Liquid residue detection device and washing equipment

Abstract

The utility model provides a liquid remaining amount detection device and washing equipment. The liquid remaining amount detection device is characterized in that a switching circuit is connected to a power supply; the temperature measuring element and the divider resistor are connected in series between the output of the switching circuit and the reference ground; the voltage amplifying and shaping circuit is connected with the divider resistor in parallel, the voltage detection circuit is connected with the voltage amplifying and shaping circuit in series, the voltage amplifying and shaping circuit amplifies and shapes voltage at the two ends of the divider resistor into voltage to be detected, and the voltage detection circuit detects the voltage to be detected output by the amplifying and shaping circuit so as to determine the liquid remaining condition. Whether the liquid balance meets the requirement or not is qualitatively analyzed by detecting parameters of the temperature measuring element; by detecting the to-be-detected voltage obtained by converting the voltages at the two ends of the divider resistor, whether the residual liquid meets the requirement or not is quantitatively analyzed, so that accurate detection of the liquid in the automatic feeding box is realized, the functions of household appliances are greatly expanded, and the automatic feeding box has wide applicability.

Description

Technical Field

[0001] The present application relates to the technical field of household appliances, and in particular to a liquid remaining amount detection device and a washing device. Background Art

[0002] Currently, household appliances with automatic liquid dispensing require timely addition of liquid to an automatic liquid dispenser box, which then automatically dispenses the appropriate amount of liquid based on the load. Some appliances incorporate a liquid level detection module within the automatic dispenser box, which typically uses a float to monitor the liquid level and remind the user to add liquid promptly. However, in other appliances, such as washing machines, structural constraints may prevent the automatic dispenser box from being equipped with a float, making the float method ineffective for liquid level detection, thus hindering the appliance's usability.

[0003] It should be noted that the above introduction to the technical background is merely intended to provide a clear and complete description of the technical solutions of this application and facilitate understanding by those skilled in the art. Simply because these solutions are described in the background technology section of this application, it should not be assumed that the above technical solutions are well known to those skilled in the art. Utility Model Content

[0004] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, one object of the present application is to provide a liquid level detection device, comprising: a power supply, a switching circuit, a temperature measuring element, a voltage dividing resistor, a voltage amplifying and shaping circuit, and a voltage detection circuit, wherein:

[0006] The switching circuit is connected to the power supply; the temperature measuring element and the voltage dividing resistor are connected in series between the output of the switching circuit and the reference ground; the voltage amplifying and shaping circuit and the voltage dividing resistor are connected in parallel, and the voltage detection circuit is connected in series with the voltage amplifying and shaping circuit. The voltage amplifying and shaping circuit amplifies and shapes the voltage across the voltage dividing resistor into a voltage to be detected, and the voltage detection circuit detects the voltage to be detected output by the amplifying and shaping circuit to determine the liquid remaining amount;

[0007] When the input of the switch circuit is at a high level, the output of the switch circuit is a power supply voltage; when there is sufficient liquid, the liquid contacts the area where the temperature measuring element is located, and takes away the heat from the area where the temperature measuring element is located.

[0008] According to one embodiment of the present application, the liquid level detection device further includes:

[0009] A stability detection circuit is connected between the output of the switching circuit and a reference ground, and is used to detect the stability of the power supply.

[0010] According to a liquid remaining amount detection device according to one embodiment of the present application, the stability detection circuit includes a first resistor, a second resistor and a voltage stabilizing element, wherein the first end of the first resistor is connected to the output of the switching circuit; the second resistor is connected between the second end of the first resistor and the reference ground; the voltage stabilizing element is connected in parallel with the first resistor, and when the fluctuation of the power supply voltage exceeds a threshold value, the voltage stabilizing element cuts off the connection between the switching circuit and the temperature measuring element.

[0011] According to a liquid remaining amount detection device according to one embodiment of the present application, the voltage stabilizing element includes a power supply fluctuation detection unit and a circuit breaker, wherein the input end of the power supply fluctuation detection unit is connected to the second end of the first resistor; the circuit breaker is connected between the first end of the first resistor and the output end of the source fluctuation detection unit.

[0012] According to the liquid remaining amount detection device of one embodiment of the present application, the temperature measuring element includes a positive temperature coefficient thermistor, a thermal resistor, and a thermocouple.

[0013] According to one embodiment of the present application, the liquid level detection device further includes:

[0014] A temperature compensation unit is connected to the temperature measuring element and is used to offset the ambient temperature of the temperature measuring element.

[0015] According to one embodiment of the present application, the liquid level detection device further includes:

[0016] A heater is in contact with the area where the temperature measuring element is located, and is used to heat the temperature measuring element.

