Waterproof key circuit and household appliance

Abstract

The utility model provides a waterproof button circuit and a household electrical appliance, the waterproof button circuit comprises a controller, a first voltage division circuit, a second voltage division circuit and a button, a first end of the first voltage division circuit is used for accessing a power supply, and a second end is connected with a detection end of the controller; the first end of the second voltage division circuit is connected with the power supply, the second end is connected with the detection end, and the total resistance value of the second voltage division circuit is greater than that of the first voltage division circuit; the first end of the key is connected with the second end of the second voltage division circuit, the second end of the key is grounded, and the controller is used for judging whether the key is conducted by liquid or not according to the voltage value at the second end of the first voltage division circuit. When no water enters the button and the button is normally pressed down, the detection end of the controller detects a low level, and when the button is conducted due to water inflow, the detection end of the controller detects a high level.

Description

Technical Field

[0001] This application relates to the field of electronic technologies, and particularly to a waterproof button circuit and a household appliance. Background Art

[0002] In the design of contemporary household appliances, touch switch buttons have been widely used due to their simple operation and high reliability. However, during the use of household appliances, it is inevitable to come into contact with moisture, such as during cleaning or accidental splashing. Once the touch switch button gets wet, false triggering may occur. This false triggering not only affects the user experience, making the operation unreliable, but may also lead to safety accidents.

[0003] In the related art, taking a travel cup as an example, when the cup lid is screwed on in place, if the touch button is invaded by moisture, it may wrongly trigger the circuit, causing the knife-carrying motor or other mechanical components to start unexpectedly. This not only causes inconvenience to the user, but may also lead to safety accidents, posing a threat to the personal safety of the user.

[0004] In addition, the touch button after getting wet may also be damaged due to short circuit, increasing the maintenance cost and the economic burden on the user. In a high-humidity or rainy environment, this problem is particularly prominent, restricting the applicable range of household appliances and reducing the reliability of household appliances. Summary of the Utility Model

[0005] Embodiments of this application provide a waterproof button circuit and a household appliance, aiming to solve the problem.

[0006] In a first aspect, embodiments of this application provide a waterproof button circuit, including:

[0007] A controller;

[0008] A first voltage dividing circuit, the first end of which is used to connect to a power supply, and the second end is connected to the detection end of the controller;

[0009] A second voltage dividing circuit, the first end of which is used to connect to a power supply, and the second end is connected to the detection end, wherein the total resistance value of the second voltage dividing circuit is greater than the total resistance value of the first voltage dividing circuit; and

[0010] A button, the first end of which is connected to the second end of the second voltage dividing circuit, and the second end is grounded;

[0011] Wherein, the controller is used to judge whether the button is conducted by liquid according to the voltage value at the second end of the first voltage dividing circuit.

[0012] In some of these embodiments, the first voltage dividing circuit includes:

[0013] The first voltage-dividing resistor, the first end of the first voltage-dividing resistor is used to connect to the power supply, and the second end is connected to the detection end of the controller.

[0014] In some embodiments, the second voltage-dividing circuit includes:

[0015] A second voltage-dividing resistor, the first end of the second voltage-dividing resistor is used to connect to the power supply, and the second end is connected to the detection end and the first end of the button.

[0016] In some embodiments, the ratio of the resistance value of the second voltage-dividing resistor to the resistance value of the first voltage-dividing resistor is not less than 1500 and not greater than 2000.

[0017] In some embodiments, the resistance value of the second voltage-dividing resistor is 100 kΩ, and the resistance value of the first voltage-dividing resistor is 50 Ω.

[0018] In some embodiments, the button waterproof circuit further includes:

[0019] A protection circuit, the first end is connected to the second end of the first voltage-dividing resistor and the detection end, and the second end is connected to the second end of the second voltage-dividing resistor and the first end of the button.

[0020] In some embodiments, the protection circuit includes:

[0021] A diode, the anode is connected to the second end of the first voltage-dividing resistor and the detection end, and the cathode is connected to the second end of the second voltage-dividing resistor and the first end of the button.

[0022] In some embodiments, the waterproof button circuit further includes:

[0023] A current-limiting circuit, the first end is connected to the second end of the first voltage-dividing circuit, and the second end is connected to the detection end.

[0024] In some embodiments, the current-limiting circuit includes:

[0025] A current-limiting resistor, the first end is connected to the second end of the first voltage-dividing circuit, and the second end is connected to the detection end.

