Power supply circuit for dielectric barrier discharge and electronic equipment

Abstract

The invention discloses a power supply circuit for dielectric barrier discharge and electronic equipment. The power supply circuit for dielectric barrier discharge comprises an alternating current oscillation circuit and an alternating current pulse control circuit, wherein the alternating current oscillation circuit is used for generating an alternating current signal of a first frequency; and the AC pulse control circuit is connected with the AC oscillation circuit and is used for controlling intermittent conduction of the AC oscillation circuit based on a control signal with a set duty ratio, so that the AC oscillation circuit outputs an intermittent AC signal. The intermittent alternating current signal is different from a continuous alternating current signal, and the intermittent alternating current signal has a higher voltage peak-to-peak value under the same input power, so that the ionization capability of air can be enhanced, and more free radicals and high-oxidability molecules can be generated; in addition, an intermittent period is introduced between the continuous alternating current signals, accumulation of ozone concentration can be effectively reduced, and the application effect of air purification and / or sterilization based on dielectric barrier discharge in indoor sealing and other scenes can be improved.

Description

Technical Field

[0001] The present application relates to the field of circuits, and in particular to a power supply circuit and electronic equipment for dielectric barrier discharge (DBD). Background Art

[0002] The principle of dielectric barrier discharge is a non-equilibrium gas discharge in which an insulating medium is inserted into the discharge space, that is, a gas discharge phenomenon in which a low-temperature discharge plasma is generated in the air gap by inserting an insulating medium into the air gap between two metal electrodes. Dielectric barrier discharge is also called dielectric barrier corona discharge or silent discharge. During the discharge process, the air will be ionized to generate plasma; it can be widely used in the production of ozone, modification, grafting, surface tension improvement, cleaning and hydrophilic modification of polymer and metal films and plates. Dielectric barrier discharge power supply generally refers to a driving power supply that can realize dielectric barrier discharge. Dielectric barrier discharge power supply is widely used in ozone generators, corona machines, UV ultraviolet light curing machines, electric spark machines, plasma jet devices, etc.

[0003] In the related art, the air purification and / or sterilization functions can be realized based on the ionization effect of dielectric barrier discharge on the air. For example, the dielectric barrier discharge device is integrated on the air conditioner to achieve the functions of sterilization and deodorization. However, when driven by an alternating current (AC) power supply, although free radicals and highly oxidizing molecules can be generated, they are accompanied by the generation of high concentrations of ozone. In addition, if you want to improve the effect of ionizing the air by increasing the peak-to-peak value of the driving AC voltage, that is, to generate more free radicals and plasma, the ozone generated will also increase, which will harm the human body and affect the application of dielectric barrier discharge. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a power supply circuit and an electronic device for dielectric barrier discharge, aiming to improve the application effect of dielectric barrier discharge in air purification and / or sterilization scenarios.

[0005] The technical solution of the embodiment of the present application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a power supply circuit for dielectric barrier discharge, comprising:

[0007] An AC oscillation circuit, used for generating an AC signal of a first frequency;

[0008] The AC pulse control circuit is connected to the AC oscillation circuit and is used to control the intermittent conduction of the AC oscillation circuit based on a control signal that sets a duty cycle, so that the AC oscillation circuit outputs an intermittent AC signal.

[0009] In some embodiments, the AC oscillation circuit is a separately excited AC oscillation circuit that controls at least two switching tubes to conduct alternately based on a driving signal, or is a self-excited AC oscillation circuit that controls at least two switching tubes to conduct alternately based on a conduction time difference.

[0010] In some embodiments, if the AC oscillation circuit is the externally driven AC oscillation circuit, the AC oscillation circuit includes:

[0011] A microcontroller, configured to output two drive signals with a phase difference of 180°, wherein the frequency of the drive signals is the first frequency;

[0012] A first switch tube and a second switch tube, wherein the two drive signals with a phase difference of 180° drive the first switch tube and the second switch tube respectively, and control the first switch tube and the second switch tube to be alternately turned on;

[0013] A transformer, the transformer comprising a first coil and a second coil located on a primary side and a third coil located on a secondary side;

[0014] Among them, the first end of the first coil and the first end of the second coil are connected and powered by a DC power supply, the second end of the first coil is connected to the first switching tube, and the second end of the second coil is connected to the second switching tube; based on the alternating conduction of the first switching tube and the second switching tube, the first coil and the second coil oscillate at the first frequency, and the third coil leads to the output terminal of the AC oscillation circuit.

