Circuit board and air conditioner

Abstract

The present invention provides a circuit board and an air conditioner. The circuit board includes: a multi-channel power factor correction circuit for adjusting the input current waveform, the power factor correction circuit includes: a power switch, the first end of the power switch is connected to the positive bus; multiple first resistive elements, the second ends of the power switches of multiple power factor correction circuits are connected to the negative bus through the first resistive elements; wherein the multiple first resistive elements are connected to the same landing point. This makes the voltage value of each power factor correction circuit at the landing point the same, avoiding the problem of inaccurate power correction and system false overcurrent caused by the voltage difference between the landing points of multiple different power factor correction circuits, thereby greatly improving the control accuracy of the power factor correction circuit, and achieving the technical effect of simplifying the circuit structure and improving the circuit working reliability.

Description

Technical Field

[0001] The present invention relates to the field of drive control technology, and in particular to a circuit board and an air conditioner. Background Art

[0002] In the existing overcurrent fault detection circuit, multiple power factor correction circuits are staggered and connected in parallel, and the sampling resistor of each power factor correction circuit is connected to the landing point through its dedicated line. That is to say, the fault detection circuit has landing points equal to the number of power factor correction circuits. In this case, because the circuit operation and component status in each power factor correction circuit cannot be exactly the same, the voltage at the landing point of each power factor correction circuit cannot be the same, resulting in a voltage difference between the multiple landing points. The voltage difference will affect the detection accuracy of the overcurrent fault detection circuit, and it is easy for the system to make a wrong overcurrent alarm, affecting the normal use of the circuit. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] To this end, one aspect of the present invention is to provide a circuit board.

[0005] Another aspect of the present invention is to provide an air conditioner.

[0006] In view of this, the present invention proposes a circuit board, which includes: a multi-channel power factor correction circuit for adjusting the input current waveform, the power factor correction circuit includes: a power switch, the first end of the power switch is connected to the positive bus; multiple first resistive elements, the second ends of the power switches of the multiple power factor correction circuits are connected to the negative bus through the first resistive elements; wherein the multiple first resistive elements are connected to the same landing point.

[0007] The present invention provides a circuit board, in which multiple power factor correction circuits are arranged, and the power factor correction circuit can adjust the current waveform input by the circuit board. Specifically, the power factor correction circuit includes a power switch and multiple first resistive elements, and the power switch is provided with two interface terminals, wherein the second terminal on the power switch is connected to the negative bus through the first resistive element, and when there are multiple first resistive elements, the multiple first resistive elements share the same landing point. By unifying the landing points of the multiple first resistive elements, the multiple landing points of the multi-channel power factor correction circuits are also unified together, that is, the multiple power factor correction circuits share the same landing point, so that the voltage value of each power factor correction circuit at the landing point is the same, avoiding the problem of inaccurate power correction and system false overcurrent caused by the voltage difference between the landing points of multiple different power factor correction circuits, thereby greatly improving the control accuracy of the power factor correction circuit, and achieving the technical effect of simplifying the circuit structure and improving the circuit working reliability.

[0008] In a general overcurrent fault detection circuit, multiple power factor correction circuits are staggered and connected in parallel, and the sampling resistor of each power factor correction circuit is connected to the landing point through its dedicated line. That is to say, the fault detection circuit has landing points equal to the number of power factor correction circuits. In this case, because the circuit operation and component status in each power factor correction circuit cannot be exactly the same, the voltage at the landing point of each power factor correction circuit cannot be the same, resulting in a voltage difference between the multiple landing points. This voltage difference will affect the detection accuracy of the overcurrent fault detection circuit, easily causing the system to make a false overcurrent alarm, affecting the normal use of the circuit. In response to this technical problem, the present invention connects the first resistive elements of multiple power factor correction circuits in series, so that the multiple first resistive elements are connected to the same landing point on the same line, so that the voltage value of each power factor correction circuit at the landing point is exactly the same, thereby solving the above-mentioned technical problem and improving the accuracy of the overcurrent fault detection circuit. Among them, the power switch is IGBT, IGBT (Insulated Gate Bipolar Transistor), an insulated gate bipolar transistor, and the MOS tube is a metal (metal)-oxide (oxide)-semiconductor (semiconductor) field effect transistor, or a metal-insulator (insulator)-semiconductor.

