Driving circuit, negative ion generator, air treatment equipment and control method

Abstract

The invention discloses a driving circuit, a negative ion generator, air treatment equipment and a control method, and the driving circuit comprises an output terminal which is used for being electrically connected with a discharge electrode of the negative ion generator, and the discharge electrode is provided with a tip; and the output terminal is configured to output a direct current negative voltage with fluctuating voltage to drive the discharge electrode to generate negative ions. The concentration of negative ions generated by the negative ion generator during long-time working cannot be reduced.

Description

Technical Field

[0001] The present invention relates to negative ion generating technology, and more particularly to a driving circuit, a negative ion generator, an air treatment device and a control method. Background Art

[0002] Negative ion generators can produce negative ions to purify the air, and are widely used in air conditioners, fresh air systems, air purifiers, car air purifiers, hair dryers and other scenarios to improve people's living environment.

[0003] The negative ion generator includes a discharge electrode, which has a tip with a small radius of curvature. After a constant negative high voltage is applied to the discharge electrode, the discharge electrode performs corona discharge, ionizing the air near the tip of the discharge electrode to generate a large number of electrons. The electrons react with the electrophilic O 2 or H 2 O and other substances combine to form negative ions, which diffuse into the air and purify the air.

[0004] However, when the negative ion generator works for a long time, the discharge of the discharge electrode will gradually decay and the concentration of negative ions generated will gradually decrease. Summary of the invention

[0005] The present application provides a driving circuit of a negative ion generator, which comprises: an output terminal for electrically connecting a discharge electrode of the negative ion generator, the discharge electrode having a pointed end;

[0006] The output terminal is configured to output a DC negative voltage with voltage fluctuation to drive the discharge electrode to generate negative ions.

[0007] In an illustrative embodiment, the negative DC voltage is formed by superimposing a constant negative DC voltage and an AC voltage.

[0008] In an illustrative embodiment, it also includes:

[0009] A boost circuit configured to boost an input voltage into an AC voltage;

[0010] a rectifier circuit, electrically connected to the boost circuit and the output terminal, for converting the AC voltage into a constant negative DC voltage output to the output terminal; and

[0011] The AC circuit is electrically connected to the boost circuit and the output terminal, and is used to transmit the AC voltage to the output terminal.

[0012] In an illustrative embodiment, the AC circuit includes a third capacitor;

[0013] The third capacitor includes a third electrode and a fourth electrode electrically connected to the output terminal;

[0014] Wherein, the third electrode is electrically connected to the boost circuit, and is used to receive the AC voltage output by the boost circuit.

[0015] In an illustrative embodiment, the negative DC voltage is formed by superimposing a constant negative DC voltage and a pulse voltage.

[0016] In an illustrative embodiment, it also includes:

[0017] A boost circuit configured to boost an input voltage into an AC voltage;

[0018] a rectifier circuit, electrically connected to the boost circuit and the output terminal, for converting the AC voltage into a constant negative DC voltage output to the output terminal; and

[0019] The pulse circuit is electrically connected to the boost circuit and the output terminal, and is used for converting the AC voltage into a pulse voltage output to the output terminal.

[0020] In an illustrative embodiment, the pulse circuit includes a sixth capacitor and a second resistor;

[0021] The sixth capacitor includes a fifth electrode and a sixth electrode electrically connected to the output terminal;

[0022] One end of the second resistor is electrically connected to the output terminal, and the boost circuit loads an AC voltage between the other end of the second resistor and the fifth electrode.

[0023] In an illustrative embodiment, the rectifier circuit is a voltage doubler rectifier circuit.

[0024] In an illustrative embodiment, the boost circuit includes a boost transformer, and the boost transformer includes a primary coil and a secondary coil having mutual inductance with the primary coil;

[0025] The rectifier circuit includes

[0026] A diode, including an anode and a cathode;

[0027] a second capacitor, comprising a first electrode electrically connected to the anode and a second electrode electrically connected to a reference ground;

[0028] Wherein, two ends of the secondary coil are electrically connected to the cathode and the second electrode respectively, and the output terminal is electrically connected to the first electrode.

[0029] In an illustrative embodiment, the boost circuit further includes:

[0030] A first input terminal, including a positive input terminal and a negative input terminal;

[0031] a switching device, comprising a collector, an emitter electrically connected to the negative input terminal, and a base;

[0032] A first inductor, one end of which is connected to the collector;

[0033] a first capacitor, an electrode of which is electrically connected to the other end of the first inductor; and

[0034] a first resistor, one end of which is electrically connected to the other electrode of the capacitor, and the other end of which is electrically connected to the base;

[0035] One end of the primary coil is electrically connected to the positive input terminal, and the other end of the primary coil is electrically connected to the collector.

[0036] In an illustrative embodiment, the boost circuit further includes a fourth capacitor and a fifth capacitor;

[0037] Two electrodes of the fourth capacitor are electrically connected to the emitter and the base, respectively. Two electrodes of the fifth capacitor are electrically connected to the positive input terminal and the negative input terminal, respectively.

[0038] The present application also proposes a negative ion generator, which comprises the driving circuit as described above and a discharge electrode electrically connected to the output terminal.

[0039] The present application also proposes an air treatment device, which includes the negative ion generator as described above.

[0040] The present application also proposes a control method for a negative ion generator, wherein the negative ion generator includes a discharge electrode, and the control method includes:

[0041] A fluctuating DC negative voltage is applied to the discharge electrode to drive the discharge electrode to generate negative ions.

