COOKING HOB ACCESSORY DEVICE

Abstract

A cooktop accessory device includes a detection coil configured to detect an inductive signal of an induction heating unit, and a signal analysis unit configured to determine a parameter of the inductive signal.

Claims

1.-12. (canceled)

13. A cooktop accessory device, comprising: a detection coil configured to detect an inductive signal of an induction heating unit; and a signal analysis unit configured to determine a parameter of the inductive signal.

14. The cooktop accessory device of claim 13, wherein the signal analysis unit is configured to determine an operating state of the induction heating unit based on the parameter.

15. The cooktop accessory device of claim 14, further comprising; a further unit; and a control unit configured to change an operating state of the further unit as a function of the operating state of the induction heating unit determined by the signal analysis unit.

16. The cooktop accessory device of claim 15, wherein the further unit comprises a sensor element.

17. The cooktop accessory device of claim 13, wherein the parameter is an oscillation parameter of the inductive signal.

18. The cooktop accessory device of claim 13, wherein the signal analysis unit is configured to determine a further parameter of the inductive signal.

19. The cooktop accessory device of claim 18, wherein the further parameter comprises an activation sequence of the inductive signal.

20. The cooktop accessory device of claim 13, wherein for a further processing of the inductive signal the signal analysis unit comprises a first low pass filter with a first limit frequency and a second low pass filter with a second limit frequency which is different from the first limit frequency.

21. The cooktop accessory device of claim 20, wherein the first low pass filter and the second low pass filter are arranged in a parallel circuit to one another.

22. The cooktop accessory device of claim 20, wherein for the further processing of the inductive signal the signal analysis unit comprises a third low pass filter with a third limit frequency which is different from the first limit frequency and the second limit frequency.

23. A cooktop accessory, comprising a cooktop accessory device, said cooktop accessory device comprising a detection coil configured to detect an inductive signal of an induction heating unit, and a signal analysis unit configured to determine a parameter of the inductive signal.

24. The cooktop accessory of claim 23, embodied as an item of cookware or an underlay mat

25. A method for operating a cooktop accessory device, the method comprising: detecting an inductive signal of an induction heating unit; and determining a parameter of the inductive signal.

26. The method of claim 25, further comprising determining an operating state of the induction heating unit based on the parameter.

27. The method of claim 25, further comprising changing an operating state of a further unit as a function of the operating state of the induction heating unit.

28. The method of claim 25, wherein the parameter is an oscillation parameter of the inductive signal.

29. The method of claim 25, further comprising determining an activation sequence of the inductive signal.

30. The method of claim 25, further comprising: generating with a first low pass filter a first analysis signal from the inductive signal; generating with a second low pass filter a second analysis signal from the inductive signal; and comparing the first analysis signal with the second analysis signal to determine the parameter of the inductive signal.

31. The method of claim 30, further comprising arranging the first low pass filter and the second low pass filter in a parallel circuit to one another.

Description

In the drawing:

[0023] FIG. 1 shows a cooktop accessory with a cooktop accessory device, comprising a detection coil, a signal analysis unit, a control unit and a further unit in a schematic view,

[0024] FIG. 2 shows a schematic electrical circuit diagram of the signal analysis unit with a first low pass filter, a second low pass filter and a third low pass filter,

[0025] FIG. 3 shows a schematic diagram for illustrating a change of an operating state of the further unit by the control unit and

[0026] FIG. 4 shows a schematic diagram for illustrating a method for operating the cooktop accessory device.

[0027] FIG. 1 shows a schematic view of a cooktop accessory 50. The cooktop accessory 50 is configured as an item of cookware. In FIG. 1 the cooktop accessory 50 is positioned above an induction heating unit 16 of a cooktop 52. The induction heating unit 16 is provided to heat the cooktop accessory 50 which is configured as an item of cookware. In an operating state of the induction heating unit 16, the induction heating unit 16 provides at least one inductive signal 14 for heating the cooktop accessory 50 which is configured as an item of cookware.

[0028] The cooktop accessory 50 has a cooktop accessory device 10. The cooktop accessory device 10 comprises a detection coil 12. The detection coil 12 is provided to detect the at least one inductive signal 14.

[0029] The cooktop accessory device 10 has a signal analysis unit 18. The signal analysis unit 18 is provided to determine at least one parameter 20 of the inductive signal 14 (see FIG. 2).

[0030] The signal analysis unit 18 is electrically conductively connected to the detection coil 12. In the operating state of the induction heating unit 16, the inductive signal 14 is induced in the detection coil 12.

[0031] In the present case, the signal analysis unit 18 is provided to determine an operating state 22 of the induction heating unit 16 by means of the parameter 20 (see FIG. 3).