[0009] In the above technical solution, further, the power factor correction circuit also includes: an inductive element, the first end of the power switch is connected to the positive bus through the inductive element; a boost diode, the first end of the power switch is connected to the positive electrode of the boost diode.

[0010] In this technical solution, the power factor correction circuit also includes: an inductive element and a boost diode. The power switch, the inductive element and the boost diode form a power factor correction circuit for adjusting the input current waveform so that the current waveform is synchronized with the input voltage waveform to reduce the loss of exchange power.

[0011] In addition, the circuit board in the above technical solution provided by the present invention may also have the following additional technical features: In the above technical solution, further, the circuit board also includes: multiple fault detection circuits, and the multiple fault detection circuits are connected one-to-one with the multiple power factor correction circuits, which are used to obtain the current signal of the power switch flowing through the power factor correction circuit, and compare the current signal with the preset current to generate a control signal to control the power switch.

[0012] In this technical solution, the circuit board is also provided with a plurality of fault detection circuits, wherein the plurality of fault detection circuits are connected to the power factor correction circuit in a one-to-one correspondence, and the power switch is controlled to be turned on and off by comparing the current signal flowing through the power switch with the preset current and generating a control signal according to the comparison result. Specifically, when it is detected that the current signal flowing through the power switch is greater than the preset current, the power switch is controlled to stop conducting, thereby realizing the protection of the power switch.

[0013] In any of the above technical solutions, further, the circuit board also includes: multiple driving circuits, which are correspondingly connected to multiple power factor correction circuits and are used to convert the control signals received from the power factor correction circuits into driving signals for the power switches.

[0014] In this technical solution, multiple drive circuits are also provided on the circuit board, and the multiple drive circuits correspond one-to-one to the multiple power factor correction circuits. When receiving a control signal such as a control chip, the analog signal of the control chip is converted into a corresponding drive signal of the power switch.

[0015] In any of the above technical solutions, further, the ground terminals of the multiple driving circuits are connected to the second terminals of the power switches of the multiple power factor correction circuits and are grounded.

[0016] In this technical solution, the grounding ends of the plurality of driving circuits are connected to the second ends of the power switches of the plurality of power factor correction circuits and connected to the negative bus, that is, the grounding ends of the plurality of driving circuits and the second ends of the power switches are connected to a common ground, thereby reducing the number of landing points.

[0017] In any of the above technical solutions, further, between the multiple driving circuits and the multi-channel power factor correction circuit, there are also: multiple second resistive elements, and the multiple second resistive elements are used to reduce the amplitude of the driving signal.

[0018] In this technical solution, since the power switch requires a driving signal to turn on and off, in order to avoid the inability to distinguish between the on and off conditions due to the large on and off voltage signals, a second resistive element is set to reduce the amplitude of the driving signal and improve the control accuracy of the power switch.

[0019] In any of the above technical solutions, further, the fault detection circuit specifically includes: a comparison module; a third resistive element, one end of the third resistive element is connected to one end of the first resistive element, and the other end is connected to the first reverse input end of the comparison module; a fourth resistive element, one end of the fourth resistive element is connected to the other end of the first resistive element, and the other end is connected to the first positive input end of the comparison module; a fifth resistive element, one end of the fifth resistive element is connected to the other end of the third resistive element; a sixth resistive element, the other end of the sixth resistive element is connected to the other end of the fourth resistive element, and the other end is connected to the other end of the fifth resistive element; a first capacitive element, one end of the first capacitive element is connected to the first output end of the comparison module, and the other end is connected to the second positive input end of the comparison module; a first diode, the anode of the first diode is connected to one end of the first capacitive element, and the other end of the first diode is the output end of the fault detection circuit; a first power supply, the first power supply is connected to the power supply end of the comparison module and to the other end of the sixth resistive element.

