EP3249302B1 - Domestic cooking device - Google Patents

Description

The invention relates to a household cooking appliance, comprising a plurality of electrically operable heating elements for heating a cooking space, a mechanically switching operating mode selector switch for switching on at least one heating element depending on its switching position, a mechanical temperature controller for regulating the connected heating element depending on a temperature of the cooking space, which temperature controller is electrically connected in series with the radiators, and an electronic circuit. The invention is particularly advantageously applicable to ovens, in particular ovens.

DE 10 2011 017 638 A1 relates to a method for operating a cooking device, in which at least one heating unit of the cooking device is operated at least temporarily by a controller unit of the cooking device, the controller unit being activated and the heating unit being operated by the controller unit during a running cooking program in a first time interval, and in a second time interval the controller unit is deactivated and a clocked operation of the heating unit is controlled by a timer of the cooking device.

EP 2 063 180 A2 discloses a heating cycle for a cooking chamber of a cooking appliance, comprising the following steps: activating at least one heating element for heating the cooking chamber until a predetermined limit temperature is reached; subsequently switching down a heating power of the at least one radiator to allow the cooking space to cool below the predetermined limit temperature; and subsequently clocked activation of at least one radiator with a predetermined clocking property for a predetermined clocking time interval for heating the cooking space until the predetermined limit temperature is reached.

EP 1 461 568 B1 discloses a method for controlling energy consumption in an oven which is filled with food when it is cold and is then heated to its operating temperature at full power during a warm-up period and during a subsequent period at which the operating temperature is kept heated by supplying full power at a certain repetition rate. An electrical circuit used to carry out the method has a thermostat which is connected in series with the heating elements, and a timer switching device which is designed to deliver the desired duty cycle and the desired repetition rate, and the effect of the thermostat during the subsequent heating period. The timer switching device can be an energy control device which is connected between the thermostat switch and the electrical elements in parallel with a first temperature switch, which is normally open and closes at a temperature of approximately 130 ° C., and in parallel with a second temperature switch, which is normally is closed and opens at a temperature of approx. 65 ° C.

DE 10313 596 A1 discloses an oven device with a mechanical temperature controller and an electronic clock. Presentation images for displaying various operating modes are integrated in a display panel of the electronic watch and can be controlled by the electronic control device of the watch depending on the respectively set operating mode, for displaying when the relevant operating mode is switched on.

EP 2 518 410 A2 discloses a method for operating a cooking device, in which the operation of at least one heating unit of the cooking device is carried out at least temporarily by a first electronic unit of the cooking device, the first electronic unit being activated in a first time interval during an ongoing cooking program and the operation of the heating unit by the first electronic unit takes place, and in a second time interval the first electronic unit is deactivated and a clocked operation of the heating unit is carried out by a second electronic unit of the cooking device

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide a household cooking appliance which enables a high number of operating modes, in particular also at least one special operating mode, at low cost.

This object is achieved in accordance with the features of the independent claims. Preferred embodiments can be found in particular in the dependent claims.

The object is achieved by a household cooking appliance, comprising a plurality of electrically operable radiators for heating a cooking space, a mechanically switching operating mode selector switch for switching on at least one radiator depending on a switching position selected or set by the user, and a mechanical temperature controller for regulating the connected radiators depending on a temperature of the cooking space, which mechanical temperature controller is electrically connected in series with the radiators, and an electronic circuit, a first relay (hereinafter referred to as "heating circuit relay" without restricting generality) electrically connected in series with the radiators and the mechanical temperature controller is and can be switched by means of the electronic circuit, the electronic circuit is connected to the operating selector switch in order to recognize a switching position set by the operating selector switch and the electr Onical circuit is set up to switch the heating circuit relay on and off as a function of the detected switching position of the operating selector switch with a predetermined switching pattern during operation.

