Air conditioner

Abstract

The invention provides an air conditioner, and relates to the technical field of electric appliances. In order to ensure the fidelity of the air conditioner under high-frequency communication on the basis of protecting a communication loop, the air conditioner comprises the communication loop, and the communication loop comprises a communication chip, a first bus, a second bus and an overvoltage protection circuit. The overvoltage protection circuit is connected with the first bus and the second bus. The overvoltage protection circuit comprises a transient suppression diode and a fuse, and the first end and the second end of the transient suppression diode are connected with the first port and the second port of the communication chip respectively and further connected with the first bus and the second bus respectively. The fuses comprise a first fuse and a second fuse, the first fuse is connected between the first end of the transient voltage suppressor and the first bus, and / or the second fuse is connected between the second end of the transient voltage suppressor and the second bus. The fuse is configured to disconnect the communication chip and the buses when the voltage between the first bus and the second bus is greater than the highest clamping voltage of the transient suppression diode.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical appliances, and in particular to an air conditioner. Background Art

[0002] Most Japanese central air conditioners use H-link communication. The communication frequency of H-link is generally 9.6KHz, which is within the range of sound that the human ear can hear, so users can hear some noise. In order to solve the noise heard by users, the communication frequency of H-link needs to be increased to above 20KHz.

[0003] An overvoltage protection circuit is usually provided in the internal communication circuit of the air conditioner. The existing overvoltage protection circuit includes a varistor, a diode and a fuse, which is used to prevent the communication circuit from being damaged due to excessive voltage input between the buses.

[0004] However, due to the increase in the communication frequency of H-link communication, the distributed capacitance of the varistor and the diode has a greater impact on the fidelity of the air conditioner in high-frequency communication. Summary of the invention

[0005] An embodiment of the present invention provides an air conditioner, wherein an overvoltage protection circuit in a communication circuit of the air conditioner adopts a transient suppression diode, thereby ensuring the fidelity of the air conditioner under high-frequency communication while protecting the communication circuit.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0007] The air conditioner provided by the present invention includes a communication circuit, and the communication circuit includes a communication chip, a first bus, a second bus and an overvoltage protection circuit. Among them, the communication chip includes a first port and a second port, the first bus is connected to the first port of the communication chip, the second bus is connected to the second port of the communication chip, and the overvoltage protection circuit is connected to the first bus and the second bus. The overvoltage protection circuit includes a transient suppression diode and a fuse, the first end of the transient suppression diode is connected to the first port of the communication chip, and is also connected to the first bus, the second end of the transient suppression diode is connected to the second port of the communication chip, and is also connected to the second bus. The fuse includes a first fuse and a second fuse, the first fuse is connected between the first end of the transient suppression diode and the first bus, and / or the second fuse is connected between the second end of the transient suppression diode and the second bus. The fuse is configured to disconnect the connection between the communication chip and the first bus and the connection between the communication chip and the second bus when the voltage applied between the first bus and the second bus is greater than the highest clamping voltage of the transient suppression diode.

[0008] When the voltage between the first bus and the second bus is normal, the transient suppression diode is in the cut-off state, and the communication circuit works normally. When the voltage applied between the first bus and the second bus is greater than the highest clamping voltage of the transient suppression diode, the transient suppression diode changes from a high-resistance state to a low-resistance state, providing a low-impedance conduction path for the transient current, and clamping the abnormal high voltage within a safe level. At this time, the transient current is large, which will cause the fuse to disconnect. Since the fuse connects the bus and the communication chip, the disconnection of the fuse is equivalent to the disconnection of the communication chip and the bus, thus preventing the communication chip from being burned when the voltage applied between the first bus and the second bus is greater than the highest clamping voltage of the transient suppression diode, thereby protecting the communication circuit. And because the transient suppression diode has the characteristic of small distributed capacitance, the communication circuit can have good fidelity under high-frequency communication.

[0009] As a possible implementation manner, the transient suppression diode is a bidirectional transient suppression diode.

[0010] As a possible implementation, the highest clamping voltage of the transient suppression diode is 80 to 100V.

[0011] As a possible implementation manner, the first fuse and the second fuse include copper foil, and the overcurrent capability of the copper foil is smaller than the overcurrent capability of the transient suppression diode.

[0012] As a possible implementation manner, packaging methods of TVS diodes include: 0603 package, 0402 package, 0805 package and 1206 package.

[0013] As a possible implementation manner, the fuse includes a fuse.