[0020] In this technical solution, the voltage of the first resistive element is collected to replace the current detection method, and the action current determined by the first resistive element can be determined by the resistance of the third resistive element and the fourth resistive element as pull-up resistors and the fifth resistive element and the sixth resistive element. In order to avoid the appearance of disturbing signals in the first resistive element, a first capacitive element is connected in parallel to the first reverse input terminal of the comparison module and the first positive input terminal of the comparison module, thereby achieving the effect of filtering interference, and at the same time, other resistive elements are provided between the first power supply and the sixth resistive element to avoid interference between different fault detection circuits.

[0021] In any of the above technical solutions, further, the fault detection circuit also includes: a seventh resistive element, the seventh resistive element is connected to the second reverse input terminal of the comparison module, and the other end is grounded; an eighth resistive element, one end of the eighth resistive element is connected to the second reverse input terminal of the comparison module, and the other end is connected to the first power supply; a ninth resistive element, one end of the ninth resistive element is connected to the other end of the first capacitive element; a tenth resistive element, one end of the tenth resistive element is connected to one end of the first capacitive element, and the other end is connected to the other end of the ninth resistive element; a second diode, the anode of the second diode is connected to one end of the tenth resistive element, and the cathode of the second diode is connected to the other end of the tenth resistive element.

[0022] In this technical solution, the first output terminal of the comparator is input to the second positive input terminal of the comparator, the first capacitive element is used to implement the delay function, and the second output terminal of the comparator is output to the control terminal of the power switch, thereby implementing overcurrent control. By setting the diode, the reverse voltage of the first capacitive element is avoided to avoid damage to the device.

[0023] In any of the above technical solutions, further, the circuit board also includes: a capacitive element, one end of the capacitive element is respectively connected to the second end of the power switch of the multi-channel power factor correction circuit, and the other end of the capacitive element is connected to the grounding point of the circuit board, which is used to eliminate parasitic currents existing in the circuit board, and the capacitive element includes a second capacitive element and a third capacitive element, and the second capacitive element and the third capacitive element are connected in parallel and are respectively arranged on the front and back of the circuit board.

[0024] In the technical scheme, a multi-channel power factor correction circuit is provided on the circuit board, the first end of the power switch included in each power factor correction circuit is connected to the positive bus, the second end of the power switch is connected to the negative bus, and the multi-channel power factor correction circuit is connected between the positive bus and the negative bus to form an interleaved parallel power factor correction circuit, each power factor correction circuit tracks the same input source, and the power switches in different power factor correction circuits have the same switching frequency. When the power factor correction circuit is three-channel, the carrier phase between each channel differs by 120 degrees, and the current ripple of the output current of the interleaved parallel power factor correction circuit formed is reduced relative to the current ripple of the input current. The second end of the power switch of each power factor correction circuit is connected to the grounding point of the circuit board through a capacitive element, and the parasitic current formed by the surge voltage in the circuit in the parasitic capacitor flows into the ground through the capacitive element, thereby avoiding the malfunction of the circuit device caused by the parasitic current in multiple surge current loops, thereby improving the anti-interference ability of the circuit.

[0025] The capacitive element includes a second capacitive element and a third capacitive element, wherein the second capacitive element and the third capacitive element are connected in parallel and are respectively arranged on the front and back sides of the circuit board, so that parasitic currents on the front and back sides of the circuit board can be quickly grounded through the second capacitive element and the third capacitive element, thereby protecting the components of the circuit board.

[0026] In any of the above technical solutions, further, the circuit board is in contact with the radiator, and the radiator dissipates heat through a refrigerant pipe.

[0027] In this technical solution, the circuit board is brought into contact with the radiator, specifically, the control end of the power switch is brought into contact with the radiator, and a refrigerant pipe is used to dissipate heat to reduce the temperature of the circuit board and increase the service life of the circuit board.

