A liquid level detection device for an atomizing sheet and an atomization frequency-tracking liquid level detection system

Abstract

The present invention discloses a liquid level detection device for an atomizing sheet and an atomization frequency tracking liquid level detection system, which includes a controller module, a driving module, and a frequency detection module. The controller module is connected to the controlled end of the driving module to control the driving module to output a driving signal. The output end of the driving module is connected to the atomizing sheet to drive the atomizing sheet to operate. The frequency detection module is respectively connected to the atomizing sheet and the controller module. The frequency detection module detects the operating frequency of the atomizing sheet to form a feedback signal and outputs it to the controller module. Among them, the operating frequency of the atomizing sheet can reflect the amount of liquid level of the liquid in the working environment where the atomizing sheet is located. When the liquid level is higher, the operating frequency is larger. When the liquid level is lower, the operating frequency is smaller. This design can be detected when the liquid in the container is less, with a simple structure, accurate detection, and not easily damaged to the atomizing sheet.

Description

Technical Field

[0001] The present invention relates to the technical field of humidifier devices, and particularly to a liquid level detection device for an atomizing sheet and an atomization frequency tracking liquid level detection system. Background Art

[0002] Humidifiers are widely used in people's lives. An atomizing sheet is arranged in a container, and the atomizing sheet is driven to operate by a controller. The atomizing sheet can atomize the liquid in the container. In addition, a liquid level detection device needs to be set up to know the liquid level through the liquid level detection device, so that the controller can reasonably control the operation of the atomizing sheet. Traditional liquid level detection methods are generally mechanical, capacitive or dry-burning. Although the mechanical water level detection method has very high sensitivity, due to the relatively complex detection structure, it increases the complexity of the humidifier structure, making the humidifier mold opening complex, with high production costs and large finished product volume; the capacitive water level detection method uses the capacitive change of a probe to judge whether there is water. Although this method has a simple structure and does not increase the complexity of the humidifier structure, its sensitivity is low, its anti-interference ability is poor, and it is prone to misjudgment; while the dry-burning water level detection method is that when the atomizing sheet is completely without water, the current of the atomizing sheet increases, and then the water level situation can be judged, which is easy to damage the atomizing sheet. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present invention provides a liquid level detection device for an atomizing sheet and an atomization frequency tracking liquid level detection system, which can reflect the liquid level of the liquid in the working environment of the atomizing sheet by detecting the operating frequency of the atomizing sheet, has a simple structure, accurate detection, and is not easy to damage the atomizing sheet.

[0004] A liquid level detection device for an atomizing sheet according to an embodiment of the first aspect of the present invention includes: a controller module; a driving module, the controller module is connected to the controlled end of the driving module to control the driving module to output a driving signal, and the output end of the driving module is connected to the atomizing sheet to drive the atomizing sheet to operate; a frequency detection module, which is respectively connected to the atomizing sheet and the controller module, and the frequency detection module detects the operating frequency of the atomizing sheet to form a feedback signal and outputs it to the controller module, wherein the operating frequency of the atomizing sheet can reflect the liquid level of the liquid in the working environment where the atomizing sheet is located. The higher the liquid level, the greater the operating frequency, and the lower the liquid level, the smaller the operating frequency.

[0005] A liquid level detection device for an atomizing sheet according to an embodiment of the present invention has at least the following

[0006] Advantages:

[0007] The liquid level detection device of the atomizing sheet of the present invention, the controller module controls the driving module to output a driving signal to the atomizing sheet, and the atomizing sheet is driven to vibrate to atomize the liquid in the container. At the same time, the frequency detection module is used to detect the operating frequency of the atomizing sheet. When the liquid level in the container is relatively high, the operation of the atomizing sheet will generate large liquid fluctuations (such as water splashes), and the liquid fluctuations will also cause changes in the operating frequency of the atomizing sheet. At this time, if the frequency detection module detects that the operating frequency of the atomizing sheet is relatively large, it proves that the liquid level in the container is relatively high. When the liquid level in the container is relatively low, the liquid fluctuations generated by the operation of the atomizing sheet are relatively small, and the frequency detection module detects that the operating frequency of the atomizing sheet is relatively small, which proves that the liquid level in the container is relatively low. This design can be detected when the liquid in the container is less, with a simple structure, accurate detection, and not easy to damage the atomizing sheet.

[0008] According to some embodiments of the present invention, the frequency detection module is a frequency tracking detection module. The frequency tracking detection module detects and demodulates the operating frequency of the atomizing sheet to form a demodulation signal, and the frequency tracking detection module outputs the demodulation signal as a feedback signal to the controller module; the controller module drives the atomizing sheet to operate through the driving module according to the operating frequency threshold. When the demodulation signal reflects that the liquid level is relatively high, the controller module drives the operating frequency of the atomizing sheet to approach the operating frequency threshold. When the demodulation signal reflects that the liquid level is relatively low, the controller module drives the operating frequency of the atomizing sheet to decrease or the controller module drives the atomizing sheet to stop.