[0026] In some embodiments, the waterproof button circuit further includes:

[0027] A filter capacitor, the first plate is connected to the second end of the current-limiting resistor, and the second plate is grounded.

[0028] In a second aspect, an embodiment of the present application provides a household appliance, including:

[0029] Any of the above waterproof button circuits;

[0030] A circuit board, wherein the controller, the first voltage dividing circuit, and the second voltage dividing circuit are all disposed on the circuit board; and

[0031] A cover body, wherein the circuit board is disposed inside the cover body, the button is disposed on the cover body, and at least a part of the button is exposed outside the cover body.

[0032] In the embodiment of the present application, by providing a controller, a first voltage dividing circuit, a second voltage dividing circuit, and a button, the first end of the first voltage dividing circuit is connected to the power supply VCC, the second end is connected to the detection terminal I / O of the controller; and the first end of the second voltage dividing circuit is connected to the power supply VCC, the second end is connected to the detection terminal I / O of the controller, and the first end of the button is connected to the second end of the second voltage dividing circuit, and the second end is grounded; thus, the controller can determine whether the button is conductively connected by liquid according to the voltage value at the second end of the first voltage dividing circuit, and by configuring the total resistance value of the second voltage dividing circuit to be greater than that of the first voltage dividing circuit, for the cases where the button is conductively connected by liquids of different water qualities, they can all be detected by the controller, broadening the detection range of the waterproof button circuit for different water qualities, and further improving the safety and reliability of the household appliance applying the waterproof button circuit when used in a water environment. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0034] Figure 1 It is a schematic cross-sectional structure diagram of a household appliance provided by an embodiment of the present application;

[0035] Figure 2 It is a schematic circuit framework diagram of a water-proof button circuit provided by an embodiment of the present application;

[0036] Figure 3 It is a schematic circuit structure diagram of a water-proof button circuit provided by an embodiment of the present application

[0037] Figure 4 It is a schematic circuit structure diagram of a water-proof button circuit provided by another embodiment of the present application.

[0038] Description of the Reference Numerals:

[0039] 1. Household appliance; 100. Waterproof key circuit; 10. Controller; 20. First voltage dividing circuit; R1. First voltage dividing resistor; 30. Second voltage dividing circuit; R2. Second voltage dividing resistor; 40. Key; 50. Protection circuit; D1. Diode; 60. Current limiting circuit; R3. Current limiting resistor; C1. Filter capacitor;

[0040] 200. Cup body; 300. Cover body. Detailed implementation manners

[0041] To make the objectives, technical solutions and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0042] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods that are consistent with some aspects of the present application as detailed in the appended claims.

[0043] In the description of the present application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. In addition, in the description of the present application, unless otherwise specified, "a plurality of" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0045] Please refer to Figure 1, embodiments of the present application provide a household appliance 1, including but not limited to a juice cup, a travel cup, etc. Taking small household appliances such as a juice cup and a travel cup as examples, the household appliance 1 includes a cup body 200 and a lid body 300 covering the cup body 200. The household appliance 1 is usually equipped with a detection mechanism for the lid body 300, such as a limit switch or a sensor, to detect whether the lid body 300 is screwed in place relative to the cup body 200. Screwing the lid body 300 in place with the cup body 200 can ensure the sealing of the household appliance 1, prevent liquid from splashing out or the blade from contacting the user during use, thus ensuring the use safety. After confirming that the lid body 300 is screwed in place, it is possible to detect whether the start switch is pressed through the circuit. The start switch is implemented by a touch switch or other types of switches to start a motor or other working components for driving the blade.

[0046] As Figure 1 and Figure 2 shown, the household appliance 1 further includes a circuit board (not shown in the figure) and a waterproof key circuit 100. The circuit board is disposed in the lid body 300, and at least a part of the waterproof key circuit 100 can be fabricated on the circuit board.

[0047] Since the juice cup and the travel cup may be exposed to water during the washing process or come into contact with liquid during use, the design of the waterproof key circuit 100 is used to prevent the mis-triggering of the key 40 due to water ingress and conduction, and can ensure the use reliability and safety of the household appliance 1 under normal use conditions and in an environment where water is easily accessible, enabling the household appliance 1 to work properly even in a humid or wet environment and preventing the household appliance 1 from being mis-triggered or mis-started.