[0017] According to a liquid remaining amount detection device according to one embodiment of the present application, the switching circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, an NPN transistor and a PNP transistor, wherein the input end of the third resistor is connected to the input signal; the fourth resistor is connected between the second end of the third resistor and the reference ground; the base of the NPN transistor is connected to the second end of the third resistor, and the emitter of the NPN transistor is connected to the reference ground; the first end of the fifth resistor is connected to the collector of the NPN transistor; the sixth resistor is connected between the second end of the fifth resistor and the power supply; the base of the PNP transistor is connected to the second end of the fifth resistor, and the emitter of the PNP transistor is connected to the power supply.

[0018] According to a liquid remaining amount detection device according to an embodiment of the present application, the voltage amplification and shaping circuit includes a first capacitor, a second capacitor, a third capacitor, an operational amplifier, a seventh resistor, an eighth resistor and a ninth resistor, wherein the second capacitor is connected between the first end of the voltage-dividing resistor and the reference ground; the first end of the ninth resistor is connected to the second end of the voltage-dividing resistor; the third capacitor is connected between the second end of the ninth resistor and the reference ground; the positive input end of the operational amplifier is connected to the first end of the voltage-dividing resistor, and the reverse input end of the operational amplifier is connected to the second end of the ninth resistor; the eighth resistor is connected between the reverse input end and the output end of the operational amplifier; the first end of the seventh resistor is connected to the output end of the operational amplifier, and the second end of the seventh resistor is connected to the voltage detection circuit, wherein the voltage to be detected is output through the second end of the seventh resistor; the first capacitor is connected between the second end of the seventh resistor and the reference ground.

[0019] Another object of the present application is to provide a washing machine, including a detergent dispensing device and a liquid remaining amount detection device provided in one embodiment of the present application, wherein the detergent dispensing device includes a detergent storage container, a liquid extraction pipe, a liquid extraction pump, a liquid return pipe, and a liquid separation box, wherein the detergent storage container, the liquid extraction pipe, the liquid return pipe, and the liquid separation box are connected in sequence; the liquid extraction pump drives the liquid in the liquid extraction pipe and the liquid return pipe;

[0020] Under the action of the liquid suction pump, the detergent is extracted from the detergent storage container, flows through the liquid suction pipe and the liquid return pipe, and enters the liquid separation box. The liquid remaining amount detection device is installed on the detergent storage container, and the area where the temperature measuring element is located is in contact with the liquid in the detergent storage container; the liquid remaining amount detection device is used to detect the remaining amount of the detergent stored in the detergent storage container.

[0021] In the present application, a temperature measuring element and a voltage divider resistor are set between the reference ground and the output of the switching circuit. By detecting the parameters of the temperature measuring element, a qualitative analysis is performed on whether the liquid remaining meets the requirements; by detecting the voltage to be detected obtained by converting the voltage across the voltage divider resistor, a quantitative analysis is performed on whether the liquid remaining meets the requirements, thereby achieving accurate detection of the liquid in the automatic dispensing box, greatly expanding the functions of household appliances, and having wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of a liquid residual amount detection device according to one embodiment of the present application;

[0023] Figure 2 This is a circuit diagram of a liquid level detection device provided according to an embodiment of the present application;

[0024] Figure 3This is a schematic structural diagram of a washing device provided according to an embodiment of the present application;

[0025] Figure 4 A schematic structural diagram of a humidifier provided according to an embodiment of the present application;

[0026] Figure 5 This is a structural schematic diagram of a household fire-fighting equipment provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0028] The embodiments of the present application are described below with reference to the accompanying drawings.

[0029] Figure 1 This is a structural diagram of a liquid residual detection device according to an embodiment of the present application. Figure 1 As shown, the liquid remaining amount detection device of the embodiment of the present application includes a power supply, a switching circuit, a temperature measuring element, a voltage dividing resistor, a voltage amplifying and shaping circuit and a voltage detection circuit.

[0030] The switching circuit is connected to the power supply and input signal. If the input signal enables the switching circuit, the switching circuit is connected to the power supply voltage; the temperature measuring element and the voltage dividing resistor are connected in series between the output of the switching circuit and the reference ground, and the lack of liquid can be identified by detecting the parameters of the temperature measuring element; the voltage amplification and shaping circuit is connected in parallel with the voltage dividing resistor, and the voltage detection circuit is connected in series with the voltage amplification and shaping circuit. Under normal circumstances, since the current of the temperature measuring element is large when working, in order to reduce power consumption, the resistance of the voltage dividing resistor is relatively small. Therefore, the voltage amplification and shaping circuit can amplify and shape the voltage across the voltage dividing resistor into a voltage to be detected, and then the voltage detection circuit detects the voltage to be detected output by the amplification and shaping circuit to determine the liquid remaining situation.

[0031] It should be noted that if Figure 1As shown, the power supply connected to the switching circuit is usually a DC power supply, and the output voltage provided by the DC power supply can be 12V. As an example, the DC power supply can be set in the form of a power adapter, which can convert AC power into 12V DC power. Specifically, the power adapter is mainly composed of an input end, a transformer, an output end and a voltage stabilizing circuit. The input end receives AC power, and after conversion by the transformer, the voltage is reduced and converted into a stable 12V DC power, while the voltage stabilizing circuit is responsible for keeping the output voltage constant. When the power adapter is working, it is necessary to ensure that the output voltage and current of the adapter match the requirements of the liquid remaining detection device.

