / or operating state.
[0016] The switching elements of the first switching unit and / or the second switching unit, in particular the first high-side switching element, the second high-side switching element, the first low-side switching element and / or the second low-side switching element, are / are preferably designed as power semiconductors. The switching elements of the first switching unit and / or the second switching unit, in particular the first high-side switching element, the second high-side switching element, the first low-side switching element and / or the second low-side switching element, are / are designed, for example, as MOSFET(s), as IGBT(s), as thyristors or the like. The switching elements of the first switching unit and / or the second switching unit, in particular the first high-side switching element, the second high-side switching element, the first low-side switching element and / or the second low-side switching element, are / are preferably switchable, in particular controllable, semiconductor components.“Low-side” and “high-side” of the switching elements refers in particular to the respective circuit arrangement relative to the corresponding induction heating unit, in particular to a relative voltage potential relative to the corresponding induction heating unit.
[0017] The second switching unit, in particular, has a capacitor. The capacitor is, in particular, connected downstream of the second high-side switching element. The second high-side switching element is, in particular, arranged in circuitry between the second center tap and the capacitor of the second switching unit. A voltage of the capacitor of the second switching unit can, in particular, be smaller or larger than an input power of the voltage source.
[0018] Preferably, the terminals of the high-side switching elements of the first switching unit and the second switching unit, which are remote from the corresponding center taps, are unconnected to one another outside the switching units, in particular the first switching unit and the second switching unit. In particular, the terminals of the high-side switching elements of the first switching unit and the second switching unit are connectable to one another through the switching elements, in particular the first high-side switching element and the second high-side switching element, and are preferably connected in at least one operating state. In particular, the induction cooking appliance device is free of an electrical connection between the terminals of the high-side switching elements of the first switching unit and the second switching unit outside the switching units, preferably the first switching unit and the second switching unit.
[0019] The first switching unit can be considered, in particular, a buck converter branch. The second switching unit, together with a heating coil of the induction heating unit, can be considered a boost converter branch. The induction cooking device can be considered, in particular, a type of buck-boost converter with a particularly adapted load arrangement.
[0020] It is further proposed that the first switching unit and the second switching unit be designed for operation at the same frequency. This advantageously allows for particularly simple control of the induction cooking device. An induction cooking device with particularly low requirements regarding electromagnetic compatibility can be provided. Preferably, the first switching unit and the second switching unit are designed for operation at a fixed frequency.
[0021] Furthermore, it is proposed that the induction cooking device have at least one third switching unit, which has a third high-side switching element and a third low-side switching element connected in series therewith, between which a third center tap is formed, and at least one further induction heating unit, which is arranged in circuitry between a further first center tap, which is arranged between the first high-side switching element and the first low-side switching element, and the third center tap. Advantageously, the induction cooking device can be adapted to different operating requirements and / or operating conditions. An induction cooking device with particularly high efficiency and improved power control can be provided.The switching elements of the third switching unit, in particular the third high-side switching element and / or the third low-side switching element, are / are preferably designed as power semiconductors. The switching elements of the third switching unit, in particular the third high-side switching element and / or the third low-side switching element, are / are designed, for example, as MOSFET(s), as IGBT(s), as thyristors or the like. The switching elements of the third switching unit, in particular the third high-side switching element and / or the third low-side switching element, are / are preferably switchable, in particular controllable, semiconductor components. Terminals of the high-side switching elements of the first switching unit and the third switching unit, which are facing away from the center taps, in particular the first center tap and the third center tap, respectively, are not connected to one another.Preferably, the terminals of the high-side switching elements of the first switching unit and the third switching unit are not connected to one another when viewed outside the switching units, in particular the first switching unit and the third switching unit. In particular, the terminals of the high-side switching elements of the first switching unit and the third switching unit are connectable to one another through the switching elements, in particular the first high-side switching element 14a and the third high-side switching element 36a, and are preferably connected in at least one operating state. In particular, the induction cooking appliance device is free of an electrical connection between the terminals of the high-side switching elements of the first switching unit and the third switching unit outside the switching units, preferably the first switching unit and the third switching unit.The third switching unit, together with a coil of the further induction heating unit, can be considered a further boost converter branch, in particular independent of the boost converter branch. The further induction heating unit is arranged in particular below the mounting plate. The induction heating unit and / or the further induction heating unit preferably have / have at least one heating coil.
