EP4120799A1 - High-frequency household appliance, preferably high-frequency kitchen appliance - Google Patents

Abstract

The invention relates to a high-frequency household appliance (1), preferably a high-frequency kitchen appliance (1), with at least one treatment chamber (11) which is designed to accommodate items to be treated with high-frequency energy, and with at least one high-frequency heating module (2nd ), which is designed to generate the high-frequency energy and to deliver it into the treatment room (11), the high-frequency heating module (2) having at least: • at least one high-frequency signal generator (21), which is designed to generate the high-frequency energy , and• at least one transition (ANT) to the treatment space (11) of a first high-frequency path (23a-23d), preferably one transition (ANT) each to the treatment space (11) of a plurality of high-frequency paths (23a-23d), which is formed , high-frequency energy into the treatment room (11).The high-frequency household appliance (1) is characterized in that the high-frequency heating module (2), preferably at least the e The first high-frequency path (23a-23d), particularly preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), of the high-frequency heating module (2), further has at least:• at least one Measuring circuit (UIM, FDIV, ADC), which is designed to detect at least one parameter of the high-frequency energy, and• at least one safety unit (22), which is designed to receive the at least one detected parameter from the measuring circuit (UIM, FDIV, ADC) and evaluate with regard to compliance with at least one predetermined limit value, the high-frequency heating module (2), preferably the safety unit (22), being designed to operate the high-frequency signal generator (21) depending on the evaluation of the parameter, preferably the high-frequency - switch off the signal generator (21) when a predetermined limit value of the parameter is exceeded.

Description

The invention relates to a high-frequency household appliance according to the preamble of patent claim 1 and a high-frequency heating module for use in such a high-frequency household appliance according to patent claim 17.

It is known to heat materials using microwaves. Microwaves are understood to mean electromagnetic waves with a frequency of about 1 to about 300 GHz, i.e. with wavelengths of about 30 cm to about 1 mm. Microwaves can excite molecules to vibrate and thereby increase the temperature of the molecules. This is used, for example, in microwave ovens to heat or cook food within the cooking chamber.

A microwave oven, also known as a microwave oven, usually has an outer housing, inside which a cooking space is provided. The cooking chamber is accessible from the outside through an access opening which can be closed and opened in a pivotable manner, for example by means of a door or a flap. Display and control elements are also usually provided on the outside, for example to enable a user to set the output and the duration of the process. An intermediate space is formed between the outer housing and the cooking chamber, in which at least one microwave generator is usually arranged, which can generate the microwaves and conduct them through at least one corresponding high-frequency waveguide into the cooking chamber as a cavity. Originally, so-called magnetrons were used to generate microwave radiation, but nowadays electronic circuits such as transistors are used for this purpose.

It is generally known to use a coaxial line with corresponding coaxial connectors between the HF module (high-frequency module) as a microwave generator and the treatment chamber of the microwave oven in order to conduct the HF energy (high-frequency energy) to the interior. The coaxial line can be designed together with an antenna, i.e. without any additional plug connection, and attached to the wall of the interior. For example, the antenna may be a monopole-type or an inverted-F-shaped antenna.

The HF energy can also be fed into the interior via a HF hollow line (high-frequency hollow line). Usual cross-sections of waveguides can be rectangular, for example or be oval. In the wall of the interior, the HF waves (high-frequency waves) can run vertically via such waveguides and pass through a rectangular or oval window, for example, in the wall of the interior and reach the interior.

The applicant is also aware of a type of kitchen appliance which is referred to as a "dialog cooker". A Dialog cooker is based on well-known or conventional ovens, which work with an energy supply such as top and bottom heat or circulating air, so that heat, precisely adjusted to the degree, penetrates the food from the outside and slowly works its way into the inside of the food. This type of cooking, such as baking, for example, has such an effect on the food as the food to be cooked that the outer layers of the food are heated for a comparatively long time or strongly, but the core of the food is heated comparatively briefly or little, since the heat dissipates during the cooking process must first spread from the outer layers to the core of the food.

In order to accelerate such cooking processes and/or to distribute the heat of the cooking process more evenly in the food as the food to be cooked, the further development of such conventional baking ovens into the Dialoggarer is known, which also uses electromagnetic waves with changing frequencies in the high-frequency spectrum, i.e. HF waves, to only heat the food being cooked and not its surroundings or the ambient air. This can be done very precisely or very specifically with regard to the heat that is to be additionally supplied to the food. This can lead to significant acceleration of the cooking process and improve the quality of the result of the cooking process.

Devices of this type for feeding high-frequency energy (HF energy) into a treatment room of a household appliance or a kitchen appliance provide a separate HF signal generator for each path or for each feed. This makes it possible to generate the HF signals of the paths with different frequencies, which can be desirable for certain methods of heating or for certain heating programs.

The use of high-frequency energy in the form of electromagnetic waves in corresponding household appliances can offer advantages for their intended use.

However, such electromagnetic waves of high-frequency energy can pose a risk to the environment of the high-frequency household appliance. This can interfere with other electronic devices. The health of living beings and in particular of the user of the high-frequency household appliance can also be endangered as a result.

the EP 2 499 505 A1 describes devices and methods for applying EM energy to a load. The devices and methods may include at least one processor configured to receive information indicative of the energy dissipated by the load for each of a plurality of modulation space elements. The processor may also be configured to associate each of the plurality of modulation space elements with a corresponding period of power application based on the information received. The processor may be further configured to regulate the power applied to the load such that, for each of the plurality of modulation space elements, power is applied to the load with the appropriate amount of power application time.