This household cooking appliance has the advantage that it can work like a purely mechanically controlled cooking appliance, with or as long as the heating circuit relay is permanently closed during operation, which enables a particularly inexpensive construction. In addition, the household cooking appliance is able to operate the radiators during operation by means of a particularly simple and inexpensive electronic unit via a corresponding control of the heating circuit relay. The electronic unit can be kept simple, since basic functionalities such as temperature setting, temperature measurement and regulation are already covered by the very inexpensive mechanical temperature controller. Such a household cooking appliance is only slightly more expensive than a purely mechanically controlled cooking appliance which has an electronic clock for a clock display or for the provision of time-controlled operation (i.e., time-limited or time-shifted operation), but is considerably cheaper than a purely electronically controlled cooking appliance ,

The functionality of switching the heating circuit relay during operation can also be described as a special functionality. An operating mode in which the heating circuit relay is switched during operation can also be referred to as a special operating mode. A special function can be, for example, the "temperature reduction" function. In this case, a cooking space temperature is adjusted to a predetermined setpoint by means of the mechanical temperature controller. If the setpoint is, for example, above a predetermined threshold value, the radiators are switched, in particular clocking, after a, possibly temperature-dependent, period of time in order to lower the cooking space temperature, for example by 30 ° C. In this way, for example, a temperature of a viewing window of a cooking space door can be kept below a desired value, which increases user safety. A cooking result is not or only slightly changed by the temperature reduction. Possibly. may extend the cooking time. An operating mode that has the special function "temperature reduction" can itself be a special operating mode ("safety cooking"). This special operating mode can be regarded as a "hybrid" operating mode if it has conventional operating sections which regulate the temperature by means of the temperature controller and which operate by switching, in particular clocking, using the radiator relay.

Another possible special operating mode can be the energy-saving mode (so-called “energy-saving mode”), in which a predetermined amount of heat is introduced into the cooking space per unit of time. This can be done by clocked operation of the radiators used with a predetermined duty cycle. The cooking chamber temperature is not regulated here. Another special mode of operation can be low-temperature cooking or a simple automatic roasting.

The heating circuit relay can also be switched to implement time-limited operation or time-shifted operation, but this is not considered a special functionality. In particular, such a switching of the radiators may not be considered as being in operation.

The fact that the electronic circuit is set up to switch the heating circuit relay as a function of the detected switching position and thus the operating mode means that the heating circuit relay is switched on and off during operation. This includes switching with a predetermined switching pattern or switching rule. In particular, the switching on and off can include clocked switching, e.g. with a predefined duty cycle, a predefined pulse duration etc.

The household cooking appliance has at least one cooking space. The household cooking appliance has at least one oven functionality, possibly also a steam addition functionality, in particular a steam cooking functionality. The household cooking device can be an independent cooking device or a cooking device / hob combination or stove.

The radiators can have, for example, at least one top heat or grill radiator, a bottom heat radiator and / or a ring or circulating air radiator. These radiators can be resistance radiators.

The mechanically switching mode selector switch is set up to open or close at least one associated electrical contact as a function of the selected or actuated switching position and thus the operating mode by means of manual actuation. In particular, by opening or closing the at least one contact, at least one heating element can be switched on for operation under the set operating mode. The operating selector switch can be used for different switching positions or operating modes switch on different radiators or combinations of radiators. The operating selector switch can also be referred to as a preselection switch.

The mechanical temperature controller is set up to regulate the cooking space temperature as a function of a target temperature set there by a user. This is done without electronic regulatory contributions, but mechanically or electromechanically, e.g. using a capillary tube regulator. A mechanical temperature controller is very inexpensive and robust.

The mechanical temperature controller can also be referred to as an electromechanical temperature controller, mechanical thermoregulator or thermostat. The mechanical temperature controller can be, for example, a capillary tube controller, a bimetal switch, etc.

The mechanical temperature controller is electrically connected in series with the radiators, so that current can flow through the radiators through the mechanical temperature controller. If the temperature at the mechanical temperature controller is above the set target temperature, an electrical contact of the mechanical temperature controller is open and no current flows through the radiators. If the temperature at the mechanical temperature controller is below the set target temperature, the electrical contact of the temperature controller is closed and current can flow through the (switched on) radiators.

The electronic circuit can be a simple electronic circuit with an integrated circuit - for example a controller - which can control or switch the heating circuit relay. The heating circuit relay can be a component of the electronic circuit. The electronic circuit can switch the heating circuit relay clocking, ie in particular with a predetermined duty cycle and a predetermined period. The electronic circuit can also keep the heating circuit relay closed for at least one specific operating mode. In general, the electronic circuit can switch and in particular have at least one relay for switching at least one consumer (in particular a radiator and / or secondary consumer), which enables a particularly compact circuit.

