CN117686552A

CN117686552A - Atomization sheet water shortage detection system and atomization sheet water shortage detection method

Info

Publication number: CN117686552A
Application number: CN202311628555.6A
Authority: CN
Inventors: 陈建化; 曹凯; 李泽涌
Original assignee: Zhejiang Shaoxing Supor Domestic Electrical Appliance Co Ltd
Current assignee: Zhejiang Shaoxing Supor Domestic Electrical Appliance Co Ltd
Priority date: 2023-11-30
Filing date: 2023-11-30
Publication date: 2024-03-12

Abstract

The invention relates to an atomized sheet water shortage detection system and an atomized sheet water shortage detection method, wherein the system comprises: the humidifying module comprises an atomizing sheet oscillating unit, and the atomizing sheet oscillating unit is used for driving the atomizing sheet to vibrate according to a received driving signal with a preset oscillating frequency so as to generate atomized water vapor; the signal detection module is connected with the atomizing sheet oscillation unit and is used for detecting an oscillation voltage signal output by the atomizing sheet oscillation unit; the control module is respectively connected with the humidifying module and the signal detection module and is used for outputting a driving signal with preset oscillation frequency to the atomizing sheet oscillation unit, acquiring the actual oscillation frequency of the atomizing sheet oscillation unit according to the oscillation voltage signal and reliably and accurately detecting whether the water tank where the atomizing sheet is located is lack of water according to the preset oscillation frequency and the actual oscillation frequency.

Description

Atomization sheet water shortage detection system and atomization sheet water shortage detection method

Technical Field

The invention relates to the technical field of detection, in particular to an atomized sheet water shortage detection system and an atomized sheet water shortage detection method.

Background

Cooking appliances such as air fryers on the market today lose a great deal of moisture from the food cooked in the cooking cavity of the fryer during the cooking process, resulting in sometimes too dry surfaces of the cooked food, resulting in too high a degreasing rate of the cooked food, which affects the mouthfeel of the food. Therefore, some manufacturers add a humidifying module based on the original air fryer, and the humidifying module is used for properly spraying a certain amount of atomized water vapor into the cooking cavity of the fryer according to the temperature in the cooking cavity of the fryer in the cooking process so as to keep the surface of the cooked food at a certain humidity, thereby achieving the ideal cooking effect.

At present, an atomization sheet is generally adopted in a humidifying module to atomize water, and the working principle is that cavitation is generated on the water by high-frequency oscillation of the atomization sheet, so that a liquid water molecule structure is scattered to generate atomized water vapor which naturally drifts. The atomizing piece is the key part of humidification module, if the basin that atomizing piece was located lacks water for a long time, can cause humidification module dry combustion method and damage, consequently, how reliably and accurately detect whether the basin that atomizing piece was located lacks water is the problem that needs to solve now.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems in the related art to some extent.

Therefore, a first object of the present invention is to provide a water shortage detection system for an atomizing sheet, which can reliably and accurately detect whether a water tank in which the atomizing sheet is located is deficient or not, based on a preset oscillation frequency of a driving signal transmitted to an atomizing sheet oscillation unit and an actual oscillation frequency of an oscillation voltage signal generated by an oscillating sheet in the atomizing sheet oscillation unit detected by a signal detection module.

The second object of the present invention is to provide a method for detecting water shortage of an atomized sheet.

To achieve the above object, an embodiment of a first aspect of the present invention provides a water shortage detection system for an atomization sheet, including: the humidifying module comprises an atomizing sheet oscillating unit, wherein the atomizing sheet oscillating unit is used for driving the atomizing sheet to vibrate according to a received driving signal with preset oscillating frequency so as to generate atomized water vapor; the signal detection module is connected with the atomizing sheet oscillation unit and is used for detecting an oscillation voltage signal output by the atomizing sheet oscillation unit; the control module is respectively connected with the humidifying module and the signal detection module, and is used for outputting a driving signal with preset oscillation frequency to the atomizing sheet oscillation unit, determining the actual oscillation frequency of the atomizing sheet oscillation unit according to the oscillation voltage signal, and detecting whether the water tank where the atomizing sheet is positioned is lack of water according to the preset oscillation frequency and the actual oscillation frequency.

The atomizing sheet water shortage detection system comprises a humidifying module, a signal detection module and a control module, wherein the signal detection module is connected with an atomizing sheet oscillation unit in the humidifying module, the control module is respectively connected with the atomizing sheet oscillation unit and the signal detection module in the humidifying module, the control module is used for outputting a driving signal with preset oscillation frequency to the atomizing sheet oscillation unit so that the atomizing sheet oscillation unit drives the atomizing sheet to vibrate according to the received driving signal with the preset oscillation frequency to generate atomized water vapor, the actual oscillation frequency of the atomizing sheet oscillation unit is determined according to an oscillation voltage signal output by the atomizing sheet oscillation unit, and then whether a water tank where the atomizing sheet is positioned is deficient or not is detected according to the preset oscillation frequency and the actual oscillation frequency. Therefore, the system can reliably and accurately detect whether the water tank where the atomizing sheet is positioned is lack of water according to the preset oscillation frequency of the driving signal sent to the atomizing sheet oscillation unit and the actual oscillation frequency of the oscillation voltage signal generated by the oscillating sheet in the atomizing sheet oscillation unit detected by the signal detection module.

In addition, the atomized sheet water shortage detection system provided by the embodiment of the first aspect of the invention can also have the following additional technical characteristics:

According to one embodiment of the present invention, when the control module is configured to determine the actual oscillation frequency of the atomizing plate oscillation unit according to the oscillation voltage signal, the control module includes:

acquiring the cycle time of at least one oscillation waveform according to the oscillation voltage signal;

and determining the actual oscillation frequency according to the average value of at least one period time.