[0028] In a second aspect of the present invention, an air conditioner is provided, wherein the air conditioner comprises any circuit board as described above.

[0029] The air conditioner proposed in the present invention includes a circuit board of any of the above technical solutions, and thus has all the beneficial technical effects of the above circuit boards, which will not be described in detail here.

[0030] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0032] Figure 1 A schematic diagram of circuit board connection according to an embodiment of the present invention is shown;

[0033] Figure 2 A schematic diagram of a power factor correction circuit connection according to an embodiment of the present invention is shown;

[0034] Figure 3 A connection diagram of a power factor correction circuit according to another embodiment of the present invention is shown;

[0035] Figure 4 A schematic diagram of a fault detection circuit connection according to an embodiment of the present invention is shown;

[0036] Figure 5 A schematic diagram of a fault detection circuit connection according to another embodiment of the present invention is shown;

[0037] Figure 6 A schematic diagram of a circuit board according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0038] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0040] like Figures 1 to 3As shown, according to a circuit board connection schematic diagram of an embodiment of the present invention, the circuit board includes: a multi-channel power factor correction circuit, used to adjust the input current waveform, the power factor correction circuit includes: a power switch, the first end of the power switch is connected to the positive bus; multiple first resistive elements, the second ends of the power switches of the multiple power factor correction circuits are connected to the negative bus through the first resistive elements; wherein the multiple first resistive elements are connected to the same landing point.

[0041] The present invention provides a circuit board, in which multiple power factor correction circuits are arranged, and the power factor correction circuit can adjust the current waveform input by the circuit board. Specifically, the power factor correction circuit includes a power switch and multiple first resistive elements, and the power switch is provided with two interface terminals, wherein the second terminal on the power switch is connected to the negative bus through the first resistive element, and when there are multiple first resistive elements, the multiple first resistive elements share the same landing point. By unifying the landing points of the multiple first resistive elements, the multiple landing points of the multi-channel power factor correction circuits are also unified together, that is, the multiple power factor correction circuits share the same landing point, so that the voltage value of each power factor correction circuit at the landing point is the same, avoiding the problem of inaccurate power correction and system false overcurrent caused by the voltage difference between the landing points of multiple different power factor correction circuits, thereby greatly improving the control accuracy of the power factor correction circuit, and achieving the technical effect of simplifying the circuit structure and improving the circuit working reliability.

[0042] like Figure 2As shown, multiple power factor correction circuits are staggered and connected in parallel, wherein the sampling resistor of each power factor correction circuit is connected to the landing point through its dedicated line, that is to say, the fault detection circuit has landing points equal to the number of power factor correction circuits. In this case, since the circuit operation and component status in each power factor correction circuit cannot be exactly the same, the voltage at the landing point of each power factor correction circuit cannot be the same, resulting in a voltage difference between the multiple landing points. The voltage difference will affect the detection accuracy of the overcurrent fault detection circuit, and it is easy for the system to make a wrong overcurrent alarm, affecting the normal use of the circuit. In response to this technical problem, the present invention connects the first resistive elements of multiple power factor correction circuits in series, so that the multiple first resistive elements are connected to the same landing point on the same line, so that the voltage value of each power factor correction circuit at the landing point is exactly the same, thereby solving the above-mentioned technical problem and improving the accuracy of the overcurrent fault detection circuit. Among them, the power switch is IGBT, IGBT (Insulated Gate Bipolar Transistor), an insulated gate bipolar transistor, and the MOS tube is a metal (metal)-oxide (oxide)-semiconductor (semiconductor) field effect transistor, or a metal-insulator (insulator)-semiconductor.

[0043] In one embodiment of the present invention, further, the power factor correction circuit also includes: an inductive element, the first end of the power switch is connected to the positive bus through the inductive element; a boost diode, the first end of the power switch is connected to the positive electrode of the boost diode.

[0044] In this embodiment, the power factor correction circuit also includes: an inductive element and a boost diode. The power switch, the inductive element and the boost diode form a power factor correction circuit for adjusting the input current waveform so that the current waveform is synchronized with the input voltage waveform to reduce the loss of exchange power.