[0032] Further, if Figure 1 As shown, when the input of the switching circuit (i.e., the input signal connected to the switching circuit) enables the switching circuit, the power supply voltage is connected (i.e., the switching circuit outputs the power supply voltage), and then the power supply voltage is transmitted to the temperature measuring element and the voltage divider resistor. By detecting the parameter value of the temperature measuring element and the voltage across the voltage divider resistor, the liquid remaining amount is determined. When the liquid remaining amount is sufficient, the liquid contacts the area where the temperature measuring element is located (i.e., the temperature measuring element is immersed in the liquid), removing heat from the area where the temperature measuring element is located. When the liquid remaining amount is insufficient (i.e., lack of liquid), the liquid does not contact the area where the temperature measuring element is located (i.e., the temperature measuring element is not immersed in the liquid), and the heat from the area where the temperature measuring element is located is not removed.

[0033] In one feasible implementation, if the switching circuit is based on high-quality components, such as low-loss magnetic materials, high-precision and high-stability sensors, control chips, and uninterruptible power supplies, these can improve the stability and efficiency of the power supply. However, high-quality components inevitably increase costs, potentially lowering user expectations and reducing the manufacturer's input-output ratio. Therefore, in practical applications, a compromise solution is often adopted to improve power supply stability.

[0034] Optionally, Figure 2 Schematic diagram of a circuit of a liquid level detection device according to an embodiment of the present application. Figure 2 As shown, the liquid remaining amount detection device also includes a stability detection circuit, which is connected between the output of the switching circuit and the reference ground, and is used to detect the stability of the power supply. The stability of the power supply is very important for the voltage divider resistor. Since the resistance of the voltage divider resistor is relatively small, if the stability of the power supply is poor, it will cause the voltage across the voltage divider resistor to be difficult to measure, thereby affecting the accurate measurement of the liquid remaining amount.

[0035] Further, if Figure 2As shown, the stability detection circuit includes a first resistor R1, a second resistor R2 and a voltage stabilizing element, wherein the first end of the first resistor R1 is connected to the output of the switching circuit; the second resistor R2 is connected between the second end of the first resistor R1 and the reference ground; the voltage stabilizing element is connected in parallel with the first resistor R1, and when the fluctuation of the power supply voltage exceeds a threshold value (the setting of the threshold value should be set according to the specific usage scenario, as an example, the threshold value can be ±2% of the power supply voltage), the voltage stabilizing element cuts off the connection between the switching circuit and the temperature measuring element. After the power supply voltage stabilizes, the voltage stabilizing element re-establishes the connection relationship between the switching circuit and the temperature measuring element.

[0036] Furthermore, if Figure 2 As shown, the voltage stabilizing element includes a power fluctuation detection unit and a circuit breaker, wherein the input end of the power fluctuation detection unit is connected to the second end of the first resistor R1; the circuit breaker is connected between the first end of the first resistor R1 and the output end of the power fluctuation detection unit. It should be noted that the power fluctuation detection unit can collect parameters such as voltage and current output of the power supply in real time; amplify, filter, and perform analog-to-digital conversion on the collected parameters to obtain accurate voltage and current values; compare the processed data with a preset threshold to determine whether the power output is stable. If the processed data exceeds the range of the threshold, for example, ±2%, the power fluctuation detection unit triggers the circuit breaker, which cuts off the connection between the switch circuit and the temperature measuring element. On the other hand, the detection results of the power fluctuation detection unit can also be output to the user in the form of numbers, text, graphics or sound, so that the user can understand the status of the power supply and take corresponding auxiliary measures.

[0037] It should be noted that the stability detection circuit can also be configured using a dedicated integrated circuit (ASIC, which is an integrated circuit designed and manufactured for a proprietary application program based on specific user requirements and specific systems. In this embodiment, the integrated circuit is characterized as a stability detection circuit), an IP core (an intellectual property core, which is a mature design of a circuit module with independent functions in chip or integrated circuit design. The circuit design can be applied to other chip or integrated circuit design projects that include the circuit module, thereby reducing the design workload, shortening the design cycle, and improving the success rate of chip or integrated circuit design. IP cores are classified into three levels: behavioral level, structural level, and physical level, corresponding to three types of IP cores: soft cores designed with hardware description language, solid cores with complete structural description, and hard cores based on physical description and process verification. The specific configuration forms will not be detailed here. As long as the stability of the power supply can be detected so that the user can understand the status of the power supply and take corresponding auxiliary measures, any configuration form of the stability detection circuit is applicable and is not limited to this embodiment.