[0048] As Figure 2 shown, in some embodiments, the waterproof key circuit 100 includes a controller 10, a first voltage dividing circuit 20, a second voltage dividing circuit 30, and a key 40. The controller 10, the first voltage dividing circuit 20, and the second voltage dividing circuit 30 are all disposed on the circuit board, and the key 40 is disposed on the lid body 300 and at least partially exposed on the lid body 300 (it can be understood that when the waterproof key circuit 100 is applied to other types of household appliances 1, the key 40 can be disposed on the lid body and at least partially exposed on the lid body) for the convenience of user operation.

[0049] The controller 10 can adopt a microcontroller unit (MCU). The microcontroller unit has voltage detection and logic judgment functions. The controller 10 can monitor the voltage value at least from the first voltage division circuit 20 through an internal analog-to-digital converter (ADC), and judge whether the button 40 is conductively connected by liquid according to a preset voltage threshold. The first end of the first voltage division circuit 20 is used to connect to the power supply VCC, and the second end of the first voltage division circuit 20 is connected to the detection terminal I / O of the controller 10. The first end of the second voltage division circuit 30 is used to connect to the power supply VCC, and the second end of the second voltage division circuit 30 is connected to the detection terminal I / O. Wherein, the total resistance value of the second voltage division circuit 30 is greater than the total resistance value of the first voltage division circuit 20. The controller 10 is used to judge whether the button 40 is conductively connected by liquid according to the voltage value at the second end of the first voltage division circuit 20, that is, the controller 10 judges whether the button 40 is conductively connected by liquid according to a preset voltage threshold.

[0050] As Figure 2 shown, when the button 40 is not flooded, if the button 40 is pressed at this time, according to the button 40 specification, the contact resistance of the button 40 is very small. For example, the release resistance of the button 40 is less than or equal to 30 mR, which is much smaller than the total resistance value of the second voltage division circuit 30. At this time, the button 40 is normally conductively connected to the ground, and the detection terminal I / O of the controller 10 detects a low level and judges that the button 40 is normally pressed.

[0051] Furthermore, for the case where the button 40 is flooded and the waterproof button circuit 100 is conductively connected, it is necessary to consider that when different quality liquids cause the button 40 to be conductively connected, the button 40 has different resistances. For example, pure water (such as distilled water or filtered water) has a low impurity content and poor conductivity. In this case, if pure water enters the area where the button 40 is located and contacts the button 40, causing the button 40 to be conductively connected, the resistance of the button 40 is relatively high, such as 100 kΩ.

[0052] And water containing impurities (such as tap water or juice, etc.) contains more ions, so it has better conductivity. If water containing impurities enters the area where the button 40 is located and contacts the button 40, causing the button 40 to be conductively connected, the resistance of the button 40 is relatively low, such as a resistance of 1 kΩ.

[0053] It can be understood that 100 kΩ and 1 kΩ are only for illustrative purposes. Due to the great differences in water quality, when different quality liquids cause the button 40 to be conductively connected, the resistance of the button 40 is also diverse and not necessarily between 1 kΩ and 100 kΩ.

[0054] To ensure that the waterproof button circuit 100 can recognize and adapt when liquids of different water qualities enter the area where the button 40 is located, the following takes the relatively large resistance value of 100 kΩ and the relatively small resistance value of 1 kΩ that may exist when water enters at the button 40 for explanation. So that the waterproof button circuit 100 can work normally even under different water quality conditions, effectively avoiding the mis-triggering of the button 40 caused by water ingress.

[0055] As Figure 2 shown, assuming that the resistance at the button 40 after water ingress is the relatively small resistance value of 1 kΩ, since the total resistance of the second voltage dividing circuit 30 is greater than the total resistance of the first voltage dividing circuit 20, and at this time, the resistance value at the button 40 is less than the total resistance of the second voltage dividing circuit 30, so it is equivalent to the second voltage dividing circuit 30 being open-circuited. That is to say, the voltage drop generated at the button 40 after the current flowing through the second voltage dividing circuit 30 flows to the button 40 can be ignored. At this time, the voltage value V1 of the voltage detected by the detection terminal of the controller 10 is mainly determined by the first voltage dividing circuit 20 and the resistance at the button 40. By reasonably configuring the total resistance of the first voltage dividing circuit 20, the first voltage dividing circuit 20 and the button 40 are reasonably voltage-divided, so that the detection terminal of the controller 10 detects a high level of I / O. That is, the level detected by the detection terminal I / O switches from the low level when the button 40 is not water-in and is normally pressed to the high level caused by the button 40 being conducted by the liquid. At this time, the controller 10 can determine that the button 40 is conducted by the liquid, and thus will not control the household appliance 1 to work, achieving the avoidance of mis-triggering.