[0009] The atomization frequency-tracking liquid level detection system according to the embodiment of the second aspect of the present invention includes an MCU controller module, a first driving module, a second driving module, an atomization sheet module, a first frequency-tracking water shortage detection module, and a second frequency-tracking water shortage detection module, wherein: the MCU controller module is used to output a first PWM driving signal and a second PWM driving signal; the first driving module is used to amplify the first PWM driving signal to obtain a first amplified signal; the second driving module is used to amplify the second PWM driving signal to obtain a second amplified signal; the atomization sheet module is used to control the oscillation of the atomization sheet for atomization according to the first amplified signal and the second amplified signal, and modulate the first amplified signal and the second amplified signal according to the size of the atomization amount to obtain a first modulation signal and a second modulation signal, where the more water there is, the larger the atomization amount, and the larger the first modulation signal and the second modulation signal are, and the less water there is, the smaller the atomization amount, and the smaller the first modulation signal and the second modulation signal are; the first frequency-tracking water shortage detection module is used to demodulate and filter the first modulation signal to obtain a first demodulated signal; the second frequency-tracking water shortage detection module is used to demodulate and filter the second modulation signal to obtain a second demodulated signal; the MCU controller module is further used to control the frequency of the first PWM driving signal according to the size of the first demodulated signal and control the frequency of the second PWM driving signal according to the size of the second demodulated signal, where the larger the first demodulated signal and the second demodulated signal are, the higher the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module are, and the smaller the first demodulated signal and the second demodulated signal are, the lower the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module are, and the larger the first PWM driving signal and the second PWM driving signal are, the closer the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module are to the operating frequency of the atomization sheet. When the frequencies of the first PWM driving signal and the second PWM driving signal reach the maximum during scanning, that frequency is the operating frequency of the atomization sheet, and then the frequency point is tracked and locked to lock the tracked frequency to achieve atomization frequency tracking. When the first PWM driving signal and the second PWM driving signal are smaller, the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module deviate further from the operating frequency of the atomization sheet. When the first PWM driving signal and the second PWM driving signal are zero, the MCU controller module does not output an atomization sheet driving signal, and at this time, the atomization work stops.

[0010] The atomization frequency-tracking liquid level detection system according to the embodiment of the present invention has at least the following beneficial effects:

[0011] The atomization frequency-tracking liquid level detection system disclosed by the present invention can control the frequency of the output PWM drive signal according to the magnitude of the atomization amount, so as to control the operation of the atomization sheet according to the magnitude of the frequency of the PWM drive signal, and can realize stopping the operation of the atomization sheet when the humidifier lacks water. The principle is simple, the sensitivity is high, the manufacturing cost is low, and it is easy to implement. At the same time, it can realize the separation of the water tank and the humidifier base without the need for wiring, combining the advantages of existing mechanical detection and capacitive detection.

[0012] According to some embodiments of the present invention, when the frequencies of the first PWM drive signal and the second PWM drive signal are equal to the natural frequency of the atomization sheet, the atomization sheet generates the maximum oscillation, the atomization amount is the largest, and the first modulation signal and the second modulation signal are the largest.

[0013] According to some embodiments of the present invention, when the water on the atomization sheet becomes less and less, the atomization amount also becomes smaller and smaller, the first modulation signal and the second modulation signal after demodulation and filtering become smaller and smaller, and the frequencies of the first PWM drive signal and the second PWM drive signal output by the MCU controller module become smaller and smaller. When there is no water on the atomization sheet, there is no signal for the first modulation signal and the second modulation signal, and the MCU controller module pauses to output the first PWM drive signal and the second PWM drive signal.

[0014] According to some embodiments of the present invention, the MCU controller module includes a control chip, the atomization sheet module includes an atomization sheet, the first drive module includes a first resistor and a first transistor, and the second drive module includes a second resistor and a second transistor. One end of the first resistor is connected to the first output end of the control chip, the other end of the first resistor is connected to the gate of the first transistor, the drain of the first transistor is connected to the atomization sheet, the source of the first transistor is grounded, one end of the second resistor is connected to the second output end of the control chip, the other end of the second resistor is connected to the gate of the second transistor, the drain of the second transistor is connected to the atomization sheet, and the source of the second transistor is grounded.

[0015] According to some embodiments of the present invention, the atomization sheet module further includes a first capacitor, a second capacitor and a first inductor. One end of the first capacitor is connected to a first power supply, the other end of the first capacitor is grounded, one end of the second capacitor is connected to one end of the first capacitor, the other end of the second capacitor is connected to the drain of the first transistor, one end of the first inductor is connected to one end of the first capacitor, and the other end of the first inductor is connected to the drain of the first transistor.

[0016] According to some embodiments of the present invention, the atomization sheet module further includes a third capacitor, a fourth capacitor, and a second inductor. One end of the third capacitor is connected to the first power supply, and the other end of the third capacitor is grounded. One end of the fourth capacitor is connected to one end of the third capacitor, and the other end of the fourth capacitor is connected to the drain of the second transistor. One end of the second inductor is connected to one end of the third capacitor, and the other end of the second inductor is connected to the drain of the second transistor.

