Water level detection circuit, household appliance and water level detection method

Abstract

This application discloses a water level detection circuit, a household appliance, and a water level detection method. The water level detection circuit includes a processing module, an amplification module, and a data acquisition module. The processing module outputs an initial signal. The amplification module is connected to the processing module and amplifies the initial signal to generate a drive signal. The data acquisition module is connected to the output of the amplification module and includes a first acquisition unit, a second acquisition unit, and a water level probe unit. The first acquisition unit samples the drive signal, and the second acquisition unit samples the detection signal from the water level probe unit. The processing module also compares the drive signal and the detection signal and determines whether water is present based on the comparison result. The water level detection circuit, household appliance, and water level detection method of this application can clearly determine the presence or absence of water based on the comparison result of the detection signal and the drive signal. In particular, it can also effectively detect the presence or absence of pure water, making water level detection more accurate.

Description

Technical Field

[0001] This application relates to the field of household appliances, and in particular to a water level detection circuit, a household appliance, and a water level detection method. Background Technology

[0002] Currently, cooking appliances use steam to heat food. These appliances consist of a steam generator and a water tank. The steam generator is connected to the water tank, which supplies water to the generator. The generator heats the water to produce steam, which is then introduced into the appliance's cavity to heat the food. However, the water tank has a limited capacity. When the tank is empty, the steam generator can easily dry out, leading to accidents. Therefore, it is necessary to provide a water level detection circuit that can detect whether there is water in the tank. Summary of the Invention

[0003] The embodiments of this application provide a water level detection circuit, a household appliance, and a water level detection method.

[0004] The water level detection circuit of this application includes a processing module, an amplification module, and a data acquisition module. The processing module outputs an initial signal; the amplification module is connected to the processing module and amplifies the initial signal to generate a driving signal; the data acquisition module is connected to the output of the amplification module, and includes a first acquisition unit, a second acquisition unit, and a water level probe unit. The first acquisition unit samples the driving signal, and the second acquisition unit samples the detection signal from the water level probe unit. The processing module also compares the driving signal and the detection signal and determines whether there is water based on the comparison result.

[0005] In some embodiments, the amplification module includes a comparator with a non-inverting input, an inverting input, and an output. The acquisition module is connected to the output of the comparator, and the processing module is connected to the non-inverting input.

[0006] In some implementations, the amplification module includes a voltage divider unit connected to the inverting input and the power supply.

[0007] In some embodiments, when the input voltage at the non-inverting input terminal is greater than the input voltage at the inverting input terminal, the amplification module is used to output a high-level drive signal; when the input voltage at the non-inverting input terminal is less than the input voltage at the inverting input terminal, the amplification module is used to output a low-level drive signal.

[0008] In some embodiments, when the drive signal is high, the processing module is used to acquire the high potential value of the drive signal and the high potential value of the detection signal; when the drive signal is low, the processing module is used to acquire the low potential value of the drive signal and the low potential value of the detection signal; the processing module is used to compare the high potential value of the drive signal and the high potential value of the detection signal, compare the low potential value of the drive signal and the low potential value of the detection signal, and determine whether there is water based on the comparison result.

[0009] In some embodiments, when the comparison result is |H1-S1|>L1, |H2-S2|>L2, the processing module is used to determine that there is water, wherein H1 is the high potential value of the detection signal, S1 is the high potential value of the drive signal, H2 is the low potential value of the detection signal, S2 is the low potential value of the drive signal, L1 is the first threshold, and L2 is the second threshold.

[0010] In some embodiments, when the comparison result is |H1-S1|≤L1, |H2-S2|≤L2, the processing module is used to determine that there is no water, wherein H1 is the high potential value of the detection signal, S1 is the high potential value of the driving signal, H2 is the low potential value of the detection signal, S2 is the low potential value of the driving signal, L1 is the first threshold, and L2 is the second threshold.

[0011] In some embodiments, the water level probe unit includes a probe and an energy storage element, the energy storage element being used to charge and discharge when the probe is in a conductive state.

[0012] The household appliance according to the embodiments of this application includes the water level detection circuit of any of the above embodiments.