[0022] It is also proposed that the third switching unit has a capacitor and the second switching unit has a capacitor, in particular the one already mentioned, which can be charged to different voltages. Advantageously, the voltages of the capacitors can be adapted to different operating requirements. Advantageously, the induction cooking device can be optimized. The efficiency of the induction cooking device can be increased. An improvement in the power control of the induction cooking device can be achieved. The capacitor of the third switching unit is in particular connected downstream of the third high-side switching element. The third high-side switching element is in particular arranged in terms of circuitry between the third center tap and the capacitor of the third switching unit.A voltage of the capacitor of the third switching unit can in particular be smaller or larger than an input power of the voltage source.
[0023] It is further proposed that the voltages of the capacitors be controllable via a duty cycle of the first switching unit, the second switching unit, and / or the third switching unit. Advantageously, the voltages of the capacitors can be adapted to different operating requirements via the duty cycle. Advantageously, the induction cooking device can be optimized. The efficiency of the induction cooking device can be increased. An improvement in the power control of the induction cooking device can be achieved.
[0024] It is also proposed that a relay be connected downstream of each of the induction heating unit and the further induction heating unit. Advantageously, the second switching unit and the third switching unit can be connected in parallel, preferably by means of the relay, preferably when only one induction heating unit is active. The current requirements in the switching units can be reduced. Advantageously, a particularly cost-effective induction cooking device can be provided. Furthermore, an induction cooking device, in particular the one already mentioned above, with an induction cooking device according to the invention is proposed. An induction cooking device with improved power control can be realized. Advantageously, an induction cooking device with an induction cooking device that is particularly easy to control can be provided. Advantageously, the output power can be adjusted particularly flexibly.The relays are particularly intended to connect the second switching unit and the third switching unit, preferably connected in parallel to each other, in series with the induction unit or the further induction unit.
[0025] Furthermore, a method for operating an induction cooking appliance, in particular one of the aforementioned, with a first switching unit, in particular one of the aforementioned, which has a first high-side switching element, in particular one of the aforementioned, and a first low-side switching element connected in series thereto, in particular one of the aforementioned, between which a first center tap, in particular one of the aforementioned, is formed, with at least one second switching unit, in particular one of the aforementioned, which has a second high-side switching element, in particular one of the aforementioned, and a second low-side switching element connected in series thereto, in particular one of the aforementioned, between which a second center tap, in particular one of the aforementioned, is formed, and with at least one induction heating unit, in particular one of the aforementioned,which is arranged in circuitry between the first center tap and the second center tap, wherein terminals of the high-side switching elements facing away from the center taps are unconnected to one another. Advantageously, an induction cooking device can be controlled particularly easily. Advantageously, the output power can be adjusted particularly flexibly. Advantageously, the induction cooking device can be operated at a fixed frequency.
[0026] Furthermore, it is proposed that an output power of the induction heating unit and of a further induction heating unit, in particular the previously mentioned one, of the induction cooking device be controlled by means of a duty cycle and phase shift between, in particular, the previously mentioned switching units, preferably the first switching unit, the second switching unit, and / or the third switching unit, of the induction cooking device. Advantageously, the induction cooking device can be controlled particularly easily. Advantageously, the output power of the induction cooking device can be adjusted particularly flexibly.
[0027] It is also proposed that the second switching unit and the third switching unit be connected in parallel when only one of the induction heating units is operating. This can reduce the current requirements in the switching units.
[0028] Advantageously, a particularly cost-effective induction cooking device can be provided.
[0029] The induction cooking device, the induction cooking device, and / or the method are not intended to be limited to the application and embodiment described above. In particular, the induction cooking device, the induction cooking device, and / or the method may have a number of individual elements, components, units, and method steps that differs from the number stated herein to fulfill a functionality described herein.