[0017] According to some embodiments of the present invention, the first frequency-tracking water shortage detection module includes a fifth capacitor, a third resistor, a first diode, a second diode, a fourth resistor, a sixth capacitor, a seventh capacitor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth capacitor, and a first triode. One end of the fifth capacitor is connected to the other end of the first inductor, and the other end of the fifth capacitor is connected to one end of the third resistor. The other end of the third resistor is connected to the negative electrode of the first diode, and the positive electrode of the first diode is grounded. The positive electrode of the second diode is connected to the other end of the third resistor, and the negative electrode of the second diode is connected to one end of the fourth resistor. The other end of the fourth resistor is grounded. One end of the sixth capacitor is connected to one end of the fourth resistor, and the other end of the sixth capacitor is connected to the other end of the fourth resistor. One end of the seventh capacitor is connected to one end of the sixth capacitor, and the other end of the seventh capacitor is connected to one end of the fifth resistor. The other end of the fifth resistor is connected to the other end of the sixth capacitor. One end of the sixth resistor is connected to one end of the fifth resistor, and the other end of the sixth resistor is connected to one end of the eighth capacitor. The other end of the eighth capacitor is grounded. One end of the seventh resistor is connected to the second power supply and the other end of the sixth resistor, and the other end of the seventh resistor is connected to the collector of the first triode. The base of the first triode is connected to one end of the fifth resistor, and the emitter of the first triode is grounded.

[0018] According to some embodiments of the present invention, the second frequency-tracking water shortage detection module includes a ninth capacitor, an eighth resistor, a third diode, a fourth diode, a ninth resistor, a tenth capacitor, an eleventh capacitor, a tenth resistor, an eleventh resistor, a twelfth capacitor, a twelfth resistor, and a second triode. One end of the ninth capacitor is connected to the other end of the second inductor, the other end of the ninth capacitor is connected to one end of the eighth resistor, the other end of the eighth resistor is connected to the negative electrode of the third diode, the positive electrode of the third diode is grounded, the positive electrode of the fourth diode is connected to the other end of the eighth resistor, the negative electrode of the fourth diode is connected to one end of the ninth resistor, the other end of the ninth resistor is grounded, one end of the tenth capacitor is connected to one end of the ninth resistor, the other end of the tenth capacitor is connected to the other end of the ninth resistor, one end of the eleventh capacitor is connected to one end of the tenth capacitor, the other end of the eleventh capacitor is connected to one end of the tenth resistor, the other end of the tenth resistor is connected to the other end of the tenth capacitor, one end of the eleventh resistor is connected to one end of the tenth resistor, the other end of the eleventh resistor is connected to one end of the twelfth capacitor, the other end of the twelfth capacitor is grounded, one end of the twelfth resistor is connected to the second power supply and the other end of the eleventh resistor respectively, the other end of the twelfth resistor is connected to the collector of the second triode, the base of the second triode is connected to one end of the tenth resistor, and the emitter of the second triode is grounded; the first input terminal of the control chip is connected to the collector of the first triode, and the second input terminal of the control chip is connected to the collector of the second triode; the first transistor and the second transistor are NMOS transistors, and the first triode and the second triode are NPN-type triodes.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 is a schematic block diagram of the principle structure of one embodiment of the water level detection device of the present invention;

[0022] Figure 2 is a schematic block diagram of the principle structure of one embodiment of the atomization frequency-tracking water level detection system of the present invention;

[0023] Figure 3 is a schematic circuit diagram of one embodiment of the atomization frequency-tracking water level detection system of the present invention.

[0024] Reference numerals:

[0025] MCU controller module 10; first driving module 11; second driving module 12; atomizing sheet module 13; atomizing sheet 131; first frequency tracking water shortage detection module 14; second frequency tracking water shortage detection module 15; controller module 200; driving module 300; frequency detection module 400. Detailed implementation manners

[0026] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0027] In the description of the present invention, it should be understood that with regard to the orientation description, for example, terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. This is only for the convenience of describing the present invention 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, and therefore should not be construed as a limitation to the present invention.

[0028] In the description of the present invention, the meaning of "several" is one or more, the meaning of "multiple" is two or more, and understandings such as "greater than", "less than", "exceeding", etc. do not include the present number, and understandings such as "above", "below", "within", etc. include the present number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0029] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Such as Figures 1-3As shown, a liquid level detection device for an atomizing sheet according to an embodiment of the first aspect of the present invention includes a controller module 200, a driving module 300, and a frequency detection module 400. The controller module 200 is connected to the controlled end of the driving module 300 to control the driving module 300 to output a driving signal. The output end of the driving module 300 is connected to the atomizing sheet to drive the atomizing sheet 131 to operate. The frequency detection module 400 is respectively connected to the atomizing sheet 131 and the controller module 200. The frequency detection module 400 detects the operating frequency of the atomizing sheet to form a feedback signal and outputs it to the controller module 200. Among them, the operating frequency of the atomizing sheet 131 can reflect the liquid level of the liquid in the working environment where the atomizing sheet is located. When the liquid level is higher, the operating frequency is larger. When the liquid level is lower, the operating frequency is smaller.