[0038] Alternatively, as an example, Figure 1 and Figure 2 As shown, in a feasible embodiment, the temperature measuring element in the liquid remaining detection device can be set in the form of a positive temperature coefficient thermistor (the full name of the positive temperature coefficient is Positive Temperature Coefficient, abbreviated as PTC), a thermal resistor (the full name of the thermal resistor in English) and a thermocouple.

[0039] Furthermore, if the temperature measuring element is implemented based on a positive temperature coefficient thermistor. Since the resistance change of the PTC thermistor is based on the characteristic of semiconductor materials that their resistance changes when the temperature changes, wherein the semiconductor material is mainly made of semiconductor materials such as metal oxides, such as platinum, nickel, manganese and iron. These materials have different resistivities at different temperatures, so the temperature can be inferred by measuring the resistance value. At low temperatures, the electronic state is unevenly distributed, resulting in low resistance; as the temperature rises, the internal lattice structure of the material is excited, forming new scattering centers, the free movement of electrons is restricted, and the resistance gradually increases. The resistance value of the PTC thermistor increases with increasing temperature. When the temperature exceeds a certain value (Curie temperature), the resistance value will increase stepwise. In other words, the relationship between the resistance value of the PTC thermistor and temperature is an exponential relationship, that is, the resistance value of the PTC thermistor changes nonlinearly with temperature. Its sensitivity is relatively high, and it can produce a large resistance change under a small temperature change, but this also limits its measurement accuracy.

[0040] Furthermore, if the temperature measuring element is implemented based on a thermistor. Since a thermistor is a sensor that measures temperature and temperature-related parameters based on the property that the resistance value of a conductor or semiconductor changes with temperature, its temperature measurement principle is based on the property that the resistance value of a metal conductor increases with increasing temperature. When the surface of the thermistor is heated, its resistance value changes. By measuring this change in resistance value, the temperature value can be inferred. Thermistors mainly use metal conductors or semiconductors such as metal oxides as temperature measurement media. Common thermistor materials include platinum and rhodium. These materials have stable physical and chemical properties and are suitable for high-precision temperature measurement. Their resistance value changes with temperature, but generally has good linearity. The resistance change of the thermistor shows a relatively stable linear relationship with temperature. Therefore, the measurement accuracy of thermistors is greater than that of PTC thermistors, and therefore the cost is relatively high. Therefore, in the specific implementation process, the setting form of the temperature measuring element should be selected according to actual needs.

[0041] Furthermore, if the temperature measuring element is implemented based on a thermocouple. Since the working principle of the thermocouple is based on the thermoelectric effect, that is, when two conductors (or semiconductors) of different materials are connected into a closed loop and the temperatures of the two contact points are different, a thermoelectromotive force will be generated in the loop, thereby generating current. The magnitude of this thermoelectromotive force is proportional to the temperature difference between the two contact points, so the temperature value can be inferred by measuring the thermoelectromotive force. Specifically, a thermocouple consists of two wires A and B made of different metals or semiconductor materials with their ends brazed together. When the temperatures at both ends of the two wires are different, a thermoelectromotive force will be generated in the loop they form.

[0042] It should be noted that the temperature measuring elements used in the liquid remaining amount detection device include but are not limited to positive temperature coefficient thermistors, thermal resistors, and thermocouples. Infrared thermometers, optical fiber sensors, capacitive sensors and other devices can also be used to set the temperature measuring elements of this embodiment. As long as the liquid remaining amount can be determined by parameter changes, any setting form of the temperature measuring element is applicable and is not limited to this embodiment.

[0043] It's important to further clarify that the parameter values represented by temperature-measuring components change with temperature; this is the fundamental principle of temperature measurement. Therefore, taking a positive temperature coefficient (PTC) thermistor (PTC) as an example, when the ambient temperature changes, the PTC thermistor's resistance also changes accordingly, affecting its measurement accuracy. This effect is particularly significant when the ambient temperature fluctuates significantly. Specifically, the accuracy of a PTC thermistor is typically specified at the calibration temperature. However, in actual applications, the ambient temperature may differ from the calibration temperature. This difference can cause a deviation between the PTC thermistor's actual measured value and the calibrated value, thus affecting its measurement accuracy. Furthermore, changes in ambient temperature can introduce other measurement errors. For example, in the event of a sudden change in ambient temperature, the PTC thermistor's response speed may not be able to keep up with the temperature change, resulting in lag or overshoot in the measurement results. Furthermore, changes in ambient temperature can affect the heat conduction and radiation conditions surrounding the PTC thermistor, further affecting its measurement accuracy.

