Humidifier water detection system

Abstract

The utility model discloses a water detection system of a humidifier. The water detection system of the humidifier comprises a control module, a capacitive water detection circuit and an AD water detection circuit, the control module is electrically connected with the capacitive water detection circuit and the AD water detection circuit. The AD water detection circuit comprises a PWM drive circuit, an asynchronous boost circuit, a sampling circuit and a multi-stage filter circuit. The output end of the control module is connected with the input end of the PWM drive circuit, the output end of the PWM drive circuit is electrically connected with the input end of the asynchronous booster circuit, and the output end of the asynchronous booster circuit is connected with the input end of the sampling circuit and the first pin of the atomization piece. The output end of the sampling circuit is respectively connected with the input end of the multi-stage filter circuit and the pin 2 of the atomization sheet; and the output end of the multi-stage filter circuit is connected with the input end of the control module. The utility model solves the technical problem of how to accurately and quickly detect whether the water tank of the humidifier is lack of water and output a result.

Description

Technical Field

[0001] The utility model relates to the technical field of humidifiers, in particular to a humidifier water detection system. Background Art

[0002] With the development of economy and the improvement of people's living standards, people's requirements for the quality of life and health are getting higher and higher. Humidifiers have thus gradually entered many families around the world and become an indispensable small household appliance product in families in dry areas. To meet people's needs for the use function and aesthetic function of humidifiers, the types of humidifier products are becoming more refined. During the process of atomizing water, the amount of water will gradually decrease and be consumed over time until there is no water. At the same time, the circuit board of the humidifier also needs to be cooled by water during operation. If it still operates in a dry-burning state without water, it will cause direct damage to the atomizing sheet and even the circuit board. To avoid the dry-burning working state of the humidifier, water shortage protection is generally added.

[0003] The patent document with the application number 201320043308.5 discloses a water level sensing structure of a humidifier, which includes a reed switch, a directional sleeve, a float and a magnet; the reed switch is arranged in the water tank of the humidifier base; the directional sleeve is arranged at the bottom of the humidifier box body, and more than two openings are axially opened in the directional sleeve, and the end of the directional sleeve can extend into the bottom of the water tank; the float is located in the directional sleeve and can move up and down, and the float can float up and down with the water in the water tank in the directional sleeve; the magnet is arranged on the float, and the reed switch can correspond to the position of the magnet so that the reed switch can sense the magnetic force of the magnet and conduct. At present, the water shortage protection mainly detects water through a reed switch and a Hall sensor. Both of the above two methods judge whether there is water shortage in the water tank through a magnetic float. This kind of water detection method has technical problems such as complex assembly, high cost and poor consistency. Because the float also involves a mechanical structure, there is also an abnormal situation where the entire protection fails due to mechanical damage. Therefore, there is an urgent need to propose a humidifier water detection system to solve the technical problem of how to accurately and quickly detect whether there is water shortage in the humidifier water tank and output the result. Summary of the Utility Model

[0004] The main purpose of the utility model is to propose a humidifier water detection system, aiming to solve the technical problem of how to accurately and quickly detect whether there is water shortage in the humidifier water tank and output the result.

[0005] To achieve the above purpose, the utility model provides a humidifier water detection system, wherein the humidifier water detection system includes:

[0006] A control module, a capacitive water detection circuit and an AD water detection circuit;

[0007] The control module is electrically connected to the capacitive water detection circuit and the AD water detection circuit respectively;

[0008] The AD water detection circuit includes a PWM drive circuit, an asynchronous boost circuit, a sampling circuit, and a multi-stage filtering circuit; the output end of the control module is connected to the input end of the PWM drive circuit, the output end of the PWM drive circuit is electrically connected to the input end of the asynchronous boost circuit, the output end of the asynchronous boost circuit is respectively connected to the input end of the sampling circuit and the pin 1 of the atomizing sheet, the output end of the sampling circuit is respectively connected to the input end of the multi-stage filtering circuit and the pin 2 of the atomizing sheet; the output end of the multi-stage filtering circuit is connected to the input end of the control module.