According to an embodiment of the present invention, the control module is configured to detect whether a water tank where the atomizing sheet is located is water-deficient according to the preset oscillation frequency and the actual oscillation frequency, and includes:

calculating an oscillation frequency difference value between the actual oscillation frequency and the preset oscillation frequency;

under the condition that the oscillation frequency difference value is larger than or equal to a preset value, determining that a water tank where the atomizing sheet is positioned is deficient in water; wherein the preset value is determined according to the preset oscillation frequency.

According to one embodiment of the present invention, the control module is further configured to stop outputting the driving signal to the atomizing sheet oscillation unit to stop the vibration of the atomizing sheet in a case where it is determined that the water tank in which the atomizing sheet is located lacks water.

According to one embodiment of the invention, the humidification module further comprises: and the power supply unit is used for supplying power to the atomizing sheet oscillation unit.

According to one embodiment of the invention, the power supply unit comprises: a diode, a first capacitor and a second capacitor; wherein,

the anode of the diode is connected with a set power supply, the first end of the first capacitor is connected with the first end of the second capacitor and then connected with the cathode of the diode, and the second end of the first capacitor is connected with the second end of the second capacitor and then grounded.

According to an embodiment of the present invention, the atomizing plate oscillation unit includes: the device comprises a triode, a first resistor, a second resistor, a third resistor, a transformer, an inductor and an atomization sheet; wherein,

the grid electrode of the triode is respectively connected with the output end of the control module through the first resistor and grounded through the second resistor, and the source electrode of the triode is grounded through the third resistor;

the first end of the primary coil of the transformer is connected with the power supply unit, the second end of the primary coil of the transformer is connected with the drain electrode of the triode, the first end of the secondary coil of the transformer is connected with the first end of the atomizing sheet through the inductor, and the second end of the secondary coil of the transformer is grounded after being connected with the second end of the atomizing sheet.

According to one embodiment of the invention, the signal detection module comprises: a fourth resistor, a fifth resistor, a sixth resistor and a third capacitor; wherein,

the first end of the fourth resistor is connected with the first end of the atomizing sheet, the second end of the fourth resistor is connected with the first end of the fifth resistor and the first end of the sixth resistor respectively, the second end of the fifth resistor is connected with the first end of the third capacitor and then grounded, and the second end of the sixth resistor is connected with the second end of the third capacitor and then connected with the input end of the control module.

According to one embodiment of the invention, the system further comprises:

the filter module is composed of a fourth capacitor and a fifth capacitor, wherein the first end of the fourth capacitor is respectively connected with the first end of the fifth capacitor, the power end of the control module and a preset power supply, and the second end of the fourth capacitor is respectively connected with the second end of the fifth capacitor and the grounding end of the control module and then grounded.

In order to achieve the above object, an embodiment of a second aspect of the present invention provides a method for detecting a lack of water in an atomized sheet, where the method for detecting a lack of water in an atomized sheet is applied to the system for detecting a lack of water in an atomized sheet, and the method includes: outputting a driving signal with preset oscillation frequency to the atomizing sheet oscillation unit so that the atomizing sheet oscillation unit drives the atomizing sheet to vibrate according to the received driving signal with the preset oscillation frequency to generate atomized water vapor; determining the actual oscillation frequency of the atomizing sheet oscillation unit according to the oscillation voltage signal output by the atomizing sheet oscillation unit; and detecting whether the water tank where the atomizing sheet is positioned is deficient or not according to the preset oscillation frequency and the actual oscillation frequency.

According to the detection method based on the atomizing sheet water shortage detection system, a driving signal with preset oscillation frequency is output to the atomizing sheet oscillation unit, so that the atomizing sheet oscillation unit drives the atomizing sheet to vibrate according to the received driving signal with the preset oscillation frequency to generate atomized water vapor, the actual oscillation frequency of the atomizing sheet oscillation unit is determined according to the oscillation voltage signal output by the atomizing sheet oscillation unit, and whether water is shortage in a water tank where the atomizing sheet is located is detected according to the preset oscillation frequency and the actual oscillation frequency. Therefore, the method can reliably and accurately detect whether the water tank where the atomizing sheet is positioned is lack of water according to the preset oscillation frequency of the driving signal sent to the atomizing sheet oscillation unit and the actual oscillation frequency of the oscillation voltage signal generated by the oscillating sheet in the atomizing sheet oscillation unit detected by the signal detection module.

In addition, the detection method based on the atomized sheet water shortage detection system provided by the embodiment of the second aspect of the invention can also have the following additional technical characteristics:

according to one embodiment of the present invention, the determining the actual oscillation frequency of the atomizing plate oscillation unit according to the oscillation voltage signal includes:

According to an embodiment of the present invention, the detecting whether the water tank where the atomizing sheet is located is lack of water according to the preset oscillation frequency and the actual oscillation frequency includes:

According to one embodiment of the invention, the method further comprises:

and under the condition that the water tank where the atomizing sheet is positioned is determined to be lack of water, stopping outputting the driving signal to the atomizing sheet oscillating unit so as to stop vibrating the atomizing sheet.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a schematic diagram of an atomized sheet water shortage detection system according to an embodiment of the present invention;

FIG. 2 is a circuit diagram of an atomized sheet water shortage detection system according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of measured waveforms at two ends of an atomizing sheet when a water tank is not deficient according to one embodiment of the present invention;

FIG. 4 is a schematic diagram of waveforms measured at two ends of an atomizing sheet when a water tank is deficient according to one embodiment of the present invention;

FIG. 5 is a flow chart of a method of detecting water shortage of an atomized sheet according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an atomized sheet water shortage detection system according to an embodiment of the invention;

fig. 7 is a flowchart of an atomized sheet water shortage detection method according to an embodiment of the present invention.