[0032] The cooktop accessory device 10 has a further unit 28. The further unit 28 is configured as a sensor unit and comprises at least one sensor element 30. In the present case, the sensor element 30 is configured as a temperature sensor. The sensor element 30 is arranged inside a food receiving space 70 of the cooktop accessory 50, which is configured as an item of cookware, and is provided for temperature measurement inside the food receiving space 70.

[0033] The cooktop accessory device 10 has a control unit 26. The control unit 26 is provided to change an operating state of the further unit 28 as a function of the operating state of the induction heating unit 16 determined by the signal analysis unit 18.

[0034] FIG. 2 shows a schematic electrical circuit diagram of the signal analysis unit 18. The signal analysis unit 18 has a rectifier diode 54 by which the inductive signal 14, which is initially present as a bipolar signal with a periodically changing electrical polarity, is rectified.

[0035] The signal analysis unit 18 has an operational amplifier 56. The operational amplifier 56 is electrically connected downstream of the rectifier diode 54 and is provided to amplify the inductive signal 14 which is rectified by the rectifier diode 54.

[0036] The signal analysis unit 18 has a first low pass filter 38 for the further processing of the inductive signal 14. The first low pass filter 38 has a first limit frequency. The signal analysis unit 18 has a second low pass filter 40 for the further processing of the inductive signal 14. The second low pass filter 40 has a second limit frequency. The second limit frequency of the second low pass filter 40 is different from the first limit frequency of the first low pass filter 38. The first low pass filter 38 and the second low pass filter 40 are arranged in a parallel circuit to one another.

[0037] The signal analysis unit 18 has a third low pass filter 42. The third low pass filter 42 has a third limit frequency. The third limit frequency of the third low pass filter 42 is different from the first limit frequency of the first low pass filter 38 and from the second limit frequency of the second low pass filter 40. In the present case, the first limit frequency of the first low pass filter 38 is higher than a maximum frequency of an alternating current by which the induction heating unit 16 can be operated. For example, the induction heating unit 16 could be operated with a high-frequency alternating current at a maximum frequency of 75 kHz and the first limit frequency of the first low pass filter 38 could be, for example, 100 kHz.

[0038] In the present exemplary embodiment, the second limit frequency of the second low pass filter 40 is lower than the first limit frequency of the first low pass filter 38 and higher than a mains frequency of a power supply network (not shown) which provides energy for supplying power to the induction heating unit 16. In the present case, the second limit frequency of the second inverter corresponds to twice the mains frequency of the power supply network and could be 100 Hz, for example, at a mains frequency of 50 Hz. In the present case, the third limit frequency of the third low pass filter 42 is lower than the second limit frequency of the second low pass filter 40 and lower than the mains frequency. The third limit frequency of the third low pass filter 42 could be 5 Hz, for example.

[0039] The first low pass filter 38 generates a first analysis signal 44 from the inductive signal 14. The signal analysis unit 18 has a first impedance converter 82. The first impedance converter 82 is connected to a computing unit (not shown) of the signal analysis unit 18 and converts the first analysis signal 44 into a form which is compatible with an input voltage of the computing unit. The second low pass filter 40 generates a second analysis signal 46 from the inductive signal 14. The signal analysis unit 18 has a second impedance converter 84 which correspondingly converts the second analysis signal 46 into a form which is compatible with an input voltage of the computing unit. The third low pass filter 42 generates a third analysis signal 48 from the inductive signal 14. The signal analysis unit 18 has a third impedance converter 86 which correspondingly converts the third analysis signal 48 into a form which is compatible with an input voltage of the computing unit.

[0040] The signal analysis unit 18 has a comparator 58. In an operating state of the signal analysis unit 18, the comparator 58 compares the first analysis signal 44 with the second analysis signal 46 and determines therefrom the parameter 20 of the inductive signal 14. The parameter 20 is an oscillation parameter 32 of the inductive signal 14. In the present case, the oscillation parameter 32 is the frequency of the high-frequency alternating current by which the induction heating unit 16 is operated.

[0041] The signal analysis unit 18 is provided to determine a further parameter 34 of the inductive signal 14.

[0042] The signal analysis unit 18 has a further comparator 60. In the operating state of the signal analysis unit 18, the further comparator 60 compares the second analysis signal 46 with the third analysis signal 48 and determines therefrom the further parameter 34 of the inductive signal 14.

[0043] The comparator 58 and the further comparator 60 are part of the computing unit (not shown) of the signal analysis unit 18.

[0044] The further parameter 34 comprises an activation sequence 36 of the inductive signal 14. The activation sequence 36 of the inductive signal 14 describes a sequence of time periods in which the induction heating unit 16 is either switched on or off, for the purpose of varying an energy provided to the cooktop accessory 50.