[0009] One of the preferred solutions, the control module includes a controller U1;

[0010] The pins 6, 7, and 16 of the controller U1 are connected to the capacitive water detection circuit;

[0011] The pin 12 of the controller U1 is respectively connected to the power supply terminal and the capacitor C12;

[0012] The pins 13 and 15 of the controller U1 are connected to the AD water detection circuit;

[0013] The pin 8 of the controller U1 and the other end of the capacitor C12 are grounded.

[0014] One of the preferred solutions, the capacitive water detection circuit includes a reference capacitor C25, a sensitivity capacitor C23, a resistor R15, and a water tank detection disc; one ends of the reference capacitor C25 and the sensitivity capacitor C23 are respectively connected to the controller U1, the other ends of the reference capacitor C25 and the sensitivity capacitor C23 are grounded; one end of the resistor R15 is connected to the controller U1, and the other end of the resistor R15 is connected to the water tank detection disc.

[0015] One of the preferred solutions, the water tank detection disc is made of a touch spring or copper paper.

[0016] One of the preferred solutions, the PWM drive circuit includes a resistor R5 and a resistor R6; one end of the resistor R5 is connected to the control module, the other end of the resistor R5 is respectively connected to the resistor R6 and the asynchronous boost circuit, and the other end of the resistor R6 is respectively connected to the asynchronous boost circuit and the sampling circuit.

[0017] One of the preferred solutions, the asynchronous boost circuit includes an MOS transistor Q1, an inductor L2, and a capacitor C6;

[0018] The gate of the MOS transistor Q1 is connected to the resistor R6 and the PWM drive circuit respectively. The source of the MOS transistor Q1 is connected to the other end of the resistor R6 and the sampling circuit respectively. The drain of the MOS transistor Q1 is connected to the inductor L2 and the capacitor C8 respectively. The other end of the inductor L2 is connected to the capacitor C6 and the power supply terminal respectively. The other end of the capacitor C6 is grounded. The other end of the capacitor C8 is connected to the pin 1 of the atomizing sheet.

[0019] One of the preferred solutions is that the sampling circuit includes a resistor R10. One end of the resistor R10 is connected to the asynchronous boost circuit and the multi-stage filtering circuit respectively, and the other end of the resistor R10 is grounded.

[0020] One of the preferred solutions is that the multi-stage filtering circuit includes a first filtering circuit and a second filtering circuit.

[0021] One end of the first filtering circuit is connected to the sampling circuit and the asynchronous boost circuit respectively. The other end of the first filtering circuit is connected to the second filtering circuit, and the second filtering circuit is connected to the control module.

[0022] One of the preferred solutions is that the first filtering circuit includes a resistor R9 and a capacitor C18. One end of the resistor R9 is connected to the sampling circuit and the asynchronous boost circuit respectively. The other end of the resistor R9 is connected to the capacitor C18 and the second filtering circuit respectively, and the other end of the capacitor C18 is grounded.

[0023] One of the preferred solutions is that the second filtering circuit includes a resistor R8 and a capacitor C17. One end of the resistor R8 is connected to the first filtering circuit. The other end of the resistor R8 is connected to the capacitor C17 and the control module respectively, and the other end of the capacitor C17 is grounded.

[0024] In the above technical solution of the present invention, the water detection system of the humidifier includes: a control module, a capacitive water detection circuit, and an AD water detection circuit. The control module is electrically connected to the capacitive water detection circuit and the AD water detection circuit respectively. The AD water detection circuit includes a PWM drive circuit, an asynchronous boost circuit, a sampling circuit, and a multi-stage filtering circuit. The output end of the control module is connected to the input end of the PWM drive circuit. The output end of the PWM drive circuit is electrically connected to the input end of the asynchronous boost circuit. The output end of the asynchronous boost circuit is connected to the input end of the sampling circuit and the pin 1 of the atomizing sheet respectively. The output end of the sampling circuit is connected to the input end of the multi-stage filtering circuit and the pin 2 of the atomizing sheet respectively. The output end of the multi-stage filtering circuit is connected to the input end of the control module. The present invention solves the technical problem of how to accurately and quickly detect whether the water tank of the humidifier is short of water and output the result. At the same time, it ensures the consistency and stability of mass production.