[0013] The water level detection method according to the embodiments of this application includes: a processing module of the water level detection circuit outputting an initial signal; an amplification module of the water level detection circuit amplifying the initial signal to generate a driving signal; a first acquisition unit of the water level detection circuit sampling the driving signal, and a second acquisition unit sampling the detection signal of the water level probe unit; and the processing module comparing the driving signal and the detection signal and determining whether there is water based on the comparison result.

[0014] The water level detection circuit, household appliance, and water level detection method of this application can clearly determine the presence or absence of water based on the comparison results of the detection signal and the drive signal. In particular, it can also effectively detect the presence or absence of pure water, making the water level detection more accurate.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0017] Figure 1 This is a schematic diagram of a water level detection circuit according to certain embodiments of this application;

[0018] Figure 2 This is a circuit diagram of a water level detection circuit according to certain embodiments of this application;

[0019] Figures 3 to 5 This is a simulation diagram of a water level detection circuit according to certain embodiments of this application;

[0020] Figure 6 This is a flowchart illustrating a water level detection method according to certain embodiments of this application. Detailed Implementation

[0021] The embodiments of this application are described in detail below. These embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0022] Please refer to the following: Figure 1 and Figure 2 The water level detection circuit 100 of this application includes a processing module 10, an amplification module 20, and a data acquisition module 30. The processing module 10 outputs an initial signal, and the amplification module 20 is connected to the processing module 10 and amplifies the initial signal to generate a drive signal. The data acquisition module 30 is connected to the output terminal 201 of the amplification module 20. The data acquisition module 30 includes a first acquisition unit 31, a second acquisition unit 32, and a water level probe unit 33. The first acquisition unit 31 samples the drive signal, and the second acquisition unit 32 samples the detection signal from the water level probe unit 33. The processing module 10 also compares the drive signal and the detection signal and determines whether there is water based on the comparison result.

[0023] The water level detection circuit 100 of this application embodiment can clearly determine the presence or absence of water based on the comparison result of the detection signal and the drive signal. In particular, it can also effectively detect the presence or absence of pure water, making the water level detection more accurate.

[0024] In related technologies, water level detection circuits typically employ dual operational amplifiers, i.e., subtraction circuits and filters, thus failing to detect minute changes and effectively detecting pure water. The water level detection circuit 100 of this application, however, has a data acquisition module 30 capable of acquiring minute changes, enabling it to determine not only the presence of tap water but also the presence of pure water.

[0025] It's worth noting that pure water, also known as deionized water, high-purity water, or purified water, is water free of impurities and has extremely high chemical purity. Pure water is pure and consists of only one element, H₂O. Pure water includes water produced through deep treatment methods such as ion exchange, reverse osmosis, microfiltration, and other appropriate physical processing methods. Using or drinking pure water can effectively prevent various germs from invading the human body, effectively and safely replenish the body's water, and has a high solubility, thus having a strong affinity for human cells and promoting metabolism. Therefore, more and more users are using pure water for cooking, drinking, washing food, bathing, and other purposes.

[0026] It is worth mentioning that the water level detection circuit 100 of this application embodiment can use an operational amplifier power supply of ±2.5V, while water level detection circuits in related technologies typically use a driving voltage of ±6V. Compared with water level detection circuits in related technologies, the water level detection circuit 100 of this application embodiment can effectively reduce the ionization of water and prevent the water level probe unit 33 from rusting and affecting the judgment result.

[0027] It should be noted that the examples and specific figures mentioned above are for the purpose of illustrating the implementation of this application and should not be construed as limiting the scope of protection of this application.

[0028] In some embodiments, the processing module 10 includes a processor, which may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0029] It is worth mentioning that the processing module 10 in this application is illustrated by taking the central control unit (NCU) in a microcontroller as an example. Taking the NCU as an example is for the purpose of understanding and illustrating the implementation of this application and should not be construed as a limitation of this application.

[0030] An NCU is a numerical control and drive unit. The NCU has logic control and drive functions. Thus, the NCU can output an initial signal and connect to an amplification module 20. The amplification module 20 can amplify the initial signal generated by the NCU to generate a drive signal. The drive signal can drive the acquisition module 30 to work. The first acquisition unit 31 of the acquisition module 30 can acquire the drive signal, and the second acquisition unit 32 can acquire the detection signal. In this way, the NCU can also receive the drive signal and the detection signal, and can determine whether there is water based on the drive signal and the detection signal.