[0015] In some embodiments, the AC oscillation circuit further comprises:

[0016] A first high-frequency filtering circuit is provided between the first switch tube and a power supply branch connected to the first end of the first coil, and is used to filter a high-frequency resonance signal of the first switch tube;

[0017] The second high-frequency filtering circuit is arranged between the second switch tube and a power supply branch connected to the first end of the second coil, and is used for filtering the high-frequency resonance signal of the second switch tube.

[0018] In some embodiments, the driving signal is a square wave pulse signal, the first coil and the second coil oscillate at the first frequency to output a sinusoidal wave signal, the peak-to-peak amplitude of the sinusoidal wave signal is m times the supply voltage of the DC power supply, the first coil and the second coil have the same number of turns and the turns ratio between them and the third coil is 1 / n, and the peak-to-peak value output by the third coil is m*n times the supply voltage of the DC power supply, wherein the value range of m is 4 to 10.

[0019] In some embodiments, if the AC oscillation circuit is the self-excited driven AC oscillation circuit, the AC oscillation circuit includes:

[0020] A first switch tube and a second switch tube, wherein a driving end of the first switch tube is connected to a DC power supply via a first resistor, and a driving end of the second switch tube is connected to the DC power supply via a second resistor;

[0021] A transformer, the transformer comprising a first coil, a second coil and a third coil located on a primary side and a fourth coil located on a secondary side;

[0022] Among them, the first end of the first coil and the first end of the second coil are connected and powered by the DC power supply, the second end of the first coil is connected to the first switch tube, the second end of the second coil is connected to the second switch tube, and the third coil is connected between the terminal of the first resistor connected to the driving end of the first switch tube and the terminal of the second resistor connected to the driving end of the second switch tube; based on the alternating conduction of the first switch tube and the second switch tube, the first coil and the second coil oscillate at the first frequency, and the third coil leads to the output terminal of the AC oscillation circuit.

[0023] In some embodiments, the AC oscillation circuit further comprises:

[0024] The first capacitor is arranged between the second end of the first coil and the second end of the second coil.

[0025] In some embodiments, the AC pulse control circuit includes: a voltage dividing resistor, a first conducting branch, and a second conducting branch;

[0026] The first end of the voltage-dividing resistor is connected to the power supply, and the second end of the voltage-dividing resistor is grounded via the first conducting branch and the second conducting branch respectively. The first conducting branch includes a switching tube that is intermittently conducted under the control signal of the set duty cycle, and the second conducting branch includes a switching tube that controls the intermittent conduction of the AC oscillation circuit.

[0027] In some embodiments, the frequency of the control signal for setting the duty cycle is less than the first frequency, and the sum of the duty cycle of the intermittent AC signal and the set duty cycle is 1.

[0028] In a second aspect, an embodiment of the present application provides an electronic device, comprising: a power supply circuit for dielectric barrier discharge as described in the first aspect of the embodiment of the present application, wherein an output end of the power supply circuit is connected to a dielectric barrier discharge generator.

[0029] In some embodiments, the electronic device is an air conditioner.

[0030] The technical solution provided by the embodiment of the present application, the power supply circuit for dielectric barrier discharge includes: an AC oscillation circuit and an AC pulse control circuit, the AC oscillation circuit is used to generate an AC signal of a first frequency; the AC pulse control circuit is connected to the AC oscillation circuit, and is used to control the intermittent conduction of the AC oscillation circuit based on a control signal that sets a duty cycle, so that the AC oscillation circuit outputs an intermittent AC signal. The intermittent AC signal is different from the continuous AC signal. Under the same input power, the intermittent AC signal has a higher peak-to-peak voltage, which can enhance the ionization ability of the air and generate more free radicals and highly oxidizing molecules; in addition, the introduction of an intermittent period in the middle of the continuous AC signal can effectively reduce the accumulation of ozone concentration, which is conducive to improving the application effect of air purification and / or sterilization based on dielectric barrier discharge in indoor sealing and other scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the structure of a power supply circuit for dielectric barrier discharge in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of the structure of a power supply circuit based on a separately excited driven AC oscillation circuit in an application example of the present application;