[0031] For the liquid level detection device of the atomizing sheet of the present invention, the controller module 200 controls the driving module 300 to output a driving signal to the atomizing sheet 131. The atomizing sheet 131 is driven to vibrate and operate to atomize the liquid in the container. At the same time, the frequency detection module 400 is used to detect the operating frequency of the atomizing sheet. When the liquid level in the container is relatively high, the operation of the atomizing sheet 131 will generate relatively large liquid fluctuations (such as water splashes), and the liquid fluctuations will also cause changes in the operating frequency of the atomizing sheet. At this time, the frequency detection module 400 detects that the operating frequency of the atomizing sheet 131 is relatively large, which proves that the liquid level in the container is relatively high. When the liquid level in the container is relatively low, the liquid fluctuations generated by the operation of the atomizing sheet are relatively small, and the frequency detection module 400 detects that the operating frequency of the atomizing sheet 131 is relatively small, which proves that the liquid level in the container is relatively low. This design can be detected when the liquid in the container is less. The structure is simple, the detection is accurate, and the atomizing sheet is not easily damaged.

[0032] In some embodiments of the present invention, the frequency detection module 400 is a frequency tracking detection module. The frequency tracking detection module detects and demodulates the operating frequency of the atomizing sheet 131 to form a demodulated signal. The frequency tracking detection module outputs the demodulated signal as a feedback signal to the controller module 200. The controller module 200 drives the atomizing sheet to operate through the driving module 300 according to the operating frequency threshold. When the demodulated signal reflects that the liquid level is relatively high, the controller module 200 drives the operating frequency of the atomizing sheet 131 to approach the operating frequency threshold. When the demodulated signal reflects that the liquid level is relatively low, the controller module 200 drives the operating frequency of the atomizing sheet 131 to decrease or the controller module 200 drives the atomizing sheet 131 to stop.

[0033] It should be noted that a natural frequency threshold is preset in the controller module 200. The natural frequency threshold here corresponds to the operating frequency threshold. The controller module 200 outputs a control instruction, which can be a PWM drive signal. The drive module 300 is driven by the control instruction to drive the atomizing sheet to operate. When the demodulation signal reflects that the liquid level is relatively high, the frequency of the PWM drive signal output by the controller module 200 can approach the natural frequency threshold (i.e., chase and lock the frequency point), so that the operating frequency of the atomizing sheet approaches the operating frequency threshold. When the demodulation signal reflects that the liquid level is relatively low, the frequency of the PWM drive signal output by the controller module 200 can be much lower than the natural frequency threshold, so that the operating frequency of the atomizing sheet is reduced. If the liquid level drops to a dangerously low level, the controller module 200 drives the atomizing sheet to stop.

[0034] Among them, the controller module can be the MCU controller module 10, the drive module can include the first drive module 11 and the second drive module 12, and the frequency detection module can include the first frequency chasing water shortage detection module 14 and the second frequency chasing water shortage detection module 15.

[0035] The MCU controller module 10, the first drive module 11, the second drive module 12, the atomizing sheet module 13, the first frequency chasing water shortage detection module 14 and the second frequency chasing water shortage detection module 15 are used to constitute at least part of the atomizing frequency chasing and water level detection system disclosed in the second aspect embodiment of the present invention, as Figure 2 、 3 shown.

[0036] The MCU controller module 10 is used to output the first PWM drive signal and the second PWM drive signal. It should be understood that the frequency ranges of the first PWM drive signal and the second PWM drive signal in this embodiment have a difference from the natural frequency of the atomizing sheet of no more than 2 MHz.

[0037] The first drive module 11 is used to amplify the first PWM drive signal to obtain a first amplified signal.

[0038] The second drive module 12 is used to amplify the second PWM drive signal to obtain a second amplified signal.

[0039] The atomizing sheet module 13 is used to control the atomizing sheet to oscillate for atomization according to the first amplified signal and the second amplified signal, and modulate the first amplified signal and the second amplified signal according to the size of the atomization amount to obtain a first modulation signal and a second modulation signal.

[0040] It can be understood that the more water there is, the greater the atomization amount, and the greater the first modulation signal and the second modulation signal; the less water there is, the smaller the atomization amount, and the smaller the first modulation signal and the second modulation signal.

[0041] That is to say, the amount of amplitude modulated by the first modulation signal and the second modulation signal is determined by the height of the atomized water droplets (i.e., the atomization amount).

[0042] The first frequency tracking water shortage detection module 14 is used to demodulate and filter the first modulation signal to obtain a first demodulation signal.

[0043] The second frequency tracking water shortage detection module 15 is used to demodulate and filter the second modulation signal to obtain a second demodulation signal.

[0044] The MCU controller module 10 is further used to control the frequency of the first PWM drive signal according to the magnitude of the first demodulation signal and to control the frequency of the second PWM drive signal according to the magnitude of the second demodulation signal.