[0031] In related technologies, the amplification module includes a dual operational amplifier module. The dual operational amplifier module has a relatively high driving voltage, which can lead to sufficient ionization of water. The gas generated by the ionization of water can easily cause oxidation and rusting of the acquisition module 30. In some embodiments of the present application, the amplification module 20 can be selected with a voltage of ±2.5V, which can reduce water ionization and prevent oxidation and rusting of the acquisition module 30.

[0032] In some embodiments, the acquisition module 30 is used to acquire multiple acquisition points to obtain driving signals and detection signals respectively. The multiple acquisition points include two acquisition points, three acquisition points, four acquisition points or more acquisition points, which are not limited here. The embodiments of this application are described using two acquisition points as an example for the purpose of facilitating the explanation and understanding of this application.

[0033] In some implementations, the amplification module 20 includes a comparator 21, which includes a non-inverting input terminal 211, an inverting input terminal 212, and an output terminal 213. The acquisition module 30 is connected to the output terminal 213 of the comparator 21, and the processing module 10 is connected to the non-inverting input terminal 211.

[0034] Specifically, comparator 21 functions as an analog-to-digital converter (ADC). It compares two or more data points to determine whether they are equal or to determine their relative magnitudes, thus achieving a comparison function. Comparator 21 compares an analog voltage signal with a reference voltage signal. It includes a non-inverting input 211 and an inverting input 212, with the reference voltage signal as the input to the inverting input 212. Both the non-inverting and inverting inputs 211 and 212 are analog signals, and the output 213 of comparator 21 outputs a binary signal of 0 or 1. In this embodiment, if the voltage signal input to the non-inverting input terminal 211 is greater than the voltage signal input to the inverting input terminal 212, the output terminal 213 outputs a binary signal of 1, that is, the signal output by the output terminal 213 is at a high level; if the voltage signal input to the non-inverting input terminal 211 is less than the voltage signal input to the inverting input terminal 212, the output terminal 213 outputs a binary signal of 0, that is, the signal output by the output terminal 213 is at a low level. The processing module 10 can generate an initial signal, which is input to the comparator 21 through the non-inverting input terminal 211, that is, the initial signal is compared with the reference voltage signal. The acquisition module 30 is connected to the output terminal 213 to detect the drive signal.

[0035] In some implementations, the amplification module 20 includes a voltage divider unit 22 connected to the inverting input terminal 212 and the power supply 23.

[0036] Specifically, power supply 23 can be connected to the inverting input terminal 212 of amplifier module 20 via voltage divider unit 22. Power supply 23 can output a 5V voltage. Voltage divider unit 22 includes two series-connected voltage divider resistors, namely a first voltage divider resistor R1 and a second voltage divider resistor R2. In this way, the 5V voltage output by power supply 23 can be divided and input to the inverting input terminal 212.

[0037] In some implementations, when the input voltage at the non-inverting input terminal 211 is greater than the input voltage at the inverting input terminal 212, the amplification module 20 outputs a high-level drive signal; when the input voltage at the non-inverting input terminal 211 is less than the input voltage at the inverting input terminal 212, the amplification module 20 outputs a low-level drive signal.

[0038] Thus, the water level detection circuit 100 can generate a high-level drive signal or a low-level drive signal by comparing the input voltage of the non-inverting input terminal 211 with the input voltage of the inverting input terminal 212.

[0039] In one embodiment, the processing module 10 outputs two initial signals with different voltages at a preset period, wherein the voltage of one initial signal is greater than the voltage of the reference signal, and the voltage of the other initial signal is less than the voltage of the reference signal. The preset period can be 50us, that is, the drive signal switches between high and low levels at a period of 50us.

[0040] In some embodiments, the acquisition module 30 includes a first acquisition unit 31 and a second acquisition unit 32, wherein the first acquisition unit 31 includes a first sampling point 311, the second acquisition unit 32 includes a second sampling point 321, the first sampling point 311 includes a first sampling capacitor C1 and a first sampling resistor R3, and the second sampling point 321 includes a second sampling capacitor C2 and a second sampling resistor R4.

[0041] The acquisition module 30 also includes a water level probe unit 33, which includes a probe 331 and an energy storage element 332. The energy storage element 332 is used to charge and discharge when the probe 331 is in the conducting state.