[0033] Figure 3 A schematic diagram of the structure of a power supply circuit based on a self-excited driven AC oscillation circuit in an application example of the present application;

[0034] Figure 4 This is a schematic diagram of an intermittent AC signal output by a power supply circuit for dielectric barrier discharge in an application example of the present application. DETAILED DESCRIPTION

[0035] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0037] The present application embodiment provides a power supply circuit for dielectric barrier discharge, such as Figure 1 As shown, the power supply circuit includes: an AC oscillation circuit 10 and an AC pulse control circuit 20. The AC oscillation circuit 10 is used to generate an AC signal of a first frequency; the AC pulse control circuit 20 is connected to the AC oscillation circuit 10 and is used to control the intermittent conduction of the AC oscillation circuit 10 based on a control signal that sets a duty cycle, so that the AC oscillation circuit 10 outputs an intermittent AC signal, for example, Figure 1 The intermittent sine wave signal shown.

[0038] In the embodiment of the present application, the intermittent AC signal is different from the continuous AC signal. Under the same input power, the intermittent AC signal has a higher peak-to-peak voltage, which can enhance the ionization ability of the air and produce more free radicals and highly oxidizing molecules. In addition, introducing an intermittent period in the middle of the continuous AC signal can effectively reduce the accumulation of ozone concentration, which is beneficial to improving the application effect of air purification and / or sterilization based on dielectric barrier discharge in scenarios such as indoor sealing.

[0039] Exemplarily, the AC oscillation circuit 10 is a separately excited AC oscillation circuit that controls at least two switching tubes to be alternately turned on based on a driving signal, or a self-excited AC oscillation circuit that controls at least two switching tubes to be alternately turned on based on a turn-on time difference.

[0040] The switching tube in the embodiment of the present application can be an IGBT (Insulated Gate Bipolar Transistor), or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or a triode, which is not limited in the embodiment of the present application.

[0041] Here, for the separately excited driven AC oscillator circuit, a microcontroller (MCU) may be used to output a driving signal so that at least two switch tubes are alternately turned on, thereby generating an AC signal of a first frequency.

[0042] Here, for the self-excited driven AC oscillation circuit, the at least two switching tubes can be alternately turned on based on the turn-on time difference of the at least two switching tubes, thereby generating an AC signal of the first frequency.

[0043] Exemplarily, the AC pulse control circuit 20 includes: a voltage-dividing resistor, a first conductive branch and a second conductive branch; the first end of the voltage-dividing resistor is connected to a power supply, and the second end of the voltage-dividing resistor is grounded via the first conductive branch and the second conductive branch respectively; the first conductive branch includes a switching tube that is intermittently conducted under the control of a control signal with a set duty cycle, and the second conductive branch includes a switching tube that controls the intermittent conduction of the AC oscillation circuit 10.

[0044] It can be understood that, under the drive of the control signal for setting the duty cycle, the switch tube of the first conducting branch is intermittently turned on. When the switch tube of the first conducting branch is turned off, the switch tube of the second conducting branch is turned on; when the switch tube of the first conducting branch is turned on, the switch tube of the second conducting branch is turned off. In this way, the AC oscillation circuit 10 can be controlled to be intermittently turned on based on the switch tube of the second conducting branch, thereby realizing the output of intermittent AC signals.

