Self-adaptive gain control circuit and humidifier

Abstract

The invention provides a self-adaptive gain control circuit and a humidifier. The self-adaptive gain control circuit comprises a reference signal output circuit, a compensation circuit, a self-activation oscillation circuit and a peak detection circuit, the reference signal output circuit is used for outputting a reference amplitude; one input end of the compensation circuit is connected with the output end of the reference signal output circuit; the input end of the self-activation oscillation circuit is connected with the output end of the compensation circuit; the input end of the peak detection circuit is connected with the output end of the self-activation oscillation circuit, and the output end of the peak detection circuit is connected with the other input end of the compensation circuit and used for outputting real-time amplitude; wherein the compensation circuit adjusts the gain of the self-excitation oscillation circuit according to the reference amplitude and the real-time amplitude. The gear of the humidifier can be adjusted through the amplitude, and the atomization effect and the atomization efficiency are improved.

Description

Technical Field

[0001] The invention relates to the technical field of humidifiers, and in particular to an adaptive gain control circuit and a humidifier. Background Art

[0002] Humidifiers are mainly used to increase ambient humidity and thus increase the moisture content in the air, which helps reduce dust, smoke and static electricity in the air, thereby improving air quality. Appropriate humidity also helps to maintain skin moisture and reduce skin dryness and itching. Therefore, humidifiers are becoming more and more popular among users.

[0003] At present, the driving circuit of the atomizer in the humidifier is mainly divided into two types of driving circuits: self-excited oscillation type and other-excited oscillation type. The self-excited oscillation driving circuit uses the resonance frequency of the atomizer itself to excite it, so that it vibrates. Since the self-excited oscillation driving circuit has low cost and good frequency selectivity, most humidifiers use the self-excited oscillation driving circuit. However, the gear adjustment of the self-excited oscillation driving circuit is generally adjusted by PWM, but the adjustment by PWM will cause the amplitude of the atomizer to be unstable, reducing the atomization efficiency and atomization effect. Summary of the invention

[0004] The present invention provides an adaptive gain control circuit and a humidifier, aiming to solve the problem of low atomization efficiency and atomization effect caused by the current humidifier adopting a PWM mode for gear adjustment.

[0005] In a first aspect, the present invention provides an adaptive gain control circuit for use in a humidifier, comprising a reference signal output circuit, a compensation circuit, a self-excited oscillation circuit and a peak detection circuit; the reference signal output circuit is used to output a reference amplitude; an input end of the compensation circuit is connected to an output end of the reference signal output circuit; an input end of the self-excited oscillation circuit is connected to an output end of the compensation circuit; an input end of the peak detection circuit is connected to an output end of the self-excited oscillation circuit, and an output end of the peak detection circuit is connected to another input end of the compensation circuit, for outputting a real-time amplitude; wherein the compensation circuit adjusts the gain of the self-excited oscillation circuit according to the reference amplitude and the real-time amplitude.

[0006] Furthermore, the reference signal output circuit includes a control module and a digital-to-analog conversion circuit; the output end of the control module is connected to the input end of the digital-to-analog conversion circuit, for obtaining the amplitude of the oscillation voltage and outputting a digital reference signal according to the amplitude; the output end of the digital-to-analog conversion circuit is connected to the compensation circuit, for converting the digital reference signal into an analog reference signal to obtain the reference amplitude.

[0007] Furthermore, the self-excited oscillation circuit includes an AC isolation circuit, a DC isolation circuit, an oscillation circuit, an atomizer sheet and an amplifier circuit; the AC isolation circuit is respectively connected to the compensation circuit, the atomizer sheet, the amplifier circuit and the oscillation circuit, the amplifier circuit is connected to the DC isolation circuit, and the DC isolation circuit is respectively connected to the atomizer sheet and the peak detection circuit.

[0008] Furthermore, the AC isolation circuit includes a first inductor and a second inductor; one end of the first inductor is connected to the output end of the compensation circuit, and the other end of the first inductor is respectively connected to the atomizer sheet, the amplifier circuit and the oscillation circuit; one end of the second inductor is connected to the amplifier circuit, and the other end of the second inductor is connected to the subsequent circuit.

[0009] Furthermore, the oscillation circuit includes a first capacitor and a second capacitor; one end of the first capacitor is connected to the AC isolation circuit, and the other end of the first capacitor is grounded; one end of the second capacitor is connected to the amplification circuit, and the other end of the second capacitor is grounded.