The invention therefore faces the problem of creating a high-frequency household appliance of the type described in the introduction, so that the protection of the environment against electromagnetic waves of high-frequency energy can be improved or even guaranteed. In particular, the propagation of impermissibly strong high-frequency energy and/or high-frequency energy of impermissible frequencies into the environment of the high-frequency household appliance should be reduced or even completely avoided. In particular, it should be possible to comply with radio and EMC limit values. This should be done in particular for high-frequency kitchen appliances. At the very least, an alternative to known high-frequency household appliances of this type should be created.

According to the invention, this problem is solved by a high-frequency household appliance having the features of patent claim 1 and by a high-frequency heating module having the features of patent claim 17 . Advantageous refinements and developments of the invention result from the following dependent claims.

• wenigstens einen Hochfrequenz-Signalgenerator, welcher ausgebildet ist, die hochfrequente Energie zu erzeugen, und
• wenigstens einen Übergang zum Behandlungsraum eines ersten Hochfrequenz-Pfades, vorzugsweise jeweils einen Übergang zum Behandlungsraum mehrerer Hochfrequenz-Pfade, welcher ausgebildet ist, hochfrequente Energie in den Behandlungsraum abzugeben.

The invention thus relates to a high-frequency household appliance, preferably a high-frequency kitchen appliance, with at least one treatment chamber which is designed to accommodate items to be treated with high-frequency energy, and with at least one high-frequency heating module which is designed to generate the high-frequency energy and to deliver into the treatment room, wherein the high-frequency heating module comprises at least:

• at least one high-frequency signal generator, which is designed to generate the high-frequency energy, and
• at least one transition to the treatment room of a first high-frequency path, preferably one transition each to the treatment room of a plurality of high-frequency paths, which is designed to emit high-frequency energy into the treatment room.

Such a high-frequency household appliance can be any technical device that can be used in a household for household chores, with the household chore being able to be carried out additionally or solely by means of high-frequency (abbreviated: HF) energy. The high-frequency energy can be emitted into the treatment room by means of electromagnetic waves, in order to warm up or heat an item to be treated there. Such high-frequency electromagnetic waves can, in particular, have frequencies in the range from approximately 1 to approximately 300 GHz, i.e. wavelengths from approximately 30 cm to approximately 1 mm.

The implementation can take place, for example, as a household appliance in the form of a washing machine, a tumble dryer, a washer-dryer and the like, so that the high-frequency energy can be used additionally or solely for heating water or detergent or for drying wet laundry inside the washing drum as a treatment room . As a high-frequency kitchen appliance, the high-frequency energy can be used additionally or solely for cooking food in the cooking space as a treatment space. Such kitchen appliances can be, for example, microwave ovens, ovens, dialog cookers or combi appliances.

• wenigstens eine Messschaltung, welche ausgebildet ist, wenigstens einen Parameter der hochfrequenten Energie zu erfassen, und
• wenigstens eine Sicherheitseinheit, welche ausgebildet ist, den wenigstens einen erfassten Parameter von der Messschaltung zu erhalten und hinsichtlich der Einhaltung wenigstens eines vorbestimmten Grenzwertes auszuwerten,

wobei das Hochfrequenz-Heizmodul, vorzugweise die Sicherheitseinheit, ausgebildet ist, den Hochfrequenz-Signalgenerator in Abhängigkeit der Auswertung des Parameters zu betreiben, vorzugsweise den Hochfrequenz-Signalgenerator bei Überschreiten eines vorbestimmten Grenzwertes des Parameters abzuschalten.The high-frequency household appliance according to the invention is characterized in that the high-frequency heating module, preferably at least the first high-frequency path, particularly preferably several high-frequency paths, very particularly preferably all high-frequency paths, of the high-frequency heating module also has at least:

• at least one measuring circuit, which is designed to detect at least one parameter of the high-frequency energy, and
• at least one safety unit, which is designed to receive the at least one recorded parameter from the measuring circuit and to evaluate it with regard to compliance with at least one predetermined limit value,

wherein the high-frequency heating module, preferably the safety unit, is designed to operate the high-frequency signal generator depending on the evaluation of the parameter, preferably to switch off the high-frequency signal generator when a predetermined limit value of the parameter is exceeded.

According to the invention, the high-frequency energy or its electromagnetic wave can be monitored in this way before it is delivered or emitted via the respective transition into the treatment room. For example, an impermissible frequency of high-frequency energy can be detected and the propagation in the treatment room can be prevented. This can serve to protect the environment and in particular to comply with radio and EMC limit values.

In order to achieve this and to prevent the propagation of high-frequency energy in the treatment room with an undesirable or even impermissible condition, at least one parameter of the high-frequency energy is recorded or determined and evaluated with regard to the fulfillment of criteria or compliance with limit values, such as will be described in more detail below on the basis of preferred variants. In any case, the safety unit can carry out an evaluation of the at least one recorded parameter to determine whether this parameter complies with at least one predetermined limit value or satisfies a predetermined criterion. This limit value or several limit values of a parameter or a limit value or several limit values of different parameters and/or the criterion or several criteria can or can enable an assessment of whether the high-frequency energy after escaping into the treatment room with regard to the corresponding parameter or criterion is desirable or permissible or not.