[0045] Exemplarily, the frequency of the control signal for setting the duty cycle is less than the first frequency, and the sum of the duty cycle of the intermittent AC signal and the set duty cycle is 1. For example, assuming that the control signal for setting the duty cycle is a pulse square wave signal, the set duty cycle is d, and the frequency of the pulse square wave signal is f, then the duty cycle of the intermittent AC signal is 1-d, and the frequency of the intermittent AC signal is f. Assuming that the AC signal of the first frequency is a sine wave signal, the first frequency of the sine wave signal is f1, and since f<f1, one cycle of the intermittent AC signal includes at least one cycle of the sine wave signal. In this way, the parameter control of the intermittent AC signal can be achieved based on the set duty cycle d, frequency f and first frequency f1 of the AC signal of the control signal, thereby effectively adjusting the ionization frequency of the DBD mode and / or the duration of the intermittent period introduced in the continuous AC signal, so as to enhance the ionization ability of the air while effectively reducing the accumulation of ozone concentration.

[0046] Exemplarily, the first frequency f1 of the AC signal can be the optimal ionization frequency of the DBD mode. The optimal ionization frequency of the DBD mode refers to the target frequency that makes the air ionization effect of the DBD better. Exemplarily, the optimal ionization frequency can be 36±5KHz (kilohertz). It should be noted that if the ionization frequency is too large, the micro-discharge of the DBD will be reduced, and the free radicals and highly oxidizing molecules generated will be reduced; if the ionization frequency is too small, it will cause uneven discharge, the slope of the electric field change will become smaller, and it will be difficult to effectively break through the air ionization. Therefore, in order to achieve a better air ionization effect, it is necessary to select the first frequency f1 as the optimal ionization frequency of the DBD mode.

[0047] It can be understood that by selecting and setting the duty cycle d, the duty cycle of the intermittent AC signal can be controlled, so that the duration of the intermittent period in a single cycle of the intermittent AC signal can meet the requirement of effectively reducing the accumulation of ozone concentration.

[0048] Exemplarily, if the AC oscillation circuit is a separately driven AC oscillation circuit, the AC oscillation circuit includes:

[0049] A microcontroller, configured to output two drive signals with a phase difference of 180°, and the frequency of the drive signal is a first frequency;

[0050] The first switch tube and the second switch tube are driven by two driving signals with a phase difference of 180°, respectively, to control the first switch tube and the second switch tube to be turned on alternately;

[0051] A transformer, the transformer comprising a first coil and a second coil located on a primary side and a third coil located on a secondary side;

[0052] Among them, the first end of the first coil and the first end of the second coil are connected and powered by a DC power supply, the second end of the first coil is connected to the first switching tube, and the second end of the second coil is connected to the second switching tube; based on the alternating conduction of the first switching tube and the second switching tube, the first coil and the second coil oscillate at a first frequency, and the third coil leads to the output terminal of the AC oscillation circuit.

[0053] In an application example, Figure 2 As shown, this application example provides a power supply circuit based on a separately excited driving type AC oscillation circuit 10A, and the power supply circuit includes: an AC pulse control circuit 20 and a separately excited driving type AC oscillation circuit 10A.

[0054] like Figure 2 As shown, the AC pulse control circuit 20 includes: a voltage-dividing resistor R3, a switch tube Q3 (i.e., the switch tube of the aforementioned second conductive branch) and a switch tube Q4 (i.e., the switch tube of the aforementioned first conductive branch). Exemplarily, the switch tube Q3 and the switch tube Q4 are MOS tubes, i.e., the abbreviation of MOSFET. The first end of the voltage-dividing resistor R3 is connected to the DC power supply DC, the second end of the voltage-dividing resistor R3 is respectively connected to the gate of the switch tube Q3 and the drain of the switch tube Q4, the source of the switch tube Q3 and the source of the switch tube Q4 are grounded, the gate of the switch tube Q4 is connected to the control signal for setting the duty cycle, and the drain of the switch tube Q3 is connected to the externally excited drive type AC oscillation circuit 10A.

[0055] The control signal for setting the duty cycle can be a square wave pulse signal with a frequency of f and a duty cycle of d, which can drive the switch tube Q4 to be intermittently turned on. When the switch tube Q4 is turned off, the switch tube Q3 is turned on; when the switch tube Q4 is turned on, the switch tube Q3 is turned off. In this way, based on the Vds (drain-source voltage) of the switch tube Q3, the separately excited drive type AC oscillation circuit 10A can be controlled to be intermittently turned on, thereby realizing the output of intermittent AC signals.