[0044] Therefore, in order to further improve the measurement accuracy of the temperature measuring element, the liquid remaining amount detection device of the embodiment of the present application further includes a temperature compensation unit. Figure 2 As shown, the temperature compensation unit is connected to the temperature measuring element to offset the ambient temperature of the temperature measuring element. Specifically, as an example, the temperature compensation unit includes a temperature sensor, a signal processing circuit, a compensation algorithm module and an output interface, wherein the temperature sensor is used to measure the ambient temperature in real time; the signal processing circuit converts the temperature information collected by the temperature sensor into an electrical signal and performs preliminary processing. As an example, the preliminary processing operation may include filtering, amplification, etc.; the compensation algorithm module adjusts the electrical signal according to a preset compensation algorithm to generate a compensation signal. As an example, the compensation algorithm may adopt a linear temperature compensation algorithm, a calibration coefficient algorithm, an overall temperature compensation algorithm, a quadratic compensation algorithm, etc., and the compensation algorithm should be selected according to actual needs; the output interface transmits the compensation signal to the temperature measuring element to compensate for the measurement error of the temperature measuring element caused by the change in ambient temperature, so as to ensure the accuracy and stability of the measurement result of the temperature measuring element.

[0045] It should be further explained that the temperature measuring element can also be thermally isolated to offset the ambient temperature of the temperature measuring element. For example, providing a thermal isolation layer around the temperature measuring element can reduce the impact of ambient temperature changes on the temperature measuring element. Regular calibration of the temperature measuring element can also be used to ensure the accuracy of its measurement results. In particular, the calibration frequency can be increased appropriately when the ambient temperature fluctuates significantly. Therefore, the appropriate method for offsetting the ambient temperature of the temperature measuring element should be selected based on the specific usage scenario.

[0046] Alternatively, as an example, Figure 2 As shown, in a feasible embodiment, the switching circuit in the liquid remaining amount detection device may include a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, an NPN transistor Q1 and a PNP transistor Q2, wherein the first end of the third resistor R3 is connected to the input signal, and the input signal controls the conduction and shutdown of the entire switching circuit; the fourth resistor R4 is connected between the second end of the third resistor R3 and the reference ground; the base of the NPN transistor Q1 is connected to the second end of the third resistor R3, and the emitter of the NPN transistor Q1 is connected to the reference ground; the first end of the fifth resistor R5 is connected to the collector of the NPN transistor Q1; the sixth resistor R6 is connected between the second end of the fifth resistor R5 and the power supply; the base of the PNP transistor Q2 is connected to the second end of the fifth resistor R5, and the emitter of the PNP transistor Q2 is connected to the power supply.

[0047] like Figure 2 As shown, when the input of the switch circuit is at a high level (i.e., the input signal connected to the first end of the third resistor R3 is at a high level), the base of the NPN transistor Q1 is at a high level, turning on the NPN transistor Q1, thereby causing the base of the PNP transistor Q2 to be at a low level, turning on the PNP transistor Q2, and the collector of the PNP transistor Q2 to be approximately equal to the power supply voltage. In other words, the output of the switch circuit is the power supply voltage, and the temperature measuring element is powered on. In summary, by controlling the level of the input signal, the operating state of the temperature measuring element is controlled. In this embodiment, if the input signal is at a high level, the temperature measuring element is turned on; if the input signal is at a low level, the temperature measuring element is turned off.

[0048] It should be noted that the switching circuit can also be set up using a dedicated integrated circuit, an IP core, a gate-level circuit, etc., and its specific setting form will not be described here one by one. As long as the opening and closing of the temperature measuring element can be controlled, any setting form of the switching circuit is applicable and is not limited to this embodiment.

[0049] It should be noted that in order to further improve the accuracy of the temperature measuring element, a preheating measure can be added to the temperature measuring element. Therefore, the liquid remaining detection device of the embodiment of the present application can also include a heater (the heater is not shown in the accompanying drawings), which is in contact with the area where the temperature measuring element is located and is used to heat the temperature measuring element. Taking the positive temperature coefficient thermistor as an example, since the resistance value of the positive temperature coefficient thermistor changes with temperature, preheating can ensure that the positive temperature coefficient thermistor reaches a relatively stable temperature state before measurement, which can reduce the resistance value change caused by temperature fluctuations, thereby improving the accuracy of the measurement. In some application scenarios, if the positive temperature coefficient thermistor quickly enters the working state directly from a low temperature state, thermal stress may be generated due to excessively rapid temperature changes, causing damage to the material. The preheating process can slow down this temperature change, reduce the generation of thermal stress, and thus extend the service life of the positive temperature coefficient thermistor. In electronic circuits requiring precise temperature or current control, positive temperature coefficient (PTC) thermistors (PTC) serve as temperature sensors or current control elements. Their performance directly impacts the stability and efficiency of the entire circuit. Preheating ensures that the PTC thermistor reaches optimal operating conditions before the circuit is started, thereby optimizing overall circuit performance. In devices requiring preheating, this process reduces the current surge during startup and protects the circuit and device from damage. Using a PTC thermistor to control the preheating time ensures that the device reaches the appropriate temperature before startup, allowing it to enter the operating state smoothly. PTC thermistors may exhibit a certain degree of hysteresis when the temperature changes, meaning that the change in resistance value cannot keep pace with the temperature change. Preheating can slow the rate of temperature change, giving the PTC thermistor sufficient time to react to the temperature change, thereby eliminating or minimizing the impact of this hysteresis on measurement results. In summary, preheating the positive temperature coefficient thermistor can improve measurement accuracy, extend service life, optimize circuit performance, reduce startup shock, and eliminate temperature hysteresis effects. These effects are of great significance for ensuring the stable and reliable operation of the positive temperature coefficient thermistor in the circuit system.

