AC input circuit and air conditioner

Abstract

The present invention discloses an AC input circuit and an air conditioner. The AC input circuit includes an AC input terminal, an EMI filtering circuit, a harmonic suppressor, and a power output terminal. The input terminal of the EMI filtering circuit is connected to the AC input terminal, the output terminal of the EMI filtering circuit is connected to the input terminal of the harmonic suppressor, and the output terminal of the harmonic suppressor is connected to the power output terminal. The EMI filtering circuit is used to filter the AC power input from the AC input terminal and output it through the power output terminal. The harmonic suppressor is used to suppress the harmonic signals in the AC power input from the AC input terminal. The present invention improves the service life of the harmonic suppressor.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and particularly to an AC input circuit and an air conditioner. Background Art

[0002] With the rapid economic development, the power load in the power grid is continuously increasing. Especially, the types of various new electrical equipment are increasing day by day. During the power consumption process of some electrical equipment, its load is usually variable. For example, equipment such as a rectifier has a non-linear load. When a large number of these equipment are connected to the power supply network, it will bring a large amount of harmonics to the power supply network, causing voltage fluctuations in the power supply network. To solve the harmonic problems generated by the power supply network, currently, a harmonic suppression device is usually set on the front-stage side of the EMI filter circuit of the power supply network to suppress the harmonics in the power supply network, so as to achieve the purpose of reducing the harmonics in the power supply network. However, in actual applications, the problem that the AC harmonic suppression device is easily damaged often occurs, reducing the service life of the harmonic suppression device. Summary of the Invention

[0003] The main object of the present invention is to propose an AC input circuit and an air conditioner, aiming to improve the service life of the harmonic suppressor.

[0004] To achieve the above object, the AC input circuit proposed by the present invention includes an AC input terminal, an EMI filter circuit, a harmonic suppressor, and a power output terminal. The input terminal of the EMI filter circuit is connected to the AC input terminal, the output terminal of the EMI filter circuit is connected to the input terminal of the harmonic suppressor, and the output terminal of the harmonic suppressor is connected to the power output terminal;

[0005] The EMI filter circuit is used to filter the AC power input from the AC input terminal and output it through the power output terminal;

[0006] The harmonic suppressor is used to suppress the harmonic signals in the AC power input from the AC input terminal.

[0007] In one embodiment, the harmonic suppressor is a positive temperature coefficient thermistor, a negative temperature coefficient thermistor, or a reactor.

[0008] In one embodiment, the EMI filter circuit includes a first capacitor, a common mode inductor, and a second capacitor. The first input terminal of the common mode inductor is connected to the first end of the first capacitor and is the input terminal of the EMI filter circuit. The first output terminal of the common mode inductor is connected to the first end of the second capacitor. The second input terminal of the common mode inductor is connected to the second end of the second capacitor. The second output terminal of the common mode inductor is connected to the second end of the first capacitor and is the output terminal of the EMI filter circuit.

[0009] In one embodiment, the EMI filtering circuit further includes a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor. The first end of the third capacitor is connected to the common end of the first end of the first capacitor and the AC input terminal. The second end of the third capacitor and the first end of the fourth capacitor are commonly grounded. The second end of the fourth capacitor is connected to the second end of the first capacitor. The first end of the fifth capacitor is connected to the first output terminal of the common mode inductor. The second end of the fifth capacitor and the first end of the sixth capacitor are commonly grounded. The second end of the sixth capacitor is connected to the second input terminal of the common mode inductor.

[0010] In one embodiment, the AC input circuit further includes a rectifying circuit, and the rectifying circuit is connected between the output terminal of the harmonic suppressor and the power output terminal.

[0011] The rectifying circuit is configured to convert the input AC power into DC power and output it through the power output terminal.

[0012] In one embodiment, the AC input circuit further includes a seventh capacitor and an eighth capacitor. The first ends of the seventh capacitor and the eighth capacitor are both connected to the first end of the rectifying circuit, and the second ends of the seventh capacitor and the eighth capacitor are both connected to the fourth end of the rectifying circuit.