The heating circuit relay can be an electrically controlled, mechanically switching relay. The heating circuit relay can alternatively be an electronically controlled switching element such as a triac or similar. his. A heating circuit relay can therefore generally be understood to mean an electrically or electronically controlled switching element.

The heating circuit relay is electrically connected in series with the (connected) radiators and the electrical contact of the mechanical temperature controller, which enables particularly simple switching.

It is an embodiment that the electronic circuit is set up to switch the heating circuit relay for at least one special operating mode (e.g. for an energy-saving operating mode) during operation and to switch at least one other, conventional operating mode to close or to keep it permanently closed. This takes advantage of the fact that a satisfactory cooking result is not achieved with mechanical temperature controllers at low temperatures, since the mechanical temperature controllers then have too high an inertia. Thus, the mechanical temperature controller for high temperatures can be used as before in mechanically controlled ovens for temperature control, in particular also in conventional operating modes such as a grill mode, a circulating air or hot air mode, an upper and / or lower heat mode, etc. At low temperatures However, clocked low-temperature operation of the radiators gives better cooking results. The clocked operation may only be controlled. The mechanical temperature controller is then preferably set so that it remains closed during the operating sequence of the low-temperature operating mode. It can then be used as additional protection against overheating. A low temperature mode can e.g. soft cooking (also known as low temperature cooking) or energy saving mode.

It is another embodiment that the electronic circuit is an electronic clock circuit ("electronic clock") for the time-limited and / or time-delayed operation of the at least one radiator. Such a clock circuit is available inexpensively and in particular requires only a few electronic components, for example a microcontroller. The clock circuit can in particular have a microcontroller, the heating circuit relay for controlling a current flow at least through the radiators and a processing of an input signal coming from the operating selector switch. The In this embodiment, electronic clock circuit can now also be used to control or regulate consumers (in particular radiators) during operation.

It is an embodiment of the fact that the heating circuit relay can be switched on and off for time-controlled, time-limited or time-shifted operation. In other words, the relay that is used in conventional clock circuits for time-controlled (i.e., time-limited or time-shifted) operation of the radiators can now also be used to switch the radiators on and off during operation. This has the advantage that conventional clock circuits only need to be modified slightly, possibly only by adapting their software or firmware.

It is a further embodiment that the mode selector switch is a rotary selector switch that has a coding switch circuit board, the output of which is connected to an input of the electronic circuit. Alternatively, the rotary selector switch can have simple switched contacts instead of a coding switch board. These configurations result in the advantage that information about a selected operating position or operating mode can be transmitted to the electronic circuit simply and inexpensively.

It is yet another embodiment that the electronic circuit has a main relay which is connected in series with the radiators and with auxiliary consumers of the household cooking appliance. As a result, a particularly large number, in particular all, of consumers can be switched off together by means of only one relay.

Auxiliary consumers can include, for example, an oven light (e.g. an oven lamp), a forced-air motor, an oven operating indicator lamp and / or a cooling fan motor.

It is also an embodiment that the electronic circuit can switch a further relay ("secondary consumer relay"), which is connected in series with at least one secondary consumer of the household cooking appliance and independently, for example in parallel, to the radiators. A radiator output is not switched in particular via the auxiliary consumer relay. As a result, the secondary consumer relay can be implemented inexpensively, since only small currents are switched. Furthermore, the at least one Ancillary consumers can also be switched independently of the radiators. This enables a more flexible option for independent - for example, time-shifted - operation of radiators and auxiliary consumers. In particular, the radiators can be switched off by means of a common relay (namely the heating circuit relay), which enables a particularly high level of safety while the at least one secondary consumer can still be operated. The electronic circuit can have the secondary consumer relay or the secondary consumer relay can be a component of the electronic clock circuit, which enables a particularly compact circuit.

It is also an embodiment that at least one cooling fan motor in series with the auxiliary consumer relay and in particular independently, e.g. parallel to the other consumers. As a result, the cooling fan motor can be switched (e.g. switched on or off) independently of the radiators (and possibly also to other secondary consumers), in particular temperature or time-controlled, by means of the electronic circuit. The control of a fan run-on via a temperature limiter (e.g. a Klixon), which is otherwise common for mechanically controlled cooking appliances, can be omitted. Furthermore, compared to circuits of mechanically controlled devices known today, it is easier to test the control and function of a cooling fan driven by the cooling fan motor in the final test. With the otherwise usual control of the cooling fan via a temperature limiter, checking the functional effect of switching the temperature limiter is only possible with additional effort, e.g. through complex heating of the temperature limiter or by additional bridging of the temperature limiter. By integrating the function into the clock circuit or electronic circuit, this can advantageously be done by switching on the auxiliary consumer relay using a test program.