[0010] Furthermore, the DC isolation circuit includes a third capacitor; one end of the third capacitor is connected to the amplifier circuit, and the other end of the third capacitor is respectively connected to the atomizer sheet and the peak detection circuit.

[0011] Furthermore, the amplification circuit includes a first switching tube; the controlled pole of the first switching tube is connected to the AC isolation circuit, the first pole of the first switching tube is respectively connected to the oscillation circuit, the DC isolation circuit and the AC isolation circuit, and the second pole of the first switching tube is grounded.

[0012] Furthermore, the first switch tube is a MOS tube, the gate of the first switch tube is connected to the AC isolation circuit, the drain of the first switch tube is respectively connected to the oscillation circuit, the DC isolation circuit and the AC isolation circuit, and the source of the first switch tube is grounded.

[0013] Furthermore, the compensation circuit is a PI compensation circuit.

[0014] In a second aspect, the present invention provides a humidifier, comprising the adaptive gain control circuit described in any one of the above items.

[0015] The humidifier disclosed in the present invention includes an adaptive gain control circuit, which includes a reference signal output circuit, a compensation circuit, a self-excited oscillation circuit and a peak detection circuit. The reference signal output circuit and the peak detection circuit are both connected to the compensation circuit, the compensation circuit is connected to the self-excited oscillation circuit, and the self-excited oscillation circuit is connected to the peak detection circuit. On the one hand, the peak detection circuit obtains the real-time amplitude of the self-excited oscillation circuit and outputs it to the compensation circuit. At the same time, the reference signal output circuit also synchronously outputs the reference amplitude to the compensation circuit. On the other hand, the compensation circuit adjusts the gain of the self-excited oscillation circuit according to the real-time amplitude and the reference amplitude to change the real-time amplitude, so that the gear of the humidifier can be changed by controlling the amplitude, avoiding the adjustment of the gear by PWM, and improving the atomization efficiency and atomization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0017] Figure 1 is a flow chart of an adaptive gain control circuit provided by an embodiment of the present invention;

[0018] Figure 2 is a flow chart of an adaptive gain control circuit provided by another embodiment of the present invention;

[0019] Figure 3 is a circuit diagram of an adaptive gain control circuit provided by an embodiment of the present invention;

[0020] Figure 4 is a circuit diagram of an adaptive gain control circuit provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, operations, elements, components and / or groups thereof.

[0023] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, the singular forms of "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0024] In addition, the directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only for reference to the directions of the attached drawings and the use status of the product. Therefore, the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention. In addition, in the drawings, structures with similar or identical structures are represented by the same reference numerals.

[0025] See also Figures 1 to 4 , Figure 1 is a flow chart of an adaptive gain control circuit 11 provided in one embodiment of the present invention; Figure 2 is a flow chart of an adaptive gain control circuit 11 provided by another embodiment of the present invention; Figure 3 is a circuit diagram of an adaptive gain control circuit 11 provided in one embodiment of the present invention; Figure 4 FIG. 1 is a circuit diagram of an adaptive gain control circuit 11 provided by another embodiment of the present invention. Figure 1 As shown, the adaptive gain control circuit 11 provided by the present invention includes a reference signal output circuit 10, a compensation circuit 20, a self-excited oscillation circuit 30 and a peak detection circuit 40; the reference signal output circuit 10 is used to output a reference amplitude; an input end of the compensation circuit 20 is connected to the output end of the reference signal output circuit 10; the input end of the self-excited oscillation circuit 30 is connected to the output end of the compensation circuit 20; the input end of the peak detection circuit 40 is connected to the output end of the self-excited oscillation circuit 30, and the output end of the peak detection circuit 40 is connected to another input end of the compensation circuit 20 for outputting a real-time amplitude; wherein the compensation circuit 20 adjusts the gain of the self-excited oscillation circuit 30 according to the reference amplitude and the real-time amplitude.

[0026] Specifically, the types of humidifiers may include hot evaporative humidifiers, cold evaporative humidifiers, pure type humidifiers and ultrasonic humidifiers. Hot evaporative humidifiers mainly use electric heating tubes to heat water to boiling to form water vapor, and then blow it into the room. Cold evaporative humidifiers mainly use high-speed fans to release water molecules, filter out impurities in the water through a humidifying filter, and then release them into the room to achieve the humidification effect. Pure type humidifiers mainly use molecular sieve evaporation technology to remove calcium and magnesium ions in the water, wash the air through a water curtain, and while humidifying, they can also filter and purify germs, dust, and particulate matter in the air, and then deliver the moist and clean air to the room through a pneumatic device. Ultrasonic humidifiers mainly convert electrical energy into mechanical energy to generate high-frequency vibrations. This high-frequency vibration acts on water to atomize the water into tiny water mist particles.