[0014] As a possible implementation, the communication loop further includes a first resistor, a second resistor, a first capacitor, and a second capacitor. The first end of the first resistor is electrically connected to the first port of the communication chip, the second end of the first resistor is electrically connected to the first pole of the first capacitor, and the second pole of the first capacitor is electrically connected to the first end of the transient suppression diode. The first end of the second resistor is electrically connected to the second port of the communication chip, the second end of the second resistor is electrically connected to the first pole of the second capacitor, and the second pole of the second capacitor is electrically connected to the second end of the transient suppression diode.

[0015] As a possible implementation, the communication circuit also includes a negative voltage protection circuit, and the communication chip also includes a third port and a fourth port. The negative voltage protection circuit includes a first diode, a second diode, a third diode and a fourth diode; the anode of the first diode is electrically connected to the fourth port of the communication chip, and the anode of the first diode is also electrically connected to the first bus; the cathode of the first diode is electrically connected to the cathode of the second diode, and the anode of the second diode is grounded. The anode of the third diode is electrically connected to the third port of the communication chip, the anode of the third diode is also electrically connected to the second bus, the cathode of the third diode is also electrically connected to the cathode of the fourth diode, and the anode of the fourth diode is grounded.

[0016] As a possible implementation, the communication loop further includes a drive circuit, and the communication chip further includes a fifth port and a sixth port. The drive circuit includes: a first switch tube and a second switch tube; the control electrode of the first switch tube is electrically connected to the fifth port of the communication chip, the first electrode of the first switch tube is electrically connected to the fourth port of the communication chip, and the second electrode of the first switch tube is grounded. The control electrode of the second switch tube is electrically connected to the sixth port of the communication chip, the first electrode of the second switch tube is electrically connected to the third port of the communication chip, and the second electrode of the second switch tube is grounded.

[0017] As a possible implementation, the communication circuit also includes a modulation circuit and a demodulation circuit. The communication chip also includes a seventh port and an eighth port. The modulation circuit includes a first input terminal, a second input terminal and an output terminal, wherein the first input terminal of the modulation circuit is connected to the first signal terminal, the second input terminal of the modulation circuit is connected to the second signal terminal, and the output terminal of the modulation circuit is electrically connected to the seventh port of the communication chip. The demodulation circuit includes an input terminal and an output terminal, the input terminal of the demodulation circuit is connected to the third signal terminal, and the output terminal of the demodulation circuit is electrically connected to the eighth port of the communication chip. The modulation circuit is configured to receive a signal input from the first signal terminal through the first input terminal, receive a signal input from the second signal terminal through the second input terminal, and output a signal synthesized by the signal input from the first signal terminal and the signal input from the second signal terminal through the output terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0019] Figure 1 A communication circuit structure diagram of an air conditioner provided in an embodiment of the present application;

[0020] Figure 2 A specific schematic diagram of a communication circuit provided in an embodiment of the present application;

[0021] Figure 3A composition diagram of an overvoltage protection circuit provided in an embodiment of the present application;

[0022] Figure 4 A waveform diagram of high-frequency communication under the influence of varistor and diode distributed capacitance provided in an embodiment of the present application;

[0023] Figure 5 An ideal output waveform diagram under high frequency communication provided by an embodiment of the present application;

[0024] Figure 6 A schematic diagram of distributed capacitance of a diode provided in an embodiment of the present application;

[0025] Figure 7 A schematic diagram of an equivalent capacitance of an overvoltage protection circuit composed of a varistor and a diode provided in an embodiment of the present application;

[0026] Figure 8 A schematic diagram of a packaging of a transient voltage suppressor diode provided in an embodiment of the present application;

[0027] Fig. 9 A schematic diagram of another overvoltage protection circuit provided in an embodiment of the present application;

[0028] Fig.10 A schematic diagram of another overvoltage protection circuit provided in an embodiment of the present application;

[0029] Fig.11 A schematic diagram of another overvoltage protection circuit provided in an embodiment of the present application;

[0030] Fig.12 Another communication circuit diagram provided in an embodiment of the present application;

[0031] Fig.13 A communication circuit composition diagram provided in an embodiment of the present application;

[0032] Fig.14 A diagram showing the composition of a negative pressure protection circuit provided in an embodiment of the present application;

[0033] Fig.15 Another communication circuit composition diagram provided in an embodiment of the present application;

[0034] Fig.16 A diagram showing the composition of a driving circuit provided in an embodiment of the present application;

[0035] Fig.17 Another communication circuit composition diagram provided for an embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, when describing the pipeline, the "connected" and "connection" used in the present invention have the meaning of conduction. The specific meaning needs to be understood in conjunction with the context.