[0042] Specifically, when water is present, probe 331 can conduct water level detection circuit 100, at which time energy storage element 332 can charge and discharge, and water level detection circuit 100 is grounded through first acquisition unit 31, second acquisition unit 32 and probe 331 respectively. When there is no water, probe 331 cannot conduct water level detection circuit 100, energy storage element 332 and probe 331 are in an open circuit state, and water level detection circuit 100 is grounded through first acquisition unit 31 and second acquisition unit 32 respectively.

[0043] It is worth mentioning that, in some embodiments, the energy storage element 332 includes a capacitor.

[0044] Please see Figures 3 to 5 , Figure 3 This is the voltage drive waveform of probe 331. Figure 4 This is the waveform of the drive signal at the first sampling point 311 when water is present. Figure 5 This is the detection signal waveform at the second sampling point 321 when water is present. The energy storage element 332 can charge and discharge when water is present, therefore... Figure 4 and Figure 5 Their shapes are not the same. Figure 4 For square waves, Figure 5 The waveforms are for charging and discharging. In the absence of water, the energy storage element 332 and probe 331 are in an open-circuit state. Therefore, the waveform signals detected by the first sampling point 311 and the second sampling point 321 are both in the absence of water. Thus, the waveforms acquired by the oscilloscope show a significant difference between the presence and absence of water. This allows for the determination of the presence or absence of water by observing the waveforms on the oscilloscope.

[0045] In some embodiments, when the drive signal is high, the processing module 10 is used to acquire the high potential value of the drive signal and the high potential value of the detection signal; when the drive signal is low, the processing module 10 is used to acquire the low potential value of the drive signal and the low potential value of the detection signal; the processing module 10 is used to compare the high potential value of the drive signal and the high potential value of the detection signal, compare the low potential value of the drive signal and the low potential value of the detection signal, and determine whether there is water based on the comparison result.

[0046] In one embodiment, when the input voltage of the non-inverting input terminal 211 is greater than the input voltage of the inverting input terminal 212, the drive signal is at a high level, and at this time, the high potential value of the drive signal and the high potential value of the detection signal can be obtained.

[0047] Since the high potential value of the detection signal differs depending on whether there is water or not, the presence or absence of water can be determined by comparing the high potential value of the driving signal and the high potential value of the detection signal.

[0048] When the input voltage of the non-inverting input terminal 211 is less than the input voltage of the inverting input terminal 212, the drive signal is low level. At this time, the low potential value of the drive signal and the low potential value of the detection signal can be obtained.

[0049] Since the low potential value of the detection signal differs depending on whether there is water or not, the presence or absence of water can be determined by comparing the low potential value of the driving signal and the low potential value of the detection signal.

[0050] In some implementations, when the comparison result is |H1-S1|>L1, |H2-S2|>L2, the processing module 10 is used to determine that there is water, where H1 is the high potential value of the detection signal, S1 is the high potential value of the drive signal, H2 is the low potential value of the detection signal, S2 is the low potential value of the drive signal, L1 is the first threshold, and L2 is the second threshold.

[0051] Specifically, in one example, L1 is 0.4V and L2 is 0.3V. When there is water and the drive signal is high, the energy storage element 332 is charged because the probe 331 is grounded through the water. This causes the high potential value of the detection signal to be relatively low at first and then gradually increase, while the drive signal remains basically unchanged. For example, H1 is 0.72V and S1 is 1.36V. At this time, |H1-S1|>L1.

[0052] When there is water and the drive signal is low, the energy storage element 332 discharges because the probe 331 is grounded through the water. This causes the low potential value of the detection signal to be relatively high at first and then gradually decrease, while the drive signal remains basically unchanged. For example, H2 is -0.15V and S2 is -1.44V. At this time, |H2-S2|>L2. Therefore, when |H1-S1|>L1 and |H2-S2|>L2, it can be determined that there is water.

[0053] It should be noted that the examples and specific figures mentioned above are for the purpose of illustrating the implementation of this application and should not be construed as limiting the scope of protection of this application.