[0025] In the present utility model, the water level in the humidifier water tank is monitored in real time by integrating a capacitive water detection circuit and an AD water detection circuit. Compared with the conventional installation of structural components such as magnetic floats, reed switches, or Hall components, the assembly method is more streamlined and stable and reliable.

[0026] In the present utility model, the capacitance value of the water tank is detected by the capacitive water detection circuit to determine whether there is water in the water tank; and the AD water detection circuit is used to determine whether the atomizer is working properly. If the atomizer works in a waterless state, it will cause a current change. By detecting the current change, it is determined whether there is water in the water tank. Two layers of water detection circuits are adopted to ensure the reliability of water shortage detection and avoid false detection.

[0027] In the present utility model, the PWM drive circuit outputs a PWM signal with an adjustable output frequency and a duty cycle of 50% to drive the MOS transistor Q1. When the PWM signal is in the positive half cycle, the MOS transistor Q1 is turned on, and the inductor L2 charges and stores energy to boost the voltage. When the PWM signal is in the negative half cycle, the MOS transistor Q1 is turned off, and the inductor L2 discharges through the capacitor C8 to the atomizing sheet. Through the repeated charge and discharge process of the inductor L2, the voltage is raised to the working voltage required by the atomizing sheet, and the waveform frequency after boosting changes with the PWM drive frequency to meet the best working resonance point of the atomizing sheet. Description of the Drawings

[0028] In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0029] Figure 1 It is the first schematic diagram of a water detection system for a humidifier according to an embodiment of the present utility model;

[0030] Figure 2 It is the second schematic diagram of a water detection system for a humidifier according to an embodiment of the present utility model;

[0031] Figure 3 It is the schematic diagram of the capacitive water detection circuit according to an embodiment of the present utility model;

[0032] Figure 4 It is the schematic diagram of the AD water detection circuit according to an embodiment of the present utility model.

[0033] Explanation of the Reference Numerals in the Drawings:

[0034] 1. Control module; 2. Capacitive water detection circuit; 3. AD water detection circuit.

[0035] The realization, functional features and advantages of the present utility model will be further described in conjunction with the embodiments with reference to the accompanying drawings.

[0036] The realization, functional features and advantages of the present utility model will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific embodiments

[0037] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present utility model.

[0038] In addition, in the present utility model, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0039] Moreover, the technical solutions between the various embodiments of the present utility model can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0040] See Figures 1 - 4 , according to one aspect of the present utility model, the present utility model provides a water detection system for a humidifier, wherein the water detection system for the humidifier includes:

[0041] A control module 1, a capacitive water detection circuit 2, and an AD water detection circuit 3;

[0042] The control module 1 is electrically connected to the capacitive water detection circuit 2 and the AD water detection circuit 3 respectively;

[0043] The AD water detection circuit 3 includes a PWM drive circuit, an asynchronous boost circuit, a sampling circuit, and a multi-stage filtering circuit; the output end of the control module is connected to the input end of the PWM drive circuit, the output end of the PWM drive circuit is electrically connected to the input end of the asynchronous boost circuit, the output end of the asynchronous boost circuit is respectively connected to the input end of the sampling circuit and the 1 pin of the atomizing sheet, the output end of the sampling circuit is respectively connected to the input end of the multi-stage filtering circuit and the 2 pin of the atomizing sheet; the output end of the multi-stage filtering circuit is connected to the input end of the control module.