If an undesirable or impermissible quality of the high-frequency energy or its electromagnetic wave is detected in this way, the high-frequency heating module and in particular its safety unit can react to this and change the operation of the high-frequency signal generator. In particular, the generation of the unwanted or impermissible high-frequency energy or its electromagnetic wave by the high-frequency signal generator can now be omitted. In any case, this can be displayed or communicated to a user in order to carry out or arrange for repairs to be made to the high-frequency household appliance.

According to the invention, the protection of the environment against electromagnetic waves of high-frequency energy can thereby be improved or even guaranteed. In particular, the propagation of impermissibly strong high-frequency energy and/or high-frequency energy of an impermissible frequency into the area surrounding the high-frequency household appliance can be reduced or even completely avoided.

According to one aspect of the invention, the predetermined limit value is based on at least one current operating parameter, preferably on the amplitude and/or on the frequency of the high-frequency energy of the high-frequency heating module, preferably of the high-frequency signal generator. In this way, according to the invention, a comparison can be made as to whether the high-frequency energy generated by the high-frequency signal generator on the path of propagation to the transition into the treatment room or to a specific point within the path of propagation corresponds to the high-frequency energy of the desired quality or through electronic components the previous one An undesirable or impermissible change has taken place as a result of the spread. This also applies to the high-frequency signal generator itself. In any case, this can be caused by defective electronic components or their incorrect parameterization.

According to a further aspect of the invention, the measuring circuit is designed as a voltage/current measuring circuit to detect the voltage and the current of the high-frequency energy, preferably a high-frequency power amplifier, and the safety unit is designed to detect the detected voltage and the detected current the voltage/current measuring circuit, to determine a direct current power consumption therefrom and to evaluate the determined direct current power consumption with regard to compliance with a predetermined limit value, the predetermined limit value preferably being based on the current direct current power consumption of the high-frequency signal generator. This can represent a possibility of implementing the previously described aspects of the present invention.

According to a further aspect of the invention, the measuring circuit is designed as a voltage/current measuring circuit to detect the voltage and the current of the high-frequency energy of a high-frequency power amplifier, with at least the first high-frequency path, preferably several high-frequency paths, particularly preferably all High-frequency paths, further comprising at least one high-frequency coupler configured to measure the power of a forward-running high-frequency wave of the emitted high-frequency energy, and the safety unit is configured to read the detected voltage and the detected current from the voltage/current Obtain measuring circuit, from which to determine a direct current power consumption, from the specific direct current power consumption and the detected power of the forward high-frequency wave to determine an efficiency and to evaluate the specific efficiency with regard to compliance with a predetermined limit value, the pre- agreed limit value is preferably based on the current DC power consumption of the high-frequency signal generator. This can represent an alternative way of implementing the previously described aspects of the present invention.

According to a further aspect of the invention, the measuring circuit is designed as a frequency divider to detect the frequency of the high-frequency energy, preferably a high-frequency power amplifier, and the safety unit is designed to receive the frequency from the frequency divider and evaluate it with regard to compliance with a predetermined limit value, preferably wherein the predetermined limit is based on the current frequency of the radio frequency signal generator. This can represent an alternative way of implementing the previously described aspects of the present invention.

According to a further aspect of the invention, the measuring circuit is designed as a sampling converter to detect a high-frequency signal sample of the high-frequency energy, preferably a high-frequency power amplifier, and the safety unit is designed to receive the high-frequency signal sample from the sampling converter and with regard to compliance at least evaluate a predetermined criterion, preferably with regard to compliance with a plurality of predetermined criteria, the measuring circuit preferably having a high-frequency synthesizer and a high-frequency mixer. This can represent an alternative way of implementing the previously described aspects of the present invention.

• wenigstens einen ersten Bandpassfilter, welcher ausgebildet ist, lediglich einen vorbestimmten Frequenzbereich der hochfrequenten Energie hindurchzulassen.

Hierdurch kann der Frequenzbereich der hochfrequenten elektromagnetischen Welle des entsprechenden Hochfrequenz-Pfads auf einen vorbestimmten Frequenzbereich eingeschränkt werden.According to a further aspect of the invention, at least one high-frequency path, preferably several high-frequency paths, particularly preferably all high-frequency paths, also have:

• at least one first bandpass filter configured to only pass a predetermined frequency range of the high-frequency energy.

As a result, the frequency range of the high-frequency electromagnetic wave of the corresponding high-frequency path can be restricted to a predetermined frequency range.

According to a further aspect of the invention, at least one radio-frequency path, preferably several radio-frequency paths, particularly preferably all radio-frequency paths, also has at least one second band-pass filter, which is configured redundantly to the first band-pass filter, with the second band-pass filter preferably behind, particularly preferably immediately behind a phase shifter. The second bandpass filter serves as a safety function to take over the function of the first bandpass filter if the first bandpass filter does not function as intended. This can improve protection of the environment from an undesirable or impermissible nature of the high-frequency energy or its electromagnetic wave.

• wenigstens einen Hochfrequenz-Leistungsverstärker, vorzugsweise ferner wenigstens einen Hochfrequenz-Vorverstärker, welcher ausgebildet ist, die hochfrequente Energie zu verstärken.

According to one aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, particularly preferably all high-frequency paths, also have:

• at least one high-frequency power amplifier, preferably also at least one high-frequency preamplifier, which is designed to amplify the high-frequency energy.