[0013] In one embodiment, the AC input circuit further includes a circuit breaker. The input terminal of the circuit breaker is connected to the AC input terminal, and the output terminal of the circuit breaker is connected to the input terminal of the EMI filtering circuit.

[0014] In one embodiment, the AC input circuit further includes a flame retarder. The input terminal of the flame retarder is connected to the input terminal of the EMI filtering circuit, and the output terminal of the flame retarder is connected to the output terminal of the EMI filtering circuit.

[0015] In one embodiment, the AC input circuit further includes a first resistor. The first end of the first resistor is connected to the input terminal of the EMI filtering circuit, and the second end of the first resistor is connected to the output terminal of the EMI filtering circuit.

[0016] The present invention also provides an air conditioner, which includes the AC input circuit as described above. The AC input circuit includes an AC input terminal, an EMI filter circuit, a harmonic suppressor, and a power output terminal. The input terminal of the EMI filter circuit is connected to the AC input terminal, the output terminal of the EMI filter circuit is connected to the input terminal of the harmonic suppressor, and the output terminal of the harmonic suppressor is connected to the power output terminal. The EMI filter circuit is configured to filter the AC power input from the AC input terminal and output it through the power output terminal. The harmonic suppressor is configured to suppress the harmonic signals in the AC power input from the AC input terminal.

[0017] According to the technical solution of the present invention, by arranging a harmonic suppressor on the rear stage side of the EMI filter circuit of the AC input circuit, the resonant current generated by the filtering of the EMI filter circuit will not pass through the harmonic suppressor when returning to the AC input terminal, avoiding the problem that the harmonic current of the EMI filter circuit is superimposed on the harmonic signals of the AC power input to the AC input circuit, resulting in an increase in the heat generation of the harmonic suppressor. In this way, when the superimposed harmonic current becomes larger, it will not cause the current flowing through the harmonic suppressor to be too large, resulting in continuous heating and damage of the harmonic suppressor, thereby improving the service life of the harmonic suppressor. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the AC input circuit of the present invention;

[0020] Figure 2 It is a schematic circuit diagram of an embodiment of the AC input circuit of the present invention.

[0021] Explanation of the Reference Numerals in the Drawings:

[0022]

[0023]

[0024] The realization of the object of the present invention, its functional features and advantages will be further described with reference to the embodiments and the drawings. Detailed Embodiments

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

[0026] It should be noted that if there are descriptions such as "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second" may explicitly or implicitly include at least one such feature.

[0027] The present invention provides an AC input circuit and an air conditioner.

[0028] In an embodiment of the present invention, as shown in Figure 1 the AC input circuit includes an AC input terminal 10, an EMI filter circuit 20, a harmonic suppressor 30, and a power output terminal 50. The input terminal of the EMI filter circuit 20 is connected to the AC input terminal 10, the output terminal of the EMI filter circuit 20 is connected to the input terminal of the harmonic suppressor 30, and the output terminal of the harmonic suppressor 30 is connected to the power output terminal 50;

[0029] The EMI filter circuit 20 is configured to filter the AC power input from the AC input terminal 10 and output it through the power output terminal 50;

[0030] The harmonic suppressor 30 is configured to suppress the harmonic signals in the AC power input from the AC input terminal 10.

[0031] In this embodiment, the EMI filter circuit 20 refers to a low-pass filter circuit composed of a series reactor and a parallel capacitor, which allows the frequency signals during normal operation of the device to enter the device and has a great obstructive effect on high-frequency interference signals. The power line is the main path for interference to enter and leave the device. Through the power line, the interference from the power grid can enter the device and interfere with the normal operation of the device. Similarly, the interference generated by the device may also be transmitted to the power grid through the power line and interfere with the normal operation of other devices. An EMI filter circuit must be added at the power input of the device. In this solution, by setting the EMI filter circuit 20 at the AC input terminal 10 of the AC power input circuit, the AC power input from the AC input terminal 10 is filtered, that is, the high-frequency interference signals in the AC power input from the AC input terminal 10 are suppressed to prevent interference to the electrical equipment connected to the user's home. It can be understood that the EMI filter circuit 20 can also suppress the interference of the electrical equipment connected to the user's home to the AC power grid.