[0042] In an illustrative embodiment, it also includes:

[0043] Generates constant negative DC voltage and AC voltage;

[0044] The constant negative DC voltage and the AC voltage are superimposed to form the fluctuating negative DC voltage.

[0045] In an illustrative embodiment, it also includes:

[0046] Generate constant DC negative voltage and pulse voltage;

[0047] The constant negative DC voltage and the pulse voltage are superimposed to form the fluctuating negative DC voltage.

[0048] In the technical solution of the present application, the driving circuit loads the fluctuating DC negative voltage onto the discharge electrode of the negative ion generator, so that a fluctuating electric field is generated around the discharge electrode. At the same time, due to the small curvature radius of the tip of the discharge electrode, the electric field around the tip of the discharge electrode is also an uneven electric field. The tip of the discharge electrode can generate a large number of electrons. These electrons cannot stably exist on the discharge electrode under the action of the fluctuating electric field, and will be separated from the discharge electrode and enter the air under the action of the fluctuating electric field. In this way, electrons will not accumulate on the discharge electrode and form a "reverse electric field" around the discharge electrode, and the concentration of negative ions generated by the negative ion generator will not decrease over time even if the negative ion generator works for a long time.

[0049] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0051] Figure 1 This is a three-dimensional schematic diagram of a negative ion generator according to the first embodiment of the present application;

[0052] Figure 2 is a schematic diagram of a driving circuit according to Embodiment 1 of the present application;

[0053] Figure 3 is a schematic diagram of a driving circuit according to a second embodiment of the present application;

[0054] Figure 4 Schematic diagram of the waveform of the first negative DC voltage in the embodiment of the present application;

[0055] Figure 5 Schematic diagram of the waveform of the second negative DC voltage in the embodiment of the present application;

[0056] Figure 6 Schematic diagram of the waveform of the third negative DC voltage in the embodiment of the present application. Description of the drawings:

[0058] 100. Negative ion generator; 1. drive circuit; 10. output terminal; 11. boost circuit; a1. positive input terminal; a2. negative input terminal; T. boost transformer; L1. primary coil; L2. secondary coil; L3. first inductor; Q. switch device; c. collector; e. emitter; b. base; R1. first resistor; C1. first capacitor; 12. rectifier circuit; D. diode; d1. anode; d2. cathode; C2. second capacitor; w1. first electrode; w2. second electrode; C3. third capacitor; w3. third electrode; w4. fourth electrode; 13. AC circuit; 1a. drive circuit; 11a. boost circuit; 14. pulse circuit; C6. sixth capacitor; w5. fifth electrode; w6. sixth electrode; R2. second resistor; 2. discharge electrode. DETAILED DESCRIPTION

[0059] In the prior art, a constant negative high voltage is loaded on the discharge electrode of the negative ion generator, so that the discharge electrode continuously ionizes the surrounding air to generate negative ions. When the constant DC negative high voltage is loaded on the tip of the discharge electrode, due to the small radius of curvature of the tip, the electric field distribution near the discharge electrode will be extremely uneven, and the conditions for breaking through the surrounding air will be reached, thereby ionizing the air to generate a large number of electrons. Most of the large number of electrons generated by the discharge electrode ionizing the air will be ejected outward under the action of the gradient electric field, away from the tip of the discharge electrode, and diffused into the air with the wind.

[0060] Since the electrons generated at the tip of the discharge electrode cannot completely detach from the tip of the discharge electrode 100%, there will always be a small amount of electrons remaining and attached to the tip of the discharge electrode. As the discharge time goes by, more and more electrons remain, gradually accumulating to form a "reverse electric field". The charge of the "reverse electric field" is the same as that of the tip of the discharge electrode, which is also a negative high-voltage electric field. The formation of the "reverse electric field" will weaken the uneven electric field around the tip of the discharge electrode, causing the corona discharge intensity to decay, resulting in a decrease in the concentration of electrons generated by the discharge electrode, and then a decrease in the concentration of negative ions. When the "reverse electric field" is close to the value of the loaded high voltage, it is even impossible to generate electrons and negative ions.

[0061] Embodiment 1

[0062] like Figure 1 As shown, this embodiment proposes a negative ion generator 100, which includes a discharge electrode 2 and a driving circuit 1. The discharge electrode 2 is a conductor. The discharge electrode 2 has a tip, which can be needle-shaped or sawtooth-shaped. The tip of the discharge electrode 2 has a small radius of curvature. The discharge electrode 2 can be made of metal, and the metal includes one or more of stainless steel, copper, aluminum, tungsten, and molybdenum. The discharge electrode 2 can also be constructed as a carbon fiber bundle.

[0063] like Figure 2As shown, the driving circuit 1 includes an output terminal 10. The output terminal 10 is electrically connected to the discharge electrode 2. The driving circuit 1 outputs a DC negative voltage to the discharge electrode 2 through the output terminal 10, and the DC negative voltage is loaded on the discharge electrode 2 to drive the discharge electrode 2 to ionize the air to generate negative ions. The DC negative voltage can be -2kV to -10kV. The negative ions combine with positively charged particles such as bacteria, viruses, and dust in the air to cause them to condense and settle, thereby achieving the purpose of reducing fine particles such as bacteria, viruses, and dust in the air.