[0045] It can be understood that the larger the first demodulation signal and the second demodulation signal are, the larger the frequencies of the first PWM drive signal and the second PWM drive signal output by the MCU controller module 10 are; the smaller the first demodulation signal and the second demodulation signal are, the smaller the frequency of the first PWM drive signal output by the MCU controller module 10 is.

[0046] It can be understood that the larger the first PWM drive signal and the second PWM drive signal are, the closer the frequencies of the first PWM drive signal and the second PWM drive signal output by the MCU controller module are to the operating frequency of the atomizing sheet. When the frequencies when scanning the first PWM drive signal and the second PWM drive signal reach the maximum are the operating frequencies of the atomizing sheet, the frequency points are tracked and locked to lock the tracked frequency to achieve atomization frequency tracking. When the first PWM drive signal and the second PWM drive signal are smaller, the frequencies of the first PWM drive signal and the second PWM drive signal output by the MCU controller module deviate further from the operating frequency of the atomizing sheet. When the first PWM drive signal and the second PWM drive signal are zero, the MCU controller module has no output of the atomizing sheet drive signal, and atomization stops at this time. That is to say, this embodiment will automatically lock the maximum frequency at which the atomizing sheet works normally, that is, automatically lock the frequency at this moment when scanning the first PWM drive signal and the second PWM drive signal reaches the maximum, and this frequency at this moment is the operating frequency of the atomizing sheet.

[0047] In some embodiments of the present invention, when the frequencies of the first PWM driving signal and the second PWM driving signal are equal to the natural frequency of the atomizing sheet, the atomizing sheet generates the maximum oscillation, the atomizing amount is the largest, and the first modulation signal and the second modulation signal are the largest. It should be understood that the MCU controller module 10 can lock the maximum first modulation signal and second modulation signal with the frequencies of the first PWM driving signal and the second PWM driving signal, so as to achieve automatic frequency tracking, that is, the frequency of the PWM driving signal is large when there is a lot of water, and the frequency of the PWM driving signal is small when there is little water, so that the water level control and water shortage protection effects can be achieved.

[0048] In some embodiments of the present invention, when the water on the atomizing sheet becomes less and less, the atomizing amount also becomes smaller and smaller, the first modulation signal and the second modulation signal after demodulation and filtering become smaller and smaller, and the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module become smaller and smaller. When there is no water on the atomizing sheet, there is no signal for the first modulation signal and the second modulation signal, and the MCU controller module pauses to output the first PWM driving signal and the second PWM driving signal. That is to say, when the humidifier has no water, there is also no water on the atomizing sheet. At this time, the MCU controller module pauses to output the first PWM driving signal and the second PWM driving signal, so as to control the humidifier to stop working.

[0049] As Figure 3 shown, the MCU controller module 10 includes a control chip, the atomizing sheet module 13 includes an atomizing sheet 131, wherein the first driving module 11 includes a first resistor R1 and a first transistor Q1, and the second driving module 12 includes a second resistor R2 and a second transistor Q2.

[0050] One end of the first resistor R1 is connected to the first output end of the control chip, the other end of the first resistor R1 is connected to the gate of the first transistor Q1, the drain of the first transistor Q1 is connected to the atomizing sheet 131, the source of the first transistor Q1 is grounded, one end of the second resistor R2 is connected to the second output end of the control chip, the other end of the second resistor R2 is connected to the gate of the second transistor Q2, the drain of the second transistor Q2 is connected to the atomizing sheet 131, and the source of the second transistor Q2 is grounded.

[0051] It can be understood that the control chip of the MCU controller module 10 outputs the first PWM driving signal to the first resistor R1 through the first output end, and outputs the second PWM driving signal to the second resistor R2 through the second output end. The first PWM driving signal is amplified by the first transistor Q1 to obtain a first amplified signal, and the second PWM driving signal is amplified by the second transistor Q2 to obtain a second amplified signal.

[0052] For example, the first transistor Q1 and the second transistor Q2 are NMOS transistors.

[0053] The atomizing sheet module 13 further includes a first capacitor C1, a second capacitor C2, and a first inductor L1. One end of the first capacitor C1 is connected to the first power supply VCC1, and the other end of the first capacitor C is grounded to GND. One end of the second capacitor C2 is connected to one end of the first capacitor C1, and the other end of the second capacitor C2 is connected to the drain of the first transistor Q1. One end of the first inductor L1 is connected to one end of the first capacitor C1, and the other end of the first inductor L1 is connected to the drain of the first transistor Q1.

[0054] It can be understood that the atomizing sheet module 13 of this embodiment modulates the first amplified signal through the circuit composed of the first capacitor C1, the second capacitor C2, and the first inductor L1 to obtain a first modulation signal.

[0055] In some embodiments of the present invention, the atomizing sheet module 13 further includes a third capacitor C3, a fourth capacitor C4, and a second inductor L2. One end of the third capacitor C3 is connected to the first power supply VCC1, and the other end of the third capacitor C3 is grounded to GND. One end of the fourth capacitor C4 is connected to one end of the third capacitor C3, and the other end of the fourth capacitor C4 is connected to the drain of the second transistor Q2. One end of the second inductor L2 is connected to one end of the third capacitor C3, and the other end of the second inductor L2 is connected to the drain of the second transistor Q2.