[0032] In this embodiment, the harmonic suppressor 30 can suppress the harmonic signals in the AC power supply input at the AC input terminal 10. It can be understood that there are harmonic components in the AC power supply input at the AC input terminal 10 of the AC input circuit. In this solution, the harmonic components in the AC power supply are suppressed by the harmonic suppressor 30. It should be noted that in the existing AC input circuit, there may be too many harmonic components in the input AC power supply, or the harmonic suppression of the electrical appliances in the user's home is insufficient, resulting in too many harmonic components in the power supply. When the harmonic components in the power supply pass through the EMI filter circuit 20, resonance will occur, causing the harmonic current flowing through the harmonic suppressor 30 to be superimposed. That is, when the harmonic suppressor 30 is arranged between the AC input terminal 10 of the AC input circuit and the EMI filter circuit 20, the EMI filter circuit 20 will resonate with the harmonic components of the AC power supply input at the AC input terminal 10, causing the superimposition of the harmonic suppression current, and the current will flow through the harmonic suppressor 30, resulting in overheating of the harmonic suppressor 30. In severe cases, it may even cause thermal breakdown and fire. When the harmonic suppressor 30 is arranged between the common mode inductor and the capacitor in the EMI filter circuit 20, it will also cause the superimposed resonance current to pass through the resonance suppressor, resulting in overheating of the harmonic suppressor 30. In severe cases, it may even cause thermal breakdown and fire.

[0033] In this solution, the harmonic suppressor 30 is arranged at the power output terminal 50 of the AC input circuit. The harmonic components resonated by the EMI filter circuit 20 will not flow through the harmonic suppressor 30. At this time, the harmonic suppressor 30 will not be overheated due to the superimposed harmonic current. It can be understood that the harmonic suppressor 30 can be arranged at any position on the rear stage side of the EMI filter circuit 20 here, that is, at a position where the resonance of the harmonic signal of the AC power supply passing through the EMI filter circuit 20 will not flow through, so that the harmonic suppressor 30 will not be interfered by the superimposed harmonic current, thereby suppressing the harmonic components in the AC power supply.

[0034] The technical solution of the present invention includes an AC input terminal 10, an EMI filter circuit 20, a harmonic suppressor 30, and a power output terminal 50 in the AC input circuit. By reasonably setting the positional relationship of each component in the AC input circuit, it is possible to prevent the harmonic components of the power supply from causing overheating of the harmonic suppression device on the AC side. In the AC input circuit, if the input AC power supply has excessive harmonic components, or the harmonic suppression of the electrical equipment in the user's home is insufficient, resulting in excessive harmonic components in the power supply, when the harmonic components in the power supply pass through the EMI filter circuit 20, resonance will occur, causing the harmonic current flowing through the harmonic suppressor 30 to be superimposed; that is, the resonance of the common-mode inductor and capacitor in the EMI filter circuit 20 causes the harmonic current output from the EMI filter circuit 20 to be superimposed to the harmonic suppressor 30. To solve the problem of overheating of the harmonic suppressor 30 on the AC side caused by the harmonic components of the power supply, this solution is to set the harmonic suppressor 30 at a position where the harmonic current output from the EMI filter circuit 20 does not flow through, that is, at the power output terminal 50 in the AC input circuit, so as to suppress the harmonic components of the AC power supply input from the AC input terminal 10 without causing excessive current flowing through the harmonic suppressor 30 to cause continuous heating. The technical solution of the present invention improves the service life of the harmonic suppressor 30.

[0035] In one embodiment, referring to Figure 1 as shown, the harmonic suppressor 30 is a positive temperature coefficient thermistor, a negative temperature coefficient thermistor, or a reactor.

[0036] It can be understood that when the harmonic suppressor 30 is a positive temperature coefficient thermistor, when the harmonic components in the AC input circuit flow through the positive temperature coefficient thermistor for harmonic suppression, the positive temperature coefficient thermistor heats up and the resistance increases accordingly. When the resistance value increases to a certain extent, the AC input circuit is equivalent to an open circuit, thereby protecting the rectifier circuit and the load connected to the harmonic suppressor 30.