[0056] Assuming that the resistance at the button 40 after water ingress is the relatively large resistance value of 100 kΩ, at this time, it can be considered that the total resistance after the first voltage dividing circuit 20 and the second voltage dividing circuit 30 are connected in parallel divides the power supply VCC with the resistance at the button 40. Since the total resistance of the second voltage dividing circuit 30 is greater than the total resistance of the first voltage dividing circuit 20, the total resistance after the first voltage dividing circuit 20 and the second voltage dividing circuit 30 are connected in parallel is relatively small, much smaller than the resistance at the button 40. At this time, the detection terminal of the controller 10 is at a high level. That is, the level detected by the detection terminal I / O switches from the low level when the button 40 is not water-in and is normally pressed to the high level caused by the button 40 being conducted by the liquid. At this time, the controller 10 can determine that the button 40 is conducted by the liquid, and thus will not control the household appliance 1 to work, achieving the avoidance of mis-triggering.

[0057] In summary, in the embodiments of the present application, by providing a controller 10, a first voltage dividing circuit 20, a second voltage dividing circuit 30, and a key 40. The first end of the first voltage dividing circuit 20 is connected to the power supply VCC, and the second end is connected to the detection terminal I / O of the controller 10; and the first end of the second voltage dividing circuit 30 is connected to the power supply VCC, the second end is connected to the detection terminal I / O of the controller 10, and the first end of the key 40 is connected to the second end of the second voltage dividing circuit 30, and the second end is grounded; thus, the controller 10 can determine whether the key 40 is electrically conducted by a liquid according to the voltage value at the second end of the first voltage dividing circuit (20), and by configuring the total resistance value of the second voltage dividing circuit 30 to be greater than the total resistance value of the first voltage dividing circuit 20, for the cases where the key 40 is electrically conducted by liquids of different water qualities, they can all be detected by the controller 10, broadening the detection range of the waterproof key circuit 100 for different water qualities, and further improving the safety and reliability of the household appliance 1 applying the waterproof key circuit 100 when used in a water environment.

[0058] As Figure 3 shown, in some embodiments, the first voltage dividing circuit 20 includes a first voltage dividing resistor R1. The first end of the first voltage dividing resistor R1 is used to connect to the power supply VCC, and the second end is connected to the detection terminal I / O of the controller 10. The first voltage dividing circuit 20 divides the voltage of the power supply VCC through the first voltage dividing resistor R1 and the key 40. By configuring the first voltage dividing circuit 20 to include the first voltage dividing resistor R1, the circuit form is simple, the hardware cost is low, and it is easy to configure the voltage dividing ratio between the first voltage dividing resistor R1 and the key 40, so as to generate a voltage value suitable for the detection terminal I / O of the controller 10 between the first voltage dividing resistor R1 and the key 40. And the first voltage dividing circuit 20 has a small number of components, which can improve the reliability and stability of the waterproof key circuit 100.

[0059] As Figure 2 shown, in some embodiments, the second voltage dividing circuit 30 includes a second voltage dividing resistor R2. The first end of the second voltage dividing resistor R2 is used to connect to the power supply VCC, and the second end is connected to the detection terminal I / O and the first end of the key 40. The second voltage dividing circuit 30 divides the voltage of the power supply VCC through the second voltage dividing resistor R2, the first voltage dividing resistor R1, and the key 40. By configuring the second voltage dividing circuit 30 to include the second voltage dividing resistor R2, the circuit form is simple, the hardware cost is low, and it is easy to configure the voltage dividing ratio between the second voltage dividing resistor R2, the first voltage dividing resistor R1, and the key 40, so as to generate a voltage value suitable for the detection terminal I / O of the controller 10 among the second voltage dividing resistor R2, the first voltage dividing resistor R1, and the key 40. And the second voltage dividing circuit 30 has a small number of components, which can improve the reliability and stability of the waterproof key circuit 100.