[0030] Further advantages will become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.
[0031] They show:
[0032] Fig. 1 is a schematic representation of an induction cooking appliance,
[0033] Fig. 2 is a schematic circuit diagram of an induction cooking device of the induction cooking device,
[0034] Fig. 3 shows a schematic sequence of a method for operating the induction cooking device and
[0035] Fig. 4 is a schematic circuit diagram of an induction cooking device in an alternative embodiment.
[0036] Figure 1 shows an induction cooking appliance 50a with an induction cooking appliance device 10a.
[0037] The induction cooking appliance 50a is designed as an induction hob. The induction cooking appliance device 10a is designed as an induction hob. Alternatively, it is conceivable that the induction cooking appliance 50a is designed as an oven, a microwave, a grill, a steamer, a combination of these, or the like.
[0038] The induction cooking device 10a is an electronic circuit, preferably for the induction cooking device 50a. The induction cooking device 10a is intended for connection to a voltage source 58a, in particular to an AC voltage source, preferably to a mains voltage. The induction cooking device 10a is connected to the voltage source 58a. The voltage source 58a is embodied here, for example, as a 230 V AC voltage source.
[0039] The induction cooking device 10a has a first switching unit 12a (see Figure 2). The first switching unit 12a has a first high-side switching element 14a and a first low-side switching element 16a connected in series therewith. A first center tap 18a is formed between the first high-side switching element 14a and the first low-side switching element 16a.
[0040] The induction cooking appliance device 10a has a rectifier unit 60a. The rectifier unit 60a is connected upstream of the first switching unit 12a. The rectifier unit 60a is connected downstream of the voltage source 58a, preferably arranged between the voltage source 58a and the first switching unit 12a. The rectifier unit 60a is provided to convert an AC voltage from the voltage source 58a into a DC voltage. It is conceivable that the rectifier unit 60a is designed as an uncontrolled rectifier or as a controllable rectifier. For example, the rectifier unit 60a has a half-wave rectifier, a center-wave rectifier, a bridge rectifier circuit, or the like.
[0041] The induction cooking device 10a has a second switching unit 20a. The second switching unit 20a has a second high-side switching element 22a and a second low-side switching element 24a connected in series therewith. A second center tap 26a is formed between the second high-side switching element 22a and the second low-side switching element 24a. The first switching unit 12a is arranged between the second switching unit 20a and the rectifier unit 60a.
[0042] The induction cooking device 10a has an induction heating unit 28a. The induction heating unit 28a is arranged between the first center tap 18a and the second center tap 26a. The induction heating unit 28a is represented in Figure 2 by a coil and a resistor.
[0043] Terminals 30a, 32a of the high-side switching elements 14a, 22a, which face away from the center taps 18a, 26a, are unconnected to one another. The terminals 30a, 32a of the high-side switching elements 14a, 22a of the first switching unit 12a and the second switching unit 20a are unconnected to one another when viewed outside the switching units 12a, 20a. The terminals 30a, 32a of the high-side switching elements 14a, 22a of the first switching unit 12a and the second switching unit 20a are connectable to one another through the switching elements 14a, 22a, preferably connected in at least one operating state. In particular, the induction cooking appliance device 10a is free of any electrical connection between the terminals 30a, 32a outside the switching units 12a, 20a.
[0044] The induction cooking device 10a has at least one third switching unit 34a. The third switching unit 34a has a third high-side switching element 36a and a third low-side switching element 38a connected in series therewith. A third center tap 40a is formed between the third high-side switching element 36a and the third low-side switching element 38a.