[0037] When the harmonic suppressor 30 is a negative temperature coefficient thermistor, at the moment when the AC power supply of the AC input circuit is input, a surge current many times higher than the normal working current will be generated in the circuit, and the initial resistance value of the negative temperature coefficient thermistor is relatively large, which can suppress the excessive current in the circuit, thereby protecting the rectifier circuit and the load connected to the harmonic suppressor 30.

[0038] When the harmonic suppressor 30 is a reactor, the rectifier circuit and the load connected to the harmonic suppressor 30 can also be protected according to the characteristics of the reactor itself.

[0039] It should be noted that the harmonic suppressor 30 in this solution can also be other devices that can suppress harmonics, which are not limited here.

[0040] In one embodiment, referring toFigure 1 As shown, the EMI filtering circuit 20 includes a first capacitor C1, a common mode inductor L, and a second capacitor C2. The first input end of the common mode inductor L is connected to the first end of the first capacitor C1 and serves as the input end of the EMI filtering circuit 20. The first output end of the common mode inductor L is connected to the first end of the second capacitor C2. The second input end of the common mode inductor L is connected to the second end of the second capacitor C2. The second output end of the common mode inductor L is connected to the second end of the first capacitor C1 and serves as the output end of the EMI filtering circuit 20.

[0041] It can be understood that the common mode inductor L, also known as a common mode choke coil, can play the role of EMI filtering and is used to suppress the electromagnetic wave radiation emitted by high-speed signal lines. The common mode inductor L in the EMI filtering circuit 20 has a first winding and a second winding. As in Figure 1 the first input end of the common mode inductor L is the input end of the first winding, the first output end of the common mode inductor L is the output end of the first winding, the second input end of the common mode inductor L is the input end of the second winding, and the second output end of the common mode inductor L is the output end of the second winding.

[0042] In this embodiment, the first capacitor C1 and the common mode inductor L can form an EMI filtering circuit 20, or the second capacitor C2 and the common mode inductor L can form an EMI filtering circuit 20, or the first capacitor C1, the second capacitor C2, and the common mode inductor L can form an EMI filtering circuit 20. It can be understood that the first input end of the common mode inductor L inputs an AC power supply, which is filtered by the first capacitor C1 and the common mode inductor L to filter out high-frequency interference signals in the AC power supply. At the same time, it will also resonate with the harmonic components in the AC power supply to cause the superposition of harmonic currents. For the EMI filtering circuit 20 composed of the first capacitor C1 and the common mode inductor L, after the harmonic currents are superimposed, they will flow back to the neutral line of the AC input end 10 through the second input end of the common mode inductor L and will not flow through the harmonic suppressor 30 connected to the subsequent stage of the EMI filtering circuit 20. Similarly, for the EMI filtering circuit 20 composed of the second capacitor C2 and the common mode inductor L, or the EMI filtering circuit 20 composed of the first capacitor C1, the second capacitor C2, and the common mode inductor L, the superimposed harmonic currents flow back to the neutral line of the AC input end 10 through the second end of the second capacitor C2 and will not flow through the harmonic suppressor 30 connected to the subsequent stage of the EMI filtering circuit 20. Thus, it is realized that the power harmonic components in the AC input circuit will not cause the overheating of the harmonic suppressor 30 on the AC side.

[0043] It should be noted that the AC input end 10 has a live wire, a neutral line, and a ground wire. Refer to Figure 1As shown, CN1 is the live wire, CN2_1 and CN2_2 are the neutral wires, and CN9 is the ground wire, and the ground wire here is the protective ground. The first input end of the common mode inductor L in this solution is connected to the live wire of the AC input end 10, and the second output end of the common mode inductor L is connected to the neutral wire of the AC input end 10.

[0044] In the above embodiment, the EMI filter circuit 20 further includes a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6. The first end of the third capacitor C3 is connected to the common end of the first capacitor C1 and the AC input end 10. The second end of the third capacitor C3 and the common end of the first end of the fourth capacitor C4 are grounded. The second end of the fourth capacitor C4 is connected to the second end of the first capacitor C1. The first end of the fifth capacitor C5 is connected to the first output end of the common mode inductor L. The second end of the fifth capacitor C5 and the common end of the first end of the sixth capacitor C6 are grounded. The second end of the sixth capacitor C6 is connected to the second input end of the common mode inductor L.