[0060] In addition, since the total resistance value of the second voltage dividing circuit 30 is greater than that of the first voltage dividing circuit 20, when the second voltage dividing circuit 30 only includes the second voltage dividing resistor R2 and the first voltage dividing circuit 20 only includes the first voltage dividing resistor R1, the resistance value of the second voltage dividing resistor R2 is greater than that of the first voltage dividing resistor R1. In this way, voltage fluctuations in the waterproof key circuit 100 can be prevented from affecting the power supply VCC through the second voltage dividing resistor R2.

[0061] Please continue to refer to Figure 2 , in some embodiments, the ratio of the resistance value of the second voltage dividing resistor R2 to the resistance value of the first voltage dividing resistor R1 is not less than 1500 and not greater than 2000. By setting a reasonable voltage division ratio, on the one hand, for liquids of different water qualities that cause the key 40 to conduct, they can all be detected by the detection terminal I / O of the controller 10, improving the detection range of the waterproof key circuit 100 for different water qualities; on the other hand, the resistance value of the second voltage dividing resistor R2 is relatively large. In this way, voltage fluctuations in the waterproof key circuit 100 can be prevented from affecting the power supply VCC through the second voltage dividing resistor R2.

[0062] Exemplarily, the resistance value of the first voltage dividing resistor R1 is 50Ω, the resistance value of the second voltage dividing resistor R2 is 100kΩ, the voltage of the power supply VCC is 5V, and the judgment threshold for the low level is 1.3V. That is, when the voltage detected by the detection terminal I / O is lower than 1.3V, the controller 10 judges that a low level is received. The judgment threshold for the high level is 3.5V. That is, when the voltage detected by the detection terminal I / O is higher than 3.5V, the controller 10 judges that a high level is received.

[0063] Assume that the resistance at the key 40 after water ingress is 1kΩ, which is much smaller than the resistance value of 100kΩ of the second voltage dividing resistor R2. Due to this significant resistance difference, the second voltage dividing circuit 30 can be regarded as an open circuit relative to the resistance at the key 40.

[0064] At this time, the voltage value V1 measured by the controller 10 at the second end of the first voltage dividing resistor R1 is:

[0065]

[0066] That is, V1≈4.76V

[0067] At this time, V1 is higher than 3.5V, and the controller 10 judges that a high level is received and determines that the key 40 is conducted by the liquid.

[0068] Assume that the resistance value at the key 40 after water ingress is 100kΩ. First, the total resistance R after the parallel connection of the first voltage dividing resistor R1 and the second voltage dividing resistor R2 can be calculated 总 as:

[0069]

[0070] R 总 ≈49.97 Ω

[0071] At this time, the voltage value V1 measured by the controller 10 at the second end of the first voltage-dividing resistor R1 is:

[0072]

[0073] That is, V1≈4.99 V

[0074] At this time, V1 is higher than 3.5 V. The controller 10 determines that a high level is received and determines that the button 40 is conductively connected by the liquid.

[0075] As Figure 4 shown, in some embodiments, the button waterproof circuit 100 further includes a protection circuit 50. The first end of the protection circuit 50 is connected to the second end of the first voltage-dividing resistor R1 and the detection terminal I / O. The second end of the protection circuit 50 is connected to the second end of the second voltage-dividing resistor R2 and the first end of the button 40. Since the second end of the button 40 is grounded, by setting the protection circuit 50, when the ground voltage fluctuates, it can limit the large voltage and large current of the ground from flowing through the button 40 to the power supply VCC and the controller 10, thereby protecting the power supply VCC and the controller 10.

[0076] As Figure 4 shown, specifically, the protection circuit 50 includes a diode D1. The diode D1 is a semiconductor device that has a unidirectional conductivity, that is, the current can only flow from the anode through the diode D1 to the cathode. When the anode voltage of the diode D1 is higher than the cathode voltage, the diode D1 conducts; when the anode voltage is lower than the cathode voltage, the diode D1 is cut off.

[0077] The anode of the diode D1 is connected to the second end of the first voltage-dividing resistor R1 and the detection terminal I / O. The cathode of the diode D1 is connected to the second end of the second voltage-dividing resistor R2 and the first end of the button 40. The diode D1 ensures that the current can only flow from the first voltage-dividing resistor R1 to the button 40 and cannot flow in the reverse direction. By using the unidirectional conductivity of the diode D1, it is possible to prevent the large voltage and large current of the ground from flowing through the button 40 to the power supply VCC and the controller 10, thereby protecting the power supply VCC and the controller 10.