[0045] In one embodiment of the present invention, Figure 4 and Figure 5 As shown, the circuit board also includes: multiple fault detection circuits, which are connected to multiple power factor correction circuits in a one-to-one correspondence, and are used to obtain the current signal of the power switch flowing through the power factor correction circuit, and compare the current signal with the preset current to generate a control signal to control the power switch.

[0046] In this embodiment, the circuit board is also provided with a plurality of fault detection circuits, wherein the plurality of fault detection circuits are connected to the power factor correction circuit in a one-to-one correspondence, and the power switch is controlled to be turned on and off by comparing the current signal flowing through the power switch with the preset current and generating a control signal according to the comparison result. Specifically, when it is detected that the current signal flowing through the power switch is greater than the preset current, the power switch is controlled to stop conducting, thereby realizing the protection of the power switch.

[0047] In one embodiment of the present invention, Figure 2 As shown, the circuit board also includes: a plurality of drive circuits, which are correspondingly connected to the multi-channel power factor correction circuits and are used to convert the control signals received from the power factor correction circuits into drive signals for the power switches.

[0048] In this embodiment, a plurality of driving circuits are also provided on the circuit board, and the plurality of driving circuits correspond one-to-one to the multi-channel power factor correction circuits. When receiving a control signal such as a control chip, the analog signal of the control chip is converted into a corresponding driving signal of the power switch.

[0049] In one embodiment of the present invention, the ground terminals of the plurality of driving circuits are connected to the second terminals of the power switches of the plurality of power factor correction circuits and are grounded.

[0050] In this embodiment, the grounding terminals of the plurality of driving circuits are connected to the second terminals of the power switches of the plurality of power factor correction circuits and connected to the negative bus, that is, the grounding terminals of the plurality of driving circuits and the second terminals of the power switches are connected to a common ground, thereby reducing the number of landing points.

[0051] In one embodiment of the present invention, Figure 2 As shown, between the multiple driving circuits and the multi-channel power factor correction circuit, there are also: multiple second resistive elements, and the multiple second resistive elements are used to reduce the amplitude of the driving signal.

[0052] In this embodiment, since the power switch requires a driving signal to turn on and off, in order to avoid the inability to distinguish between the on and off conditions due to the large on and off voltage signals, a second resistive element is set to reduce the amplitude of the driving signal to improve the control accuracy of the power switch.

[0053] In one embodiment of the present invention, Figure 4As shown, the fault detection circuit specifically includes: a comparison module; a third resistive element, one end of the third resistive element is connected to one end of the first resistive element, and the other end is connected to the first reverse input end of the comparison module; a fourth resistive element, one end of the fourth resistive element is connected to the other end of the first resistive element, and the other end is connected to the first positive input end of the comparison module; a fifth resistive element, one end of the fifth resistive element is connected to the other end of the third resistive element; a sixth resistive element, the other end of the sixth resistive element is connected to the other end of the fourth resistive element, and the other end is connected to the other end of the fifth resistive element; a first capacitive element, one end of the first capacitive element is connected to the first output end of the comparison module, and the other end is connected to the second positive input end of the comparison module; a first diode, the anode of the first diode is connected to one end of the first capacitive element, and the other end of the first diode is the output end of the fault detection circuit; a first power supply, the first power supply is connected to the power supply end of the comparison module and to the other end of the sixth resistive element.

[0054] In this embodiment, the voltage of the first resistive element is collected to replace the current detection method, and the action current determined by the first resistive element can be determined by the resistance of the third resistive element and the fourth resistive element as pull-up resistors and the fifth resistive element and the sixth resistive element. In order to avoid the appearance of disturbing signals in the first resistive element, a first capacitive element is connected in parallel to the first reverse input terminal of the comparison module and the first positive input terminal of the comparison module, thereby achieving the effect of filtering interference, and at the same time, other resistive elements are provided between the first power supply and the sixth resistive element to avoid interference between different fault detection circuits.