As a result, the power of the high-frequency electromagnetic wave there can be amplified within the high-frequency path or within the high-frequency feed. This can be done in one or more stages to achieve higher performance.

• wenigstens einen Hochfrequenz-Koppler, welcher ausgebildet ist, eine vorwärtslaufende und bzw. oder eine rückwärtslaufende Hochfrequenz-Welle der abgegebenen hochfrequenten Energie zu messen,

wobei vorzugsweise zwischen dem Hochfrequenz-Koppler und dem Übergang kein Verstärker angeordnet ist.According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, particularly preferably all high-frequency paths, also have:

• at least one high-frequency coupler, which is designed to measure a forward-running and/or a backward-running high-frequency wave of the emitted high-frequency energy,

preferably no amplifier is arranged between the high-frequency coupler and the transition.

In this way, a forward and/or reverse high-frequency wave of the emitted high-frequency energy can be detected and the recorded data can be evaluated, for example to determine the generation of the high-frequency electromagnetic wave by the high-frequency signal generator and/or other electronic components within of the respective high-frequency path. This can increase the design latitude of the high-frequency electromagnetic wave that is emitted into the treatment room. Such a high-frequency coupler can be designed, for example, as a 4-port coupler or as a 6-port coupler.

• wenigstens ein Dämpfungsglied, welches ausgebildet ist, die Amplitude der hochfrequenten Energie zu verändern.

Hierdurch kann im Laufe des entsprechenden Hochfrequenz-Pfads gezielt Einfluss auf die Amplitude der hochfrequenten elektromagnetischen Welle genommen werden.According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, particularly preferably all high-frequency paths, also have:

• at least one attenuator configured to vary the amplitude of the high-frequency energy.

As a result, the amplitude of the high-frequency electromagnetic wave can be influenced in a targeted manner in the course of the corresponding high-frequency path.

• wenigstens einen Phasenschieber, welcher ausgebildet ist, die Phase der hochfrequenten Energie zu verändern.

According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, particularly preferably all high-frequency paths, also have:

• at least one phase shifter configured to change the phase of the radio frequency energy.

As a result, the phase of the high-frequency electromagnetic wave can be influenced in a targeted manner in the course of the corresponding high-frequency path.

• wenigstens einen Hochfrequenz-Isolator, welcher ausgebildet ist, eine rückwärtslaufende Hochfrequenz-Welle der abgegebenen hochfrequenten Energie zu blockieren,

wobei vorzugsweise zwischen dem Hochfrequenz-Isolator und dem Übergang kein Verstärker angeordnet ist.According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, particularly preferably all high-frequency paths, also have:

• at least one high-frequency isolator, which is designed to block a reverse-running high-frequency wave of the emitted high-frequency energy,

preferably no amplifier is arranged between the high-frequency isolator and the junction.

Such a high-frequency isolator can be implemented, for example, by means of a high-frequency circulator with a high-frequency load resistor. In any case, this allows the electronic components of the corresponding high-frequency path to be protected against powerful reverse-running high-frequency waves of the high-frequency energy emitted, in order to avoid damage or destruction of the electronic components of the corresponding high-frequency path.

• wenigstens einen Oberwellen-Filter, welcher ausgebildet ist, Oberwellen in einer vorwärtslaufenden Welle der hochfrequenten Energie zu blockieren,

wobei vorzugsweise zwischen dem Oberwellen-Filter und dem Übergang kein Verstärker angeordnet ist.According to a further aspect of the invention, at least the first high-frequency path, preferably several high-frequency paths, particularly preferably all high-frequency paths, also have:

• at least one harmonic filter configured to block harmonics in a forward wave of the high-frequency energy,

preferably no amplifier is arranged between the harmonic filter and the transition.

In this way, corresponding harmonics in the forward high-frequency wave of the emitted high-frequency energy can be avoided.

• Messdaten einer vorwärtslaufenden und bzw. oder einer rückwärtslaufenden Hochfrequenz-Welle der abgegebenen hochfrequenten Energie, vorzugsweise von einem Hochfrequenz-Koppler, zu erhalten und
• aus den erhaltenen Messdaten wenigstens eine Amplitude und bzw. oder eine Phase einer vorwärtslaufenden und bzw. oder einer rückwärtslaufenden Hochfrequenz-Welle der abgegebenen hochfrequenten Energie zu bestimmen.

According to a further aspect of the invention, the high-frequency heating module has at least one control unit which is designed

• to obtain measurement data of a forward running and/or a reverse running high-frequency wave of the emitted high-frequency energy, preferably from a high-frequency coupler, and
• to determine at least one amplitude and/or one phase of a forward running and/or a backward running high-frequency wave of the emitted high-frequency energy from the measurement data obtained.

The corresponding measurement data can be acquired, for example, by means of the high-frequency coupler described above, which for this purpose can have circuits such as ADCs (analog-to-digital converters or analog-to-digital converters) and the like.

In any case, a corresponding influence can be exerted on the forward-running high-frequency wave of the emitted high-frequency energy in this way, because since the amplitude and the phase of a high-frequency wave running forwards and backwards at the high-frequency coupler of the respective high-frequency path depend on the high-frequency wave fields in the treatment room, these measurement data contain information about the loading of the treatment room, e.g. about food, about the high-frequency wave fields and about the high-frequency energy supply. This information can be used by heating programs of the control unit to control the frequency of the high-frequency signal generator and, if necessary, of actuators of the respective high-frequency path such as attenuators and/or phase shifters, and thus advantageously regulate the high-frequency energy supply.