[0050] Further, as an example, Figure 2 As shown, the temperature measuring element is set by a positive temperature coefficient thermistor. When the input signal controls the positive temperature coefficient thermistor to turn on, when the positive temperature coefficient thermistor is energized, the heater (the heater is not in Figure 2(as shown in the figure) preheats the positive temperature coefficient thermistor. The preheating time can be set as needed, for example, it can be preheated for 20 seconds. If the positive temperature coefficient thermistor is not immersed in liquid, the heat in the area where the positive temperature coefficient thermistor is located will not be taken away. At this time, the temperature of the positive temperature coefficient thermistor will be greater than the first calibration value (as an example, the first calibration value is 70°C), and the resistance value of the positive temperature coefficient thermistor is at the second calibration value (as an example, the second calibration value is 120 ohms). In the liquid remaining amount detection device, the positive temperature coefficient thermistor is divided according to the second calibration value. If the positive temperature coefficient thermistor is immersed in liquid, the heat generated by the positive temperature coefficient thermistor will be largely taken away by the liquid. At this time, the temperature of the positive temperature coefficient thermistor will be lower than the first calibration value, and the resistance value of the positive temperature coefficient thermistor will be lower than the second calibration value, so the divided voltage of the positive temperature coefficient thermistor will be significantly reduced. Therefore, when the input signal controls the positive temperature coefficient thermistor to turn on, by detecting the resistance value of the positive temperature coefficient thermistor and comparing the resistance value with the second calibration value, it is judged whether the liquid is in a liquid-deficient state or in a liquid-free state based on the size relationship, thereby performing a qualitative analysis on whether the liquid remaining meets the demand.

[0051] Alternatively, as an example, Figure 2 As shown, in a feasible embodiment, the voltage amplification and shaping circuit in the liquid remaining amount detection device includes a first capacitor C1, a second capacitor C2, a third capacitor C3, an operational amplifier, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9, wherein the second capacitor C2 is connected between the first end of the voltage-dividing resistor and the reference ground; the first end of the ninth resistor R9 is connected to the second end of the voltage-dividing resistor; the third capacitor C3 is connected between the second end of the ninth resistor R9 and the reference ground; the positive input end of the operational amplifier is connected to the first end of the voltage-dividing resistor, and the reverse input end of the operational amplifier is connected to the second end of the ninth resistor R9; the eighth resistor R8 is connected between the reverse input end and the output end of the operational amplifier; the first end of the seventh resistor R7 is connected to the output end of the operational amplifier, and the second end of the seventh resistor R7 is connected to the voltage detection circuit, wherein the voltage to be detected is output through the second end of the seventh resistor R7, and the voltage detection circuit detects the voltage to be detected to determine the liquid remaining amount; the first capacitor C1 is connected between the second end of the seventh resistor R7 and the reference ground.

[0052] Specifically, as an example, Figure 2 As shown, the temperature measuring element is set by a positive temperature coefficient thermistor. When the input signal controls the positive temperature coefficient thermistor to complete the power supply, due to the large current on the positive temperature coefficient thermistor, in order to control the power consumption of the liquid residual detection device, the resistance of the voltage divider resistor in series with the positive temperature coefficient thermistor is relatively small (this is because power = I 2*R. If both I and R are large, the power will increase exponentially, so the resistance of the voltage divider resistor needs to be reduced. As a result, the voltage across the voltage divider resistor is relatively small, which increases the difficulty of detecting the liquid remaining amount. Therefore, the voltage across the voltage divider resistor can be amplified and shaped by a voltage amplification and shaping circuit to obtain the voltage to be detected, and then the voltage detection circuit can obtain the specific value of the voltage to be detected.

[0053] As an example, the voltage detection circuit can be set to a voltage range. If the data is less than the lower limit of the voltage range, it indicates a lack of liquid. If the lower limit of the voltage range is ≤ the data ≤ the upper limit of the voltage range, it indicates that there is no lack of liquid. The voltage range is then divided into scales, with each scale representing a specific parameter of the remaining liquid. Furthermore, the voltage range is associated with the resistance value of a positive temperature coefficient thermistor, and the resistance value of the positive temperature coefficient thermistor can be associated with the remaining liquid, thereby establishing a corresponding relationship between the voltage range and the remaining liquid. The further detailed description of this corresponding relationship is not repeated here. In this embodiment, if the voltage to be detected is less than the lower limit of the voltage range, it means that the resistance value of the positive temperature coefficient thermistor is relatively large, and there is no liquid to take away the heat, and the device is in a liquid-deficient state; if the lower limit of the voltage range is ≤ the voltage to be detected ≤ the upper limit of the voltage range, it means that the resistance value of the positive temperature coefficient thermistor is relatively small, the liquid has taken away the heat, and the device is in a liquid-free state, and the specific parameters of the liquid residue can be obtained through the specific value of the voltage to be detected, that is, by detecting the voltage to be detected obtained by converting the voltage across the voltage divider resistor, a quantitative analysis is performed on whether the liquid residue meets the requirements, thereby achieving accurate detection of the liquid in the automatic dispensing box.