[0056] like Figure 2As shown, the separately excited driven AC oscillation circuit 10A includes: a microcontroller MCU, a first switch tube Q1, a second switch tube Q2 and a transformer T, and the MCU generates two drive signals with a phase difference of 180°, and the frequency of the drive signal is f1. Exemplarily, the first switch tube Q1 and the second switch tube Q2 can be MOS tubes. One drive signal is connected to the gate of the first switch tube Q1, and the other drive signal is connected to the gate of the second switch tube Q2. The transformer T includes: a first coil L1 and a second coil L2 located on the primary side and a third coil L3 located on the secondary side; wherein the first end of the first coil L1 and the first end of the second coil L2 are connected and powered by a DC power supply DC, the second end of the first coil L1 is connected to the drain of the first switch tube Q1, and the second end of the second coil L2 is connected to the drain of the second switch tube Q2; the source of the first switch tube Q1 and the source of the second switch tube Q2 are both connected to the drain of the switch tube Q3. Based on the alternating conduction of the first switch tube Q1 and the second switch tube Q2, the first coil L1 and the second coil L2 oscillate at the first frequency f1, and the third coil L3 leads to the output terminal of the AC oscillation circuit, which is connected to the dielectric barrier discharge generator to provide working power for the dielectric barrier discharge generator to achieve dielectric barrier discharge.

[0057] Exemplarily, the driving signal is a square wave pulse signal, the first coil L1 and the second coil L2 oscillate and output a sine wave signal at a first frequency f1, the peak-to-peak amplitude of the sine wave signal is m times the supply voltage of the DC power supply, the first coil L1 and the second coil L2 have the same number of turns and the turns ratio between them and the third coil L3 is 1 / n, the peak-to-peak value output by the third coil L3 is m*n times the supply voltage of the DC power supply DC, where the value range of m is 4 to 10. In an application example, the peak-to-peak amplitude of the sine wave signal is 4 times the supply voltage of the DC power supply DC, and the peak-to-peak value output by the third coil L3 is 4n times the supply voltage of the DC power supply DC.

[0058] Exemplarily, the duty cycle of the square wave pulse signal is close to 50% but less than 50%, so that a set dead zone can be reserved to prevent iron loss caused by excessive current when the first switch tube Q1 and the second switch tube Q2 are turned on at the same time.

[0059] Exemplarily, considering that in the separately excited driving mode, when the transformer T oscillates at the first frequency f1, the leakage inductance of the transformer T is small, and it is easy to form a high-frequency resonance. Based on this, the separately excited driving type AC oscillation circuit 10A also includes: a first high-frequency filtering circuit and a second high-frequency filtering circuit. The first high-frequency filtering circuit is arranged between the first switch tube and the power supply branch connected to the first end of the first coil, and is used to filter the high-frequency resonance signal of the first switch tube; the second high-frequency filtering circuit is arranged between the second switch tube and the power supply branch connected to the first end of the second coil, and is used to filter the high-frequency resonance signal of the second switch tube.

[0060] Exemplarily, the first high-frequency filter circuit and the second high-frequency filter circuit are both RCD high-frequency filter circuits. Figure 2 As shown, the diode D3, the capacitor C2 and the resistor R4 constitute a first high-frequency filtering circuit; the diode D4, the capacitor C3 and the resistor R5 constitute a second high-frequency filtering circuit.

[0061] Exemplarily, if the AC oscillation circuit is a self-excitation driven AC oscillation circuit, the AC oscillation circuit includes:

[0062] A first switch tube and a second switch tube, wherein a driving end of the first switch tube is connected to a DC power supply via a first resistor, and a driving end of the second switch tube is connected to the DC power supply via a second resistor;

[0063] A transformer, the transformer comprising a first coil, a second coil and a third coil located on a primary side and a fourth coil located on a secondary side;

[0064] Among them, the first end of the first coil and the first end of the second coil are connected and powered by a DC power supply, the second end of the first coil is connected to the first switching tube, the second end of the second coil is connected to the second switching tube, and the third coil is connected between the terminal of the first resistor connected to the driving end of the first switching tube and the terminal of the second resistor connected to the driving end of the second switching tube; based on the alternating conduction of the first switching tube and the second switching tube, the first coil and the second coil oscillate at the first frequency, and the third coil leads to the output terminal of the AC oscillation circuit.