[0064] The DC negative voltage outputted by the output terminal 10 of the driving circuit 1 is a fluctuating DC negative voltage, that is, the voltage value of the DC negative voltage will oscillate over time. The potential of the output terminal 10 of the driving circuit 1 is lower than the potential of the reference ground.

[0065] In this way, the driving circuit 1 loads the fluctuating DC negative voltage onto the discharge electrode 2 of the negative ion generator 100, so that a fluctuating electric field is generated around the discharge electrode 2. At the same time, since the curvature radius of the tip of the discharge electrode 2 is small, the electric field around the tip of the discharge electrode 2 is also an uneven electric field. The tip of the discharge electrode 2 can generate a large number of electrons. These electrons cannot stably exist on the discharge electrode 2 under the action of the fluctuating electric field, and will be separated from the discharge electrode 2 and enter the air under the action of the fluctuating electric field. In this way, electrons will not accumulate on the discharge electrode 2 and form a "reverse electric field" around the discharge electrode 2, and the concentration of negative ions generated by the negative ion generator 100 will not decrease over time even if the negative ion generator 100 works for a long time.

[0066] In an illustrative embodiment, the driving circuit 1 first generates a constant negative DC voltage and an AC voltage, and then transmits the constant negative DC voltage and the AC voltage to the output terminal 10 of the driving circuit 1 to superimpose a fluctuating negative DC voltage on the output terminal 10 of the driving circuit 1. The waveform of the AC voltage may be a sine wave. The absolute value of the maximum voltage value of the AC voltage is less than or equal to the absolute value of the voltage value of the constant negative DC voltage.

[0067] In this way, the DC negative voltage output by the output terminal 10 of the driving circuit 1 is formed by superimposing a constant DC negative voltage and an AC voltage. The AC voltage is superimposed on the constant DC negative voltage, causing the voltage value of the constant DC negative voltage to fluctuate greatly, thereby generating a fluctuating DC negative voltage.

[0068] In a set of comparative tests, the negative ion generator 100 in the present technical solution uses a carbon fiber bundle as the discharge electrode 2, and the output terminal 10 of the driving circuit 1 outputs a DC negative voltage to the discharge electrode 2. The voltage of the DC negative voltage fluctuates between -5.1 kV and -8.1 kV. The voltage falling edge speed of the DC negative voltage is 138 V / us and the voltage frequency is 19 KHz. The electrical signal waveform of the DC negative voltage is as shown in FIG. Figure 4As shown, the negative ion generator 100 was operated continuously for 720 hours under three operating conditions of relative humidity of 30% RH, 60% RH and 90% RH, and no attenuation of negative ion concentration was observed.

[0069] The negative ion generator 100 in the prior art uses a carbon fiber bundle as the discharge electrode 2, and the output terminal 10 of the driving circuit 1 outputs a constant DC negative voltage to the discharge electrode 2, and the constant DC negative voltage is -5.13kV. The negative ion generator 100 is continuously operated for 2 hours at an ambient relative humidity of 30% RH, and the negative ion concentration generated is attenuated by 30%, and the negative ion concentration generated after 4 hours of operation is attenuated by 50%; the negative ion concentration generated is attenuated by 20% after continuous operation for 12 hours at 60% RH; and the negative ion concentration generated is attenuated by 30% after continuous operation for 168 hours at 90% RH.

[0070] In an illustrative embodiment, the driving circuit 1 includes a boost circuit 11, a rectifier circuit 12 and an AC circuit 13. The boost circuit 11 includes a first input terminal and a first output terminal. The first input terminal is connected to an external power supply for receiving an input voltage. The power supply can be a DC power supply or an AC power supply. The input voltage received by the first input terminal can be a DC voltage or an AC voltage. The boost circuit 11 boosts the input voltage and converts it into an AC voltage and outputs it from the first output terminal.

[0071] The boost circuit 11 can use a boost transformer to boost the voltage of the input voltage. When the input voltage is a DC voltage, the input voltage can be first converted into an AC voltage through an inverter circuit or a self-excited oscillation circuit, and then the AC voltage is transmitted to the boost transformer for boosting. When the input voltage is an AC voltage, the AC voltage can be directly transmitted to the boost transformer for boosting.

[0072] The rectifier circuit 12 is a circuit that converts AC power into DC power. The rectifier circuit 12 can be a half-wave rectifier circuit, a full-wave rectifier circuit, a bridge rectifier or a voltage doubler rectifier circuit. The rectifier circuit 12 includes a second input terminal and a second output terminal. The second input terminal of the rectifier circuit 12 is electrically connected to the first output terminal of the boost circuit 11. The second output terminal of the rectifier circuit 12 is electrically connected to the output terminal 10. The rectifier circuit 12 is configured to convert the AC voltage input by the boost circuit 11 into a constant DC negative voltage, and transmit the constant DC negative voltage to the output terminal 10.

[0073] The AC circuit 13 includes a third input terminal and a third output terminal. The third input terminal of the AC circuit 13 is electrically connected to the first output terminal of the boost circuit 11. The third output terminal of the AC circuit 13 is electrically connected to the output terminal 10. The AC circuit 13 is configured to transmit the AC voltage output by the boost circuit 11 to the output terminal 10.

[0074] In this way, after the boost circuit 11 increases the input voltage and converts it into an AC voltage, the rectifier circuit 12 converts the AC voltage into a constant DC negative voltage and transmits it to the output terminal 10, and the AC circuit 13 transmits the AC voltage to the output terminal 10 and superimposes it with the constant DC negative voltage to generate a fluctuating DC negative voltage at the output terminal 10.