It is a further development of the fact that the oven lighting, the circulating air motor and the oven operating indicator lamp (possibly all the secondary consumers located apart from the cooling fan motor, if present) are each connected in series with the operating selector switch, in particular in such a way that when the operating selector switch is in the off position, the Circuits of these consumers are interrupted. It can thereby be achieved that only the cooling fan motor can also be operated in an off position of the operating selector switch.

In particular, at least one cooling fan motor can be switched independently of the other consumers depending on the position of the rotary selector and can be arranged in series with the main relay in this position of the rotary selector. At least one cooling fan motor can also be switched independently of the other consumers as a function of the position of the rotary selector and can be arranged in series with the secondary consumer relay in this position of the rotary selector.

It is also an embodiment that the electronic circuit is connected to a temperature sensor or temperature sensor for measuring a cooking space temperature. By integrating the simple "electronic temperature measurement", the possibility is created in an inexpensive manner that control and / or regulation functions brought about by the electronic circuit can take place as a function of the cooking space temperature. For example, when switching, in particular clocked, operation of the radiators via the electronic circuit, the electronic parameters (e.g. the cycle ratio) can now be adapted to the current cooking chamber temperature. The electronic circuit can regulate the cooking space temperature by switching the heating circuit relay or control it depending on the temperature. The mechanical temperature controller that is still present can be used in particular to ensure operational safety, in particular against overheating. For example, it can also be avoided that the electronic circuit must meet increased safety requirements, which would make it considerably more expensive.

It is a further development that a parameterization of control values for clocked operating modes is used, which enables higher energy savings (e.g. in energy saving mode). This also improves the reliability of achieving a good cooking result, since a better adapted energy input is possible.

It is a special further development that a temperature-dependent parameterization of control values for clocked operating modes is used, which enables even greater energy savings. The electronic temperature measurement consequently makes it possible to provide better adapted control parameters for a switched, in particular clocked, operation of the radiators during operation. The parameters for the clocked operation can thus depend on the cooking space temperature can be varied to achieve higher energy savings with improved cooking quality.

In a further development, a run-on of a cooling fan (e.g. its duration or "run-on period") and / or its speed can be controlled as a function of the cooking space temperature, for example by a temperature-dependent switching of the auxiliary consumer relay. This has the advantage that the run-on time is not unnecessarily long, but sufficient cooling and dewatering of the cooking space can be achieved. This reduces energy consumption and noise pollution during fan run-on.

It is also a further development that a temperature-based door opening detection is integrated in the electronic circuit, for example to ensure subsequent operation (i.e. operation after a preset cooking time has expired) without disadvantages for the cooking result. This can be implemented with the aid of the electronic temperature measurement and a correspondingly implemented algorithm for evaluating the temperature profile of the cooking device. For example, the oven temperature can be controlled and / or regulated differently after detection of a drop in the cooking space temperature in order to compensate for the influence of this drop in temperature. In particular, the clocked operation can be interrupted for the required compensation period. The drop in temperature can e.g. be caused by opening a cooking chamber door.

It is a further development that the cooking space temperature can be reduced on the device side depending on the electronically measured cooking space temperature, in particular can be controlled or regulated as a function of time and / or temperature. This can include, for example, that a cooking space temperature set by the user using the thermostat (e.g. of 270 ° C) is automatically lowered (e.g. to 230 ° C) after a predetermined period of time in order to limit a front temperature on the cooking space door. This lowering of the cooking space temperature can e.g. can be achieved by opening the heating circuit relay for a correspondingly long time and / or frequently.

The temperature sensor is preferably on the holder of the sensor of the temperature controller (preferably capillary tube controller) with which it is attached to or in the oven. attached, because there are identical temperature values relative to a cooking space center temperature in different operating modes.

The object is also achieved by a method for operating the household cooking appliance as described above, wherein when an operating mode is selected in which at least one radiator is operated in a clocked manner, the mechanical temperature controller is set to a temperature which is higher than one maximum cooking space temperature to be expected, in particular to a maximum adjustable temperature. In this way, it can be prevented particularly safely and with simple means that the mechanical temperature controller intervenes in the operation of at least one consumer during switching, in particular clocked operation, since the mechanical temperature controller then remains closed, as expected.