Detailed Description

In order to enable a person skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. The implementations described in the following exemplary examples do not represent all implementations consistent with the invention. Rather, they are merely examples of apparatus and methods consistent with aspects of the invention as detailed in the accompanying claims.

The following describes an atomized sheet water shortage detection system and an atomized sheet water shortage detection method according to an embodiment of the present invention with reference to the drawings.

In the related art, whether the water tank where the atomizing sheet is located is deficient or not is detected by detecting whether the amplitude of the oscillating voltage signal of the atomizing sheet is increased to a certain extent through the signal detection module, and if the amplitude of the oscillating voltage signal generated by the atomizing sheet is increased to a certain extent, the water tank where the atomizing sheet is located is judged to be deficient. The technical scheme is feasible in most cases, but in some cases, for example, when the mains voltage instantaneously fluctuates greatly, an interference signal is generated so that the amplitude of the oscillating voltage signal cannot be increased, or an interference signal is generated so that the amplitude of the oscillating voltage signal is increased, but the potential of the increased oscillating voltage signal is always lower than that of the reference voltage signal, and the situation that whether the water tank where the atomizing sheet is located is lack of water cannot be detected in the above manner is caused.

Based on the above problems, the existing technical scheme for detecting the lack of water in the atomized sheet still has room for improvement. Therefore, the invention provides a water shortage detection system for an atomizing sheet, which can reliably and accurately detect whether a water tank where the atomizing sheet is positioned is deficient or not according to the preset oscillation frequency of a driving signal sent to an atomizing sheet oscillation unit and the actual oscillation frequency of an oscillation voltage signal generated by an oscillating sheet in the atomizing sheet oscillation unit detected by a signal detection module, and can not influence the accuracy of detecting the water shortage signal of the atomizing sheet due to interference of instantaneous voltage fluctuation, current fluctuation and the like.

Fig. 1 is a schematic diagram of an atomized sheet water shortage detection system according to an embodiment of the present invention.

As shown in fig. 1, an atomized sheet water shortage detection system according to an embodiment of the present invention includes: a humidification module 10, a signal detection module 20, and a control module 30.

The humidifying module 10 includes an atomizing plate oscillating unit 11, where the atomizing plate oscillating unit 11 is configured to drive the atomizing plate to vibrate according to a received driving signal with a preset oscillating frequency to generate atomized water vapor. The signal detection module 20 is connected with the atomizing plate oscillation unit 11, and the signal detection module 20 is used for detecting an oscillation voltage signal output by the atomizing plate oscillation unit 11. The control module 30 is respectively connected with the humidifying module 10 and the signal detecting module 20, and the control module 30 is used for outputting a driving signal with preset oscillation frequency to the atomizing sheet oscillation unit 11, determining the actual oscillation frequency of the atomizing sheet oscillation unit 11 according to the oscillation voltage signal, and detecting whether the water tank where the atomizing sheet is located is deficient or not according to the preset oscillation frequency and the actual oscillation frequency.

In the present invention, the humidifying module 10 is typically disposed on top of a cooking appliance, such as an air fryer. The control module 30 is configured to output a driving signal, such as a PWM (Pulse Width Modulation ) driving signal, with a preset oscillation frequency f2 (i.e., a resonant frequency or an operating frequency of the atomizing sheet) to the atomizing sheet oscillating unit 11 according to a temperature in a cooking cavity of the fryer during cooking, so that the atomizing sheet ejects a certain amount of atomized water vapor into the cooking cavity of the fryer. The cooking utensil is also internally provided with a signal detection module 20, the signal detection module 20 is electrically connected with the humidifying module 10, and the signal detection module 20 is a detection circuit of the actual oscillation frequency f1 of the atomizing sheet.

When the atomizing sheet is in a load state, the atomizing sheet is not lack of water (water in the water tank can continuously provide water source for the atomizing sheet), at the moment, the current and voltage signals of the atomizing sheet are stable, and the energy generated by the alternating current voltage signals at two ends of the atomizing sheet can be stably and continuously released, so that the deviation between the actual oscillation frequency f1 detected by the control module 30 and the preset oscillation frequency f2 is smaller.

In the no-load state of the atomizing sheet, the atomizing sheet lacks water (no water exists in the water tank and can not provide water source for the atomizing sheet), in the no-water state, energy generated by alternating voltage signals at two ends of the atomizing sheet can not be released stably and effectively, so that parameters of an oscillating circuit of the atomizing sheet are changed, an actual oscillating frequency f1 in the no-load state generates a certain amount of offset, a difference value between the detected actual oscillating frequency f1 and a preset oscillating frequency f2 is larger than or equal to a preset value x1, and the voltage amplitude of the alternating voltage signals in the no-load state can also become larger than that in the load state.