[0045] It should be noted that the values of the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, and the sixth capacitor C6 here can be selected according to the measured value of EMI in the actual application scenario, and are not limited here.

[0046] In one embodiment, as shown in Figure 1 the AC input circuit further includes a rectifier circuit 40, and the rectifier circuit 40 is connected between the output end of the harmonic suppressor 30 and the power output end 50;

[0047] The rectifier circuit 40 is configured to convert the input AC power into DC power and output it through the power output end 50.

[0048] It can be understood that the rectifier circuit 40 in the AC input circuit can convert the AC power input from the AC input end 10 into DC power through the EMI filter circuit 20 and the harmonic suppressor 30 to supply power to the electrical appliances in the user's home. Here, the harmonic suppressor 30 can also protect the rectifier circuit 40 when the electrical appliances in the user's home are powered on instantaneously. Further, since the resistance value of the harmonic suppressor 30 is large, it can suppress the large current at the moment of power-on to protect the rectifier circuit 40.

[0049] Based on the above embodiments, the AC input circuit further includes a seventh capacitor C7 and an eighth capacitor C8. The first ends of the seventh capacitor C7 and the eighth capacitor C8 are both connected to the first end of the rectification circuit 40, and the second ends of the seventh capacitor C7 and the eighth capacitor C8 are both connected to the fourth end of the rectification circuit 40. It should be noted that the seventh capacitor C7 is a polarized capacitor. The first end of the seventh capacitor C7 is the positive terminal of the seventh capacitor C7, and the second end of the seventh capacitor C7 is the negative terminal of the seventh capacitor C7.

[0050] In one embodiment, as shown in Figure 1 the AC input circuit further includes a circuit breaker FR. The input terminal of the circuit breaker FR is connected to the AC input terminal 10, and the output terminal of the circuit breaker FR is connected to the input terminal of the EMI filter circuit 20. It can be understood that by providing the circuit breaker FR at the AC input terminal 10 of the AC input circuit, overload, short - circuit, and under - voltage protection of the AC input circuit can be achieved.

[0051] In one embodiment, as shown in Figure 1 the AC input circuit further includes a flame retarder ZR1. The input terminal of the flame retarder ZR1 is connected to the input terminal of the EMI filter circuit 20, and the output terminal of the flame retarder ZR1 is connected to the output terminal of the EMI filter circuit 20. It can be understood that the flame retarder ZR1 in this solution is a flame - retardant resistor, which is used to protect the AC input circuit or the electrical appliances in the user's home from the surge current generated by lightning strikes during thunderstorms.

[0052] In one embodiment, as shown in Figure 1 the AC input circuit further includes a first resistor R1. The first end of the first resistor R1 is connected to the input terminal of the EMI filter circuit 20, and the second end of the first resistor R1 is connected to the output terminal of the EMI filter circuit 20. It can be understood that the first resistor R1 is a protection resistor set according to national standards, which can prevent the user from getting an electric shock when the user needs to unplug the plug of the electrical appliance.

[0053] It should be noted that the electrical appliances mentioned in the above embodiments can be air conditioners, refrigerators, induction cookers, heaters, etc., which are not limited here.

[0054] The present invention also provides an air conditioner, which includes the AC input circuit as described above. The AC input circuit includes an AC input terminal 10, an EMI filter circuit 20, a harmonic suppressor 30, and a power output terminal 50. The input terminal of the EMI filter circuit 20 is connected to the AC input terminal 10, the output terminal of the EMI filter circuit 20 is connected to the input terminal of the harmonic suppressor 30, and the output terminal of the harmonic suppressor 30 is connected to the power output terminal 50. The EMI filter circuit 20 is used to filter the AC power input from the AC input terminal 10 and output it through the power output terminal 50. The harmonic suppressor 30 is used to suppress the harmonic signals in the AC power input from the AC input terminal 10. For the specific structure of this air conditioner, refer to the above-mentioned embodiments. Since this air conditioner adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.

