A piezoelectric ceramic negative oxygen ion generator

Abstract

The present invention discloses a piezoelectric ceramic negative oxygen ion generator, comprising a negative ion generation module and a housing. The negative ion generation module includes a PCB control board, a piezoelectric ceramic transformer, and negative ion output carbon brushes. The PCB control board includes a MUC, an oscillation circuit, a drive circuit, a voltage multiplier circuit, and an energy feedback circuit. The present invention belongs to the technical field of negative ion generators and specifically provides a piezoelectric ceramic negative oxygen ion generator that adjusts the PWM output frequency through DC high-voltage output voltage feedback detection to prevent the risk of electric shock to humans while maintaining constant high-voltage output power. The generator has the advantages of small size, high isolation voltage, safety and reliability, wider applicability, and improved reliability and stability of the negative ion generator.

Description

Technical Field

[0001] The present invention belongs to the technical field of negative ion generators and is mainly used in household air purifiers, household air conditioners, refrigerators, automobile air purification, medical negative oxygen ion auxiliary treatment equipment, etc. Specifically, it refers to a piezoelectric ceramic negative oxygen ion generator with integrated feedback control and adjustable frequency. Background Art

[0002] As air pollution becomes increasingly severe, particulate matter, microparticles, dust, and viruses in the air are becoming increasingly serious, seriously affecting human health. Negative air ions, also known as negative oxygen ions, are oxygen ions that have gained one or more electrons and carry a negative charge. Research has shown that high concentrations of negative oxygen ions have excellent purification and dust removal effects, effectively boosting human immunity and effectively settling airborne dust, particles, bacteria, and other particles, thereby purifying the air.

[0003] Under the influence of a strong negative electric field, negative oxygen ions rapidly diffuse into the surrounding air. As they are released into the surrounding air, they quickly neutralize positively charged floating particles like dust and bacteria, transforming them into neutral substances and rapidly settling particulate matter, dust, and viruses. This can effectively improve sleep quality, lung function, lower blood sugar, and enhance disease resistance. Negative oxygen ions maintain the balance of the body's vital autonomic nervous system and are effective in treating insomnia caused by excessive stress.

[0004] Currently, most negative ion generators on the market use a high-voltage coil to generate instantaneous DC high voltage. After rectification and voltage multiplication, it outputs a fixed negative high voltage, which is then discharged into the air. There is no energy feedback safety control circuit. Due to the structure and manufacturing process of the high-voltage coil, its insulation voltage is only about 1500V, and the high-voltage coil turns are prone to breakdown and short circuits. However, to generate the voltage required for negative air ions, a voltage of more than 3500V is required. Therefore, transformers with a high winding turn ratio are prone to overheating during operation and cause leakage current breakdown. During the voltage coupling process, high-voltage breakdown and leakage current will occur, generating a certain high-voltage AC current, which is released into the air through the rectifier diode. As the AC current discharges into the air, it will produce ozone derivatives, which will pose an electric shock hazard to the human body and surrounding electrical equipment. The human body is prone to electric shock, and the power of the negative ion generator is uncontrollable. Summary of the Invention

[0005] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a piezoelectric ceramic negative oxygen ion generator that adjusts the PWM output frequency through DC high-voltage output voltage feedback detection to prevent the risk of electric shock to the human body. At the same time, the output power at the high-voltage end is constant, which has the advantages of small size, high isolation voltage, safety and reliability, and wider applicability, thereby improving the reliability and stability of the negative ion generator.

[0006] The technical solution adopted by the present invention is as follows: The present invention provides a piezoelectric ceramic negative oxygen ion generator, including a negative ion generation module and a shell, the shell is provided with an air inlet and an air outlet, the negative ion generation module is arranged in the shell, and the negative ion generation module is arranged at the air outlet of the shell; the negative ion generation module includes a PCB control board, a piezoelectric ceramic transformer and a negative ion output carbon brush, the piezoelectric ceramic transformer is connected to the output end of the PCB control board, the piezoelectric ceramic transformer is used to convert the alternating current generated by the PCB control board into direct current high voltage, the negative ion output carbon brush is connected to the output end of the piezoelectric ceramic transformer through a wire, and the negative ion output carbon brush outputs negative ions into the air.