[0056] It can be understood that the atomizing sheet module 13 of this embodiment modulates the second amplified signal through the circuit composed of the third capacitor C3, the fourth capacitor C4, and the second inductor L2 to obtain a second modulation signal.

[0057] Of course, the atomizing sheet module 13 is also provided with an atomization amount detection unit, which can detect the atomization amount on the atomizing sheet in real time.

[0058] The first frequency-tracking water shortage detection module 14 includes a fifth capacitor C5, a third resistor R3, a first diode D1, a second diode D2, a fourth resistor R4, a sixth capacitor C6, a seventh capacitor C7, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth capacitor C8, and a first triode Q3. One end of the fifth capacitor C5 is connected to the other end of the first inductor L1, the other end of the fifth capacitor C5 is connected to one end of the third resistor R3, the other end of the third resistor R3 is connected to the negative electrode of the first diode D1, the positive electrode of the first diode D1 is grounded to GND, the positive electrode of the second diode D2 is connected to the other end of the third resistor R3, the negative electrode of the second diode D2 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is grounded to GND, one end of the sixth capacitor C6 is connected to one end of the fourth resistor R4, the other end of the sixth capacitor C6 is connected to the other end of the fourth resistor R4 to GND, one end of the seventh capacitor C7 is connected to one end of the sixth capacitor C6, the other end of the seventh capacitor C7 is connected to one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to the other end of the sixth capacitor C6, one end of the sixth resistor R6 is connected to one end of the fifth resistor R5, the other end of the sixth resistor R6 is connected to one end of the eighth capacitor C8, the other end of the eighth capacitor C8 is grounded to GND, one end of the seventh resistor R7 is connected to the second power supply VCC2 and the other end of the sixth resistor R6 respectively, the other end of the seventh resistor R7 is connected to the collector of the first triode Q3, the base of the first triode Q3 is connected to one end of the fifth resistor R5, and the emitter of the first triode Q3 is grounded to GND.

[0059] In some embodiments of the present invention, the first input terminal of the control chip is connected to the collector of the first triode Q3. It should be understood that the first modulation signal modulated by the atomization sheet module is coupled to the first diode D1 and the second diode D2 through the fifth capacitor C5 for voltage doubling detection and demodulation, then filtered by the fourth resistor R4 and the sixth capacitor C6 to obtain a low-frequency signal, and finally the first demodulation signal is obtained through the first triode Q3 and input to the control chip through the first input terminal of the control chip for feedback, so that the control chip controls the frequency of the first PWM driving signal according to the magnitude of the first demodulation signal.

[0060] The second frequency-tracking water shortage detection module 15 includes a ninth capacitor C9, an eighth resistor R8, a third diode D3, a fourth diode D4, a ninth resistor R9, a tenth capacitor C10, an eleventh capacitor C11, a tenth resistor R10, an eleventh resistor R11, a twelfth capacitor C12, a twelfth resistor R12, and a second triode Q4. One end of the ninth capacitor C9 is connected to the other end of the second inductor L2, the other end of the ninth capacitor C9 is connected to one end of the eighth resistor R8, the other end of the eighth resistor R8 is connected to the negative electrode of the third diode D3, the positive electrode of the third diode D3 is grounded to GND, the positive electrode of the fourth diode D4 is connected to the other end of the eighth resistor R8, the negative electrode of the fourth diode D4 is connected to one end of the ninth resistor R9, the other end of the ninth resistor R9 is grounded to GND, one end of the tenth capacitor C10 is connected to one end of the ninth resistor R9, the other end of the tenth capacitor C10 is connected to the other end of the ninth resistor R9, one end of the eleventh capacitor C11 is connected to one end of the tenth capacitor C10, the other end of the eleventh capacitor C11 is connected to one end of the tenth resistor R10, the other end of the tenth resistor R10 is connected to the other end of the tenth capacitor C10, one end of the eleventh resistor R11 is connected to one end of the tenth resistor R10, the other end of the eleventh resistor R11 is connected to one end of the twelfth capacitor C12, the other end of the twelfth capacitor C12 is grounded to GND, one end of the twelfth resistor R12 is respectively connected to the second power supply VCC2 and the other end of the eleventh resistor R11, the other end of the twelfth resistor R12 is connected to the collector of the second triode Q4, the base of the second triode Q4 is connected to one end of the tenth resistor R10, and the emitter of the second triode Q4 is grounded to GND.

[0061] In some embodiments of the present invention, the second input end of the control chip is connected to the collector of the second triode Q4. It should be understood that the second modulation signal modulated by the atomizing sheet module is coupled to the third diode D3 and the fourth diode D4 through the ninth capacitor C9 for voltage doubling detection and demodulation, and then the low-frequency signal is obtained through filtering by the ninth resistor R9 and the tenth capacitor C10. Finally, the second demodulation signal is obtained through the second triode Q4 and input to the control chip through the second input end of the control chip for feedback, so that the control chip controls the frequency of the second PWM driving signal according to the magnitude of the second demodulation signal.