[0027] The adaptive gain control circuit 11 provided by the present invention, that is, the atomizer plate Y driving circuit, is mainly used in an ultrasonic humidifier to drive the atomizer plate Y in the ultrasonic humidifier. The power of the atomizer plate Y is changed by controlling the amplitude at both ends of the atomizer plate Y to achieve the switching of the gear of the humidifier.

[0028] The adaptive gain control circuit 11 includes a reference signal output circuit 10, a compensation circuit 20, a self-excited oscillation circuit 30, and a peak detection circuit 40. The reference signal output circuit 10 is mainly used to provide a reference amplitude, which is related to the gear currently corresponding to the humidifier. For example, the humidifier can be preset with multiple gears, different gears correspond to different oscillation voltages, and each oscillation voltage corresponds to an amplitude. When the user sets the gear, the reference signal output circuit 10 can obtain the amplitude corresponding to the oscillation voltage of the gear set by the user, and then output the reference amplitude according to the obtained amplitude.

[0029] The input end of the self-excited oscillation circuit 30 is connected to the compensation circuit 20. The working principle of the self-excited oscillation circuit 30 is mainly based on the positive feedback principle. It can form a positive feedback network and can generate a stable oscillation signal without external signal input. The oscillation signal is used to drive the atomizer sheet Y to vibrate and realize the humidification function. That is, the self-excited oscillation circuit 30 can include an atomizer sheet Y, and an oscillation signal can be applied to both ends of the atomizer sheet Y so that the atomizer sheet Y works normally.

[0030] The input end of the peak detection circuit 40 is connected to the output end of the self-excited oscillation circuit 30, and the output end of the peak detection circuit 40 is connected to the input end of the compensation circuit 20, which is mainly used to detect the maximum value of the oscillation voltage at both ends of the atomizer Y of the self-excited oscillation circuit 30, that is, the real-time amplitude. The peak detection circuit 40 may include components such as a diode, a capacitor, a resistor, an operational amplifier, and a comparator. The diode can be used as a detector to convert the peak voltage in the AC signal into a DC voltage. When the oscillation voltage reaches a peak value, the diode is turned on, and the peak voltage is captured and stored in the capacitor, that is, when the diode is turned on, the capacitor is charged to the peak voltage, and when the diode is cut off, the capacitor remains charged, thereby realizing the preservation of the peak voltage. The resistor is used to control the charging and discharging speed of the capacitor, and the charging time constant of the capacitor can be changed by adjusting the resistance value of the resistor to achieve the adjustment of the peak voltage capture accuracy. The operational amplifier and the comparator are used to further process and amplify the peak voltage to meet different needs. It is understandable that the peak detection circuit 40 can be any detection circuit commonly used by those skilled in the art composed of the above-mentioned elements, and its specific circuit structure is not limited here.

[0031] One input end of the compensation circuit 20 is connected to the reference signal output circuit 10 for receiving a reference amplitude. The other input end of the compensation circuit 20 is connected to the peak detection circuit 40 for receiving a real-time amplitude. The compensation circuit 20 compares the difference between the real-time amplitude and the reference amplitude to obtain an error voltage, which is output to the self-excited oscillation circuit 30 for adjusting the gain of the self-excited oscillation circuit 30, thereby changing the amplitude of the oscillation voltage at both ends of the atomizer sheet Y of the self-excited oscillation circuit 30, so that the amplitude at both ends of the atomizer sheet Y gradually approaches and is locked on the reference amplitude, thereby achieving adjustment of the gear position.

[0032] During actual use, when the user switches the gear, causing the reference amplitude to change, the compensation circuit 20 outputs an error voltage to the self-excited oscillation circuit 30 based on the reference amplitude and the real-time amplitude, and the amplitude of the oscillation voltage at both ends of the atomizer sheet Y in the self-excited oscillation circuit 30 changes accordingly and approaches the reference amplitude, and the peak detection circuit 40 will continue to output the real-time amplitude to the compensation circuit 20, so that the error voltage output by the compensation circuit 20 changes with the real-time amplitude, and the gain of the self-excited oscillation circuit 30 can be dynamically adjusted until the amplitude of the oscillation voltage at both ends of the atomizer sheet Y in the self-excited oscillation circuit 30 is consistent with the reference amplitude.