The task is also solved by methods which correspond to the special functions and / or special operating modes listed above, e.g. Temperature reduction, energy saving mode, etc.

Fig.1

zeigt eine erste Schaltung eines ersten Backofens;

Fig.2

zeigt eine zweite Schaltung eines zweiten Backofens; und

Fig.3

zeigt eine dritte Schaltung eines dritten Backofens.

The properties, features and advantages of this invention described above and the manner in which they are achieved can be more clearly understood in connection with the following schematic description of an exemplary embodiment, which is explained in more detail in connection with the drawings.

Fig.1

shows a first circuit of a first oven;

Fig.2

shows a second circuit of a second oven; and

Figure 3

shows a third circuit of a third oven.

Fig.1 shows a first circuit 1 for operating a household appliance in the form of a first oven B1 under several operating modes. For this purpose, the oven B1 has several radiators, namely here, for example, a first top heat or grill heater 2, a second top heat or grill heater 3, a bottom heat radiator 4 and a circulating air or ring heater 5. The heaters 2 to 5 are electrically connected to an outer conductor L. (eg operated with an AC voltage of 230 V) and connected to a neutral conductor N. The radiators 2 to 5 are arranged here, for example, electrically parallel to one another.

A temperature limiter 6 is connected between the radiators 2 to 5 on the one hand and the neutral conductor N on the other hand. Furthermore, between the outer conductor L and the radiators 2 to 5 in series: a main relay 7, a mechanical rotary selector switch 8, a mechanical temperature controller - here e.g. formed as a user-adjustable capillary tube controller 9 - and a heating circuit relay 10 switched. The main relay 7 and the heating circuit relay 10 are components of a clock circuit 11.

The clock circuit 11 is constructed as an electronic circuit and, in addition to the relays 7 and 10, can have at least one integrated circuit (e.g. a microcontroller, not shown) etc. The clock circuit 11 is used, among other things, to control the time of the oven B1 (e.g. to implement a timer function and to display the time) and can also have a display device 12 (e.g. a 7-segment display). The clock circuit 11 is connected here directly between the outer conductor L and the neutral conductor N. The clock circuit 11 is also set up so that it can switch the heating circuit relay 10 and / or the main relay 7.

Furthermore, an input 13 of the clock circuit 11 is connected to an output 14 of the rotary selector switch 8. The rotary selector switch 8 is equipped with a coding device 15 (e.g. in the form of a coding switch circuit board, e.g. based on bit coding by means of, for example, a gray code), which assigns an output signal or a unique electrical interface configuration to each rotary position of the rotary selector switch 8. Therefore, the clock circuit 11 can recognize (for example by means of suitable evaluation logic or evaluation circuit) in which rotary position the rotary selector switch 8 is located. A rotary position of the rotary selector switch 8 can in particular correspond to a respective operating mode.

The rotary selector switch 8 is also designed and arranged such that it has a connection between the main relay 7 and the capillary tube regulator 9, between the temperature limiter 6 and the neutral conductor N, between the radiators 2 to 5 and the heating circuit regulator 10, between the radiators 2 to 5 and the clock circuit 11, between the radiators 2 to 5 and a circulating air motor 16 and between the circulating air motor 16 and the neutral conductor N can optionally close and open. All of these connections can be individually closed or opened depending on the selected rotary position his. In an off or zero position in which no operating mode is selected, the rotary selector switch 8 can be set up in such a way that all connections are open. In particular, each of these connections can be assigned a mechanical individual switch Sn (n = 1,..., 9) of the rotary selector switch 8, which then has a corresponding number of such mechanical individual switches Sn. The individual switches Sn can be actuated, for example, by means of a suitable shaft, for example connected to a rotary knob. In principle, any, but fixed, combination of the closed states (open / closed) of the individual switches Sn can be assigned to each selected position of the rotary selector switch 8.