When it is detected that the difference between the actual oscillation frequency f1 of the atomizing sheet and the preset oscillation frequency f2 is greater than or equal to a preset value x1, that is, (f 1-f 2) > x1, or (f 2-f 1) > x1, the value formula of x1 is x1=f2×k1, it is determined that the humidifying module 10 is in an idle state currently, that is, the atomizing sheet of the humidifying module 10 is already deficient in water. When detecting that the atomizing piece of humidification module 10 lacks water, close the drive signal of humidification module 10 immediately, make humidification module 10 outage and stop work (atomizing piece then stops spraying after the humidification module 10 outage), still can send alarm information through man-machine interaction module simultaneously and prompt the user in time to add water to the basin that links to each other with the atomizing piece. The preset oscillation frequency f2 is the frequency of the PWM driving signal output from the PWM port (see P1.0/PWM port in fig. 2) of the control module 30 to the gate (i.e., G pole) of the switching tube Q1 in the humidifying module 10.

The atomising flakes are divided into two different categories, namely low frequency and high frequency, the two operating principles and spray methods being different. The working frequency of the real-hole atomizing sheet is higher, also called high-frequency atomizing sheet, and three working frequencies are conventionally available: 1.7MHz, 2.4MHz and 3.0MHz. The conventional operating frequency range of microporous atomizer plates is 108KHz to 195KHz.

The preset oscillation frequency f2 needs to be selected according to the atomizing sheets with different working frequencies, and the working frequency (i.e. the resonant frequency) of the atomizing sheets is generally selected as the preset oscillation frequency f2.

The value range of K1 is 0.006-0.07, and the preferred value range of K1 is 0.01-0.03, which are empirical data obtained by testing a large number of atomized sheet samples of different specifications.

The whole working flow of the cooking utensil is as follows:

step 1: the user selects a cooking function and starts cooking.

Step 2: the control module 30 determines whether the humidification module 10 is currently required to operate, and if the humidification module 10 is currently required to operate, outputs a PWM driving signal to enable the atomizing sheet to obtain power for atomizing, wherein the frequency of the PWM driving signal is a preset oscillation frequency f2. Specifically, the control module 30 outputs a PWM driving signal to the switching tube Q1 of the humidifying module 10, so that the switching tube Q1 is rapidly switched in an on state and an off state, the PWM driving signal is boosted by the switching power supply transformer T1 and then is output to the atomizing sheet of the humidifying module 10, and thus the two ends of the atomizing sheet are driven to work after obtaining a driving signal (ac voltage), and atomized water vapor is sprayed into the cooking cavity; if the humidification module 10 is not currently required to operate, the PWM drive signal is turned off to cause the atomizing plate to lose power and stop spraying.

Step 3: the controller determines an actual oscillation frequency f1 according to the oscillation voltage signal of the atomizing sheet detected by the signal detection circuit, if the oscillation frequency difference between the actual oscillation frequency f1 and the preset oscillation frequency f2 is greater than or equal to a preset value x1, namely (f 1-f 2) is not less than x1, or (f 2-f 1) is not less than x1, the value formula of x1 is x1=f2×k1, the control module 30 determines that the water tank where the current atomizing sheet is positioned is already deficient, and immediately turns off the output of the PWM driving signal at the moment, so that the atomizing sheet of the humidifying module 10 loses power and stops working; when the difference value between the actual oscillation frequency f1 and the preset oscillation frequency f2 is smaller than the preset value x1, the current water tank where the atomizing sheet is positioned is judged to be free from water shortage, and the PWM driving signal is continuously output at the preset oscillation frequency f2 so that the atomizing sheet is continuously sprayed by the power supply.

Therefore, the water shortage detection system of the atomizing sheet can reliably and accurately detect whether the water tank where the atomizing sheet is positioned is deficient or not according to the preset oscillation frequency of the driving signal sent to the atomizing sheet oscillation unit 11 and the actual oscillation frequency of the oscillation voltage signal generated by the oscillating sheet in the atomizing sheet oscillation unit 11 detected by the signal detection module 20, and the accuracy of the detection of the water shortage signal of the atomizing sheet is not affected by the interference of instantaneous voltage fluctuation, current fluctuation and the like.

According to one embodiment of the present invention, the control module 30 is configured to obtain the actual oscillation frequency of the atomizing plate oscillation unit 11 according to the oscillation voltage signal, and includes: acquiring the cycle time of at least one oscillating waveform according to the oscillating voltage signal; the actual oscillation frequency is determined from an average value of the period time of at least one oscillation waveform.

The present invention utilizes periodic measurements to determine the actual oscillation frequency. Specifically, the control module 30 detects a time Ta1 at which the 1 st voltage is 0V in the 1 st oscillation waveform, a time Tc1 at which the 3 rd voltage is 0V in the 1 st oscillation waveform, and a time Tx1 used for Ta1 to Tc1, tx1 being a time of the 1 st oscillation waveform, is obtained from Tx 1= (Tc 1-Ta 1). By analogy, tx2= (Tc 2-Ta 2), tx3= (Tc 3-Ta 3), tx4= (Tc 4-Ta 4), …, txn= (Tcn-Tan), sampling the time Txn taken from Tan to Tcn of n oscillation waveforms, and averaging the collected time data Tx1, tx2, tx3, tx4, …, txn after accumulation, namely: the average time T1 of the n oscillation waveforms is found from the calculation formula t1= (Tx 1+tx2+tx3+tx4. And then the current actual oscillation frequency f1 of the atomizing sheet is calculated by a frequency calculation formula f1=1/T1, and the influence of interference signals can be eliminated by the software filtering algorithm, so that the detection accuracy of the actual oscillation frequency f1 is improved. Wherein 2< = n < = 1000, n being a natural number.

The water shortage detection system of the present invention will be described with reference to fig. 2.

As shown in fig. 2, the humidification module 10 further includes: and a power supply unit for supplying power to the atomizing plate oscillation unit 11.