[0007] As a preferred solution, the PCB control board includes a top board, a middle board and a bottom board. The top board is a conductive silver paste layer pressed together with a ceramic sheet. A conductive silver paste of a fixed shape is sintered on the high-insulation ceramic sheet and connected through a conductive probe via a via. The middle board is an intermediate conductive layer, and the intermediate conductive layer is a conductive copper clad layer. The intermediate conductive layer is a wire connected to the pad position of the bottom board through a via. A resistor voltage divider circuit is provided on the bottom board. The resistor voltage divider effect is achieved through the resistor voltage divider circuit, and the current is converted into voltage. The voltage is connected to the ADC sampling port with the variable voltage signal Vout along with Vin.

[0008] Among them, Vout=Vin / (R1+R2)×R2 can be calculated to obtain Vout.

[0009] Furthermore, the PCB control board includes a MUC, an oscillation circuit, a drive circuit, a voltage multiplication circuit, and an energy feedback circuit;

[0010] The oscillation circuit is connected to the MUC, the output end of the oscillation circuit is connected to the input end of the drive circuit, the drive circuit is used to generate an alternating voltage, the output end of the drive circuit is connected to the piezoelectric ceramic transformer, the piezoelectric ceramic transformer is used to generate a pure sine wave under the action of the alternating voltage generated by the drive module, the input end of the voltage doubler circuit is connected to the output end of the piezoelectric ceramic transformer, one end of the energy feedback circuit is connected to the oscillation circuit, and the other end of the energy feedback circuit is connected to the voltage doubler circuit, the voltage doubler circuit is used to amplify the output voltage of the piezoelectric ceramic transformer again, and output negative ions into the air through the negative ion output carbon brush.

[0011] Furthermore, when the piezoelectric ceramic transformer discharges into the air, the voltage changes with the proximity of a conductor, and the voltage across the conductive silver paste also changes. The MUC reads this data change through its internal ADC. Once it reaches a certain threshold, the MCU shuts off the PWM output, protecting anyone nearby from the risk of electric shock.

[0012] Furthermore, the PCB control board is formed by pressing a top layer board, a middle layer board and a bottom layer board together, and the PCB control board is made using an immersion gold process.

[0013] In a preferred embodiment, the negative ion output carbon brush is a conductive carbon brush.

[0014] This solution is a piezoelectric ceramic negative oxygen ion generator, which is mainly used to solve the problems of uncontrollable power and leakage of negative ion generators in the prior art. The beneficial effects achieved by the present invention using the above structure are as follows:

[0015] 1. Using chip SOP packaging technology, the MCU processor and piezoelectric ceramic transformer are integrally packaged. The feedback magnetic stripe circuit designed in this solution then feeds back to the MCU processor's analog-to-digital converter (ADC) input port for DC high-voltage output voltage detection and adjustment of the PWM output frequency. This prevents the risk of electric shock while maintaining constant high-voltage output power. This device offers the advantages of a small size, high isolation voltage, and safety and reliability. The excellent isolation prevents positive charge accumulation, improving conversion efficiency and enabling integration into any home appliance application.

[0016] 2. Utilizing the positive and negative piezoelectric effects of piezoelectric ceramic materials, and by designing the electrodes and polarization orientation characteristics of the piezoelectric ceramic body, the negative piezoelectric effect is used to cause the piezoelectric ceramic body connected to the input end to generate mechanical vibration under the action of voltage. The positive piezoelectric effect is then used to cause the piezoelectric ceramic body connected to the output end to generate voltage. The MCU is used to drive the piezoelectric ceramic transformer by outputting a variable-frequency PWM waveform to generate a driving sine wave of a certain frequency. The mechanical energy is converted into electrical energy, which is then rectified and multiplied by the high-voltage silicon stack and output to the discharge carbon brush to discharge the air. The piezoelectric ceramic transformer has high insulation and reliability, as well as zero attenuation characteristics. This very cleverly solves the problem of ozone derivatives generated by AC leakage while generating negative ions, thereby improving the reliability and stability of the negative ion generator.

[0017] 3. The design of the energy feedback circuit: when the air is ionized to generate negative ions, when a person approaches the discharge end, the voltage at the high-voltage output end changes due to the conductive properties of the human body. The feedback circuit reads the voltage through the MCU to determine whether there is a conductor approaching, and can quickly shut down the high-voltage output, effectively protecting the safety of people and equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of the negative ion generation module in this scheme;

[0019] Figure 2 This is a schematic diagram of the principle of the piezoelectric ceramic negative oxygen ion generator in this scheme;

[0020] Figure 3 This is a circuit diagram of the piezoelectric ceramic transformer driving circuit in this solution;

[0021] Figure 4 This is the circuit diagram of the PWM signal output and optocoupler isolation in this solution;

[0022] Figure 5 This is the circuit schematic diagram of the MCU in this solution.