The individual switches S1 to S8 can include, for example: a single switch S1 between the capillary tube regulator 9 and the heating relay 7, a single switch S2 between the first grill heater 2 and the heating circuit relay 10, a single switch S3 between the second grill heater 3 and the heating circuit relay 10, a single switch S4 between the bottom heat radiator 4 and the heating circuit relay 10, a single switch S5 between the circulating air heater 5 and the heating circuit relay 10, a single switch S6 between the neutral conductor N and the temperature limiter 6, a single switch S7 between the individual switches S2 to S5 and a signal input of the clock circuit 11, one Single switch S8 between the single switch S6 and the air motor 16 and a single switch S9 between the individual switches S2 to S5 and the air motor 16. The clock circuit 11 can the off position of the rotary selector 8 by a corresponding bit code - for example "000" - recognize.

In addition to the air motor 16, other auxiliary consumers are connected between the outer conductor L and the neutral conductor N. For example, there is an oven lamp 17 which is connected on the one hand between the individual switch S1 of the rotary selector switch 8 and the capillary tube regulator 9 and on the other hand between the temperature limiter 6 and the individual switch S6. An oven operating indicator lamp 18 is connected in parallel with the oven lamp 17. A cooling fan motor 19 is connected on the one hand directly to the neutral conductor N and on the other hand is connected between the individual switch S1 of the rotary selector switch 8 and the main relay 7. All of the consumers 2 to 5 and 16 to 19 described except for the clock circuit 11 are electrically connected in series with the main relay 7, so that when the main relay 7 is open, these consumers 2 to 5 and 16 to 19 are not supplied with electrical voltage and are therefore switched off are.

To operate the oven 1, a user turns the rotary selector switch 8 from its off or zero position to an operating position which corresponds to an operating mode desired by the user. The operating mode can be an operating mode that is usual for ovens with mechanical oven regulators (e.g. capillary tube regulators 9), such as a grill mode, a bottom heat and / or top heat mode, or a recirculation mode. However, the heating circuit relay 10, which can be controlled by the clock circuit 11, also enables switching operation with special operating modes such as soft cooking (low-temperature cooking), energy-saving cooking (for example an "energy-saving mode"), etc. For the conventional operating modes, the heating circuit relay 10 is not required for controlling a cooking space temperature and is in use ongoing operation permanently closed.

For example, if a user sets the grill operating mode on the rotary selector switch 8, the rotary selector switch 8 closes the individual switch S1 between the capillary tube regulator 9 and the heating relay 7, the individual switch S6 between the neutral conductor N and the temperature limiter 6, and the individual switches S2 and S3 between the grill radiators 2 or 3 and the heating circuit relay 10. In addition, the individual switch S7 between the grill radiators 2 and 3 and the clock circuit 11 will be closed, so that the clock circuit 11 receives feedback that at least one of the radiators 2 to 5 is at a voltage and therefore - if the temperature limiter 6 is closed - the radiator heats.

In contrast, the individual switches S4 and S5 are open, so that the radiators 4 and 5 are not operated. In addition, the individual switches S8 and S9 are open, so that the air motor 16 is not operated.

Furthermore, a corresponding bit code can now be read from the clock circuit 11 on the rotary selector switch 8 or a corresponding bit code is now output by the rotary selector switch 8 to the clock circuit 11. The clock circuit 11 processes the bit code (for example by means of a corresponding processing device) and switches the heating circuit relay 10 accordingly or leaves it in the starting position. This also creates an electrical connection between the grill element 2 and the capillary tube regulator 9, so that the grill element 2 is now connected both to the outer conductor L and to the neutral conductor N and therefore with electrical energy is available. The associated temperature control takes place, as usual, via a temperature setting on the capillary tube regulator 9.

Via the clock circuit 11, a time-shifted and / or a time-limited operation of the grill mode can also be set, e.g. starting in one hour after activation with a duration of two hours. The clock circuit 11 opens and closes the main relay 7 and the heating circuit relay 10 accordingly.

If an air recirculation mode is selected on the rotary selector switch 8, the switch S5 can be closed instead of the switches S2 and S3 in order to operate only the air circulation heater 5. In this case, the switch S8 can be closed in order to also operate the circulating air motor 16.

The functionality of the capillary tube regulator 9 is not sufficient for special operating modes, since it is not possible, depending on the selected operating mode, e.g. to control an energy input into the oven via parameters of the clock circuit 11. If a special operating mode is selected on the rotary selector switch 8, e.g. an energy-saving mode, the suitable at least one radiator from the group of radiators 2 to 5 is switched on by closing the corresponding individual switches S2 to S5, similarly to the selection of a previously customary operating mode, and possibly also the circulating air motor 16.