Claims

1. An AC input circuit, characterized in that, The AC input circuit includes an AC input terminal, an EMI filter circuit, a harmonic suppressor, and a power output terminal. The input terminal of the EMI filter circuit is connected to the AC input terminal, the output terminal of the EMI filter circuit is connected to the input terminal of the harmonic suppressor, and the output terminal of the harmonic suppressor is connected to the power output terminal; The EMI filter circuit is configured to filter the AC power input from the AC input terminal and output it through the power output terminal; The harmonic suppressor is configured to suppress harmonic signals in the AC power input from the AC input terminal; Among them, the AC input terminal has a live wire and a neutral wire. The first input terminal of the common-mode inductor is connected to the live wire of the AC input terminal. The EMI filter circuit includes a common-mode inductor, a first capacitor, and / or a second capacitor. When the EMI filter circuit includes a common-mode inductor and a first capacitor, the common-mode inductor outputs the harmonic current generated by the EMI filter circuit to the neutral wire of the AC input terminal through the second input terminal. When the EMI filter circuit includes a common-mode inductor, a first capacitor, and a second capacitor, the second capacitor outputs the harmonic current generated by the EMI filter circuit to the neutral wire of the AC input terminal through the second terminal; The harmonic suppressor is arranged at a position where the resonance of the harmonic signal of the AC power supply passing through the EMI filter circuit will not flow through; The AC input circuit further includes a first resistor. The first end of the first resistor is connected to the input terminal of the EMI filter circuit, and the second end of the first resistor is connected to the output terminal of the EMI filter circuit; When the harmonic signal in the AC power input from the AC input terminal passes through the EMI filter circuit, resonance will occur. The harmonic suppressor is a positive temperature coefficient thermistor, a negative temperature coefficient thermistor, or a reactor.

2. The AC input circuit according to claim 1, wherein The EMI filter circuit includes a first capacitor, a common-mode inductor, and a second capacitor. The first input terminal and the second input terminal of the common-mode inductor are both connected to the AC input terminal. The first output terminal of the common-mode inductor is connected to the first end of the first capacitor, the second output terminal of the common-mode inductor is connected to the second end of the second capacitor, and the second end of the first capacitor is connected to the first end of the second capacitor.

3. The AC input circuit according to claim 2, wherein, The EMI filter circuit further includes a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor. The first end of the third capacitor is connected to the AC input terminal, the common terminal of the second end of the third capacitor and the first end of the fourth capacitor is grounded, the second end of the fourth capacitor is connected to the second input terminal of the common-mode inductor, the first end of the fifth capacitor is connected to the first input terminal of the common-mode inductor, the second end of the fifth capacitor is grounded, the first end of the sixth capacitor is connected to the first output terminal of the common-mode inductor, and the second end of the sixth capacitor is connected to the second output terminal of the common-mode inductor.

4. The AC input circuit according to claim 1, wherein The AC input circuit further includes a rectifier circuit connected between the output terminal of the harmonic suppressor and the power output terminal; The rectifier circuit is configured to convert the input AC power into a DC power and output it through the power output terminal.

5. The AC input circuit according to claim 4, wherein The AC input circuit further includes a seventh capacitor and an eighth capacitor. The first ends of the seventh capacitor and the eighth capacitor are both connected to the first end of the rectifier circuit, and the second ends of the seventh capacitor and the eighth capacitor are both connected to the fourth end of the rectifier circuit.

6. The AC input circuit according to any one of claims 1-5, characterized in that, The AC input circuit further includes a circuit breaker. The input end of the circuit breaker is connected to the AC input end, and the output end of the circuit breaker is connected to the input end of the EMI filter circuit.

7. The AC input circuit according to any one of claims 1-5, characterized in that, The AC input circuit further includes a flame retarder. The input end of the flame retarder is connected to the input end of the EMI filter circuit, and the output end of the flame retarder is connected to the output end of the EMI filter circuit.

8. An air conditioner, characterized in that, The air conditioner includes the AC input circuit according to any one of claims 1-7.

Images