[0033] See also Figure 2As a further embodiment, the reference signal output circuit 10 includes a control module and a digital-to-analog conversion circuit 12; the output end of the control module is connected to the input end of the digital-to-analog conversion circuit 12, for obtaining the amplitude of the oscillation voltage and outputting a digital reference signal according to the amplitude; the output end of the digital-to-analog conversion circuit 12 is connected to the compensation circuit 20, for converting the digital reference signal into an analog reference signal to obtain the reference amplitude.

[0034] Among them, the control module is mainly used to control the operation of the humidifier and obtain the amplitude of the oscillation voltage, that is, the gear switching of the humidifier is mainly realized by the control module. When the user switches the gear, the control module can obtain the amplitude of the oscillation voltage corresponding to the gear to be switched, and output the corresponding digital reference signal to the digital-to-analog conversion circuit 12. The digital-to-analog conversion circuit 12 converts the digital reference signal into an analog reference signal to obtain the real-time amplitude. It can be understood that the digital-to-analog conversion circuit 12 can be a conversion circuit commonly used by those skilled in the art, and its specific structure is not limited here.

[0035] like Figure 4 As shown, the control module may include an MCU, which is used to obtain the amplitude of the oscillation voltage. The DAC is a digital-to-analog conversion circuit 12. The DAC outputs a reference amplitude Vf to the compensation circuit 20 according to the digital reference signal output by the MCU. At the same time, the peak detection circuit 40 outputs a real-time amplitude Va to the compensation circuit 20. The compensation circuit 20 outputs an error voltage Ve to the self-excited oscillation circuit 30 according to Va and Vf. When the gear position remains unchanged, Vf remains unchanged. Va is related to the amplitude of the oscillation voltage at both ends of the atomizer sheet Y in the self-excited oscillation circuit 30. Therefore, Ve will change with Va until the amplitude of the oscillation voltage at both ends of the atomizer sheet Y in the self-excited oscillation circuit 30 is consistent with the reference amplitude.

[0036] As a further embodiment, the self-excited oscillation circuit 30 includes an AC isolation circuit 31, a DC isolation circuit, an oscillation circuit 32, an atomizer sheet Y and an amplifier circuit; the AC isolation circuit 31 is respectively connected to the compensation circuit 20, the atomizer sheet Y, the amplifier circuit and the oscillation circuit 32, the amplifier circuit is connected to the DC isolation circuit, and the DC isolation circuit is respectively connected to the atomizer sheet Y and the peak detection circuit 40.

[0037] Among them, the AC isolation circuit 31 is mainly used to isolate the AC component to prevent the oscillation voltage from interfering with the operation of the power supply and the compensation circuit 20. The DC isolation circuit is mainly used to isolate the DC component to facilitate the atomizer sheet Y to obtain an unbiased AC voltage. The oscillation circuit 32 is mainly used to determine the feedback coefficient of the self-excited oscillation circuit 30 and affect the circuit oscillation. The atomizer sheet Y is used to realize the humidification function of the humidifier. The switching circuit is mainly used to adjust the conduction degree by receiving the error voltage Ve output by the PI compensation network, thereby realizing the control of the gain of the self-excited oscillation circuit 32.

[0038] See also Figure 3 As a further embodiment, the AC isolation circuit 31 includes a first inductor L1 and a second inductor L2; one end of the first inductor L1 is connected to the output end of the compensation circuit 20, and the other end of the first inductor L1 is respectively connected to the atomizer sheet Y, the amplifier circuit and the oscillation circuit 32; one end of the second inductor L2 is connected to the amplifier circuit, and the other end of the second inductor L2 is connected to the subsequent circuit.

[0039] One end of the first inductor L1 is connected to the output end of the compensation circuit 20, the other end of the first inductor L1 is connected to the atomizer Y, the amplifier circuit and the oscillation circuit 32, and the second inductor L2 is connected to the amplifier circuit and the subsequent circuit respectively. The first inductor L1 and the second inductor L2 are mainly used to isolate the AC component to prevent the oscillation voltage from interfering with the operation of the power supply and the compensation circuit 20.