As shown in fig. 2, the power supply unit includes: a diode, a first capacitor C1 and a second capacitor C2; the anode of the diode is connected with a set power supply, the first end of the first capacitor C1 is connected with the first end of the second capacitor C2 and then is connected with the cathode of the diode, and the second end of the first capacitor C1 is connected with the second end of the second capacitor C2 and then is grounded. The diode prevents current from flowing backward, and the first capacitor C1 and the second capacitor C2 filter a preset power source, such as a +5v power source.

As shown in fig. 2, the atomizing plate oscillation unit 11 includes: the device comprises a triode, a first resistor R1, a second resistor R2, a third resistor R3, a transformer T1, an inductor L1 and an atomization sheet; the gate of the triode is connected with the output end of the control module 30 through a first resistor R1 and grounded through a second resistor R2, and the source of the triode is grounded through a third resistor R3; the first end of the primary coil of the transformer T1 is connected with the power supply unit, the second end of the primary coil of the transformer T1 is connected with the drain electrode of the triode, the first end of the secondary coil of the transformer T1 is connected with the first end of the atomizing sheet through the inductor L1, and the second end of the secondary coil of the transformer T1 is connected with the second end of the atomizing sheet and then grounded.

In the present invention, when the humidification module 10 needs to be turned on, the P1.0 port of the control module 30 outputs a corresponding PWM driving signal at a preset oscillation frequency f2, the frequency of the PWM driving signal output at this time is the preset oscillation frequency f2, the PWM driving signal is applied to the G pole (i.e., the gate) of the switching tube Q1 through the first resistor R1, when a high level appears in the PWM driving signal, the switching tube Q1 is in a conducting state, and after the switching tube Q1 is conducted, the D pole (drain) and the S pole (source) of the switching tube Q1 are turned on, and at this time, the voltage of the D pole is close to 0V. The +5V voltage source is rectified by a diode, filtered by a first capacitor C1 and a second capacitor C2 and connected to one end of a primary coil of the transformer T1, and then flows through the other end of the primary coil of the transformer T1, the D pole, the S pole and GND (i.e. ground) of the switching tube Q1 in sequence, so that a complete loop is formed. The transformer T1 acts to boost the voltage of the PWM drive signal to a higher voltage in order to better drive the atomizing plate. The inductor L1 functions as a freewheel, and when a high level occurs in the PWM driving signal, the voltage boosted by the secondary winding of the transformer T1 charges the inductor L1.

When the PWM driving signal has low level, the switching tube Q1 is in a cut-off state, the D pole and the S pole of the switching tube Q1 are disconnected after the switching tube Q1 is cut-off, the inductor L1 performs reverse discharge, and alternating current driving voltage is provided for the atomizing sheet.

Thus, the control module 30 outputs a PWM driving signal to the switching tube Q1 of the humidification module 10, so that the switching tube Q1 is rapidly switched between an on state and an off state, the PWM driving signal is boosted by the transformer T1 and then is output to the atomizing sheet of the humidification module 10, and thus both ends of the atomizing sheet are driven by the driving signal (ac voltage).

As shown in fig. 2, the signal detection module 20 includes: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a third capacitor C3; the first end of the fourth resistor R4 is connected to the first end of the atomizing sheet, the second end of the fourth resistor R4 is connected to the first end of the fifth resistor R5 and the first end of the sixth resistor R6, the second end of the fifth resistor R5 is connected to the first end of the third capacitor C3 and then grounded, and the second end of the sixth resistor R6 is connected to the second end of the third capacitor C3 and then connected to the input end of the control module 30.

In the invention, the fourth resistor R4 and the fifth resistor R5 have the functions of dividing the voltage, after the vibration voltage signal of the atomizing sheet is divided by the fourth resistor R4 and the fifth resistor R5, the voltage is reduced to be lower than the level that the I/O port of the control module 30 can bear (the voltage that the I/O port of the control module 30 can bear is 5V), and then the vibration voltage signal is connected to the P1.1 port of the control module 30 through the sixth resistor R6, wherein the I/O port is used for detecting the actual oscillation frequency f1 of the vibration voltage signal output by the oscillation unit 11 of the atomizing sheet, and the actual oscillation frequency f1 can be measured by using a periodic measurement method.

As shown in fig. 2, the above system further includes: the first end of the fourth capacitor C4 is respectively connected with the first end of the fifth capacitor C5, the power end of the control module 30 and a preset power supply, and the second end of the fourth capacitor C4 is respectively connected with the second end of the fifth capacitor C5 and the grounding end of the control module 30 and then grounded. The fourth capacitor C4 and the fifth capacitor C5 are filter capacitors, and function to filter the control module 30.

FIG. 3 is a schematic diagram of the measured waveforms at the two ends of the atomizing plate when the water tank is not deficient according to one embodiment of the present invention.

Assuming n=5, txn=tx 5.

As shown in fig. 3, the 1 st oscillation waveform starts from Ta1 to Tc1, and the 1 st oscillation waveform starts from Ta1 at a time point of 0V at a time point Tb1 at which the 2 nd voltage is 0V and from a time point Tc1 at which the 3 rd voltage is 0V. The end time Tc1 of the 1 st oscillation waveform, that is, the start time Ta2 of the 2 nd oscillation waveform, and so on.

When the water tank where the atomizing sheet is positioned is not deficient in water, namely the atomizing sheet is in a load state, the working current is relatively stable at the moment, so that the deviation between the detected actual oscillation frequency f1 and the preset oscillation frequency f2 is smaller, and the difference between f1 and f2 is smaller than x1.