[0055] In one embodiment of the present invention, Figure 4 As shown, the fault detection circuit also includes: a seventh resistive element, the seventh resistive element is connected to the second reverse input terminal of the comparison module, and the other end is grounded; an eighth resistive element, one end of the eighth resistive element is connected to the second reverse input terminal of the comparison module, and the other end is connected to the first power supply; a ninth resistive element, one end of the ninth resistive element is connected to the other end of the first capacitive element; a tenth resistive element, one end of the tenth resistive element is connected to one end of the first capacitive element, and the other end is connected to the other end of the ninth resistive element; a second diode, the anode of the second diode is connected to one end of the tenth resistive element, and the cathode of the second diode is connected to the other end of the tenth resistive element.

[0056] In this embodiment, the first output terminal of the comparator is input to the second positive input terminal of the comparator, the first capacitive element is used to implement the delay function, and the second output terminal of the comparator is output to the control terminal of the power switch to achieve overcurrent control. By setting the diode, the reverse voltage of the first capacitive element is avoided to avoid damage to the device.

[0057] In one embodiment of the present invention, the circuit board also includes: a capacitive element, one end of the capacitive element is respectively connected to the second end of the power switch of the multi-channel power factor correction circuit, and the other end of the capacitive element is connected to the ground point of the circuit board, which is used to eliminate parasitic current existing in the circuit board. The capacitive element includes a second capacitive element and a third capacitive element, and the second capacitive element and the third capacitive element are connected in parallel and are respectively arranged on the front and back of the circuit board.

[0058] In this embodiment, a multi-channel power factor correction circuit is provided on the circuit board, the first end of the power switch included in each power factor correction circuit is connected to the positive bus, the second end of the power switch is connected to the negative bus, and the multi-channel power factor correction circuit is connected between the positive bus and the negative bus to form an interleaved parallel power factor correction circuit, each power factor correction circuit tracks the same input source, and the power switches in different power factor correction circuits have the same switching frequency. When the power factor correction circuit is three-channel, the carrier phase difference between each channel is 120 degrees, and the current ripple of the output current of the interleaved parallel power factor correction circuit formed is reduced relative to the current ripple of the input current. The second end of the power switch of each power factor correction circuit is connected to the ground point of the circuit board through a capacitive element, and the parasitic current formed by the surge voltage in the circuit in the parasitic capacitor flows into the ground through the capacitive element, thereby avoiding the malfunction of the circuit device caused by the parasitic current in multiple surge current loops, thereby improving the anti-interference ability of the circuit.

[0059] The capacitive element includes a second capacitive element and a third capacitive element, wherein the second capacitive element and the third capacitive element are connected in parallel and are respectively arranged on the front and back sides of the circuit board, so that parasitic currents on the front and back sides of the circuit board can be quickly grounded through the second capacitive element and the third capacitive element, thereby protecting the components of the circuit board.

[0060] In one embodiment of the present invention, the circuit board is in contact with a heat sink, and the heat sink dissipates heat through a refrigerant pipe.

[0061] In this embodiment, the circuit board is brought into contact with the heat sink, specifically, the control end of the power switch is brought into contact with the heat sink, and the refrigerant pipe is used to dissipate heat, so as to reduce the temperature of the circuit board and increase the service life of the circuit board.

[0062] In one embodiment of the present invention, since there are naturally multiple IGBTs in staggered parallel connection, there must be multiple sampling resistors and corresponding landing points. The existing overcurrent protection solution is to sample the voltage drop of each resistor. The problem is that multiple landing points are generated, and the voltage difference between the landing points is very difficult to handle. If the layout is not careful, the system is very likely to falsely report overcurrent.

[0063] like Figure 6 As shown in the figure, a centralized overcurrent protection landing solution is proposed: the landing points of the three PFC sampling resistors are placed together, and the landing points of the three overcurrent protection circuits naturally become one. The specific implementation method is:

[0064] 1. When the power switch and its associated circuits are placed together, the landing points of the first resistive element are combined into one.