[0045] The first switching unit 12a, the second switching unit 20a, and the third switching unit 34a are designed to operate at the same frequency. Alternatively, an induction cooking device 10a with only the first switching unit 12a and the second switching unit 20a is also conceivable, in particular without a third switching unit 34a, wherein the first switching unit 12a and the second switching unit 20a are preferably operated at the same frequency. In an induction cooking device 10a with only the first switching unit 12a and the second switching unit 14a, it is conceivable that the first switching unit 12a and the second switching unit 14a are operated with a different duty cycle and / or with a switching operation that is delayed relative to one another.The switching elements 14a, 16a, 22a, 24a, 36a, 38a of the first switching unit 12a, the second switching unit 20a, and the third switching unit 34a, in particular the first high-side switching element 14a, the second high-side switching element 22a, the third high-side switching element 36a, the first low-side switching element 16a, the second low-side switching element 24a, and the third low-side switching element 38a, are designed, for example, as MOSFETs, IGBTs, thyristors, or the like. The switching elements 14a, 16a, 22a, 24a, 36a, 38a are preferably switchable, in particular controllable, semiconductor components.
[0046] Terminals 30a, 66a of the high-side switching elements 14a, 36a of the first switching unit 12a and the third switching unit 34a, which face away from the center taps 18a, 40a, in particular the first center tap 18a and the third center tap 40a, respectively, are unconnected to one another. The terminals 30a, 66a of the high-side switching elements 14a, 36a of the first switching unit 12a and the third switching unit 34a are unconnected to one another when viewed outside the switching units 12a, 34a. The terminals 30a, 66a of the high-side switching elements 14a, 36a of the first switching unit 12a and the third switching unit 34a are connectable to one another through the switching elements 14a, 36a, preferably connected in at least one operating state.
[0047] The induction cooking device 10a has a further induction heating unit 42a. The further induction heating unit 42a is arranged in circuitry between a further first center tap 44a, which is arranged between the first high-side switching element 14a and the first low-side switching element 16a, and the third center tap 40a. The further induction heating unit 42a is represented in Figure 2 by a coil and a resistor.
[0048] The induction heating units 28a, 42a are provided for heating a cooking utensil (not shown here). The cooking utensil is designed, for example, as a pot, a pan, a roasting pan, or as another cooking utensil that a person skilled in the art would deem appropriate. When placed on a support plate 56a, in particular a hob plate, of the induction hob, in particular of the induction hob device, the cooking utensil can be supplied with energy, at least for heating, at least partially, preferably inductively, in particular by means of the induction heating unit 28a and / or the further induction heating unit 42a. The induction heating unit 28a and / or the further induction heating unit 42a are / are arranged below the support plate 56a. The induction cooking device 10a has a control (not shown here) for the switching units 12a, 20a, 34a, in particular the switching elements 14a, 16a, 22a, 24a, 36a, 38a.For example, the controller is provided to switch at least the first high-side switching element 14a and the second low-side switching element 24a with the same signal, and in particular to switch the first low-side switching element 16a and the second high-side switching element 22a with an identical further signal.
[0049] For example, when the first high-side switching element 14a and the second low-side switching element 24a are closed, the first switching unit 12a and the second switching unit 20a are in a boost configuration. For example, when the first high-side switching element 14a and the second low-side switching element 24a are open, the first switching unit 12a and the second switching unit 20a are in a buck configuration.
[0050] The induction heating elements 28a, 42a are designed here, for example, as loads with a maximum of 3600 watts. The switching elements 14a, 16a, 22a, 24a, 36a, 38a have, for example, a line resistance of 70 mOhm. The size of the induction cooking device 10a is, for example, 85.8 mm. 2 Alternatively, however, it is also conceivable that the size of the induction cooking device 10a is smaller than 85.8 mm 2 or greater than 85.8 mm 2 .
[0051] The third switching unit 34a has a capacitor 46a. The capacitor 46a is connected downstream of the second high-side switching element 22a. The second high-side switching element 22a is arranged between the second center tap 26a and the capacitor 46a of the second switching unit 20a. A voltage of the capacitor 46a of the second switching unit 20a can be less than or greater than an input power of the voltage source 58a.
[0052] The second switching unit 20a has a capacitor 48a. The capacitor 48a is connected downstream of the third high-side switching element 36a. The third high-side switching element 36a is arranged between the third center tap 40a and the capacitor 48a of the third switching unit 34a. A voltage of the capacitor 48a of the third switching unit 34a can be less than or greater than an input power of the voltage source 58a. The capacitors 46a, 48a can be charged to different voltages. The voltages of the capacitors 46a, 48a can be controlled via a duty cycle of the first switching unit 12a, the second switching unit 20a, and / or the third switching unit 34a.