[0065] Exemplarily, the AC oscillation circuit further includes:

[0066] The first capacitor is arranged between the second end of the first coil and the second end of the second coil.

[0067] In an application example, Figure 3 As shown, this application example provides a power supply circuit based on a self-excited driven AC oscillation circuit 10B, and the power supply circuit includes: an AC pulse control circuit 20 and a self-excited driven AC oscillation circuit 10B.

[0068] The AC pulse control circuit 20 is similar to the aforementioned Figure 2 The AC pulse control circuit 20 shown is similar, and the details can be referred to the above description, which will not be repeated here.

[0069] like Figure 3As shown, the self-excited driven AC oscillation circuit 10B includes: a first switch tube Q1, a second switch tube Q2 and a transformer T. Here, the first switch tube Q1 and the second switch tube Q2 are triodes, and the transformer T includes: a first coil L1, a second coil L2 and a third coil L3 located on the primary side and a fourth coil L4 located on the secondary side. The first end of the first coil L1 and the first end of the second coil L2 are connected and powered by a DC power supply DC, the second end of the first coil L1 is connected to the collector of the first switch tube Q1, and the second end of the second coil L2 is connected to the collector of the second switch tube Q2. The base of the first switch tube Q1 is connected to the DC power supply DC via the first resistor R1, and the base of the second switch tube Q2 is connected to the DC power supply DC via the second resistor R2. The third coil L3 is connected between the terminal of the first resistor R1 connected to the base of the first switch tube Q1 and the terminal of the second resistor R2 connected to the base of the second switch tube Q2. A first capacitor C1 is arranged between the second end of the first coil L1 and the second end of the second coil L2. The emitter of the first switch tube Q1 and the emitter of the second switch tube Q2 are connected to the drain of the switch tube Q3 .

[0070] Understandably, Figure 3 In the self-excitation driven AC oscillation circuit 10B shown, under the power supply of the DC power supply DC, the first switch tube Q1 and the second switch tube Q2 are both powered on, but due to the time difference between the first switch tube Q1 and the second switch tube Q2 being turned on, when the first switch tube Q1 is turned on, the first coil L1 and the third coil L3 are mutually inductive, and the second switch tube Q2 is turned off; when the second switch tube Q2 is turned on, the second coil L2 and the third coil L3 are mutually inductive, and the first switch tube Q1 is turned off. Based on the alternating conduction of the first switch tube Q1 and the second switch tube Q2, the first coil L1 and the second coil L2 oscillate at the first frequency f1, and the fourth coil L4 leads to the output terminal of the AC oscillation circuit, which is connected to the dielectric barrier discharge generator to provide working power for the dielectric barrier discharge generator to achieve dielectric barrier discharge.

[0071] Exemplarily, the first coil L1 and the second coil L2 oscillate and output a sinusoidal wave signal at a first frequency f1, and a peak-to-peak amplitude of the sinusoidal wave signal is 4 times the supply voltage of the DC power supply.

[0072] Exemplarily, the calculation formula of the first frequency f1 is as follows:

[0073]

[0074] Wherein, L1 is the inductance of the first coil L1, and the inductance of the first coil L1 and the second coil L2 are equal, C1 is the capacitance of the primary coupling capacitor (i.e., the first capacitor C1), and CP is the capacitance of the secondary coupling capacitor. Exemplarily, the number of turns of the first coil L1 and the second coil L2 are the same and the turn ratio between them and the fourth coil L4 is 1 / n, then CP=n 2*Load capacitance, that is, the first frequency f1 decreases as the load capacitance (that is, output capacitance) increases.

[0075] It can be understood that the self-excited driven AC oscillation circuit 10B can eliminate the MCU, so that the circuit cost is reduced and the volume is smaller. However, its first frequency f1 will change with the change of load capacitance.