[0023] Among them, 1. Top layer board, 2. Middle layer board, 3. Bottom layer board.

[0024] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] like Figure 1-5 As shown, the present invention provides a piezoelectric ceramic negative oxygen ion generator, comprising a negative ion generating module and a housing, wherein the housing is provided with an air inlet and an air outlet, the negative ion generating module is arranged within the housing, and the negative ion generating module is arranged at the air outlet of the housing; the negative ion generating module comprises a PCB control board, a piezoelectric ceramic transformer and a negative ion output carbon brush, the piezoelectric ceramic transformer is connected to the output end of the PCB control board, the piezoelectric ceramic transformer is used to convert the alternating current generated by the PCB control board into direct current high voltage, the negative ion output carbon brush is connected to the output end of the piezoelectric ceramic transformer via a wire, and the negative ion output carbon brush outputs negative ions into the air.

[0027] like Figure 1As shown, the PCB control board includes a top board, a middle board, and a bottom board. The top board is a conductive silver paste layer pressed together with a ceramic sheet. A fixed-shape conductive silver paste is sintered on the high-insulation ceramic sheet and connected through a conductive probe via a via. The middle board is an intermediate conductive layer, and the intermediate conductive layer is a conductive copper-clad layer. The intermediate conductive layer is a wire connected to the pad position of the bottom board through a via. A resistor voltage divider circuit is provided on the bottom board. The resistor voltage divider effect is achieved through the resistor voltage divider circuit, and the current is converted into voltage. The voltage is connected to the ADC sampling port with a variable voltage signal Vout according to Vin. The PCB control board is formed by pressing together the top board, the middle board, and the bottom board, and the PCB control board is made using an immersion gold process.

[0028] like Figure 2-3 As shown, the PCB control board includes MUC, oscillation circuit, drive circuit, voltage multiplication circuit, and energy feedback circuit;

[0029] The oscillation circuit is connected to the MUC, the output end of the oscillation circuit is connected to the input end of the drive circuit, the drive circuit is used to generate an alternating voltage, the output end of the drive circuit is connected to the piezoelectric ceramic transformer, the piezoelectric ceramic transformer is used to generate a pure sine wave under the action of the alternating voltage generated by the drive module, the input end of the voltage doubler circuit is connected to the output end of the piezoelectric ceramic transformer, one end of the energy feedback circuit is connected to the oscillation circuit, and the other end of the energy feedback circuit is connected to the voltage doubler circuit, the voltage doubler circuit is used to amplify the output voltage of the piezoelectric ceramic transformer again, and output negative ions into the air through the negative ion output carbon brush.

[0030] Wherein, Vout=Vin / (R1+R2)×R2, and Vout can be calculated based on the input voltage and the resistance values ​​of R1 and R2.

[0031] In the embodiment, when the piezoelectric ceramic transformer discharges to the air, if a conductor approaches, the voltage will change as the conductor approaches, and the voltage on the conductive silver paste will also change.

[0032] The MUC reads data changes through the internal ADC. When a certain threshold is reached, the MCU will turn off the PWM output to protect nearby people from the risk of electric shock.

[0033] like Figure 3As shown in the figure, this circuit, based on the above, also includes a delayed drive circuit. The delayed start circuit consists of F1, R12, Q2, Q3, and R20. When powered by 12V, the internal resistance of the piezoelectric ceramic transformer is relatively low. If the MCU does not output the PWM control waveform correctly, the startup current will be too high, and F1's self-recovery fuse will overheat. The MCU controls the startup time of Q3 to achieve delayed startup. After the MCU is powered on and operating normally, it first configures the PWM output. After a software delay of 1.5 seconds, it outputs a high level, starting Q3 and turning on PMOS transistor Q2 to power the piezoelectric ceramic transformer. This effectively prevents damage to the piezoelectric ceramic caused by excessive current at power-on, extending its service life while improving the reliability of the entire circuit. The high-voltage feedback signal in the energy feedback circuit passes through R14, D3, and Q4 in sequence, and is finally stabilized at around 6.2V. This protects the base voltage of the switching transistor Q4 from being damaged by overvoltage. When the piezoelectric ceramic outputs a high voltage, Q4 is turned on, and the output terminal Feedback of the feedback point R11 changes from a high level to a low level. The MCU reads this voltage to determine whether the ceramic starts up normally. If not, the MCU will send a low-level signal to the base of Q3 to cut off the power supply to the piezoelectric ceramic and protect the entire circuit.