[0045] FIG. 3 shows a schematic diagram for illustrating by way of example a time curve of the operating state 22 of the induction heating unit 16 determined by the signal analysis unit 18. In the operating state 22 of the induction heating unit 16, the further unit 28 is in an active operating state 24. As soon as the operating state 22 of the induction heating unit 16 determined by the signal analysis unit 18 changes, a first control period 72 starts. During the first control period 72, the further unit 28 is also in the active operating state 24. The first control period 72 can correspond to a multiple of a period of a mains voltage of a power supply network (not shown). For example, the first control period 72 could correspond to three times the period of the mains voltage and last for a time period of three milliseconds at a mains frequency of 50 Hz.

[0046] After the elapse of the first control period 72 the control unit 26 obtains first status information 76 relative to the operating state 22 of the induction heating unit 16 from the signal analysis unit 18. If the first status information 76 comprises that the induction heating unit 16 was inactive during the control period 72, using the operating state 22 of the induction heating unit 16 determined by the signal analysis unit 18 the control unit 26 changes the operating state 22 of the further unit 28 from the active operating state 24 into an inactive operating state 66. In the inactive operating state 66 an energy consumption of the further unit 28 is reduced.

[0047] After the elapse of a second control period 74 which includes the first control period 72, and which corresponds to a multiple of the first control period 72, for example a duration of at least 2 seconds, the control unit 26 obtains further status information which can be either first further status information 78 or second further status information 80. The first further status information 78 comprises a change of the operating state 22, in the present case a renewed start-up of the induction heating unit 16. Using the first further status information 78 the control unit 26 changes the operating state of the further unit 28 from the inactive operating state 66 into the active operating state 24.

[0048] The second further status information 80 comprises no change of the operating state 22 of the induction heating unit 16 determined by the signal analysis unit 18. During a third control period 88, which in turn corresponds to a multiple of the second control period 76, the control unit 26 regularly obtains status information from the signal analysis unit 18. If during the third control period 88 the control unit 26 obtains the status information 76 and the second further status information 80 from the signal analysis unit 18 repeatedly in succession, in the present case for example three times in succession, the control unit 26 changes the operating state of the further unit 28 from the inactive operating state 66 into an idling operating state 68. In the idling operating state 68 an energy consumption of the further unit 28 is further reduced relative to the inactive operating state 66.

[0049] FIG. 4 shows a schematic diagram for illustrating a method for operating the cooktop accessory device 10. In the method, the at least one inductive signal 14 of the at least one induction heating unit 16 is detected and at least the parameter 20 of the inductive signal 14 is determined. The method comprises a method step 62. In the method step 62, the inductive signal 14 is detected and namely by means of the detection coil 12 (see FIG. 1).

[0050] The method comprises a further method step 64. In the further method step 64, at least the parameter 20 is determined. In the further method step 64, the inductive signal 14 is initially rectified and namely by means of the rectifier diode 54 of the signal analysis unit 18.

[0051] In the further method step 64, the rectified inductive signal 14 is then amplified and namely by means of the operational amplifier 56 of the signal analysis unit 18. From the rectified and amplified inductive signal, the first analysis signal 44 is then generated by means of the first low pass filter 38 of the signal analysis unit 18. At the same time, the second analysis signal 46 is generated by means of the second low pass filter 40 of the signal analysis unit 18, and the third analysis signal 48 is generated by means of the third low pass filter 42 of the signal analysis unit 18. Then in the further method step 64, the first analysis signal 44 is compared with the second analysis signal 46, and namely by means of the comparator 58 of the signal analysis unit 18, and the parameter 20 of the inductive signal 14 is determined therefrom. At the same time, in the further method step 64 the second analysis signal 46 is compared with the third analysis signal 48, and namely by means of the further comparator 60, and the further parameter 34 is determined therefrom.

REFERENCE SIGNS

[0052] 10 Cooktop accessory device [0053] 12 Detection coil [0054] 14 Inductive signal [0055] 16 Induction heating unit [0056] 18 Signal analysis unit [0057] 20 Parameter [0058] 22 Operating state [0059] 24 Active operating state [0060] 26 Control unit [0061] 28 Further unit [0062] 30 Sensor element [0063] 32 Oscillation parameter [0064] 34 Further parameter [0065] 36 Activation sequence [0066] 38 First low pass filter [0067] 40 Second low pass filter [0068] 42 Third low pass filter [0069] 44 First analysis signal [0070] 46 Second analysis signal [0071] 48 Third analysis signal [0072] 50 Cooktop accessory [0073] 52 Cooktop [0074] 54 Rectifier diode [0075] 56 Operational amplifier [0076] 58 Comparator [0077] 60 Further comparator [0078] 62 Method step [0079] 64 Further method step [0080] 66 Inactive operating state [0081] 68 Idling operating state [0082] 70 Food receiving space [0083] 72 First control period [0084] 74 Second control period [0085] 76 Status information [0086] 78 First further status information [0087] 80 Second further status information [0088] 82 First impedance converter [0089] 84 Second impedance converter [0090] 86 Third impedance converter [0091] 88 Third control period