[0078] And if there are instantaneous voltage spikes in the waterproof button circuit 100, the diode D1 can play a role in overvoltage protection to prevent these spike voltages from damaging the controller 10 or other circuit components. Using the diode D1 as a protection component can also simplify the circuit design because the diode D1 is a relatively simple device and is easy to integrate into the circuit.

[0079] It should be noted that since the diode D1 is a semiconductor device, it allows current to flow in only one direction. In the forward-biased state, the PN junction inside the diode D1 allows current to pass through, but a nearly constant voltage drop is generated during this process. When the diode D1 is a silicon diode, this voltage drop is 0.7V, and when the diode D1 is a germanium diode, this voltage drop is 0.3V. The following takes the diode D1 being a silicon diode as an example for illustration.

[0080] Based on Figure 4 In the shown scheme, exemplarily, the resistance value of the first voltage-dividing resistor R1 is 50Ω, the resistance value of the second voltage-dividing resistor R2 is 100kΩ, the voltage of the power supply VCC is 5V, the judgment threshold for the low level is 1.3V, that is, when the voltage detected by the detection terminal I / O is lower than 1.3V, the controller 10 judges that a low level is received, and the judgment threshold for the high level is 3.5V, that is, when the voltage detected by the detection terminal I / O is higher than 3.5V, the controller 10 judges that a high level is received.

[0081] When the button 40 is not waterlogged, if the button 40 is pressed at this time, the contact resistance of the button 40 is about 30mΩ. Due to the existence of the diode D1, the voltage measured by the detection terminal I / O of the controller 10 is approximately the voltage drop of the diode D1, that is, 0.7V. At this time, the controller 10 judges that a low level is received, determines that the button 40 is normally pressed, and controls other components of the household appliance 1 to work properly.

[0082] Assume that the resistance at the button 40 after water ingress is 1kΩ. At this time, the voltage value V1 measured by the controller 10 at the second end of the first voltage-dividing resistor R1 is:

[0083]

[0084] V1≈4.80V

[0085] At this time, V1 is higher than 3.5V, and the controller 10 judges that a high level is received and determines that the button 40 is conductively connected by liquid.

[0086] Assume that the resistance at the button 40 after water ingress is 100kΩ. At this time, first calculate the voltage value Vk at the first end of the button 40 as:

[0087]

[0088] Vk≈4.29V

[0089] At this time, the voltage value V1 measured by the controller 10 at the second end of the first voltage-dividing resistor R1 is:

[0090] V1 = Vk + 0.7

[0091] V1≈4.97V

[0092] At this time, V1 is higher than 3.5V, and the controller 10 determines that a high level is received and determines that the button 40 is electrically conducted by the liquid.

[0093] As Figure 4 shown, in some embodiments, the waterproof button circuit 100 further includes a current limiting circuit 60. The current limiting circuit 60 is generally composed of one or more resistors and is used to limit the current flowing through the circuit. The first end of the current limiting circuit 60 is connected to the second end of the first voltage dividing circuit 20, and the second end of the current limiting circuit 60 is connected to the detection terminal I / O. The current limiting circuit 60 can prevent excessive current from flowing through the detection terminal I / O, thereby protecting the controller 10 from overcurrent damage. By limiting the current flowing through the detection terminal I / O, the current limiting circuit 60 helps to maintain the stability of the waterproof button circuit 100, especially when the voltage of the power supply VCC fluctuates or the resistance of the button 40 changes.

[0094] When the button 40 is pressed or released, the current limiting circuit 60 can slow down the change rate of the current, thereby reducing voltage mutations and improving the response smoothness of the circuit. The current limiting circuit 60 helps to reduce the sensitivity of the circuit to external electromagnetic interference because it can reduce the circuit's response to rapid voltage changes. By reducing current fluctuations and overload conditions, the current limiting circuit 60 helps to extend the service life of sensitive components in the waterproof button circuit 100.

[0095] As Figure 2 shown, specifically, the current limiting circuit 60 includes a current limiting resistor R3. The current limiting resistor R3 can limit the maximum current flowing through the circuit, prevent overcurrent caused by short circuits or other faults, thereby protecting other components in the waterproof button circuit 100. The first end of the current limiting resistor R3 is connected to the second end of the first voltage dividing circuit 20, and the second end of the current limiting resistor R3 is connected to the detection terminal I / O, which can prevent the controller 10 from being damaged due to overcurrent, especially in abnormal situations such as when the button 40 gets wet. The current limiting resistor R3 helps to stabilize the voltage signal of the detection terminal I / O of the controller 10, avoid voltage fluctuations caused by current fluctuations, and improve the accuracy of voltage detection.