According to a further aspect of the invention, the control unit is also designed to control at least the high-frequency signal generator, preferably also at least one attenuator and/or a phase shifter of at least one high-frequency path, preferably several high-frequency paths, particularly preferably all high-frequency paths of the determined amplitude and/or the determined phase, preferably to change the frequency of the high-frequency energy. In this way, a corresponding influence can be exerted on the forward-running high-frequency wave of the high-frequency energy emitted.

The present invention also relates to a high-frequency heating module for use in a high-frequency household appliance as described above. As a result, a high-frequency heating module can be made available in order to implement a high-frequency household appliance according to the invention and to be able to use its properties and advantages.

In other words, according to the invention, an HF heating module is created in whose HF power amplifiers voltage and/or current measuring circuits (UIM) can be arranged, which enable measurement and monitoring of the DC power consumption(s) of the HF power amplifiers during operation .

During operation, a safety uC can regularly measure the direct current power consumption(s) of the HF power amplifier (P_DC) for each path and compare these with direct current power consumption values that should be given based on the current operating parameters, such as in particular the amplitude and frequency of the HF signal. If there are deviations between these values that are greater than predetermined limit values, the Safety-uC can stop the HF generation.

This avoids the risk of the RF power amplifier going into self-oscillation (e.g. due to a component failure), which could generate a strong RF signal at a frequency that is out of range. A strong RF wave with the wrong frequency could then reach the treatment room. Since the microwave trap on the door of the treatment room is usually only designed for a permissible frequency range, an impermissible amount of HF energy could escape from the device, so that the permissible limit values for HF fields could be exceeded.

However, this case can be prevented according to the invention by using the knowledge that the direct current power consumption during self-oscillation deviates noticeably from the direct current power consumption values that should be given based on the current operating parameters, such as in particular the amplitude and frequency of the HF signal. Such a deviation can be recognized as described and the HF generation can be stopped in this case.

The measurement of dc power consumption values can be simplified to the measurement of dc consumption values and the assumption of known or less frequently or precisely measured dc voltage values.

Alternatively, according to the invention, the respective powers of the forward running HF waves (P_FWD) can also be determined by means of HF couplers of each path. An efficiency (EFF) can thus be determined for each path from the ratio of P_FWD to P_DC. In this case, the safety uC can regularly determine the efficiency (EFF) for each path during operation and compare it with efficiency values that should be given based on the current operating parameters, such as P_DC in particular. If there are deviations between these values that are greater than predetermined limit values, the Safety-uC can also stop the HF generation.

In this way, the risk described above can also be avoided, since the efficiency in the case of self-oscillation also deviates noticeably from the efficiency values that should be given on the basis of the current operating parameters, such as in particular P_DC. Such a deviation can be recognized as described and the HF generation can also be stopped in this case.

The circuits on the HF couplers can be designed by means of filters in such a way that they are relatively effective or sensitive in the permissible HF range and relatively ineffective or insensitive in the impermissible HF range.

Alternatively, according to the invention, an HF frequency divider can be arranged, which divides down the frequency of a signal sample coupled out behind the HF power amplifiers.

In this case, the Safety-uC can regularly measure the frequency of the divided signal during operation and compare it with the frequency that should be given based on the frequency currently set on the HF signal generator. If there are deviations between these values that are greater than predetermined limit values, the Safety-uC can stop the HF generation.

The Safety-uC can also regularly measure the period of the divided signal during operation and compare it with the period that should be given based on the frequency currently set on the HF signal generator. If there are deviations between these values that are greater than predetermined limit values, the Safety-uC can also stop the HF generation.

The danger described above can also be avoided in this way, since the frequency or period of the divided signal also deviates noticeably in the case of self-oscillation from the frequency or period value that should be given based on the frequency currently set on the HF signal generator. Such a deviation can be recognized as described and the HF generation can be stopped in this case.

A frequency-to-voltage converter can optionally be arranged instead of or in addition to the frequency divider.

Alternatively, according to the invention, an HF converter consisting of an HF synthesizer and an HF mixer for downmixing an HF signal sample coupled out behind the HF power amplifiers to an intermediate frequency range (IF_range) can also be arranged for monitoring the HF generation during operation . A sample converter can allow the safety uC to sample and analyze the IF signal sample. The Safety-uC can tune the HF synthesizer to a frequency of a relatively large HF range, so that the HF conversion of the signal sample into the (relatively small) IF range from a relatively large HF range and thus a successive analysis of a relatively large HF range can be made possible.

The Safety-uC can now regularly analyze HF areas of the signal sample during operation and check them for criteria. If, for example, a criterion is violated that the signal sample has a level in an HF range that is permissible for safe operation and is in an expected or plausible level range, the Safety uC can stop the HF generation. If a criterion is met that the signal sample has a level above a threshold value in an HF range that is not permissible for safe operation, the Safety-uC can also stop the HF generation. If the criterion is violated that the signal sample has a level below a threshold value in an HF range that is not permissible for safe operation, the Safety-uC stops the HF generation.

The danger described above can also be avoided in this way, since criteria are regularly checked as described above and the HF generation can be stopped if necessary.