[0062] For example, the first triode Q3 and the second triode Q4 are NPN-type triodes.

[0063] In summary, the atomization frequency tracking and water level detection system of the atomization sheet disclosed in the present invention can control the frequency of the output PWM drive signal according to the magnitude of the atomization amount, thereby controlling the operation of the atomization sheet according to the magnitude of the frequency of the PWM drive signal. It can achieve stopping the operation of the atomization sheet when the humidifier lacks water. The principle is simple, with high sensitivity, low manufacturing cost, and easy to implement. At the same time, it can separate the water tank from the humidifier base without the need for wiring, combining the advantages of existing mechanical detection and capacitive detection.

[0064] The water level detection devices described above are only several embodiments. For example, the application of the water level detection device in wireless, wired, single-arm, and double-arm all fall within the protection scope. The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered to be within the scope described in this specification.

[0065] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A liquid level detection device for an atomizing sheet, characterized in that Comprising: A controller module; A driving module, the controlled end of the controller module is connected to the driving module to control the driving module to output a driving signal, and the output end of the driving module is connected to the atomizing sheet to drive the atomizing sheet to operate; A frequency detection module, which is respectively connected to the atomizing sheet and the controller module, and the frequency detection module detects the operating frequency of the atomizing sheet to form a feedback signal and outputs it to the controller module; The controller module drives the atomizing sheet to operate through the driving module according to the operating frequency threshold. Among them, the operating frequency of the atomizing sheet can reflect the liquid level of the liquid in the working environment where the atomizing sheet is located. When the liquid level is higher, the operating frequency is greater; when the liquid level is lower, the operating frequency is smaller; The frequency detection module is a frequency tracking detection module, and the frequency tracking detection module detects and demodulates the operating frequency of the atomizing sheet to form a demodulated signal, and the frequency tracking detection module outputs the demodulated signal as a feedback signal to the controller module; The module drives the atomizing sheet to operate. When the demodulated signal reflects that the liquid level of the liquid is relatively high, the controller module drives the operating frequency of the atomizing sheet to approach the operating frequency threshold. When the demodulated signal reflects that the liquid level of the liquid is relatively low, the controller module drives the operating frequency of the atomizing sheet to decrease or the controller module drives the atomizing sheet to stop; The liquid level detection device further includes an MCU controller module, a first driving module, a second driving module, an atomizing sheet module, a first frequency tracking water shortage detection module, and a second frequency tracking water shortage detection module, wherein: The MCU controller module is used to output a first PWM driving signal and a second PWM driving signal; The first driving module is used to amplify the first PWM driving signal to obtain a first amplified signal; The second driving module is used to amplify the second PWM driving signal to obtain a second amplified signal; The atomizing sheet module is used to control the atomizing sheet to oscillate for atomization according to the first amplified signal and the second amplified signal, and modulate the first amplified signal and the second amplified signal according to the size of the atomization amount to obtain a first modulation signal and a second modulation signal. The more water there is, the greater the atomization amount, and the greater the first modulation signal and the second modulation signal; the less water there is, the smaller the atomization amount, and the smaller the first modulation signal and the second modulation signal; The first frequency tracking water shortage detection module is used to perform demodulation and filtering processing on the first modulation signal to obtain a first demodulated signal; The second frequency tracking water shortage detection module is used to perform demodulation and filtering processing on the second modulation signal to obtain a second demodulated signal; The MCU controller module is further configured to control the frequency of the first PWM driving signal according to the magnitude of the first demodulation signal and to control the frequency of the second PWM driving signal according to the magnitude of the second demodulation signal. The larger the first demodulation signal and the second demodulation signal are, the larger the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module are. The smaller the first demodulation signal and the second demodulation signal are, the smaller the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module are. Moreover, the larger the first PWM driving signal and the second PWM driving signal are, the closer the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module are to the operating frequency of the atomizing sheet. When the frequencies of the first PWM driving signal and the second PWM driving signal reach the maximum, the frequency is the operating frequency of the atomizing sheet. Then, the frequency point is tracked and locked to lock the tracked frequency to achieve atomization frequency tracking. When the first PWM driving signal and the second PWM driving signal are smaller, the frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module deviate further from the operating frequency of the atomizing sheet. When the first PWM driving signal and the second PWM driving signal are zero, the MCU controller module does not output an atomizing sheet driving signal, and atomization stops working at this time.

2. The atomizing frequency tracking liquid level detection system according to claim 1, wherein: When the frequencies of the first PWM driving signal and the second PWM driving signal are equal to the natural frequency of the atomizing sheet, the atomizing sheet generates the maximum oscillation and the maximum atomization amount, and the first modulation signal and the second modulation signal are the maximum.

3. The atomizing frequency tracking liquid level detection system according to claim 2, characterized in that: When the water on the atomizing sheet becomes less and less, the atomization amount also becomes smaller and smaller. The first modulation signal and the second modulation signal after demodulation and filtering become smaller and smaller. The frequencies of the first PWM driving signal and the second PWM driving signal output by the MCU controller module become smaller and smaller. When there is no water on the atomizing sheet, there is no signal for the first modulation signal and the second modulation signal, and the MCU controller module pauses to output the first PWM driving signal and the second PWM driving signal.