[0076] In an application example, Figure 4 As shown, the intermittent AC signal output by the power supply circuit for dielectric barrier discharge is an intermittent sinusoidal wave signal, wherein the peak-to-peak value of the intermittent AC signal is U, which is 4n times the supply voltage of the DC power supply DC. The higher the peak-to-peak value, the better the air ionization effect; the first frequency f1 (i.e., the frequency of the sine wave) = 1 / t3, the frequency of the intermittent AC signal = 1 / t2, and the output duty cycle of the intermittent AC signal = t1 / t2.

[0077] It should be noted that the duration t1 affects the sterilization and / or deodorization effect and the concentration of ozone. The duration t3 is related to the dielectric barrier material and structure. By adjusting the duration T3, the optimal ionization frequency of the DBD mode can be obtained, thereby ensuring a better air ionization effect.

[0078] The embodiment of the present application also provides an electronic device, which includes a power supply circuit for dielectric barrier discharge as described in the embodiment of the present application, and the output end of the power supply circuit is connected to a plasma generator or a dielectric barrier discharge generator. In this way, based on the intermittent AC signal output by the power supply circuit as a driving power supply, the dielectric barrier discharge generator can achieve sterilization, deodorization and other effects based on dielectric barrier discharge, and can effectively reduce the ozone concentration.

[0079] It can be understood that the intermittent AC signal is different from the continuous AC signal. Under the same input power, the intermittent AC signal has a higher peak-to-peak voltage, which can enhance the ionization ability of the air and produce more free radicals and highly oxidizing molecules. In addition, introducing an intermittent period in the middle of the continuous AC signal can effectively reduce the accumulation of ozone concentration, which is beneficial to improving the application effect of air purification and / or sterilization based on dielectric barrier discharge in scenarios such as indoor sealing.

[0080] Exemplarily, the electronic device may be an air conditioner. The air conditioner is used to adjust the temperature, humidity, etc. of the environment. The air conditioner may be a cooling-only air conditioner or a cooling-heating dual-purpose air conditioner. The air conditioner may be a wall-mounted air conditioner, a cabinet-type air conditioner, a window-type air conditioner, or a ceiling-mounted air conditioner, etc., which is not specifically limited in the embodiments of the present application.

[0081] Exemplarily, the dielectric barrier discharge generator can be arranged in the air duct of the air conditioner, and can utilize the free radicals and highly oxidizing molecules generated by the dielectric barrier discharge to eliminate bacteria in the air duct and the indoor environment, thereby purifying the air well. An intermittent AC signal is used as a driving power source. The intermittent AC signal has a higher peak-to-peak voltage, thereby enhancing the ionization ability of the air and generating more free radicals and highly oxidizing molecules. In addition, introducing an intermittent period in the middle of the continuous AC signal can effectively reduce the accumulation of ozone concentration, which is beneficial to improving the application effect of air purification and / or sterilization based on dielectric barrier discharge in scenarios such as indoor sealing.

[0082] For example, the indoor unit of the air conditioner can provide the aforementioned control signal for setting the duty cycle to the AC pulse control circuit, and then the AC pulse control circuit controls the intermittent conduction of the AC oscillation circuit. The control signal for setting the duty cycle provided by the indoor unit can be a pulse square wave signal for setting the duty cycle.

[0083] It is understandable that, in other embodiments, the electronic device may also be an electronic device with air purification function such as a fresh air blower.

[0084] It should be noted that: "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0085] In addition, the technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict.

[0086] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power supply circuit for dielectric barrier discharge, characterized in that: include: An AC oscillation circuit, used for generating an AC signal of a first frequency; The AC pulse control circuit is connected to the AC oscillation circuit and is used to control the intermittent conduction of the AC oscillation circuit based on a control signal that sets a duty cycle, so that the AC oscillation circuit outputs an intermittent AC signal.

2. The power supply circuit according to claim 1, characterized in that: The AC oscillation circuit is a separately excited AC oscillation circuit that controls at least two switching tubes to conduct alternately based on a driving signal, or a self-excited AC oscillation circuit that controls at least two switching tubes to conduct alternately based on a conduction time difference.