In contrast to one of the usual operating modes, however, the heating circuit relay 10 is now switched on and off, in particular clocked, by the clock circuit 11, so that the suitable radiators 2 to 5 are also switched on and off, in particular clocked. In particular, there is no regulation of the temperature in an associated cooking space or oven space of the oven 1, or the timing (for example a period, a duty cycle, etc.) is not dependent on an oven temperature in the oven space. For this purpose, the capillary tube regulator 9 can have been set by a user to a temperature value (at which the capillary tube regulator 9 opens or interrupts) which is above a temperature value typically achievable in the selected special operating mode, for example to a maximum adjustable temperature value. The clock circuit 11 can determine or define the clocking parameters (period, duty cycle, etc.) suitable for the selected special operating mode on the basis of the bit code transmitted or read out by the rotary selector switch 8.

Consequently, the oven 1 can carry out modes of operation (in particular, modes of operation that are customary for this) by means of mechanical-thermal control via the mechanically adjustable rotary selector switch 8 and the capillary tube regulator 9 and can perform a switching, in particular clocked, controlled heating operation in at least one operating mode in a simple and particularly inexpensive manner.

A function, e.g. an energy-saving mode and / or a temperature reduction are offered in cooking devices with mechanical control. The electronic unit designed here as a clock circuit 11 can be kept particularly simple, since basic functionalities (temperature setting, temperature measurement and control), in particular for conventional operating modes, are already covered by the very inexpensive mechanical control element (e.g. the capillary tube regulator 9).

Fig.2 shows a second circuit 21 of a second oven B2. The circuit 21 differs from the circuit 1 in that the main relay 7 is missing, but there is a further relay (“secondary consumer relay” 22) on the clock circuit 23. The secondary consumer relay 22 is electrically connected in series with the secondary consumers 16, 17 and 19, so that they can advantageously also be operated when the radiators 2 to 5 are switched off by continuously opening the heating circuit relay 10. In addition, the cooling fan motor 19 can now be operated independently of the radiators 2 to 5 by the baking oven B2, for example in order to allow a cooling fan motor 19 to run on and a dewatering associated therewith in a simple manner. The heating circuit relay 10 has the same function in the circuit 21 as in the circuit 1.

Figure 3 shows a third circuit 31 of a third oven B3, which differs from the second circuit 21 in that a temperature sensor or temperature sensor 32 for measuring an oven temperature is also connected to the clock circuit 23, for example an NTC resistor or a PTC resistor, for example a platinum measuring resistor, for example of the Pt 500 type. The clock circuit 23 can have a suitable measuring circuit for this purpose. The temperature sensor 32 also enables temperature control for special programs in which the capillary tube regulator 9 is set in such a way that it has no control function takes over. However, the capillary tube regulator 9 - as in Fig.1 and Fig.2 - Take over a safety function, so that the clock circuit 23 is still particularly simple and inexpensive to implement.

By integrating such a simple “electronic temperature measurement”, the possibility is created in an inexpensive manner that control and / or regulation functions brought about by the electronic circuit 23 can take place as a function of the cooking space temperature. In particular, temperature-dependent parameterization of control values for clocked operating modes can be used. Furthermore, a follow-up of a cooling fan or the associated cooling fan motor 19 can now be controlled as a function of the cooking chamber temperature by means of the clock circuit 11. The clock circuit 11 can also be set up to implement temperature-based door opening detection. In addition, the clock circuit 11 can be set up to reduce the cooking space temperature on the device side as a function of the electronically measured cooking space temperature.

The temperature sensor 32 is preferably attached to the holder (not shown) of the sensor of the capillary tube regulator 9.

Of course, the present invention is not limited to the exemplary embodiments shown.

In general, "a", "an" etc. can be understood to mean a singular or a plurality, in particular in the sense of "at least one" or "one or more" etc., as long as this is not explicitly excluded, e.g. by the expression "exactly one" etc.

A number can also include the specified number as well as a usual tolerance range, as long as this is not explicitly excluded.