4. The atomizing frequency tracking liquid level detection system according to claim 1, characterized in that: The MCU controller module includes a control chip. The atomizing sheet module includes an atomizing sheet. The first driving module includes a first resistor and a first transistor. The second driving module includes a second resistor and a second transistor. One end of the first resistor is connected to the first output terminal of the control chip. The other end of the first resistor is connected to the gate of the first transistor. The drain of the first transistor is connected to the atomizing sheet. The source of the first transistor is grounded. One end of the second resistor is connected to the second output terminal of the control chip. The other end of the second resistor is connected to the gate of the second transistor. The drain of the second transistor is connected to the atomizing sheet. The source of the second transistor is grounded.

5. The atomizing frequency-tracking liquid level detection system according to claim 4, characterized in that: The atomizing sheet module further includes a first capacitor, a second capacitor and a first inductor. One end of the first capacitor is connected to a first power supply, and the other end of the first capacitor is grounded. One end of the second capacitor is connected to one end of the first capacitor, and the other end of the second capacitor is connected to the drain of the first transistor. One end of the first inductor is connected to one end of the first capacitor, and the other end of the first inductor is connected to the drain of the first transistor.

6. The atomizing frequency-tracking liquid level detection system according to claim 5, characterized in that: The atomizing sheet module further includes a third capacitor, a fourth capacitor and a second inductor. One end of the third capacitor is connected to the first power supply, and the other end of the third capacitor is grounded. One end of the fourth capacitor is connected to one end of the third capacitor, and the other end of the fourth capacitor is connected to the drain of the second transistor. One end of the second inductor is connected to one end of the third capacitor, and the other end of the second inductor is connected to the drain of the second transistor.

7. The atomizing frequency tracking liquid level detection system according to claim 6, wherein: The first frequency-tracking water shortage detection module includes a fifth capacitor, a third resistor, a first diode, a second diode, a fourth resistor, a sixth capacitor, a seventh capacitor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth capacitor and a first triode. One end of the fifth capacitor is connected to the other end of the first inductor, and the other end of the fifth capacitor is connected to one end of the third resistor. The other end of the third resistor is connected to the negative electrode of the first diode, and the positive electrode of the first diode is grounded. The positive electrode of the second diode is connected to the other end of the third resistor, and the negative electrode of the second diode is connected to one end of the fourth resistor. The other end of the fourth resistor is grounded. One end of the sixth capacitor is connected to one end of the fourth resistor, and the other end of the sixth capacitor is connected to the other end of the fourth resistor. One end of the seventh capacitor is connected to one end of the sixth capacitor, and the other end of the seventh capacitor is connected to one end of the fifth resistor. The other end of the fifth resistor is connected to the other end of the sixth capacitor. One end of the sixth resistor is connected to one end of the fifth resistor, and the other end of the sixth resistor is connected to one end of the eighth capacitor. The other end of the eighth capacitor is grounded. One end of the seventh resistor is connected to a second power supply and the other end of the sixth resistor respectively, and the other end of the seventh resistor is connected to the collector of the first triode. The base of the first triode is connected to one end of the fifth resistor, and the emitter of the first triode is grounded.

8. The atomizing frequency-tracking liquid level detection system according to claim 7, wherein: The second frequency-tracking water shortage detection module includes a ninth capacitor, an eighth resistor, a third diode, a fourth diode, a ninth resistor, a tenth capacitor, an eleventh capacitor, a tenth resistor, an eleventh resistor, a twelfth capacitor, a twelfth resistor, and a second triode. One end of the ninth capacitor is connected to the other end of the second inductor, the other end of the ninth capacitor is connected to one end of the eighth resistor, the other end of the eighth resistor is connected to the negative electrode of the third diode, the positive electrode of the third diode is grounded, the positive electrode of the fourth diode is connected to the other end of the eighth resistor, the negative electrode of the fourth diode is connected to one end of the ninth resistor, the other end of the ninth resistor is grounded, one end of the tenth capacitor is connected to one end of the ninth resistor, the other end of the tenth capacitor is connected to the other end of the ninth resistor, one end of the eleventh capacitor is connected to one end of the tenth capacitor, the other end of the eleventh capacitor is connected to one end of the tenth resistor, the other end of the tenth resistor is connected to the other end of the tenth capacitor, one end of the eleventh resistor is connected to one end of the tenth resistor, the other end of the eleventh resistor is connected to one end of the twelfth capacitor, the other end of the twelfth capacitor is grounded, one end of the twelfth resistor is respectively connected to the second power supply and the other end of the eleventh resistor, the other end of the twelfth resistor is connected to the collector of the second triode, the base of the second triode is connected to one end of the tenth resistor, and the emitter of the second triode is grounded; the first input end of the control chip is connected to the collector of the first triode, and the second input end of the control chip is connected to the collector of the second triode; the first transistor and the second transistor are NMOS transistors, and the first triode and the second triode are NPN-type triodes.

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