[0075] In an exemplary embodiment, the first input terminal includes a positive input terminal a1 and a negative input terminal a2. The positive input terminal a1 is used to electrically connect to the positive electrode of the DC power supply, and the negative input terminal a2 is used to electrically connect to the negative electrode of the DC power supply. The negative input terminal a2 can be connected to a reference ground.

[0076] The boost circuit 11 also includes a boost transformer T, a first inductor L3, a switch device Q, a first resistor R1 and a first capacitor C1. The switch device Q can be a triode or a field effect transistor. The switch device Q includes a collector c, an emitter e and a base b. The first inductor L3, the first capacitor C1 and the first resistor R1 are connected in series between the collector c and the base b of the switch device Q. The collector c of the switch device Q is electrically connected to one end of the first inductor L3, the other end of the first inductor L3 is electrically connected to an electrode of the first capacitor C1, the other electrode of the capacitor is electrically connected to one end of the first resistor R1, and the other end of the first resistor R1 is electrically connected to the base b of the switch device Q. The emitter e of the switch device Q is electrically connected to the negative input terminal a2.

[0077] The step-up transformer T includes a primary coil L1 and a secondary coil L2. The primary coil L1 and the secondary coil L2 are mutually inducted. The number of turns of the primary coil L1 is less than the number of turns of the secondary coil L2. One end of the primary coil L1 is electrically connected to the positive input terminal a1, and the other end of the primary coil L1 is electrically connected to the collector c of the switching device Q. Both ends of the secondary coil L2 are the first output ends of the step-up circuit 11.

[0078] In this way, the boost circuit 11 is a self-excited oscillation circuit. The first capacitor C1 and the first inductor L3 cause the current in the primary coil L1 to oscillate during the alternating charge and discharge process, and then generate an electromotive force in the secondary coil L2 through mutual inductance, so that the two ends of the secondary coil L2 can output an AC voltage. Since the number of turns of the primary coil L1 is smaller than the number of turns of the secondary coil L2, the AC voltage output by the boost transformer T is greater than the DC voltage input from the first input end. Therefore, the first output end of the boost circuit 11 can output a high-voltage AC voltage.

[0079] In an illustrative embodiment, the rectifier circuit 12 is a voltage doubling rectifier circuit. The rectifier circuit 12 may be a half voltage doubling rectifier circuit, a single voltage doubling rectifier circuit, or a multiple voltage doubling rectifier circuit. The multiple voltage doubling rectifier circuit may be a double voltage doubling rectifier circuit or a triple voltage doubling rectifier circuit.

[0080] In the present embodiment, the rectifier circuit 12 is a half-voltage rectifier circuit. The rectifier circuit 12 also includes a diode D and a second capacitor C2. The diode D includes an anode d1 and a cathode d2. The diode D can only pass the current flowing from the anode d1 to the cathode d2. The second capacitor C2 includes a first electrode w1 and a second electrode w2 opposite to the first electrode w1. The anode d1 of the diode D is electrically connected to the first electrode w1 of the second capacitor C2. The cathode d2 of the diode D is electrically connected to one end of the secondary coil L2, and the second electrode w2 of the second capacitor C2 is electrically connected to the other end of the secondary coil L2. The second electrode w2 of the second capacitor C2 and the end of the secondary coil L2 electrically connected to the second electrode w2 are both electrically connected to the reference ground. A current limiting resistor R3 can be set between the second electrode w2 of the second capacitor C2 and the reference ground. The negative input terminal a2 and the second electrode w2 of the second capacitor C2 can be connected through a current limiting resistor R4.

[0081] The two ends of the second input end of the rectifier circuit 12 are the cathode d2 of the diode D and the second electrode w2 of the second capacitor C2. The second output end of the rectifier circuit 12 is the first electrode w1 and the second electrode w2 of the second capacitor C2. The first electrode w1 of the second capacitor C2 is also electrically connected to the output terminal 10 of the drive circuit 1.

[0082] The boost circuit 11 loads an AC voltage between the cathode d2 of the diode D and the second electrode w2 of the second capacitor C2. Since the second electrode w2 can only pass the current flowing from the anode d1 to the cathode d2, the current can only flow from the first electrode w1 of the second capacitor C2 to the second electrode w2. Therefore, the first electrode w1 of the second capacitor C2 is a constant negative DC voltage, and the constant negative DC voltage is transmitted to the output terminal 10 of the drive circuit 1.

[0083] In an illustrative embodiment, the AC circuit 13 includes a third capacitor C3. The third capacitor C3 includes a third electrode w3 and a fourth electrode w4. The third electrode w3 is electrically connected to one end of the secondary coil L2 connected to the diode D. The fourth electrode w4 of the third capacitor C3 is electrically connected to the output terminal 10 of the drive circuit 1. The third electrode w3 of the third capacitor C3 is the third input terminal of the AC circuit 13, and the fourth electrode w4 of the third capacitor C3 is the third output terminal of the AC circuit 13.

[0084] Since one end of the secondary coil L2 is connected to the reference ground and there is a parasitic capacitance between the discharge electrode 2 and the air, when an AC voltage is generated on the secondary coil L2, the third capacitor C3 will be charged and discharged as the AC voltage changes, and the voltage on the fourth electrode w4 of the third capacitor C3 will also oscillate to form an AC voltage output to the output terminal 10 of the drive circuit 1.