[0044] Specifically, in this embodiment, the control module 1 is used to determine whether the humidifier water tank is short of water according to the capacitance value of the humidifier water tank and the AD value of the humidifier atomizing sheet; the control module 1 includes a controller U1; pins 6, 7, and 16 of the controller U1 are connected to the capacitive water detection circuit 2; pin 12 of the controller U1 is respectively connected to the power supply terminal and the capacitor C12; pins 13 and 15 of the controller U1 are connected to the AD water detection circuit 3; pin 8 of the controller U1 and the other end of the capacitor C12 are grounded; in the present utility model, the controller U1 adopts an A / D type 8-bit MCU of the model PT8M2305S16, which is not specifically limited in the present utility model and can be specifically set according to needs.

[0045] Specifically, in this embodiment, the capacitive water detection circuit 2 is used to detect the capacitance value of the humidifier water tank; the capacitive water detection circuit 2 includes a reference capacitor C25, a sensitivity capacitor C23, a resistor R15, and a water tank detection disc; one end of the reference capacitor C25 is connected to pin 6 of the controller U1, and the other end of the reference capacitor C25 is grounded; one end of the sensitivity capacitor C23 is connected to pin 7 of the controller U1, and the other end of the sensitivity capacitor C23 is grounded; one end of the resistor R15 is connected to pin 16 of the controller U1, and the other end of the resistor R15 is connected to the water tank detection disc; the capacitance value C2 of the water volume in the water tank is obtained through the water tank detection disc, and a buffer interval C1 and a reference capacitance value C3 are set in the control module 1. Based on the reference capacitor C3, when the capacitance C2 of the water tank is greater than the reference capacitor C3, it indicates that the water tank has water, and when the sum of the capacitance C2 of the water tank and the buffer interval C1 is less than the reference capacitor C3, it indicates that the water tank is empty; the buffer interval C1 is to prevent the water level in the water tank from jittering during the critical state.

[0046] Specifically, in this embodiment, the water tank detection disc is made of a touch spring or copper paper, and the water tank detection disc directly contacts the water tank to detect the capacitance value of the water tank.

[0047] Specifically, in this embodiment, the AD water detection circuit 3 is used to control the resonance frequency of the humidifier atomizing sheet and to detect the AD value of the working current of the humidifier atomizing sheet; the AD water detection circuit 3 includes a PWM drive circuit, an asynchronous boost circuit, a sampling circuit, and a multi-stage filtering circuit; the PWM drive circuit is electrically connected to the asynchronous boost circuit, the asynchronous boost circuit is respectively connected to the sampling circuit and pin 1 of the atomizing sheet, and the sampling circuit is respectively connected to the multi-stage filtering circuit and pin 2 of the atomizing sheet.

[0048] Specifically, in this embodiment, the PWM driving circuit includes a resistor R5 and a resistor R6; one end of the resistor R5 is connected to the 13th pin of the controller U1, the other end of the resistor R5 is respectively connected to the resistor R6 and the asynchronous boost circuit, and the other end of the resistor R6 is respectively connected to the asynchronous boost circuit and the sampling circuit.

[0049] Specifically, in this embodiment, the asynchronous boost circuit includes a MOS transistor Q1, an inductor L2, and a capacitor C6; the gate of the MOS transistor Q1 is respectively connected to the resistor R6 and the PWM driving circuit, the source of the MOS transistor Q1 is respectively connected to the other end of the resistor R6 and the sampling circuit, the drain of the MOS transistor Q1 is respectively connected to the inductor L2 and the capacitor C8, the other end of the inductor L2 is respectively connected to the capacitor C6 and the power supply terminal, the other end of the capacitor C6 is grounded, and the other end of the capacitor C8 is connected to the 1st pin of the atomizing sheet. During the asynchronous boost process, a voltage signal is generated across the sampling resistor R10, which passes through the first filtering circuit and the second filtering circuit in sequence and is sent to the ADC detection port of the controller U1, that is, the 15th pin of the controller U1. Since during the operation of the atomizing sheet, when there is water and when there is no water, the change in the load of the atomizing sheet will cause the current flowing through both ends of the resistor R10 to change. This current signal is transmitted to the controller U1, and the current signal is subjected to analog-to-digital conversion through the control module 1 and compared with the predicted value set in the controller, thereby determining whether there is a water shortage.