[0040] As a further embodiment, the oscillation circuit 32 includes a first capacitor C1 and a second capacitor C2; one end of the first capacitor C1 is connected to the AC isolation circuit 31, and the other end of the first capacitor C1 is grounded; one end of the second capacitor C2 is connected to the amplification circuit, and the other end of the second capacitor C2 is grounded.

[0041] Among them, the first capacitor C1 is connected to the AC isolation circuit 31, and the second capacitor C2 is connected to the amplifier circuit. The first capacitor C1 and the second capacitor C2 are used to determine the feedback coefficient, which affects the oscillation ability of the circuit. The feedback coefficient can be adjusted by adjusting the ratio of the first capacitor C1 to the second capacitor C2.

[0042] As a further embodiment, the DC isolation circuit includes a third capacitor C3; one end of the third capacitor C3 is connected to the amplifier circuit, and the other end of the third capacitor C3 is connected to the atomizer sheet Y and the peak detection circuit 40 respectively.

[0043] The third capacitor C3 is respectively connected to the discharge circuit, the atomizer sheet Y and the peak detection circuit 40 for isolating the DC component so that the atomizer sheet Y can obtain an unbiased AC voltage.

[0044] As a further embodiment, the amplifier circuit includes a first switch tube Q1; the controlled electrode of the first switch tube Q1 is connected to the AC isolation circuit 31, the first electrode of the first switch tube Q1 is respectively connected to the oscillation circuit 32, the DC isolation circuit and the AC isolation circuit 31, and the second electrode of the first switch tube Q1 is grounded. As a further embodiment, the first switch tube Q1 is a MOS tube, the gate of the first switch tube Q1 is connected to the AC isolation circuit 31, the drain of the first switch tube Q1 is respectively connected to the oscillation circuit 32, the DC isolation circuit and the AC isolation circuit 31, and the source of the first switch tube Q1 is grounded.

[0045] Wherein, the first switch tube Q1 can be a MOS tube, and the gate of the first switch tube Q1 is connected to the AC isolation circuit 31, the drain of the first switch tube Q1 is respectively connected to the oscillation circuit 32, the DC isolation circuit and the AC isolation circuit 31, and the source of the first switch tube Q1 is grounded. The first switch tube Q1 works in the linear region, and adjusts its conduction degree by receiving the error voltage output by the compensation circuit 20, thereby realizing the control of the gain of the self-excited oscillation circuit 30. When the error voltage changes, the conduction degree of the first switch tube Q1 changes accordingly, thereby affecting the current flowing through the atomizer sheet Y, and achieving the purpose of changing the amplitude of the oscillation voltage at both ends of the atomizer sheet Y.

[0046] As a further embodiment, the compensation circuit 20 is a PI compensation circuit.

[0047] Among them, the PI compensation circuit may include a proportional part and an integral part. The proportional part is used to amplify the difference between the error voltage and the reference amplitude and the actual amplitude, quickly adjust the system output, and reduce the error. The integral part is used to integrate the accumulated value of the error voltage, eliminate the steady-state error of the system, and improve the stability of the system.

[0048] The present invention also provides a humidifier, which includes an adaptive gain control circuit 11, and the adaptive gain control circuit 11 includes a reference signal output circuit 10, a compensation circuit 20, a self-excited oscillation circuit 30 and a peak detection circuit 40; the reference signal output circuit 10 is used to output a reference amplitude; an input end of the compensation circuit 20 is connected to the output end of the reference signal output circuit 10; the input end of the self-excited oscillation circuit 30 is connected to the output end of the compensation circuit 20; the input end of the peak detection circuit 40 is connected to the output end of the self-excited oscillation circuit 30, and the output end of the peak detection circuit 40 is connected to another input end of the compensation circuit 20, for outputting a real-time amplitude; wherein the compensation circuit 20 adjusts the gain of the self-excited oscillation circuit 30 according to the reference amplitude and the real-time amplitude.

[0049] Specifically, the types of humidifiers may include hot evaporative humidifiers, cold evaporative humidifiers, pure type humidifiers and ultrasonic humidifiers. Hot evaporative humidifiers mainly use electric heating tubes to heat water to boiling to form water vapor, and then blow it into the room. Cold evaporative humidifiers mainly use high-speed fans to release water molecules, filter out impurities in the water through a humidifying filter, and then release them into the room to achieve the humidification effect. Pure type humidifiers mainly use molecular sieve evaporation technology to remove calcium and magnesium ions in the water, wash the air through a water curtain, and while humidifying, they can also filter and purify germs, dust, and particulate matter in the air, and then deliver the moist and clean air to the room through a pneumatic device. Ultrasonic humidifiers mainly convert electrical energy into mechanical energy to generate high-frequency vibrations. This high-frequency vibration acts on water to atomize the water into tiny water mist particles.