[0054] In some implementations, when the comparison result is |H1-S1|≤L1, |H2-S2|≤L2, the processing module 10 is used to determine that there is no water, where H1 is the high potential value of the detection signal, S1 is the high potential value of the drive signal, H2 is the low potential value of the detection signal, S2 is the low potential value of the drive signal, L1 is the first threshold, and L2 is the second threshold.

[0055] Specifically, in one example, L1 is 0.4V and L2 is 0.3V. When there is no water and the drive signal is high, the energy storage element 332 is disconnected because the probe 331 cannot be grounded, causing the detection signal and drive signal to remain basically unchanged. For example, H1 is 1.28V and S1 is 1.36V, at which point |H1-S1|≤L1. When there is no water and the drive signal is low, the energy storage element 332 is disconnected because the probe 331 cannot be grounded, causing the detection signal and drive signal to remain basically unchanged. In one example, H2 is -1.35V and S2 is -1.44V, at which point |H2-S2|≤L2. Therefore, when |H1-S1|≤L1 and |H2-S2|≤L2, it can be determined that there is no water.

[0056] It should be noted that the examples and specific figures mentioned above are for the purpose of illustrating the implementation of this application and should not be construed as limiting the scope of protection of this application.

[0057] In some implementations, the acquisition module 30 includes a resistor R5 located between the first sampling point 311 and the second sampling point 321. The resistor R5 can prevent the driving signal from coupling with the detection signal, making the data sampled by the first sampling unit 31 and the second sampling unit 32 more accurate.

[0058] In some embodiments, the water level probe unit 33 includes a resistor R6 located between the energy storage element 332 and the probe 331, and the resistor R6 has a current limiting function.

[0059] This application also discloses a household appliance, which includes a water level detection circuit 100.

[0060] The household appliance described in this application can clearly determine the presence or absence of water based on the comparison results of the detection signal and the drive signal. In particular, it can also effectively detect the presence or absence of pure water, making the water level detection more accurate.

[0061] Specifically, the water level detection circuit 100 can be installed inside a household appliance, which may include, but is not limited to, steam ovens, water dispensers, water heaters, etc. This application uses a steam oven as an example to illustrate the household appliance described. The water level detection circuit 100 can detect whether there is water in the water tank inside the steam oven, thus preventing the steam oven from burning dry and causing accidents.

[0062] In some implementations, taking a steam oven as an example, the steam oven may also include a cavity, a door, a water tank, a steam generator, and other devices. The water level detection circuit 100 can determine whether there is water in the water tank. If there is water, the user can open the door and place food in the cavity. The steam generator can turn the water in the water tank into steam, so the user can use the steam to process the food.

[0063] The household appliances described in this application are illustrated using a steam oven as an example. This example is for the purpose of explaining the implementation of this application and should not be construed as limiting the scope of protection of this application.

[0064] The door and cavity of the steam oven can be made of the same metal or different materials. The door and cavity are connected. The cavity contains a cooking chamber with an opening on its front side. In some embodiments, the door is rotatably connected to the front of the cavity, allowing the opening to be opened and closed. That is, the cavity has an open front, and the door is used to open and close the cooking chamber, where food is placed. A handle can be provided on the door for easy operation and opening / closing. The handle can be a recessed handle, embedded in the top of the door, and can be integrally formed with the door, reducing manufacturing processes and saving costs. Additionally, the recessed handle is aesthetically pleasing and practical. The water tank of the steam oven can also be a water storage box; its size and placement can be determined based on the shape of the steam oven and are not limited here.

[0065] In some embodiments, the steam oven may also include a water inlet, one end of which can be connected to a water pipe and a water valve, and the other end of which is connected to a water tank. When the water level detection circuit 100 determines that there is no water in the water tank, it can control the water valve to open, so that water in the water pipe flows automatically into the water tank through the water inlet. This can prevent the steam oven from burning dry and can extend the service life of the steam oven.

[0066] In some embodiments, the steam oven may also include a protection module. When the water level detection circuit 100 determines that there is no water in the water tank, the protection module can be activated. The protection module can switch the steam generator from a working state to a non-working state, or the protection module can switch the steam oven from a working state to a non-working state. This is not limited here. This can prevent the steam oven from burning dry and can extend the service life of the steam oven.