Figur 1

eine schematische Darstellung eines erfindungsgemäßen Hochfrequenz-Haushaltsgerätes; und

Figur 2

eine schematische Darstellung eines erfindungsgemäßen Hochfrequenz-Heizmoduls des Hochfrequenz-Haushaltsgerätes gemäß einem ersten Ausführungsbeispiel;

Figur 3

eine schematische Darstellung eines erfindungsgemäßen Hochfrequenz-Heizmoduls des Hochfrequenz-Haushaltsgerätes gemäß einem zweiten Ausführungsbeispiel;

Figur 4

eine schematische Darstellung eines erfindungsgemäßen Hochfrequenz-Heizmoduls des Hochfrequenz-Haushaltsgerätes gemäß einem dritten Ausführungsbeispiel; und

Figur 5

eine schematische Darstellung eines erfindungsgemäßen Hochfrequenz-Heizmoduls des Hochfrequenz-Haushaltsgerätes gemäß einem vierten Ausführungsbeispiel.

Several exemplary embodiments of the invention are shown purely schematically in the drawings and are described in more detail below. It shows

figure 1

a schematic representation of a high-frequency household appliance according to the invention; and

figure 2

a schematic representation of a high-frequency heating module according to the invention of the high-frequency household appliance according to a first embodiment;

figure 3

a schematic representation of a high-frequency heating module according to the invention of the high-frequency household appliance according to a second embodiment;

figure 4

a schematic representation of a high-frequency heating module according to the invention of the high-frequency household appliance according to a third embodiment; and

figure 5

a schematic representation of a high-frequency heating module according to the invention of the high-frequency household appliance according to a fourth exemplary embodiment.

A high-frequency household appliance 1 according to the invention is considered using the example of a high-frequency kitchen appliance 1 , which can be a microwave oven 1 , a microwave oven 1 or a Dialog cooker 1 , for example. The high-frequency kitchen appliance 1 has an outer housing 10 which encloses and protects the components of the high-frequency kitchen appliance 1 from the outside. Inside the high-frequency kitchen appliance 1 is a Treatment room 11 is provided, which is enclosed or formed by a wall 12 . An intermediate space 13 is formed between the outer housing 10 and the wall 12 of the treatment chamber 11 and accommodates the electrical and electronic components of the high-frequency kitchen appliance 1 . The treatment room 11 can be made accessible and closed by opening a closure element (not shown), for example in the form of a door or flap.

A cooking process of the high-frequency kitchen appliance 1 can be carried out in the treatment chamber 11, which can also be referred to as the interior 11, the cooking chamber 11 or the cavity 11. For this purpose, when the closure element is open, food can be put into the treatment chamber 11 by a person as the user and the treatment chamber 11 can then be closed to the outside by closing the closure element. The cooking process can be carried out solely by the energy of high-frequency electromagnetic waves, such as in a microwave oven 1, or also in addition to, for example, circulating air in a Dialog cooker 1.

In any case, the high-frequency energy in the form of high-frequency electromagnetic waves is generated by a high-frequency heating module 2 of the high-frequency kitchen appliance 1 , which is essentially arranged in the intermediate space 13 . The high-frequency heating module 2 has precisely one high-frequency signal generator 21 which is designed to generate the high-frequency energy for the treatment room 11 . The high-frequency signal generator 21 is operated by a control unit 20 as a functional microcontroller 20 . The high-frequency energy generated is distributed equally to a plurality of, for example four, high-frequency paths 23a-23d as high-frequency feeds 23a-23d and is emitted into the treatment room 11 via the high-frequency paths 23a-23d. Each of the four high-frequency paths 23a-23d has its own transition ANT in the form of an antenna ANT, which extends into the treatment room 11 and can therefore deliver or emit the respective portion of the high-frequency energy into the treatment room 11. This takes place at the frequency with which the high-frequency energy was generated by the high-frequency signal generator 21 . Thus, multiple high-frequency paths 23a-23d can be implemented with just a single high-frequency signal generator 21.

The four high-frequency paths 23a-23d are of identical design and each have different electrical or electronic components or assemblies in the following order, which change the high-frequency energy between the high-frequency signal generator 21 and the respective transition ANT to the treatment room 11 and/or .or have other properties.

Thus, each high-frequency path 23a-23d first has an attenuator PGA which is designed to change the amplitude of the high-frequency energy. A first bandpass filter BPF is then provided for each high-frequency path 23a-23d, which is designed to only let through a predetermined frequency range of the high-frequency energy. A phase shifter PHS follows, which is designed to change the phase of the high-frequency energy, followed by a second bandpass filter BPF, which is identical and therefore redundant to the first bandpass filter BPF.

Next, a two-stage amplification of the high-frequency energy is performed by first using a high-frequency preamplifier PRE and then a high-frequency power amplifier HPA. This is followed by a high-frequency isolator ISO, which is designed to block a backward-running high-frequency wave of the high-frequency energy emitted and thus to protect the high-frequency power amplifier HPA and the other preceding electronic components or electronic assemblies.

A high-frequency coupler CPL is then provided, which is designed to measure a forward-running and/or a backward-running high-frequency wave of the emitted high-frequency energy. Finally, there is a harmonic filter HSF, which is designed to block harmonics in a forward wave of high-frequency energy.