[0050] The adaptive gain control circuit 11 provided by the present invention, that is, the atomizer plate Y driving circuit, is mainly used in an ultrasonic humidifier to drive the atomizer plate Y in the ultrasonic humidifier. The power of the atomizer plate Y is changed by controlling the amplitude at both ends of the atomizer plate Y to achieve the switching of the gear of the humidifier.

[0051] The adaptive gain control circuit 11 includes a reference signal output circuit 10, a compensation circuit 20, a self-excited oscillation circuit 30, and a peak detection circuit 40. The reference signal output circuit 10 is mainly used to provide a reference amplitude, which is related to the gear currently corresponding to the humidifier. For example, the humidifier can be preset with multiple gears, different gears correspond to different oscillation voltages, and each oscillation voltage corresponds to an amplitude. When the user sets the gear, the reference signal output circuit 10 can obtain the amplitude corresponding to the oscillation voltage of the gear set by the user, and then output the reference amplitude according to the obtained amplitude.

[0052] The input end of the self-excited oscillation circuit 30 is connected to the compensation circuit 20. The working principle of the self-excited oscillation circuit 30 is mainly based on the positive feedback principle. It can form a positive feedback network and can generate a stable oscillation signal without external signal input. The oscillation signal is used to drive the atomizer sheet Y to vibrate and realize the humidification function. That is, the self-excited oscillation circuit 30 can include an atomizer sheet Y, and an oscillation signal can be applied to both ends of the atomizer sheet Y so that the atomizer sheet Y works normally.

[0053] The input end of the peak detection circuit 40 is connected to the output end of the self-excited oscillation circuit 30, and the output end of the peak detection circuit 40 is connected to the input end of the compensation circuit 20, which is mainly used to detect the maximum value of the oscillation voltage at both ends of the atomizer Y of the self-excited oscillation circuit 30, that is, the real-time amplitude. The peak detection circuit 40 may include components such as a diode, a capacitor, a resistor, an operational amplifier, and a comparator. The diode can be used as a detector to convert the peak voltage in the AC signal into a DC voltage. When the oscillation voltage reaches a peak value, the diode is turned on, and the peak voltage is captured and stored in the capacitor, that is, when the diode is turned on, the capacitor is charged to the peak voltage, and when the diode is cut off, the capacitor remains charged, thereby realizing the preservation of the peak voltage. The resistor is used to control the charging and discharging speed of the capacitor, and the charging time constant of the capacitor can be changed by adjusting the resistance value of the resistor to achieve the adjustment of the peak voltage capture accuracy. The operational amplifier and the comparator are used to further process and amplify the peak voltage to meet different needs. It is understandable that the peak detection circuit 40 can be any detection circuit commonly used by those skilled in the art composed of the above-mentioned elements, and its specific circuit structure is not limited here.

[0054] One input end of the compensation circuit 20 is connected to the reference signal output circuit 10 for receiving a reference amplitude. The other input end of the compensation circuit 20 is connected to the peak detection circuit 40 for receiving a real-time amplitude. The compensation circuit 20 compares the difference between the real-time amplitude and the reference amplitude to obtain an error voltage, which is output to the self-excited oscillation circuit 30 for adjusting the gain of the self-excited oscillation circuit 30, thereby changing the amplitude of the oscillation voltage at both ends of the atomizer sheet Y of the self-excited oscillation circuit 30, so that the amplitude at both ends of the atomizer sheet Y gradually approaches and is locked on the reference amplitude, thereby achieving adjustment of the gear position.

[0055] During actual use, when the user switches the gear, causing the reference amplitude to change, the compensation circuit 20 outputs an error voltage to the self-excited oscillation circuit 30 based on the reference amplitude and the real-time amplitude, and the amplitude of the oscillation voltage at both ends of the atomizer sheet Y in the self-excited oscillation circuit 30 changes accordingly and approaches the reference amplitude, and the peak detection circuit 40 will continue to output the real-time amplitude to the compensation circuit 20, so that the error voltage output by the compensation circuit 20 changes with the real-time amplitude, and the gain of the self-excited oscillation circuit 30 can be dynamically adjusted until the amplitude of the oscillation voltage at both ends of the atomizer sheet Y in the self-excited oscillation circuit 30 is consistent with the reference amplitude.