[0054] It should be noted that the voltage amplification and shaping circuit and the voltage detection circuit can also be set up in the form of dedicated integrated circuits, IP cores, gate-level circuits, etc., and their specific setting forms will not be described here one by one. As long as the voltage across the voltage divider resistor can be amplified and shaped into the voltage to be detected, and the voltage to be detected output by the amplification and shaping circuit is detected to determine the liquid remaining amount, any setting form of the voltage amplification and shaping circuit and the voltage detection circuit is applicable, and is not limited to this embodiment.

[0055] To summarize, in the present application, a temperature measuring element and a voltage divider resistor are set between the reference ground and the output of the switching circuit. By detecting the parameters of the temperature measuring element, a qualitative analysis is performed on whether the liquid remaining meets the requirements; by detecting the voltage to be detected obtained by converting the voltage across the voltage divider resistor, a quantitative analysis is performed on whether the liquid remaining meets the requirements, thereby achieving accurate detection of the liquid in the automatic dispensing box, greatly expanding the functions of household appliances, and having wide applicability.

[0056] In particular, according to an embodiment of the present application, the structural schematic diagram and circuit schematic diagram of the liquid remaining amount detection device referred to above can be implemented as a washing device. In an exemplary embodiment, Figure 3 Schematic diagram of the structure of a washing device provided according to an embodiment of the present application. Figure 3 As shown, the washing equipment of the present application includes a detergent dispensing device and a liquid remainder detection device provided in an embodiment of the present application, wherein the detergent dispensing device includes a detergent storage container, a liquid suction pipe, a liquid suction pump, a liquid return pipe and a liquid separation box, wherein the detergent storage container, the liquid suction pipe, the liquid return pipe and the liquid separation box are connected in sequence; the liquid suction pump drives the liquid in the liquid suction pipe and the liquid return pipe, and in this embodiment, the liquid is detergent; under the action of the liquid suction pump, the detergent is extracted from the detergent storage container, flows through the liquid suction pipe and the liquid return pipe, enters the liquid separation box, and enters the washing drum from the liquid separation box, and the washing operation is completed by the washing drum; the liquid remainder detection device is installed on the detergent storage container, and the area where the temperature measuring element is located is in contact with the liquid in the detergent storage container; the liquid remainder detection device is used to detect the remaining detergent stored in the detergent storage container.

[0057] In particular, according to an embodiment of the present application, the structural schematic diagram and circuit schematic diagram of the liquid remaining amount detection device referred to above can be implemented as a humidifier. In an exemplary embodiment, Figure 4 Schematic diagram of the structure of a humidifier provided according to an embodiment of the present application. Figure 4 As shown, the humidifier of the present application includes a wetting agent storage container, a spray device and a liquid remaining amount detection device provided in an embodiment of the present application, wherein the wetting agent storage container is used to store the wetting agent; based on the driving operation, the wetting agent is drawn out from the wetting agent storage container and enters the spray device, and the wetting agent is sprayed by the spray device; the liquid remaining amount detection device is installed on the wetting agent storage container, and the area where the temperature measuring element is located is in contact with the liquid in the wetting agent storage container; the liquid remaining amount detection device is used to detect the remaining amount of wetting agent stored in the wetting agent storage container.

[0058] In particular, according to an embodiment of the present application, the structural schematic diagram and circuit schematic diagram of the liquid remaining detection device referenced above can be implemented as a domestic fire fighting device. In an exemplary embodiment, Figure 5 This is a structural diagram of a household fire-fighting equipment provided according to an embodiment of the present application. Figure 5As shown, the household fire-fighting equipment of the present application includes a fire-fighting medium storage container, a spraying device and a liquid remaining detection device provided in an embodiment of the present application, wherein the fire-fighting medium storage container is used to store fire-fighting medium; based on the driving operation, the fire-fighting medium is drawn out from the fire-fighting medium storage container and enters the spraying device, and the fire-fighting medium is released by the spraying device; the liquid remaining detection device is installed on the fire-fighting medium storage container, and the area where the temperature measuring element is located is in contact with the liquid in the fire-fighting medium storage container; the liquid remaining detection device is used to detect the remaining amount of fire-fighting medium stored in the fire-fighting medium storage container.