When the atomizing piece does not lack water, the atomizing piece is in the load state promptly, because working current is more stable, so the peak value change of the voltage waveform at atomizing piece both ends is less, namely: the difference in peak voltages of adjacent two waveforms is very small, i.e. the value of Ua-Ub is very small (typically less than 1V). As shown in fig. 3, ua is the forward peak voltage in the first full waveform and Ub is the forward peak voltage in the second full waveform. Each complete waveform consists of a sine wave of the positive half cycle and a sine wave of the negative half cycle.

Example 1:

the P1.0 port of the control module 30 outputs a corresponding PWM driving signal to the gate (i.e., the G pole) of the switching tube Q1 of the atomizing plate oscillating unit at a preset oscillation frequency f2=114 KHz.

Assuming that the control module 30 detects that the time Ta1 at which the 1 st time voltage is 0V in the 1 st oscillation waveform is 20us and the time Tc1 at which the 3 rd time voltage is 0V in the 1 st oscillation waveform is 28.76us through the P1.1 port, the time Tx 1=tc1-Ta 1=8.76 us of the 1 st oscillation waveform. By analogy, assume that the values of the times Tx1 to Tx5 of the 1 st to 5 th oscillation waveforms are shown in table 1, respectively.

TABLE 1

Tx1(us)	Tx2(us)	Tx3(us)	Tx4(us)	Tx5(us)	T1(us)	f1(KHz)
							8.76	8.75	8.73	8.76	8.77	8.75	114.2

Assuming n=5 in this example, substituting the data in table 1 into t1= (Tx 1+ Tx2+ Tx3+ tx4., +txn)/n, t1= (Tx 1+ Tx2+ Tx3+ Tx4+ Tx 5)/5= (8.76 +8.75+8.73+8.76+ 8.77)/5 = 43.77/5 = 8.75us, f1 = 1/t1 = 114.2KHz, f1-f2 = 114.2-114 = 0.2KHz.

The preset oscillation frequency f2 is 114KHz, the optimal range of the K1 value is 0.01-0.03, according to the actual measurement data of the atomizing sheet, the K1 value is 0.02, x1 = f2 x K1 = 114 x 0.02 = 2.28KHz, and because 0.2KHz is less than 2.28KHz, (f 1-f 2) < x1, the current atomizing sheet is judged to be in a load state without water shortage.

Fig. 4 is a schematic diagram of waveforms actually measured at two ends of an atomizing sheet when a water tank lacks water according to an embodiment of the present invention.

Assuming n=5, txn=tx 5.

As shown in fig. 4, the 1 st oscillation waveform is Ta1 at the 1 st time point of 0V voltage, tb1 at the 2 nd time point of 0V voltage, tc1 at the 3 rd time point of 0V voltage, and the 1 st oscillation waveform starts from Ta1 to Tc 1. The end time Tc1 of the 1 st oscillation waveform, that is, the start time Ta2 of the 2 nd oscillation waveform, and so on.

When the atomizing sheet lacks water, i.e. the atomizing sheet is in an empty load state (i.e. no water is dry-burned), the energy generated by the alternating voltage signals at two ends of the atomizing sheet cannot be released stably and effectively due to the lack of water, so that the parameters of the oscillating circuit of the atomizing sheet are changed, the difference between the detected actual oscillating frequency f1 and the preset oscillating frequency f2 is finally larger than the preset x1, and the amplitude of the alternating voltage signals is also larger.

In the no-load state, the difference between the peak voltages of two adjacent waveforms increases significantly, i.e. the value of Ua-Ub increases significantly. As shown in fig. 4, ua is the forward peak voltage in the first full waveform and Ub is the forward peak voltage in the second full waveform. Each complete waveform consists of a sine wave of the positive half cycle and a sine wave of the negative half cycle.

Example 2:

the P1.0 port of the control module 30 outputs a corresponding PWM driving signal to the gate (i.e., the G pole) of the switching tube Q1 of the atomizing sheet oscillation circuit at a preset oscillation frequency f2=114 KHz.

Assuming that the control module 30 detects that the time Ta1 at which the 1 st time voltage is 0V in the 1 st oscillation waveform is 10us and the time Tc1 at which the 3 rd time voltage is 0V in the 1 st oscillation waveform is 18.5us through the P1.1 port, the time Tx 1=tc1-Ta 1=8.5 us of the 1 st oscillation waveform. By analogy, assume that the values of the times Tx1 to Tx5 of the 1 st to 5 th oscillation waveforms are shown in table 2, respectively.

TABLE 2

Tx1(us)	Tx2(us)	Tx3(us)	Tx4(us)	Tx5(us)	T1(us)	f1(KHz)
							8.50	8.53	8.52	8.76	8.45	8.50	117.6

Assuming n=5 in this example, substituting the data in table 2 into t1= (Tx 1+tx2+tx3+tx4.,. The term +txn)/n, t1= (Tx 1+tx2+tx3+tx4+tx 5)/5= (8.50+8.53+8.52+8.45+8.51)/5=42.51/5=8.50 us, f1=1/t1=1/8.50 us=117.6 KHz, f1-f2=117.6-114=3.6 KHz.

The preset oscillation frequency f2 is 114KHz, the optimal range of the K1 value is 0.01-0.03, according to the actual measurement data of the atomizing sheet, the K1 value is 0.02, x1 = f2 x K1 = 114 x 0.02 = 2.28KHz, and because 3.6KHz is greater than 2.28KHz, (f 1-f 2) is greater than x1, the current atomizing sheet is judged to be in a dry heating state due to water shortage, namely in an idle state.