[0056] The adaptive gain control circuit and humidifier disclosed in the present invention, on the one hand, the peak detection circuit obtains the real-time amplitude of the self-excited oscillation circuit and outputs it to the compensation circuit, and the reference signal output circuit also synchronously outputs the reference amplitude to the compensation circuit, on the other hand, the compensation circuit adjusts the gain of the self-excited oscillation circuit according to the real-time amplitude and the reference amplitude to change the real-time amplitude, so that the gear of the humidifier can be changed by controlling the amplitude, avoiding the adjustment of the gear by PWM, and can improve the atomization efficiency and atomization effect.

[0057] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An adaptive gain control circuit, characterized in that: Applications in humidifiers, including: A reference signal output circuit, wherein the reference signal output circuit is used to output a reference amplitude; a compensation circuit, wherein an input terminal of the compensation circuit is connected to an output terminal of the reference signal output circuit; A self-excited oscillation circuit, wherein an input end of the self-excited oscillation circuit is connected to an output end of the compensation circuit; A peak detection circuit, wherein an input end of the peak detection circuit is connected to an output end of the self-excited oscillation circuit, and an output end of the peak detection circuit is connected to another input end of the compensation circuit, for outputting a real-time amplitude; The compensation circuit adjusts the gain of the self-excited oscillation circuit according to the reference amplitude and the real-time amplitude.

2. The adaptive gain control circuit according to claim 1, characterized in that: The reference signal output circuit includes a control module and a digital-to-analog conversion circuit; The output end of the control module is connected to the input end of the digital-to-analog conversion circuit, and is used to obtain the amplitude of the oscillation voltage and output a digital reference signal according to the amplitude; The output end of the digital-to-analog conversion circuit is connected to the compensation circuit, and is used to convert the digital reference signal into an analog reference signal to obtain the reference amplitude.

3. The adaptive gain control circuit according to claim 1, characterized in that: The self-excited oscillation circuit includes an AC isolation circuit, a DC isolation circuit, an oscillation circuit, an atomizer, and an amplifier circuit; The AC isolation circuit is respectively connected to the compensation circuit, the atomizer sheet, the amplifier circuit and the oscillation circuit; the amplifier circuit is connected to the DC isolation circuit; and the DC isolation circuit is respectively connected to the atomizer sheet and the peak detection circuit.

4. The adaptive gain control circuit according to claim 3, characterized in that: The AC isolation circuit includes a first inductor and a second inductor; One end of the first inductor is connected to the output end of the compensation circuit, and the other end of the first inductor is connected to the atomizer sheet, the amplifier circuit and the oscillation circuit respectively; One end of the second inductor is connected to the amplifier circuit, and the other end of the second inductor is connected to the subsequent circuit.

5. The adaptive gain control circuit according to claim 3, characterized in that: The oscillation circuit comprises a first capacitor and a second capacitor; One end of the first capacitor is connected to the AC isolation circuit, and the other end of the first capacitor is grounded; One end of the second capacitor is connected to the amplifier circuit, and the other end of the second capacitor is grounded.

6. The adaptive gain control circuit according to claim 3, characterized in that: The DC isolation circuit includes a third capacitor; One end of the third capacitor is connected to the amplifier circuit, and the other end of the third capacitor is connected to the atomizer sheet and the peak detection circuit respectively.

7. The adaptive gain control circuit according to claim 3, characterized in that: The amplifying circuit comprises a first switching tube; The controlled pole of the first switch tube is connected to the AC isolation circuit, the first pole of the first switch tube is respectively connected to the oscillation circuit, the DC isolation circuit and the AC isolation circuit, and the second pole of the first switch tube is grounded.

8. The adaptive gain control circuit according to claim 7, characterized in that: The first switch tube is a MOS tube, the gate of the first switch tube is connected to the AC isolation circuit, the drain of the first switch tube is respectively connected to the oscillation circuit, the DC isolation circuit and the AC isolation circuit, and the source of the first switch tube is grounded.

9. The adaptive gain control circuit according to claim 1, characterized in that: The compensation circuit is a PI compensation circuit.

10. A humidifier, characterized in that: Comprising the adaptive gain control circuit as described in any one of claims 1-9.

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