[0065] 2. The landing point of the sampling circuit is the collection point of the three shunt meters.

[0066] In a second aspect of the present invention, an air conditioner is provided, wherein the air conditioner comprises any circuit board as described above.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A circuit board, characterized in that: include: A multi-channel power factor correction circuit is used to adjust the input current waveform, the power factor correction circuit comprising: a power switch, a first end of the power switch is connected to the positive bus; A plurality of first resistive elements, wherein the second ends of the power switches of the plurality of power factor correction circuits are connected to the negative bus through the first resistive elements; Wherein, a plurality of the first resistive elements are connected to the same landing point; The circuit board further includes: a plurality of fault detection circuits, the plurality of fault detection circuits being connected to the plurality of power factor correction circuits in a one-to-one correspondence, and being used to obtain a current signal of a power switch flowing through the power factor correction circuit, and compare the current signal with a preset current, and generate a control signal to control the power switch; The fault detection circuit specifically comprises: Comparison module; a third resistive element, one end of the third resistive element being connected to one end of the first resistive element, and the other end of the third resistive element being connected to the first inverting input end of the comparison module; a fourth resistive element, one end of the fourth resistive element being connected to the other end of the first resistive element, and the other end of the fourth resistive element being connected to the first positive input end of the comparison module; a fifth resistive element, one end of the fifth resistive element being connected to the other end of the third resistive element; a sixth resistive element, wherein the other end of the sixth resistive element is connected to the other end of the fourth resistive element, and the other end of the sixth resistive element is connected to the other end of the fifth resistive element; a first capacitive element, one end of which is connected to the first output end of the comparison module, and the other end of which is connected to the second positive input end of the comparison module; a first diode, wherein an anode of the first diode is connected to one end of the first capacitive element, and the other end of the first diode is an output end of the fault detection circuit; A first power supply, the first power supply is connected to a power supply terminal of the comparison module and is connected to the other end of the sixth resistive element; The circuit board is in contact with a radiator, and the radiator dissipates heat through a refrigerant pipe.

2. The circuit board according to claim 1, characterized in that: Also includes: A plurality of driving circuits are connected to the plurality of power factor correction circuits correspondingly, and are used to convert the control signal received from the power factor correction circuit into a driving signal for the power switch.

3. The circuit board according to claim 2, characterized in that: The grounding terminals of the plurality of driving circuits are connected to the second terminals of the power switches of the plurality of power factor correction circuits and are grounded.

4. The circuit board according to claim 3, characterized in that: The plurality of driving circuits and the plurality of power factor correction circuits further include: A plurality of second resistive elements are provided, and the plurality of second resistive elements are used to reduce the amplitude of the driving signal.

5. The circuit board according to claim 1, characterized in that: The fault detection circuit also includes: a seventh resistive element, wherein the seventh resistive element is connected to the second inverting input terminal of the comparison module and the other end of the seventh resistive element is grounded; an eighth resistive element, one end of the eighth resistive element being connected to the second inverting input end of the comparison module, and the other end of the eighth resistive element being connected to the first power supply; a ninth resistive element, one end of the ninth resistive element being connected to the other end of the first capacitive element; a tenth resistive element, one end of the tenth resistive element being connected to one end of the first capacitive element, and the other end of the tenth resistive element being connected to the other end of the ninth resistive element; A second diode, wherein an anode of the second diode is connected to one end of the tenth resistive element, and a cathode of the second diode is connected to the other end of the tenth resistive element.

6. The circuit board according to claim 1, characterized in that: Also includes: A capacitive element, one end of which is respectively connected to the second ends of the power switches of the multiple power factor correction circuits, and the other end of which is connected to the grounding point of the circuit board, for eliminating parasitic currents existing in the circuit board. The capacitive element includes a second capacitive element and a third capacitive element, which are connected in parallel and are respectively arranged on the front and back sides of the circuit board.

7. An air conditioner, characterized in that: Comprising the circuit board as claimed in any one of claims 1 to 6.

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