[0050] Specifically, in this embodiment, the sampling circuit includes a resistor R10; one end of the resistor R10 is respectively connected to the asynchronous boost circuit and the multi-stage filtering circuit, and the other end of the resistor R10 is grounded.

[0051] Specifically, in this embodiment, the multi-stage filtering circuit includes a first filtering circuit and a second filtering circuit; one end of the first filtering circuit is respectively connected to the sampling circuit and the asynchronous boost circuit, the other end of the first filtering circuit is connected to the second filtering circuit, and the second filtering circuit is connected to the control module 1; in the present utility model, by providing two-stage RC filtering circuits to filter the signal output by the sampling circuit, a smooth direct current is obtained.

[0052] Specifically, in this embodiment, the first filtering circuit includes a resistor R9 and a capacitor C18; one end of the resistor R9 is respectively connected to the sampling circuit and the asynchronous boost circuit, the other end of the resistor R9 is respectively connected to the capacitor C18 and the second filtering circuit, and the other end of the capacitor C18 is grounded.

[0053] Specifically, in this embodiment, the second filter circuit includes a resistor R8 and a capacitor C17; one end of the resistor R8 is connected to the first filter circuit, the other end of the resistor R8 is respectively connected to the capacitor C17 and the 15th pin of the controller U1, and the other end of the capacitor C17 is grounded.

[0054] Specifically, in this embodiment, the control module 1 and the PWM output module output a PWM signal with adjustable frequency and a fixed duty cycle of 50%, outputting the resonant frequency point required by the atomizing sheet, such as 1.7 MHZ. After passing through the current-limiting resistor R5, it drives the MOS transistor Q1 for asynchronous boost. When the PWM signal is in the positive half-cycle, the MOS transistor Q1 conducts, and the inductor L2 charges and stores energy to boost the voltage to the ground. When the PWM is in the negative half-cycle, the MOS transistor Q2 turns off, and the inductor L2 discharges through the capacitor C8 with the atomizing sheet as the load. Through the repeated charging and discharging process of the inductor L2, the voltage is raised to the working voltage required by the atomizing sheet. In the present invention, the working voltage of the atomizing sheet is 90V, and the waveform frequency after boosting changes with the PWM driving frequency to meet the best working resonant point of the atomizing sheet; when the surface of the atomizing sheet is with water or without water during operation, due to the change of the load, it will cause a change in the output power of the asynchronous boost circuit, resulting in a change in the voltage across the sampling resistor R10 through which the boost charging current passes. This voltage is sent to the control module 1 after passing through the first filter circuit and the second filter circuit, and is subjected to analog-to-digital conversion through the control module 1. The obtained current signal is compared with the predicted value to determine whether the humidifier is operating in a waterless state.

[0055] Specifically, in this embodiment, the water volume in the humidifier water tank is monitored in real time by integrating two methods of capacitive water detection and AD water detection. Compared with the conventional installation of structural components such as magnetic floats, reed switches, or Hall components, the assembly method is more streamlined, and stable and reliable; in the present invention, since the AD water detection is affected by the atomizing sheet and other interferences on the circuit, therefore, the capacitive water detection is used as the primary water detection circuit, and the AD water detection is used as the secondary water detection circuit. Even if the protection of the capacitive water detection circuit 2 fails, the AD water detection circuit 3 of the secondary water detection circuit can still generate a protection effect to prevent damage to the circuit board and the atomizing sheet, improve the reliability of water shortage detection of the humidifier, and avoid false detection.

[0056] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

[0057] The above are only the preferred embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent structural transformation made under the inventive concept of the present utility model by using the content of the specification and drawings of the present utility model, or any direct / indirect application in other related technical fields shall be included in the patent protection scope of the present utility model.