3. The power supply circuit according to claim 2, characterized in that: If the AC oscillation circuit is the externally excited driven AC oscillation circuit, the AC oscillation circuit includes: A microcontroller, configured to output two drive signals with a phase difference of 180°, wherein the frequency of the drive signals is the first frequency; A first switch tube and a second switch tube, wherein the two drive signals with a phase difference of 180° drive the first switch tube and the second switch tube respectively, and control the first switch tube and the second switch tube to be alternately turned on; A transformer, the transformer comprising a first coil and a second coil located on a primary side and a third coil located on a secondary side; Among them, the first end of the first coil and the first end of the second coil are connected and powered by a DC power supply, the second end of the first coil is connected to the first switching tube, and the second end of the second coil is connected to the second switching tube; based on the alternating conduction of the first switching tube and the second switching tube, the first coil and the second coil oscillate at the first frequency, and the third coil leads to the output terminal of the AC oscillation circuit.

4. The power supply circuit according to claim 3, characterized in that: The AC oscillation circuit also includes: A first high-frequency filtering circuit is provided between the first switch tube and a power supply branch connected to the first end of the first coil, and is used to filter a high-frequency resonance signal of the first switch tube; The second high-frequency filtering circuit is arranged between the second switch tube and a power supply branch connected to the first end of the second coil, and is used for filtering the high-frequency resonance signal of the second switch tube.

5. The power supply circuit according to claim 3, characterized in that: The driving signal is a square wave pulse signal, the first coil and the second coil oscillate and output a sinusoidal wave signal at the first frequency, the peak-to-peak amplitude of the sinusoidal wave signal is m times the supply voltage of the DC power supply, the first coil and the second coil have the same number of turns and the turns ratio between the first coil and the second coil and the third coil is 1 / n, and the peak-to-peak value output by the third coil is m*n times the supply voltage of the DC power supply, wherein the value range of m is 4 to 10.

6. The power supply circuit according to claim 2, characterized in that: If the AC oscillation circuit is the self-excitation driven AC oscillation circuit, the AC oscillation circuit includes: A first switch tube and a second switch tube, wherein a driving end of the first switch tube is connected to a DC power supply via a first resistor, and a driving end of the second switch tube is connected to the DC power supply via a second resistor; A transformer, the transformer comprising a first coil, a second coil and a third coil located on a primary side and a fourth coil located on a secondary side; Among them, the first end of the first coil and the first end of the second coil are connected and powered by the DC power supply, the second end of the first coil is connected to the first switch tube, the second end of the second coil is connected to the second switch tube, and the third coil is connected between the terminal of the first resistor connected to the driving end of the first switch tube and the terminal of the second resistor connected to the driving end of the second switch tube; based on the alternating conduction of the first switch tube and the second switch tube, the first coil and the second coil oscillate at the first frequency, and the third coil leads to the output terminal of the AC oscillation circuit.

7. The power supply circuit according to claim 6, characterized in that: The AC oscillation circuit also includes: The first capacitor is arranged between the second end of the first coil and the second end of the second coil.

8. The power supply circuit according to claim 1, characterized in that: The AC pulse control circuit comprises: a voltage dividing resistor, a first conducting branch and a second conducting branch; The first end of the voltage-dividing resistor is connected to the power supply, and the second end of the voltage-dividing resistor is grounded via the first conducting branch and the second conducting branch respectively. The first conducting branch includes a switching tube that is intermittently conducted under the control signal of the set duty cycle, and the second conducting branch includes a switching tube that controls the intermittent conduction of the AC oscillation circuit.

9. The power supply circuit according to claim 1, characterized in that: The frequency of the control signal for setting the duty cycle is less than the first frequency, and the sum of the duty cycle of the intermittent AC signal and the set duty cycle is 1.

10. An electronic device, characterized in that: include: The power supply circuit for dielectric barrier discharge according to any one of claims 1 to 9, wherein the output end of the power supply circuit is connected to a dielectric barrier discharge generator.

11. The electronic device according to claim 10, characterized in that: The electronic device is an air conditioner.

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