According to the first exemplary embodiment, each of the four high-frequency paths 23a-23d has figure 2 also a voltage/current measuring circuit UIM as an example of a measuring circuit UIM, FDIV, ADC, which detects the voltage and the current of the high-frequency energy currently being generated after it emerges from the high-frequency power amplifier HPA. The detected voltage and the detected current are transferred from the voltage/current measuring circuit UIM to a safety unit 22 in the form of a safety microcontroller 22 of the high-frequency heating module 2, which uses this to determine a DC power consumption of the high-frequency power amplifier HPA. The security unit 22 also receives the current direct current power consumption of the high-frequency signal generator 21 or the corresponding voltage and current values in order to determine the current direct current power consumption of the high-frequency signal generator 21 therefrom. The safety unit 22 now evaluates the determined direct current power consumption with regard to compliance with a predetermined limit value, this predetermined limit value being the current direct current power consumption of the high-frequency signal generator 21 .

If the safety unit 22 detects that the predetermined limit value has been exceeded, this is evaluated as impermissible high-frequency energy and thus the high-frequency signal generator 21 is switched off in order to protect the surroundings of the high-frequency kitchen appliance 1 from the impermissible high-frequency energy.

According to the second embodiment of the figure 3 the radio-frequency coupler CPL of the radio-frequency paths 23a-23d, which is present anyway, is used to measure the power of a forward-running radio-frequency wave of the radio-frequency energy emitted. The safety unit 22 is designed to determine a current direct current power consumption from the detected voltage and from the detected current, to determine an efficiency from the determined direct current power consumption and from the detected power of the forward-running high-frequency wave, and to evaluate the determined efficiency with regard to compliance with a predetermined limit value , wherein the predetermined limit value is based on the current DC power consumption of the high-frequency signal generator 21. This may allow an alternative implementation.

According to the third embodiment of the figure 4 a frequency divider FDIV is designed as a measuring circuit UIM, FDIV, ADC to detect the frequency of the high-frequency energy at the output of the high-frequency power amplifier HPA. The safety unit 22 is designed to receive the frequency from the frequency divider FDIV and to evaluate it with regard to compliance with a predetermined limit value, the predetermined limit value being based on the current frequency of the high-frequency signal generator 21 . This may allow an alternative implementation.

According to the fourth embodiment of the figure 5 a scanning converter ADC is designed as a measuring circuit UIM, FDIV, ADC to acquire a high-frequency signal sample of the high-frequency energy of the high-frequency power amplifier HPA. The safety unit 22 is designed to receive the high-frequency signal sample from the sampling converter ADC and to evaluate it with regard to compliance with a predetermined criterion, the measurement circuit UIM, FDIV, ADC also having a high-frequency synthesizer SYN and a high-frequency mixer MIX. This may allow an alternative implementation.

List of reference symbols (part of the description)

ADC

scan converters; Analog to digital converter

ANT

Transitions or antennas to the treatment room 11

BPF

bandpass filter

cpl

high frequency coupler

FDIV

frequency divider

HPA

high frequency power amplifier; High power amplifiers

HSF

harmonic filter; Harmony suppression filter

ISO

High Frequency Isolator

MIX

high frequency mixer

PGA

(programmable) attenuator; programmable attenuator; Programmable Gain Amplifier

PHS

phase shifter

PRE

high frequency preamplifier; Preamplifier

SYN

High frequency synthesizer

UIM

Voltage/current measurement circuit

1

high-frequency household appliance; high-frequency kitchen appliance; microwave oven; microwave oven; Dialog oven

10

outer casing

11

treatment room; Inner space; cooking space; cavity

12

Interior wall 11

13

space

2

High frequency heating module

20

control unit; functional microcontroller

21

High frequency signal generator

22

security unit; security microcontroller

23a-23d

first through fourth high-frequency paths; first to fourth high-frequency feed

Claims (17)