[0096] In addition, the addition of the current limiting resistor R3 improves the reliability of the circuit because it can provide an additional layer of protection when the circuit is abnormal. And using the current limiting resistor R3 as the current limiting element can simplify the circuit design. It is a commonly used, easy-to-understand and implement circuit element.

[0097] As Figure 2As shown, in some embodiments, the waterproof button circuit 100 further includes a filtering capacitor C1, which is used to reduce or eliminate the noise and ripple on the power supply VCC or signal line. The first plate of the filtering capacitor C1 is connected to the second end of the current-limiting resistor R3, and the second plate is grounded. By eliminating high-frequency noise, the filtering capacitor C1 helps to improve the quality of the voltage signal detected by the controller 10, making it more accurate and reliable.

[0098] In addition, by setting the filtering capacitor C1, the waterproof button circuit 100 has enhanced resistance to external interference (such as electromagnetic interference), so that it can maintain good performance even in a complex environment, reduce the noise and ripple in the circuit, and help to extend the service life of circuit components, because they will not age rapidly due to frequent voltage fluctuations.

[0099] In the drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation of the present application. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0100] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A waterproof button circuit, characterized in that, Comprising: A controller; A first voltage dividing circuit, the first end of which is used to connect to a power supply, and the second end of which is connected to the detection end of the controller; A second voltage dividing circuit, the first end of which is used to connect to a power supply, and the second end of which is connected to the detection end, wherein the total resistance value of the second voltage dividing circuit is greater than the total resistance value of the first voltage dividing circuit; and A button, the first end of which is connected to the second end of the second voltage dividing circuit, and the second end of which is grounded; Wherein, the controller is used to judge whether the button is conducted by liquid according to the voltage value at the second end of the first voltage dividing circuit.

2. The waterproof button circuit according to claim 1, wherein The first voltage dividing circuit includes: A first voltage dividing resistor, the first end of which is used to connect to a power supply, and the second end of which is connected to the detection end of the controller.

3. The waterproof button circuit according to claim 2, wherein The second voltage dividing circuit includes: A second voltage dividing resistor, the first end of which is used to connect to a power supply, and the second end of which is connected to the detection end and the first end of the button.

4. The waterproof button circuit according to claim 3, wherein, The ratio of the resistance value of the second voltage dividing resistor to the resistance value of the first voltage dividing resistor is not less than 1500 and not greater than 2000.

5. The waterproof button circuit according to claim 4, wherein The resistance value of the second voltage dividing resistor is 100 kΩ, and the resistance value of the first voltage dividing resistor is 50 Ω.

6. The waterproof button circuit according to claim 3, wherein The button waterproof circuit further includes: A protection circuit, the first end of which is connected to the second end of the first voltage dividing resistor and the detection end, and the second end of which is connected to the second end of the second voltage dividing resistor and the first end of the button.

7. The waterproof button circuit according to claim 6, characterized in that, The protection circuit includes: A diode, the anode of which is connected to the second end of the first voltage dividing resistor and the detection end, and the cathode of which is connected to the second end of the second voltage dividing resistor and the first end of the button.

8. The waterproof button circuit according to any one of claims 1-7, characterized in that, The waterproof button circuit further includes: A current limiting circuit, the first end of which is connected to the second end of the first voltage dividing circuit, and the second end of which is connected to the detection end.

9. The waterproof button circuit according to claim 8, characterized in that, The current limiting circuit includes: A current limiting resistor, the first end of which is connected to the second end of the first voltage dividing circuit, and the second end of which is connected to the detection end.

10. The waterproof button circuit according to claim 9, characterized in that, The waterproof button circuit further includes: A filter capacitor, the first electrode plate of which is connected to the second end of the current limiting resistor, and the second electrode plate of which is grounded.

11. A household appliance, characterized in that, Comprising: The waterproof button circuit according to any one of claims 1-10; A circuit board, on which the controller, the first voltage dividing circuit and the second voltage dividing circuit are all arranged; And A cover body, on which the circuit board is arranged, the button is arranged on the cover body, and at least part of the button is exposed outside the cover body.

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