LIST OF REFERENCE NUMBERS

1

circuit

2

First grill radiator

3

Second grill radiator

4

Bottom heating element

5

Recirculating air heating

6

Temperature

7

main relay

8th

rotary dial

9

Capillary tube

10

Heizkreisrelais

11

watch circuit

12

display

13

Input of the clock circuit

14

Output of the rotary selector switch

15

coding

16

recirculated air motor

17

oven light

18

Oven pilot lamp

19

Cooling fan motor

21

circuit

22

In addition to consumer relay

23

watch circuit

31

circuit

32

temperature sensor

A

outer conductor

B1

oven

B2

oven

B3

oven

N

neutral

S1-S9

Single switch

Claims (14)

1. Household cooking appliance (B1; B2; B3), having

   - a plurality of electrically operable heating elements (2-5) for heating a cooking compartment,

   - a mechanically switching operation selection switch (8) for connecting at least one heating element (2-5) as a function of the switch position thereof,

   - a mechanical temperature regulator (9) for regulating the connected heating element (2-5) as a function of a temperature of the cooking compartment, which mechanical temperature regulator (9) is connected electrically in series with the heating elements (2-5), and

   - an electronic circuit (11; 23),
   wherein

   - a heating circuit relay (10) is connected electrically in series with the heating elements (2-5) and the mechanical temperature regulator (9) and is able to be switched by means of the electronic circuit (11; 23) and

   - the electronic circuit (11; 23) is connected to the operation selection switch (8) in order to identify a switch position set by the operation selection switch (8), characterised in that

   - the electronic circuit (11; 23) is configured to switch the heating circuit relay (10) on and off during continuous operation as a function of the identified switch position with a predefined switching pattern.
2. Household cooking appliance (B1; B2; B3) according to claim 1, characterised in that the electronic circuit (11; 23) is configured to connect the heating circuit relay (10) in a timed manner for at least one special operating mode and in a closing manner for at least one further operating mode.
3. Household cooking appliance (B1; B2; B3) according to one of the preceding claims, characterised in that the electronic circuit (11; 23) is an electronic timing circuit for the time-controlled operation of the at least one heating element (2-5).
4. Household cooking appliance (B1; B2; B3) according to claim 3, characterised in that the heating circuit relay (10) is able to be switched on and off for the time-controlled operation.
5. Household cooking appliance (B1; B2; B3) according to one of the preceding claims, characterised in that the operation selection switch (8) is a rotary selection switch, the output of which is connected to an input of the electronic circuit (11; 23).
6. Household cooking appliance (B1) according to one of the preceding claims, characterised in that the electronic circuit (11) has a main relay (7), which is connected in series with the heating elements (2-5) and with auxiliary consumers (16-19) of the household cooking appliance (B1).
7. Household cooking appliance (B2; B3) according to one of the preceding claims, characterised in that the electronic circuit (23) has an auxiliary consumer relay (22), which is connected in series with at least one auxiliary consumer (16-18) of the household cooking appliance (B2; B3) and is switched independently of the heating elements (2-5).
8. Household cooking appliance (B3) according to one of the preceding claims, characterised in that the electronic circuit (23) is connected to a temperature sensor (32) for measuring a cooking compartment temperature and is configured to regulate or control the cooking compartment temperature measured in this way by switching the heating circuit relay.
9. Household cooking appliance (B3) according to claim 8, characterised in that a subsequent running of a cooling fan (19) is able to be controlled as a function of the cooking compartment temperature measured by means of the temperature sensor (32).
10. Household cooking appliance (B3) according to one of the preceding claims, characterised in that the electronic circuit (23) is configured to use a parameterisation, in particular temperature-dependent parameterisation, of control values for operating modes timed by means of the heating circuit relay (10).
11. Household cooking appliance (B3) according to one of claims 8 to 10, characterised in that the electronic circuit (23) is configured for carrying out a door opening identification.
12. Household cooking appliance (B3) according to one of claims 8 to 11, characterised in that the cooking compartment temperature is able to be reduced on the appliance side as a function of the cooking compartment temperature measured by means of the temperature sensor (32).
13. Household cooking appliance (31) according to one of claims 8 to 12, characterised in that the temperature sensor (32) is attached to a holder of a probe of the mechanical temperature regulator (9), with which it is fastened to or in the cooking compartment.
14. Method for operating a household cooking appliance (B1; B2; B3) according to one of the preceding claims, characterised in that when an operating mode is chosen, in which at least one heating element (2-5) is operated in a timed manner, the mechanical temperature regulator (9) is set to a temperature which is higher than a maximum cooking compartment temperature to be anticipated, in particular to a maximum temperature which can be set.

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