[0085] Embodiment 2

[0086] Embodiment 2 proposes another negative ion generator 100, which includes a discharge electrode 2 and a driving circuit 1a. The discharge electrode 2 is a conductor. The discharge electrode 2 has a tip, which can be needle-shaped or sawtooth-shaped. The tip of the discharge electrode 2 has a small radius of curvature. The discharge electrode 2 can be made of metal, which includes one or more of stainless steel, copper, aluminum, tungsten, and molybdenum. The discharge electrode 2 can also be constructed as a carbon fiber bundle.

[0087] like Figure 3 As shown, the driving circuit 1a includes an output terminal 10. The output terminal 10 is electrically connected to the discharge electrode 2. The driving circuit 1a outputs a DC negative voltage to the discharge electrode 2 through the output terminal 10, and the DC negative voltage is loaded on the discharge electrode 2 to drive the discharge electrode 2 to ionize the air to generate negative ions. The DC negative voltage can be -2kV to -10kV. The negative ions combine with positively charged particles such as bacteria, viruses, and dust in the air to cause them to condense and settle, thereby achieving the purpose of reducing fine particles such as bacteria, viruses, and dust in the air.

[0088] The driving circuit 1a first generates a constant DC negative voltage and a pulse voltage, and then transmits the constant DC negative voltage and the pulse voltage to the output terminal 10 of the driving circuit 1a to superimpose a fluctuating DC negative voltage on the output terminal 10 of the driving circuit 1a. The waveform of the pulse voltage can be a sharp pulse wave, a triangular pulse or a rectangular wave. The pulse voltage can be a negative pulse voltage or a positive pulse voltage. The absolute value of the maximum voltage value of the pulse voltage is less than or equal to the absolute value of the voltage value of the constant DC negative voltage, so that the potential of the output terminal 10 of the driving circuit 1a is less than the potential of the reference ground.

[0089] The pulse voltage is superimposed on the constant negative DC voltage, causing the voltage value of the constant negative DC voltage to fluctuate greatly, thereby generating a fluctuating negative DC voltage, which is transmitted to the discharge electrode 2 through the output terminal 10 of the drive circuit 1 a.

[0090] In this way, the driving circuit 1a loads the fluctuating DC negative voltage onto the discharge electrode 2 of the negative ion generator 100, so that a fluctuating electric field is generated around the discharge electrode 2. At the same time, since the curvature radius of the tip of the discharge electrode 2 is small, the electric field around the tip of the discharge electrode 2 is also an uneven electric field. The tip of the discharge electrode 2 can generate a large number of electrons. These electrons cannot stably exist on the discharge electrode 2 under the action of the fluctuating electric field, and will be separated from the discharge electrode 2 and enter the air under the action of the fluctuating electric field. In this way, electrons will not accumulate on the discharge electrode 2 and form a "reverse electric field" around the discharge electrode 2, and the concentration of negative ions generated by the negative ion generator 100 will not decrease over time even if the negative ion generator 100 works for a long time.

[0091] In a verification test, the negative ion generator 100 uses a carbon fiber bundle as the discharge electrode 2, and the output terminal 10 of the driving circuit 1a outputs a DC negative voltage to the discharge electrode 2. The voltage of the DC negative voltage fluctuates between -5.32 kV and -5.88 kV. The voltage falling edge speed of the DC negative voltage is 76 V / us and the voltage frequency is 36.8 KHz. The electrical signal waveform of the DC negative voltage is as shown in FIG. Figure 5 As shown, the negative ion generator 100 was operated continuously for 720 hours under three operating conditions of relative humidity of 30% RH, 60% RH and 90% RH, and no attenuation of negative ion concentration was observed.

[0092] In an illustrative embodiment, the driving circuit 1a includes a boost circuit 11a, a rectifier circuit 12 and a pulse circuit 14. The boost circuit 11a includes a first input terminal and a first output terminal. The first input terminal is connected to an external power supply for receiving an input voltage. The power supply can be a DC power supply or an AC power supply. The input voltage received by the first input terminal can be a DC voltage or an AC voltage. The boost circuit 11a boosts the input voltage and converts it into an AC voltage and outputs it from the first output terminal.

[0093] The boost circuit 11a can use a boost transformer T to boost the voltage of the input voltage. When the input voltage is a DC voltage, the input voltage can be first converted into an AC voltage through an inverter circuit or a self-excited oscillation circuit, and then the AC voltage is transmitted to the boost transformer T for boosting. When the input voltage is an AC voltage, the AC voltage can be directly transmitted to the boost transformer T for boosting.

[0094] The rectifier circuit 12 is a circuit that converts AC power into DC power. The rectifier circuit 12 can be a half-wave rectifier circuit, a full-wave rectifier circuit, a bridge rectifier or a voltage doubler rectifier circuit. The rectifier circuit 12 includes a second input terminal and a second output terminal. The second input terminal of the rectifier circuit 12 is electrically connected to the first output terminal of the boost circuit 11a. The second output terminal of the rectifier circuit 12 is electrically connected to the output terminal 10. The rectifier circuit 12 is configured to convert the AC voltage input by the boost circuit 11a into a constant DC negative voltage, and transmit the constant DC negative voltage to the output terminal 10.