Claims

1. A water detection system for a humidifier, characterized in that, The humidifier water detection system includes: a control module, a capacitive water detection circuit, and an AD water detection circuit; The control module is electrically connected to the capacitive water detection circuit and the AD water detection circuit respectively; The AD water detection circuit includes a PWM drive circuit, an asynchronous boost circuit, a sampling circuit, and a multi-stage filtering circuit; the output end of the control module is connected to the input end of the PWM drive circuit, the output end of the PWM drive circuit is electrically connected to the input end of the asynchronous boost circuit, the output end of the asynchronous boost circuit is respectively connected to the input end of the sampling circuit and the 1-pin of the atomizing sheet, the output end of the sampling circuit is respectively connected to the input end of the multi-stage filtering circuit and the 2-pin of the atomizing sheet; the output end of the multi-stage filtering circuit is connected to the input end of the control module.

2. The water detection system of a humidifier according to claim 1, characterized in that The control module includes a controller U1; The 6th, 7th, and 16th pins of the controller U1 are connected to the capacitive water detection circuit; The 12th pin of the controller U1 is respectively connected to the power supply terminal and the capacitor C12; The 13th and 15th pins of the controller U1 are connected to the AD water detection circuit; The 8th pin of the controller U1 and the other end of the capacitor C12 are grounded.

3. A water detection system for a humidifier according to any one of claims 1-2, characterized in that, The capacitive water detection circuit includes a reference capacitor C25, a sensitivity capacitor C23, a resistor R15, and a water tank detection disc; one end of the reference capacitor C25 and the sensitivity capacitor C23 are respectively connected to the controller U1, and the other ends of the reference capacitor C25 and the sensitivity capacitor C23 are grounded; one end of the resistor R15 is connected to the controller U1, and the other end of the resistor R15 is connected to the water tank detection disc.

4. The water detection system of a humidifier according to claim 3, characterized in that, The water tank detection disc is made of a touch spring or copper paper.

5. A water detection system for a humidifier according to any one of claims 1-2, characterized in that The PWM drive circuit includes a resistor R5 and a resistor R6; one end of the resistor R5 is connected to the control module, the other end of the resistor R5 is respectively connected to the resistor R6 and the asynchronous boost circuit, and the other end of the resistor R6 is respectively connected to the asynchronous boost circuit and the sampling circuit.

6. A humidifier water detection system according to any one of claims 1-2, characterized in that, The asynchronous boost circuit includes a MOS transistor Q1, an inductor L2, and a capacitor C6; The gate of the MOS transistor Q1 is respectively connected to the resistor R6 and the PWM drive circuit, the source of the MOS transistor Q1 is respectively connected to the other end of the resistor R6 and the sampling circuit, the drain of the MOS transistor Q1 is respectively connected to the inductor L2 and the capacitor C8, the other end of the inductor L2 is respectively connected to the capacitor C6 and the power supply terminal, the other end of the capacitor C6 is grounded, and the other end of the capacitor C8 is connected to the 1-pin of the atomizing sheet.

7. A water detection system for a humidifier according to any one of claims 1-2, characterized in that The sampling circuit includes a resistor R10; one end of the resistor R10 is respectively connected to the asynchronous boost circuit and the multi-stage filtering circuit, and the other end of the resistor R10 is grounded.

8. A water detection system for a humidifier according to any one of claims 1-2, characterized in that The multi-stage filtering circuit includes a first filtering circuit and a second filtering circuit; One end of the first filtering circuit is respectively connected to the sampling circuit and the asynchronous boost circuit, the other end of the first filtering circuit is connected to the second filtering circuit, and the second filtering circuit is connected to the control module.

9. The water detection system of a humidifier according to claim 8, characterized in that, The first filtering circuit includes a resistor R9 and a capacitor C18; one end of the resistor R9 is connected to the sampling circuit and the asynchronous boost circuit respectively, the other end of the resistor R9 is connected to the capacitor C18 and the second filtering circuit respectively, and the other end of the capacitor C18 is grounded.

10. The water detection system of a humidifier according to claim 8, characterized in that, The second filtering circuit includes a resistor R8 and a capacitor C17; one end of the resistor R8 is connected to the first filtering circuit, the other end of the resistor R8 is connected to the capacitor C17 and the control module respectively, and the other end of the capacitor C17 is grounded.

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