[0053] Figure 3 shows a schematic flow of a method for operating the induction cooking device 10a. The output power of the induction heating unit 28a and the further induction heating unit 42a is controlled by means of the duty cycle and phase shift between the switching units 12a, 20a, 34a.
[0054] In a method step 62a, the first switching unit 12a is switched. In a further method step 64a, the second switching unit 20a and / or the third switching unit 36a are switched. It is conceivable that the first switching unit 12a, the second switching unit 20a, and the third switching unit 34a are switched with a time delay relative to one another. The switching units 12a, 20a, and 34a can be operated with different duty cycles. The induction cooking appliance device 10a has six control parameters, in particular the duty cycles of the switching units 12a, 20a, and 34a and a respective time delay for the switching of the second switching unit 20a and the third switching unit 34a relative to the first switching unit 12a.
[0055] Figure 4 shows a further embodiment of the invention. The following descriptions are essentially limited to the differences between the embodiments, whereby reference can be made to the description of the embodiment in Figures 1 to 3 with regard to identical components, features and functions. To distinguish the embodiments, the letter a in the reference numerals of the embodiment in Figures 1 to 3 has been replaced by the letter b in the reference numerals of the embodiment in Figure 4. With regard to components with the same designation, in particular with regard to components with the same reference numerals, reference can also be made to the drawings and / or the description of the embodiment in Figures 1 to 3.
[0056] Figure 4 shows an induction cooking device 10b. The induction cooking device 10b has a first switching unit 12b. The first switching unit 12b has a first
[0057] High-side switching element 14b and a first low-side switching element 16b connected in series therewith. A first center tap 18b is formed between the first high-side switching element 14b and the first low-side switching element 16b.
[0058] The induction cooking device 10b has a second switching unit 20b. The second switching unit 20b has a second high-side switching element 22b and a second low-side switching element 24b connected in series therewith. A second center tap 26b is formed between the second high-side switching element 22b and the second low-side switching element 24b.
[0059] The induction cooking device 10b has an induction heating unit 28b. The induction heating unit 28b is arranged between the first center tap 18b and the second center tap 26b.
[0060] Terminals 30b, 32b of the high-side switching elements 14b, 22b, which are remote from the center taps 18b, 26b, are not connected to each other.
[0061] The induction cooking device 10b has at least one third switching unit 34b. The third switching unit 34b has a third high-side switching element 36b and a third low-side switching element 38b connected in series therewith. A third center tap 40b is formed between the third high-side switching element 36b and the third low-side switching element 38b.
[0062] The induction cooking device 10b has a further induction heating unit 42b. The further induction heating unit 42b is arranged in circuitry between a further first center tap 44b, which is arranged between the first high-side switching element 14b and the first low-side switching element 16b, and the third center tap 44b.
[0063] A relay 52b, 54b is connected downstream of the induction heating unit 28b and the further induction heating unit 42b. The second switching unit 20b and the third switching unit 34b are connected in parallel when only one of the induction heating units 28b, 42b is operating.
[0064] The switching elements 14b, 16b here have, for example, a line resistance of 70 mOhm. The switching elements 22b, 24b, 36b, 38b here have, for example, a nominal line resistance of 140 mOhm. The size of the induction cooking device 10a here is, for example, 57.2 mm.2 Alternatively, however, it is also conceivable that a size of the induction cooking device 10a is smaller than 57.2 mm 2 or larger than 57.2 mm 2 .