[0095] The pulse circuit 14 includes a fourth input terminal and a fourth output terminal. The fourth input terminal of the pulse circuit 14 is electrically connected to the first output terminal of the boost circuit 11a. The fourth output terminal of the pulse circuit 14 is electrically connected to the output terminal 10. The pulse circuit 14 is configured to convert the AC voltage output by the boost circuit 11a into a pulse voltage and transmit it to the output terminal 10.

[0096] In this way, after the boost circuit 11a boosts the input voltage and converts it into an AC voltage, the rectifier circuit 12 converts the AC voltage into a constant DC negative voltage and transmits it to the output terminal 10, and the pulse circuit 14 converts the AC voltage into a pulse voltage and transmits it to the output terminal 10 and superimposes it with the constant DC negative voltage to generate a fluctuating DC negative voltage at the output terminal 10.

[0097] In an exemplary embodiment, the first input terminal includes a positive input terminal a1 and a negative input terminal a2. The positive input terminal a1 is used to electrically connect to the positive electrode of the DC power supply, and the negative input terminal a2 is used to electrically connect to the negative electrode of the DC power supply. The negative input terminal a2 can be connected to a reference ground.

[0098] The boost circuit 11a also includes a boost transformer T, a first inductor L3, a switch device Q, a first resistor R1, a first capacitor C1, a fourth capacitor C4 and a fifth capacitor C5. The switch device Q can be a triode or a field effect transistor. The switch device Q includes a collector c, an emitter e and a base b. The first inductor L3, the first capacitor C1 and the first resistor R1 are connected in series between the collector c and the base b of the switch device Q. The collector c of the switch device Q is electrically connected to one end of the first inductor L3, the other end of the first inductor L3 is electrically connected to one electrode of the first capacitor C1, the other electrode of the capacitor is electrically connected to one end of the first resistor R1, and the other end of the first resistor R1 is electrically connected to the base b of the switch device Q. The emitter e of the switch device Q is electrically connected to the negative input terminal a2.

[0099] The step-up transformer T includes a primary coil L1 and a secondary coil L2. The primary coil L1 and the secondary coil L2 are mutually inductive. The number of turns of the primary coil L1 is less than the number of turns of the secondary coil L2. One end of the primary coil L1 is electrically connected to the positive input terminal a1, and the other end of the primary coil L1 is electrically connected to the collector c of the switching device Q. Both ends of the secondary coil L2 are the first output ends of the step-up circuit 11a.

[0100] Two electrodes of the fourth capacitor C4 are respectively electrically connected to the emitter e and the base b of the switch device Q. Two electrodes of the fifth capacitor C5 are respectively electrically connected to the positive input terminal a1 and the negative input terminal a2.

[0101] In this way, the boost circuit 11a is a self-excited oscillation circuit. The first capacitor C1 and the first inductor L3 cause the current in the primary coil L1 to oscillate during the alternating charge and discharge process, and then generate an electromotive force in the secondary coil L2 through mutual inductance, so that the two ends of the secondary coil L2 can output an AC voltage. Since the number of turns of the primary coil L1 is smaller than the number of turns of the secondary coil L2, the AC voltage output by the boost transformer T is greater than the DC voltage input from the first input end. Therefore, the first output end of the boost circuit 11a can output a high-voltage AC voltage.

[0102] In an illustrative embodiment, the rectifier circuit 12 is a voltage doubling rectifier circuit. The rectifier circuit 12 may be a half voltage doubling rectifier circuit, a single voltage doubling rectifier circuit, or a multiple voltage doubling rectifier circuit. The multiple voltage doubling rectifier circuit may be a double voltage doubling rectifier circuit or a triple voltage doubling rectifier circuit.

[0103] In the present embodiment, the rectifier circuit 12 is a half-voltage rectifier circuit. The rectifier circuit 12 also includes a diode D and a second capacitor C2. The diode D includes an anode d1 and a cathode d2. The diode D can only pass the current flowing from the anode d1 to the cathode d2. The second capacitor C2 includes a first electrode w1 and a second electrode w2 opposite to the first electrode w1. The anode d1 of the diode D is electrically connected to the first electrode w1 of the second capacitor C2. The cathode d2 of the diode D is electrically connected to one end of the secondary coil L2, and the second electrode w2 of the second capacitor C2 is electrically connected to the other end of the secondary coil L2. The second electrode w2 of the second capacitor C2 and one end of the secondary coil L2 electrically connected to the second electrode w2 are both electrically connected to the reference ground. A current limiting resistor can be set between the second electrode w2 of the second capacitor C2 and the reference ground.

[0104] The two ends of the second input end of the rectifier circuit 12 are the cathode d2 of the diode D and the second electrode w2 of the second capacitor C2. The second output end of the rectifier circuit 12 is the first electrode w1 and the second electrode w2 of the second capacitor C2. The first electrode w1 of the second capacitor C2 is also electrically connected to the output terminal 10 of the drive circuit 1a.

[0105] The boost circuit 11a loads an AC voltage between the cathode d2 of the diode D and the second electrode w2 of the second capacitor C2. Since the second electrode w2 can only pass the current flowing from the anode d1 to the cathode d2, the current can only flow from the first electrode w1 of the second capacitor C2 to the second electrode w2. Therefore, the first electrode w1 of the second capacitor C2 is a constant negative DC voltage, and the constant negative DC voltage is transmitted to the output terminal 10 of the drive circuit 1a.