Therefore, the atomization sheet water shortage detection system can reliably and accurately detect whether the water tank where the atomization sheet is positioned is deficient in water or not according to the preset oscillation frequency of the driving signal sent to the atomization sheet oscillation unit and the actual oscillation frequency of the oscillation voltage signal generated by the oscillation sheet in the atomization sheet oscillation unit detected by the signal detection module, and the accuracy of detection of the atomization sheet water shortage signal is not affected by the interference of instantaneous voltage fluctuation, current fluctuation and the like.

In order to enable a person skilled in the art to more clearly understand the detection method based on the atomized sheet water shortage detection system according to the present invention, as shown in fig. 5, the detection method based on the atomized sheet water shortage detection system according to the embodiment of the present invention includes the following steps:

s501, the user starts the cooking function to start cooking.

S502, when detecting that the current humidification module needs to work, the control module outputs PWM driving signals with preset oscillation frequency f2 (f 2 is the resonant frequency of the atomizing sheet) to a switching tube of the humidification module, so that the switching tube is rapidly switched in an on state and an off state, the PWM driving signals are boosted by a transformer and then output to the atomizing sheet of the humidification module, the PWM driving signals obtained at two ends of the atomizing sheet work, and atomized water vapor is sprayed into a cooking cavity.

S503, detecting the current oscillation frequency f1 of the atomizing sheet by an atomizing sheet oscillation frequency detection circuit. The method comprises the following steps: the time Tx1 used for Ta1 to Tc1 is obtained from Tx1= (Tc 1-Ta 1) when the time Ta1 at which the first time voltage in the 1 st oscillation waveform is 0V is detected and the time Tc1 at which the 3 rd time voltage in the 1 st oscillation waveform is 0V is detected. And so on, using the time Txn from Tan to Tcn of n oscillation waveforms, and adding up and averaging the collected time data Tx1, tx2, tx3, … and Txn, namely: the average time T1 of n oscillation waveforms is calculated from the calculation formula t1= (Tx 1+ Tx2+ Tx3+ … + Txn)/n, and the current actual oscillation frequency f1 of the atomizing sheet is calculated from the frequency calculation formula f1=1/T1.

S504, judging whether |f1-f2|is equal to or greater than x1, wherein x1=f2|K1, the value range of K1 is 0.006-0.07, f1 is the current actual oscillation frequency of the atomizing sheet, and f2 is the preset oscillation frequency. If |f1-f2|is not less than x1, then executing step S505; if not, the process returns to step S503.

S505, judging that the water tank where the current atomizing sheet is positioned is deficient in water, sending a water deficiency signal to the control module, and immediately closing the output of the PWM driving signal after the control module receives the water deficiency signal, so that the humidifying module stops working, and the two ends of the atomizing sheet lose voltage to stop working.

Fig. 6 is a schematic diagram of an atomized sheet water shortage detection system according to an embodiment of the present invention.

As shown in fig. 6, the atomized sheet water shortage detection system according to the embodiment of the present invention further includes: the device comprises an air circulation module, a key module, a storage module, a power module, a top temperature detection module, a heating module, a display module and a sound prompt module.

The control module is used for processing various input and output signals so as to control the normal operation of the cooking utensil.

The air circulation module comprises a shaded pole motor and fan blades arranged on the shaded pole motor, and when the shaded pole motor rotates, the fan blades on the shaded pole motor can be driven to rotate rapidly, so that air in a cooking cavity of the air fryer circulates continuously and rapidly, the temperature distribution in the cooking cavity is more uniform, and the cooked food is more uniform and delicious.

The key module is used for providing an operation interface for a user.

The storage module is used for storing key data in the cooking process, and can be a part of the control module or a module independent of the control module.

The power supply module is used for rectifying, reducing and filtering the mains voltage and providing a direct-current low-voltage power supply for the control module and the like.

The top temperature detection module is used for collecting the temperature of the top of the cooking utensil, converting the temperature into corresponding AD values and transmitting the AD values to the control module for processing.

The heating module is used for heating the cooking utensil and comprises a heating device and a heating driving circuit. For example: the heating device can be an electric heating tube and other devices. The heating driving circuit refers to a related circuit capable of controlling the heating or non-heating of the electric heating tube.

The display module is used for providing a display interface for a user.

The voice prompt module is used for providing voice prompts for users.

In summary, the atomized sheet water shortage detection system according to the embodiment of the present invention is composed of a humidification module, a signal detection module and a control module, the signal detection module is connected with an atomized sheet oscillation unit in the humidification module, the control module is respectively connected with the atomized sheet oscillation unit and the signal detection module in the humidification module, the control module is configured to output a driving signal with a preset oscillation frequency to the atomized sheet oscillation unit, so that the atomized sheet oscillation unit drives the atomized sheet to vibrate according to the received driving signal with the preset oscillation frequency to generate atomized water vapor, and determine an actual oscillation frequency of the atomized sheet oscillation unit according to an oscillation voltage signal output by the atomized sheet oscillation unit, and then detect whether a water tank where the atomized sheet is located is deficient or not according to the preset oscillation frequency and the actual oscillation frequency. Therefore, the system can reliably and accurately detect whether the water tank where the atomizing sheet is positioned is lack of water according to the preset oscillation frequency of the driving signal sent to the atomizing sheet oscillation unit and the actual oscillation frequency of the oscillation voltage signal generated by the oscillating sheet in the atomizing sheet oscillation unit detected by the signal detection module.