[0059] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0061] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0062] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0063] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0064] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A liquid residual detection device, characterized in that: It includes power supply, switching circuit, temperature measuring element, voltage dividing resistor, voltage amplifying and shaping circuit and voltage detection circuit, among which: The switching circuit is connected to the power supply; the temperature measuring element and the voltage dividing resistor are connected in series between the output of the switching circuit and the reference ground; the voltage amplifying and shaping circuit and the voltage dividing resistor are connected in parallel, and the voltage detection circuit is connected in series with the voltage amplifying and shaping circuit. The voltage amplifying and shaping circuit amplifies and shapes the voltage across the voltage dividing resistor into a voltage to be detected, and the voltage detection circuit detects the voltage to be detected output by the amplifying and shaping circuit to determine the liquid remaining amount; When the input of the switch circuit is at a high level, the output of the switch circuit is a power supply voltage; when there is sufficient liquid, the liquid contacts the area where the temperature measuring element is located, and takes away the heat from the area where the temperature measuring element is located.

2. The liquid level detection device according to claim 1, wherein: Also includes: A stability detection circuit is connected between the output of the switching circuit and a reference ground, and is used to detect the stability of the power supply.

3. The liquid level detection device according to claim 2, wherein: The stability detection circuit includes a first resistor, a second resistor and a voltage stabilizing element, wherein the first end of the first resistor is connected to the output of the switching circuit; the second resistor is connected between the second end of the first resistor and the reference ground; the voltage stabilizing element is connected in parallel with the first resistor, and when the fluctuation of the power supply voltage exceeds a threshold value, the voltage stabilizing element cuts off the connection between the switching circuit and the temperature measuring element.

4. The liquid level detection device according to claim 3, wherein: The voltage stabilizing element includes a power fluctuation detection unit and a circuit breaker, wherein the input end of the power fluctuation detection unit is connected to the second end of the first resistor; the circuit breaker is connected between the first end of the first resistor and the output end of the power fluctuation detection unit.

5. The liquid level detection device according to claim 1, wherein: The temperature measuring elements include positive temperature coefficient thermistors, thermal resistors, and thermocouples.

6. The liquid remaining amount detection device according to claim 1 or 5, characterized in that: Also includes: A temperature compensation unit is connected to the temperature measuring element and is used to offset the ambient temperature of the temperature measuring element.

7. The liquid remaining amount detection device according to claim 1 or 5, characterized in that: Also includes: A heater is in contact with the area where the temperature measuring element is located, and is used to heat the temperature measuring element.

8. The liquid level detection device according to claim 1, wherein: The switching circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, an NPN transistor and a PNP transistor, wherein the first end of the third resistor is connected to the input signal; the fourth resistor is connected between the second end of the third resistor and the reference ground; the base of the NPN transistor is connected to the second end of the third resistor, and the emitter of the NPN transistor is connected to the reference ground; the first end of the fifth resistor is connected to the collector of the NPN transistor; the sixth resistor is connected between the second end of the fifth resistor and the power supply; the base of the PNP transistor is connected to the second end of the fifth resistor, and the emitter of the PNP transistor is connected to the power supply.

9. The liquid remaining amount detection device according to claim 1, characterized in that: The voltage amplification and shaping circuit includes a first capacitor, a second capacitor, a third capacitor, an operational amplifier, a seventh resistor, an eighth resistor and a ninth resistor, wherein the second capacitor is connected between the first end of the voltage-dividing resistor and the reference ground; the first end of the ninth resistor is connected to the second end of the voltage-dividing resistor; the third capacitor is connected between the second end of the ninth resistor and the reference ground; the positive input end of the operational amplifier is connected to the first end of the voltage-dividing resistor, and the reverse input end of the operational amplifier is connected to the second end of the ninth resistor; the eighth resistor is connected between the reverse input end and the output end of the operational amplifier; the first end of the seventh resistor is connected to the output end of the operational amplifier, and the second end of the seventh resistor is connected to the voltage detection circuit, wherein the voltage to be detected is output through the second end of the seventh resistor; and the first capacitor is connected between the second end of the seventh resistor and the reference ground.

10. A washing device, characterized in that: A detergent dispensing device and a liquid remaining amount detection device according to any one of claims 1 to 9, wherein the detergent dispensing device comprises a detergent storage container, a liquid extraction pipe, a liquid extraction pump, a liquid return pipe, and a liquid separation box, wherein the detergent storage container, the liquid extraction pipe, the liquid return pipe, and the liquid separation box are connected in sequence; the liquid extraction pump drives the liquid in the liquid extraction pipe and the liquid return pipe; Under the action of the liquid suction pump, the detergent is extracted from the detergent storage container, flows through the liquid suction pipe and the liquid return pipe, and enters the liquid separation box. The liquid remaining amount detection device is installed on the detergent storage container, and the area where the temperature measuring element is located is in contact with the liquid in the detergent storage container; the liquid remaining amount detection device is used to detect the remaining amount of the detergent stored in the detergent storage container.

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