[0106] In an illustrative embodiment, the pulse circuit 14 includes a sixth capacitor C6 and a second resistor R2. The sixth capacitor C6 includes a fifth electrode w5 and a sixth electrode w6. The fifth electrode w5 of the sixth capacitor C6 is electrically connected to one end of the secondary coil L2 connected to the diode D, and one end of the second resistor R2 is electrically connected to the other end of the secondary coil L2. The other end of the second resistor R2 and the sixth electrode w6 of the sixth capacitor C6 are both electrically connected to the output terminal 10 of the drive circuit 1a. The fifth electrode w5 of the sixth capacitor C6 and the second resistor R2 are electrically connected to one end of the secondary coil L2 as the fourth input terminal of the pulse circuit 14, and the sixth electrode w6 of the sixth capacitor C6 is the fourth output terminal of the pulse circuit 14.

[0107] When an AC voltage is generated on the secondary coil L2, the sixth capacitor C6 will be charged and discharged as the AC voltage changes, and the voltage on the sixth electrode w6 of the sixth capacitor C6 will also oscillate accordingly. At the same time, the second resistor R2 can accelerate the charging and discharging process of the sixth capacitor C6, thereby generating a pulse voltage at the sixth electrode w6 of the sixth capacitor C6, and the pulse voltage can be transmitted to the output terminal 10 of the drive circuit 1a.

[0108] In an exemplary embodiment, the voltage falling edge speed of the pulse voltage is greater than or equal to 200 V / us. After the pulse voltage is superimposed on the constant DC negative voltage, the voltage falling edge speed of the resulting fluctuating DC negative voltage is also greater than or equal to 200 V / us.

[0109] When the voltage amplitude on the discharge electrode 2 is lower than 3kV, the energy of the electrons generated on the discharge electrode 2 is low, which in turn leads to low energy of negative ions. Low energy of negative ions leads to poor sterilization effect. When the voltage falling edge speed of the fluctuating DC negative voltage is greater than or equal to 200V / us, the DC negative voltage has the characteristics of extremely fast voltage falling edge speed and extremely narrow pulse width, so that the voltage loaded on the discharge electrode 2 can reach the peak value in a very short time. The strong electric field formed by the discharge of the discharge electrode 2 makes the electrons with smaller mass continuously accelerated by the voltage pulse to become high-energy electrons, and the positive ions with larger mass after losing electrons basically remain stationary in the pulse moment due to inertia. Therefore, the energy provided by the discharge is almost entirely used to generate high-energy electrons, thereby improving energy utilization efficiency. Pulse voltage can inject more energy into space electrons under low-voltage discharge conditions, generate more high-energy electrons and higher concentrations of negative ions, thereby improving the sterilization effect.

[0110] In a verification test, the negative ion generator 100 uses a carbon fiber bundle as the discharge electrode 2, and the output terminal 10 of the driving circuit 1a outputs a DC negative voltage to the discharge electrode 2. The voltage of the DC negative voltage fluctuates between -0.32 kV and -1.01 kV. The voltage falling edge speed of the DC negative voltage is 581 V / us and the voltage frequency is 238 Hz. The electrical signal waveform of the DC negative voltage is as shown in FIG. Figure 6 As shown in the figure, the discharge electrode 2 is loaded with a low voltage of less than 1kV to ionize the air, and the amount of negative ions generated can still reach 10 million / cm 3 Moreover, under the three working conditions of relative humidity of 30%RH, 60%RH and 90%RH, the negative ion concentration did not decrease after continuous operation for 720h.

[0111] Embodiment 3

[0112] This embodiment also proposes an air treatment device, which can take in and out air, and has unlimited air treatment functions, for example, it can perform at least one of the air temperature adjustment, humidification, purification, circulation and other treatment functions. The air treatment device includes but is not limited to an air conditioner, and the air treatment device can also be a purifier, a humidifier, a fan, etc. After the specific type of the air treatment device is determined, those skilled in the art can know the composition of the air treatment function of the air treatment device, which will not be described in detail here.

[0113] The air treatment device includes a housing, a fan and the negative ion generator 100 in Embodiment 1 or Embodiment 2. The housing is provided with an air inlet, an air outlet and an air duct. The two ends of the air duct are respectively connected to the air inlet and the air outlet. The fan is arranged in the air duct. The fan can be a cross-flow fan or a centrifugal fan. After the fan is started, it can drive the air in the air duct to move from the air inlet to the air outlet, so that the air inlet sucks the air in the surrounding environment into the air duct, and the air flows through the air duct and then is discharged from the air outlet to the surrounding environment. The negative ion generator 100 is arranged in the air inlet or the air duct.

[0114] Embodiment 4

[0115] This embodiment further proposes a control method for the negative ion generator 100 , and the control method can be implemented based on the negative ion generator 100 in the first embodiment or the second embodiment.

[0116] The control method comprises the following steps:

[0117] Step S1: A fluctuating DC negative voltage is applied to the discharge electrode 2 of the negative ion generator 100 to drive the discharge electrode 2 to generate negative ions.

[0118] The driving circuit 1a applies a fluctuating negative DC voltage to the discharge electrode 2 of the negative ion generator 100, so that a fluctuating electric field is generated around the discharge electrode 2. At the same time, since the curvature radius of the tip of the discharge electrode 2 is small, the electric field around the tip of the discharge electrode 2 is also an uneven electric field. The tip of the discharge electrode 2 can generate a large number of electrons. These electrons cannot stably exist on the discharge electrode 2 under the action of the fluctuating electric field, and will be separated from the discharge electrode 2 and enter the air under the action of the fluctuating electric field. In this way, electrons will not accumulate on the discharge electrode 2 and form a "reverse electric field" around the discharge electrode 2, and the concentration of negative ions generated by the negative ion generator 100 will not decrease over time even if the negative ion generator 100 works for a long time.