[0065] Reference symbol
[0066] 10 Induction cooking device
[0067] 12 Switching unit
[0068] 14 High-side switching element
[0069] 16 Low-side switching element
[0070] 18 Center tap
[0071] 20 switching unit
[0072] 22 High-side switching element
[0073] 24 Low-side switching element
[0074] 26 Center tap
[0075] 28 Induction heating unit
[0076] 30 connection
[0077] 32 connection
[0078] 34 Switching unit
[0079] 36 High-side switching element
[0080] 38 Low-side switching element
[0081] 40 center tap
[0082] 42 Induction heating unit
[0083] 44 funds withdrawn
[0084] 46 Capacitor
[0085] 48 Capacitor
[0086] 50 induction cooking appliances
[0087] 52 relays
[0088] 54 relays
[0089] 56 mounting plate
[0090] 58 Voltage source
[0091] 60 Rectifier unit
[0092] 62 process steps
[0093] 64 Process step 66 Connection
Claims
Claims 1. Induction cooking appliance device (10a; 10b) with a first switching unit (12a; 12b) which has a first high-side switching element (14a; 14b) and a first low-side switching element (16a; 16b) connected in series therewith, between which a first center tap (18a; 18b) is formed, with at least one second switching unit (20a; 20b) which has a second high-side switching element (22a; 22b) and a second low-side switching element (24a; 24b) connected in series therewith, between which a second center tap (26a; 26b) is formed, and with at least one induction heating unit (28a; 28b) which is circuit-wise connected between the first center tap (18a; 18b) and the second center tap (26a; 26b), wherein terminals (30a, 32a; 30b, 32b) of the high-side switching elements (14a, 22a; 14b; 22b) facing away from the center taps (18a, 26a; 18b, 26b) are not connected to one another.
2. Induction cooking device (10a; 10b) according to claim 1, characterized in that the first switching unit (12a; 12b) and the second switching unit (20a; 20b) are provided for operation at the same frequency.
3. Induction cooking appliance device (10a; 10b) according to claim 1 or 2, characterized by at least one third switching unit (34a; 34b) which has a third high-side switching element (36a; 36b) and a third low-side switching element (38a; 38b) connected in series therewith, between which a third center tap (40a; 40b) is formed, and at least one further induction heating unit (42a; 42b) which is arranged in terms of circuitry between a further first center tap (44a; 44b), which is arranged between the first high-side switching element (14a; 14b) and the first low-side switching element (16a; 16b), and the third center tap (44a; 44b).
4. Induction cooking device (10a; 10b) according to claim 3, characterized in that the third switching unit (34a; 34b) has a capacitor (48a; 48b) and the second switching unit (20a; 20b) has a capacitor (46a; 46b), which can be charged to different voltages.
5. Induction cooking device (10a; 10b) according to claim 4, characterized in that the voltages of the capacitors (46a, 48a; 46b; 48b) are controllable via a duty cycle of the first switching unit (12a; 12b), the second switching unit (20a; 20b) and / or the third switching unit (34a; 34b).
6. Induction cooking device (10b) according to one of claims 3 to 5, characterized in that a relay (52b, 54b) is connected downstream of the induction heating unit (28b) and the further induction heating unit (42b).
7. Induction cooking appliance (50a) with an induction cooking appliance device (10a; 10b) according to one of the preceding claims.
8. A method for operating an induction cooking appliance with a first switching unit, which has a first high-side switching element (14a; 14b) and a first low-side switching element (16a; 16b) connected in series thereto, between which a first center tap (18a; 18b) is formed, with at least one second switching unit (20a; 20b), which has a second high-side switching element (22a; 22b) and a second low-side switching element (24a; 24b) connected in series thereto, between which a second center tap (26a; 26b) is formed, and with at least one induction heating unit (28a; 28b), which is arranged in terms of circuitry between the first center tap (18a; 18b) and the second center tap (26a; 26b), wherein connections (30a, 32a; 30b, 32b) of the high-side switching elements (14a, 22a; 14b, 22b), which are remote from the center taps (18a, 26a; 18b, 26b), are unconnected to one another.
9. The method according to claim 8, characterized in that an output power of the induction heating unit (28a; 28b) and a further induction heating unit (42a; 42b) of the induction cooking device (10a; 10b) is controlled by means of duty cycle and phase shift between switching units (12a, 20a, 34a; 12b, 20b, 34b) of the induction cooking device (10a; 10b).
10. The method according to claim 9, characterized in that the second switching unit (20b) and the third switching unit (34b) are connected in parallel when only one of the induction heating units (28b, 42b) is in operation.