High-frequency household appliance (1), preferably high-frequency kitchen appliance (1), with at least one treatment room (11) which is designed to accommodate an item to be treated with high-frequency energy, and with at least one high-frequency heating module (2), which is designed to generate the high-frequency energy and to deliver it into the treatment room (11), wherein the high-frequency heating module (2) has at least: • at least one high-frequency signal generator (21), which is designed to generate the high-frequency energy, and • at least one transition (ANT) to the treatment room (11) of a first high-frequency path (23a-23d), preferably one transition (ANT) to the treatment room (11) of a plurality of high-frequency paths (23a-23d), which is formed high-frequency deliver energy into the treatment room (11), characterized in that
the high-frequency heating module (2), preferably at least the first high-frequency path (23a-23d), particularly preferably several high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), of the high-frequency heating module (2), further comprising at least: • at least one measuring circuit (UIM, FDIV, ADC), which is designed to record at least one parameter of the high-frequency energy, and • at least one safety unit (22), which is designed to receive the at least one recorded parameter from the measuring circuit (UIM, FDIV, ADC) and to evaluate it with regard to compliance with at least one predetermined limit value, wherein the high-frequency heating module (2), preferably the safety unit (22), is designed to operate the high-frequency signal generator (21) depending on the evaluation of the parameter, preferably the high-frequency signal generator (21) when a predetermined limit value of the parameter is exceeded turn off High-frequency household appliance (1) according to claim 1, characterized in that
the predetermined limit value is based on at least one current operating parameter, preferably on the amplitude and/or on the frequency of the high-frequency energy, of the high-frequency heating module (2), preferably of the high-frequency signal generator (21). High-frequency household appliance (1) according to claim 1 or 2, characterized in that the measurement circuit (UIM, FDIV, ADC) is designed as a voltage/current measurement circuit (UIM) to detect the voltage and the current of the high-frequency energy, preferably a high-frequency power amplifier (HPA), and the safety unit (22) is designed to receive the detected voltage and the detected current from the voltage/current measuring circuit (UIM), to determine a direct current power consumption therefrom and to evaluate the determined direct current power consumption with regard to compliance with a predetermined limit value, wherein the predetermined limit value is preferably based on the current direct current power consumption of the high-frequency signal generator (21). High-frequency domestic appliance (1) according to claim 1 or 2, characterized in that the measuring circuit (UIM, FDIV, ADC) is designed as a voltage/current measuring circuit (UIM) to record the voltage and the current of the high-frequency energy of a high-frequency power amplifier (HPA), wherein at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), further comprises at least one high-frequency coupler (CPL), which is formed to measure the power of a high-frequency forward wave of the emitted high-frequency energy, and the safety unit (22) is designed to receive the detected voltage and the detected current from the voltage/current measurement circuit (UIM), to determine a DC power consumption therefrom, from the determined DC power consumption and the detected power of the forward running High-frequency wave to determine an efficiency and to evaluate the determined efficiency with regard to compliance with a predetermined limit value, wherein the predetermined limit value is preferably based on the current direct current power consumption of the high-frequency signal generator (21). High-frequency household appliance (1) according to claim 1 or 2, characterized in that the measuring circuit (UIM, FDIV, ADC) is designed as a frequency divider (FDIV), to detect the frequency of the high-frequency energy, preferably a high-frequency power amplifier (HPA), and the safety unit (22) is designed to receive the frequency from the frequency divider (FDIV) and to evaluate it with regard to compliance with a predetermined limit value, wherein the predetermined limit value is preferably based on the current frequency of the high-frequency signal generator (21). High-frequency household appliance (1) according to claim 1 or 2, characterized in that the measurement circuit (UIM, FDIV, ADC) is designed as a sampling converter (ADC), to acquire a high-frequency signal sample of the high-frequency energy, preferably a high-frequency power amplifier (HPA), and the safety unit (22) is designed to receive the high-frequency signal sample from the scanning converter (ADC) and to evaluate it with regard to compliance with at least one predetermined criterion, preferably with regard to compliance with a plurality of predetermined criteria, wherein the measuring circuit (UIM, FDIV, ADC) preferably has a high-frequency synthesizer (SYN) and a high-frequency mixer (MIX). High-frequency household appliance (1) according to one of the preceding claims, characterized in that
at least one high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), further comprising: • has at least one first bandpass filter (BPF), which is designed to only pass a predetermined frequency range of the high-frequency energy. High-frequency domestic appliance (1) according to claim 7, characterized in that at least one high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), furthermore at least one second band-pass filter (BPF) which is redundant to the first band-pass filter ( BPF) is trained, wherein the second bandpass filter (BPF) is preferably arranged after, more preferably immediately after, a phase shifter (PHS). High-frequency household appliance (1) according to one of the preceding claims, characterized in that
at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), further comprises: • at least one high-frequency power amplifier (HPA), preferably also at least one high-frequency pre-amplifier (PRE), which is designed to amplify the high-frequency energy. High-frequency household appliance (1) according to one of the preceding claims, characterized in that
at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), further comprises: • at least one high-frequency coupler (CPL), which is designed to measure a forward running and/or a backward running high-frequency wave of the emitted high-frequency energy, wherein preferably no amplifier (HPA, PRE) is arranged between the high-frequency coupler (CPL) and the transition (ANT). High-frequency household appliance (1) according to one of the preceding claims, characterized in that
at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), further comprises: • at least one attenuator (PGA), which is designed to change the amplitude of the high-frequency energy. High-frequency household appliance (1) according to one of the preceding claims, characterized in that
at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), further comprises: • at least one phase shifter (PHS) which is designed to change the phase of the high-frequency energy. High-frequency household appliance (1) according to one of the preceding claims, characterized in that
at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), further comprises: • at least one high-frequency isolator (ISO), which is designed to block a reverse-running high-frequency wave of the high-frequency energy emitted, no amplifier (HPA, PRE) preferably being arranged between the high-frequency isolator (ISO) and the transition (ANT). High-frequency household appliance (1) according to one of the preceding claims, characterized in that
at least the first high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), further comprises: • at least one harmonic filter (HSF) configured to block harmonics in a forward wave of high-frequency energy, no amplifier (HPA, PRE) preferably being arranged between the harmonics filter (HSF) and the transition (ANT). High-frequency household appliance (1) according to one of the preceding claims, characterized in that
the high-frequency heating module (2) has at least one control unit (20) which is designed • obtain measurement data of a forward wave and/or a reverse wave of the emitted radio frequency energy, preferably from a radio frequency coupler (CPL), and • to determine at least one amplitude and/or one phase of a forward-running and/or a backward-running high-frequency wave of the emitted high-frequency energy from the measurement data obtained. High-frequency household appliance (1) according to claim 15, characterized in that
the control unit (20) is also embodied, at least the high-frequency signal generator (21), preferably also at least one attenuator (PGA) and/or a phase shifter (PHS) of at least one high-frequency path (23a-23d), preferably a plurality of high-frequency paths (23a-23d), particularly preferably all high-frequency paths (23a-23d), depending on the determined amplitude and/or the determined phase, preferably to change the frequency of the high-frequency energy. High-frequency heating module (2) for use in a high-frequency household appliance (1) according to one of the preceding claims.

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