[0119] In an illustrative embodiment, the control method further includes a step S1a before step S1.

[0120] Step S1a: Generate a constant negative DC voltage and an AC voltage, and superimpose the constant negative DC voltage and the AC voltage into a fluctuating negative DC voltage.

[0121] In an illustrative embodiment, the control method further includes a step S1b before step S1.

[0122] Step S1b: Generate a constant DC negative voltage and a pulse voltage, and superimpose the constant DC negative voltage and the pulse voltage into a fluctuating DC negative voltage.

[0123] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A driving circuit for a negative ion generator, characterized in that: include: An output terminal, used for electrically connecting to a discharge electrode of the negative ion generator, wherein the discharge electrode has a pointed end; The output terminal is configured to output a DC negative voltage with voltage fluctuation to drive the discharge electrode to generate negative ions.

2. The driving circuit according to claim 1, characterized in that: The negative DC voltage is formed by superposition of a constant negative DC voltage and an AC voltage.

3. The driving circuit according to claim 2, characterized in that: Also includes: A boost circuit configured to boost an input voltage into an AC voltage; a rectifier circuit, electrically connected to the boost circuit and the output terminal, for converting the AC voltage into a constant negative DC voltage output to the output terminal; and The AC circuit is electrically connected to the boost circuit and the output terminal, and is used to transmit the AC voltage to the output terminal.

4. The driving circuit according to claim 3, characterized in that: The AC circuit includes a third capacitor; The third capacitor includes a third electrode and a fourth electrode electrically connected to the output terminal; Wherein, the third electrode is electrically connected to the boost circuit, and is used to receive the AC voltage output by the boost circuit.

5. The driving circuit according to claim 1, characterized in that: The DC negative voltage is formed by superposition of a constant DC negative voltage and a pulse voltage.

6. The driving circuit according to claim 1, characterized in that: The voltage falling edge speed of the pulse voltage is greater than or equal to 200V / us.

7. The driving circuit according to claim 5, characterized in that: Also includes: A boost circuit configured to boost an input voltage into an AC voltage; a rectifier circuit, electrically connected to the boost circuit and the output terminal, for converting the AC voltage into a constant negative DC voltage output to the output terminal; as well as The pulse circuit is electrically connected to the boost circuit and the output terminal, and is used for converting the AC voltage into a pulse voltage output to the output terminal.

8. The driving circuit according to claim 6, characterized in that: The pulse circuit includes a sixth capacitor and a second resistor; The sixth capacitor includes a fifth electrode and a sixth electrode electrically connected to the output terminal; One end of the second resistor is electrically connected to the output terminal, and the boost circuit loads an AC voltage between the other end of the second resistor and the fifth electrode.

9. The driving circuit according to any one of claims 3, 4, 7 and 8, characterized in that: The rectifier circuit is a voltage doubler rectifier circuit.

10. The driving circuit according to claim 9, characterized in that: The boost circuit comprises a boost transformer, wherein the boost transformer comprises a primary coil and a secondary coil having mutual inductance with the primary coil; The rectifier circuit includes A diode, including an anode and a cathode; a second capacitor, comprising a first electrode electrically connected to the anode and a second electrode electrically connected to a reference ground; Wherein, two ends of the secondary coil are electrically connected to the cathode and the second electrode respectively, and the output terminal is electrically connected to the first electrode.

11. The driving circuit according to claim 10, characterized in that: The boost circuit further includes: A first input terminal, including a positive input terminal and a negative input terminal; a switching device, comprising a collector, an emitter electrically connected to the negative input terminal, and a base; A first inductor, one end of which is connected to the collector; a first capacitor, an electrode of which is electrically connected to the other end of the first inductor; and a first resistor, one end of which is electrically connected to the other electrode of the capacitor, and the other end of which is electrically connected to the base; One end of the primary coil is electrically connected to the positive input terminal, and the other end of the primary coil is electrically connected to the collector.

12. The driving circuit according to claim 11, characterized in that: The boost circuit further includes a fourth capacitor and a fifth capacitor; Two electrodes of the fourth capacitor are electrically connected to the emitter and the base, respectively. Two electrodes of the fifth capacitor are electrically connected to the positive input terminal and the negative input terminal, respectively.

13. A negative ion generator, characterized in that: The method comprises the drive circuit according to any one of claims 1 to 12 and a discharge electrode electrically connected to the output terminal.

14. An air treatment device, characterized in that: Comprising the negative ion generator as described in claim 13.

15. A method for controlling a negative ion generator, characterized in that: The negative ion generator includes a discharge electrode, and the control method includes: A fluctuating DC negative voltage is applied to the discharge electrode to drive the discharge electrode to generate negative ions.

16. The control method according to claim 15, characterized in that: Also includes: Generates constant negative DC voltage and AC voltage; The constant negative DC voltage and the AC voltage are superimposed to form the fluctuating negative DC voltage.

17. The control method according to claim 15, characterized in that: Also includes: Generate constant DC negative voltage and pulse voltage; The constant negative DC voltage and the pulse voltage are superimposed to form the fluctuating negative DC voltage.

Images