As shown in fig. 7, the atomized sheet water shortage detection method according to the embodiment of the invention includes the following steps:

s701, outputting a driving signal with preset oscillation frequency to the atomizing sheet oscillation unit, so that the atomizing sheet oscillation unit drives the atomizing sheet to vibrate according to the received driving signal with the preset oscillation frequency to generate atomized water vapor.

S702, determining the actual oscillation frequency of the atomizing sheet oscillation unit according to the oscillation voltage signal output by the atomizing sheet oscillation unit.

S703, detecting whether the water tank where the atomizing sheet is positioned is deficient or not according to the preset oscillation frequency and the actual oscillation frequency.

According to one embodiment of the present invention, determining an actual oscillation frequency of the atomizing plate oscillation unit from the oscillation voltage signal includes:

acquiring the cycle time of at least one oscillating waveform according to the oscillating voltage signal;

the actual oscillation frequency is determined from an average value of at least one cycle time.

According to one embodiment of the present invention, detecting whether a water tank in which an atomizing sheet is located is deficient in water according to a preset oscillation frequency and an actual oscillation frequency includes:

Under the condition that the oscillation frequency difference value is larger than or equal to a preset value, determining that a water tank where the atomizing sheet is positioned is deficient in water; wherein the preset value is determined according to a preset oscillation frequency.

According to one embodiment of the invention, the method further comprises:

under the condition that the water tank where the atomizing sheet is positioned is determined to lack water, the output of the driving signal to the atomizing sheet oscillating unit is stopped, so that the atomizing sheet stops vibrating.

It should be noted that, for details not disclosed in the detection method based on the atomized sheet water shortage detection system in the embodiment of the present invention, please refer to details disclosed in the atomized sheet water shortage detection system in the embodiment of the present invention, and details are not described here again.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and additional implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order from that shown or discussed, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the embodiments of the present invention.

Logic and/or steps represented in the flowcharts or otherwise described herein, e.g., a ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program is printed, as the program may be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.

It is to be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the various steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As with the other embodiments, if implemented in hardware, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.

Those of ordinary skill in the art will appreciate that all or a portion of the steps carried out in the method of the above-described embodiments may be implemented by a program to instruct related hardware, where the program may be stored in a computer readable storage medium, and where the program, when executed, includes one or a combination of the steps of the method embodiments.

In addition, each functional unit in the embodiments of the present invention may be integrated in one processing module, or each unit may exist alone physically, or two or more units may be integrated in one module. The integrated modules may be implemented in hardware or in software functional modules. The integrated modules may also be stored in a computer readable storage medium if implemented in the form of software functional modules and sold or used as a stand-alone product.

The above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, or the like. While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims

1. An atomized sheet water shortage detection system, characterized by comprising:

the humidifying module comprises an atomizing sheet oscillating unit, wherein the atomizing sheet oscillating unit is used for driving the atomizing sheet to vibrate according to a received driving signal with preset oscillating frequency so as to generate atomized water vapor;

the signal detection module is connected with the atomizing sheet oscillation unit and is used for detecting an oscillation voltage signal output by the atomizing sheet oscillation unit;

the control module is respectively connected with the humidifying module and the signal detection module, and is used for outputting a driving signal with preset oscillation frequency to the atomizing sheet oscillation unit, determining the actual oscillation frequency of the atomizing sheet oscillation unit according to the oscillation voltage signal, and detecting whether the water tank where the atomizing sheet is positioned is lack of water according to the preset oscillation frequency and the actual oscillation frequency.

2. The atomizing patch water shortage detection system according to claim 1, wherein the control module is configured to determine an actual oscillation frequency of the atomizing patch oscillation unit from the oscillation voltage signal, and comprises:

3. The system of claim 1, wherein the control module is configured to detect whether the water tank in which the atomizing sheet is located is deficient according to the preset oscillation frequency and the actual oscillation frequency, and comprises:

4. The atomizing sheet water shortage detection system according to claim 1, wherein the control module is further configured to stop outputting the driving signal to the atomizing sheet oscillation unit to stop the vibration of the atomizing sheet in the case where it is determined that the water tank in which the atomizing sheet is located is deficient in water.

5. The atomizing sheet water deficiency detection system of claim 1, wherein said humidification module further comprises: and the power supply unit is used for supplying power to the atomizing sheet oscillation unit.

6. The atomizing sheet water deficiency detection system according to claim 5, wherein said power supply unit comprises: a diode, a first capacitor and a second capacitor; wherein,

7. The atomizing sheet water shortage detection system according to claim 1, characterized in that the atomizing sheet oscillation unit includes: the device comprises a triode, a first resistor, a second resistor, a third resistor, a transformer, an inductor and an atomization sheet; wherein,

8. The atomized sheet water shortage detection system according to claim 1, wherein the signal detection module includes: a fourth resistor, a fifth resistor, a sixth resistor and a third capacitor; wherein,

9. The atomized sheet water shortage detection system according to claim 1, wherein the system further comprises:

10. A method for detecting lack of water in an atomized sheet, wherein the method for detecting lack of water in an atomized sheet is applied to the system for detecting lack of water in an atomized sheet according to any one of claims 1 to 9, and the method comprises:

Outputting a driving signal with preset oscillation frequency to the atomizing sheet oscillation unit so that the atomizing sheet oscillation unit drives the atomizing sheet to vibrate according to the received driving signal with the preset oscillation frequency to generate atomized water vapor;

determining the actual oscillation frequency of the atomizing sheet oscillation unit according to the oscillation voltage signal output by the atomizing sheet oscillation unit;

and detecting whether the water tank where the atomizing sheet is positioned is deficient or not according to the preset oscillation frequency and the actual oscillation frequency.