[0034] like Figure 4 As shown, the PWM signal output by the MCU passes through high-speed optocoupler U2 and directly drives Q1. Q1 drives step-up transformer T1, applying a fixed-frequency sinusoidal signal to the piezoelectric ceramic. This causes the piezoelectric ceramic T2 to physically vibrate, thereby converting mechanical energy into electrical energy. The positive piezoelectric effect then generates a voltage in the piezoelectric ceramic connected to the output terminal. The MCU processor drives the piezoelectric ceramic transformer by outputting a variable-frequency PWM waveform, generating a driving sine wave of a constant frequency. This converts mechanical energy into electrical energy, which is then rectified and voltage-doubled by a high-voltage silicon stack before being output to the discharge carbon brushes for discharge into the air. The piezoelectric ceramic transformer offers high insulation, reliability, and zero attenuation, cleverly addressing the issue of ozone derivatives generated by AC leakage during negative ion generation. This improves the reliability and stability of the negative ion generator.

[0035] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0036] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

[0037] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A piezoelectric ceramic negative oxygen ion generator, comprising a negative ion generating module and a housing, wherein the housing is provided with an air inlet and an air outlet, the negative ion generating module is disposed within the housing, and the negative ion generating module is disposed at the air outlet of the housing, characterized in that: The negative ion generating module includes a PCB control board, a piezoelectric ceramic transformer, and a negative ion output carbon brush. The piezoelectric ceramic transformer is connected to the output end of the PCB control board and is used to convert the alternating current generated by the PCB control board into a high-voltage direct current. The negative ion output carbon brush is connected to the output end of the piezoelectric ceramic transformer via a wire and outputs negative ions into the air. The PCB control board includes MUC, oscillation circuit, drive circuit, voltage multiplication circuit and energy feedback circuit; The PCB control board includes a top board, a middle board and a bottom board. The top board is a conductive silver paste layer pressed together with a ceramic sheet. A conductive silver paste of a fixed shape is sintered on the high-insulation ceramic sheet and connected through a conductive probe via a via. The middle board is an intermediate conductive layer, and the intermediate conductive layer is a conductive copper clad layer. The intermediate conductive layer is a wire connected to the pad position of the bottom board through a via. A resistor voltage divider circuit is provided on the bottom board. The resistor voltage divider circuit realizes a resistor voltage divider effect and converts current into voltage. The output voltage Vout generated by the resistor voltage divider circuit varies with the input voltage Vin, and the output voltage Vout is connected to the ADC sampling port inside the MUC. The oscillation circuit is connected to the MUC, the output end of the oscillation circuit is connected to the input end of the drive circuit, the drive circuit is used to generate an alternating voltage, the output end of the drive circuit is connected to the piezoelectric ceramic transformer, the piezoelectric ceramic transformer is used to generate a pure sine wave under the action of the alternating voltage generated by the drive module, the input end of the voltage doubling circuit is connected to the output end of the piezoelectric ceramic transformer, one end of the energy feedback circuit is connected to the oscillation circuit, and the other end of the energy feedback circuit is connected to the voltage doubling circuit, the voltage doubling circuit is used to amplify the output voltage of the piezoelectric ceramic transformer again, and output negative ions to the air through the negative ion output carbon brush; When the piezoelectric ceramic transformer discharges into the air, if a conductor approaches, the output voltage Vout will change accordingly, and the voltage on the conductive silver paste layer of the top plate will also change accordingly; The MUC reads the change of voltage data through the internal ADC sampling port and performs DC high voltage output voltage feedback detection to adjust the PWM output frequency; The MUC reads the change of voltage data through the internal ADC sampling port. When the voltage data reaches a certain threshold, the MCU turns off the PWM output. The PCB control board is formed by pressing a top layer board, a middle layer board and a bottom layer board together, and the PCB control board is made by using an immersion gold process.

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