[0067] Please see Figure 6 This application also discloses a water level detection method, which includes:

[0068] Step 01: The processing module 10 of the water level detection circuit 100 outputs an initial signal;

[0069] Step 02: The amplification module 20 of the water level detection circuit 100 amplifies the initial signal to generate a drive signal;

[0070] Step 03: The first acquisition unit 31 of the water level detection circuit 100 samples the drive signal, and the second acquisition unit 32 samples the detection signal of the water level probe unit 33;

[0071] Step 04: Processing module 10 compares the drive signal and the detection signal and determines whether there is water based on the comparison result.

[0072] The water level detection method of this application embodiment can be implemented by the water level detection circuit 100 of this application embodiment.

[0073] The water level detection method of this application can clearly determine the presence or absence of water based on the comparison results of the detection signal and the drive signal. In particular, it can also effectively detect the presence or absence of pure water, making the water level detection more accurate.

[0074] It should be noted that the above description of the implementation method and beneficial effects of the water level detection circuit also applies to the water level detection method of this embodiment. To avoid redundancy, it will not be elaborated in detail here.

[0075] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0076] Furthermore, in the various embodiments of this application, each functional module can be integrated into a processing module, or each module can exist physically separately, or two or more modules can be integrated into a single module.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0078] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. The scope of this application is defined by the claims and their equivalents. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A water level detection circuit, characterized in that, include: The processing module is used to output the initial signal; An amplification module is connected to the processing module and is used to amplify the initial signal to generate a driving signal; A data acquisition module is connected to the output of the amplification module. The data acquisition module includes a first data acquisition unit, a second data acquisition unit, a resistor, and a water level probe unit. The first data acquisition unit is used to sample the driving signal, and the second data acquisition unit is used to sample the detection signal of the water level probe unit. One end of the resistor is connected to the output of the amplification module and the first sampling point of the first data acquisition unit, and the other end of the resistor is connected to the water level probe unit and the second sampling point of the second data acquisition unit. The water level probe unit includes a probe and an energy storage element, which is used to charge and discharge when the probe is in a conductive state; the energy storage element is a capacitor. The processing module is also used to compare the driving signal and the detection signal and determine whether there is water based on the comparison result; The amplification module includes a comparator, which has a non-inverting input, an inverting input, and an output. The acquisition module is connected to the output of the comparator, and the processing module is connected to the non-inverting input. The amplification module also includes a voltage divider unit, which is connected to the inverting input and a power supply. The amplification module is powered by an operational amplifier power supply with a voltage of ±2.5V. When the input voltage at the non-inverting input terminal is greater than the input voltage at the inverting input terminal, the amplification module is used to output the high-level drive signal; When the input voltage at the non-inverting input terminal is less than the input voltage at the inverting input terminal, the amplification module is used to output the low-level drive signal.

2. The water level detection circuit according to claim 1, characterized in that, When the driving signal is high, the processing module is used to acquire the high potential value of the driving signal and the high potential value of the detection signal; When the driving signal is low, the processing module is used to acquire the low potential value of the driving signal and the low potential value of the detection signal; The processing module is used to compare the high potential value of the driving signal with the high potential value of the detection signal, compare the low potential value of the driving signal with the low potential value of the detection signal, and determine whether there is water based on the comparison result.

3. The water level detection circuit according to claim 2, characterized in that, The comparison result is , At that time, the processing module is used to determine the presence of water, wherein, The high potential value of the detection signal. The high potential value of the driving signal. The low potential value of the detection signal. The low potential value of the driving signal. The first threshold, This is the second threshold.

4. The water level detection circuit according to claim 2, characterized in that, The comparison result is , At that time, the processing module is used to determine that there is no water, wherein, The high potential value of the detection signal. The high potential value of the driving signal. The low potential value of the detection signal. The low potential value of the driving signal. The first threshold, This is the second threshold.

5. A household appliance, characterized in that, Includes the water level detection circuit according to any one of claims 1-4.

6. A water level detection method, employing the water level detection circuit according to any one of claims 1-5, characterized in that, The water level detection method includes: The processing module of the water level detection circuit outputs an initial signal; The amplification module of the water level detection circuit amplifies the initial signal to generate a driving signal; The first acquisition unit of the water level detection circuit samples the driving signal, and the second acquisition unit samples the detection signal of the water level probe unit; The processing module compares the driving signal and the detection signal and determines whether there is water based on the comparison result.

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