[0040] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0041] With the continuous development of economy, the popularity of air conditioners is also increasing. Mainstream Japanese central air conditioners, such as Hitachi, Daikin, Toshiba, etc., often use H-link communication. H-link communication refers to a communication system formed by connecting the indoor unit and the outdoor unit with a control line. In addition to the indoor unit and the outdoor unit, the control line can also be connected to the user management center, communication interface, etc. Through the management system software, all-round control of the air conditioner can be achieved, such as operating temperature, mode, air volume, wind direction, heating and cooling, time, fault alarm, etc.

[0042] The frequency of H-link communication is generally 9.6KHz, and the human ear can hear sounds between 20Hz and 20KHz. Therefore, users can hear the ticking sound when the air conditioner is running. This ticking sound greatly affects the user experience. In order to solve the user's pain points, the frequency of H-link communication needs to be increased to above 20KHz.

[0043] See also Figure 1 , Figure 1 The communication circuit structure diagram of the air conditioner provided in the present application is shown. The air conditioner includes an indoor unit 100 and an outdoor unit 200, and a communication circuit 10 is provided between the indoor unit 100 and the outdoor unit 200. The communication circuit 10 is a channel for communication between the indoor unit 100 and the outdoor unit 200, and the communication circuit 10 also includes a communication chip 1 and an overvoltage protection circuit 2.

[0044] For example, the specific schematic diagram of the communication circuit 10 is as follows: Figure 2 As shown. In the following embodiments, the communication chip 1 uses MM1192 for illustration, but in some other embodiments, the communication chip 1 can also use other types as a replacement for MM1192. MM1192 has a total of 16 pins, of which the 15th pin and the 16th pin of MM1192 are respectively recorded as the second port and the first port in the following description.

[0045] Reference Figure 2 The first port of the communication chip 1 is connected to the first bus 3, the second port of the communication chip 1 is connected to the second bus 4, and an overvoltage protection circuit 2 is connected between the first bus 3 and the second bus 4. The communication chip 1 is the core of the communication circuit 10, and the overvoltage protection circuit 2 is used to prevent the communication chip 1 from burning out due to excessive voltage between the first bus 3 and the second bus 4, resulting in the consequence that the indoor unit and the outdoor unit cannot communicate normally.

[0046] In some embodiments, the existing overvoltage protection circuit is composed of Figure 3 See Figure 3 The overvoltage protection circuit 2 includes a first varistor 21 , a second varistor 22 , a first diode 23 , a second diode 24 and a fuse 25 .

[0047] The first end of the first varistor 21 is electrically connected to the first port of the communication chip 1 , and the second end of the first varistor 21 is electrically connected to the cathode of the first diode 23 . The anode of the first diode 24 is electrically connected to the second port of the communication chip 1 .

[0048] The first end of the first varistor 21 is also electrically connected to the first end of the second varistor 22, the first end of the second varistor 22 is also electrically connected to the first bus 3 through the fuse 25, the second end of the second varistor 22 is electrically connected to the positive electrode of the second diode 24, the negative electrode of the second diode 24 is electrically connected to the positive electrode of the first diode 23, and the negative electrode of the second diode 24 is also electrically connected to the second bus 4.

[0049] A varistor is a resistor device with nonlinear volt-ampere characteristics. It is often used to clamp voltage when the circuit is subjected to overvoltage. When the voltage applied to the varistor is lower than its threshold, the current flowing through it is extremely small, and it is equivalent to a resistor with infinite resistance. In other words, when the voltage applied to it is lower than its threshold, it is equivalent to a switch in the open state. When the voltage applied to the varistor exceeds its threshold, the current flowing through it surges, and it is equivalent to a resistor with infinite resistance. In other words, when the voltage applied to it is higher than its threshold, it is equivalent to a switch in the closed state.

[0050] For example, when the voltage applied between the first bus and the second bus is 220V, and the potential of the first bus is higher than that of the second bus, due to the unidirectional conductivity of the diode, the first diode is in a cut-off state, and the 220V voltage between the first bus and the second bus will not act on the first varistor. The 220V voltage between the first bus and the second bus acts on the second varistor, which is greater than the threshold of the second varistor. At this time, the second varistor is equivalent to a resistor with an infinitesimal resistance, and the current flowing through the second varistor surges. A path is formed from the first bus to the fuse, the second varistor, the second diode, and then to the second bus. Since the second varistor is equivalent to a resistor with an infinitesimal resistance, the current flowing through the second varistor surges, the fuse is blown, and there is no longer a path between the communication chip and the first bus and the second bus, preventing the 220V voltage between the first bus and the second bus from acting on the communication chip and burning the chip.

[0051] When the voltage applied between the first bus and the second bus is 220V, and the potential of the first bus is lower than that of the second bus, due to the unidirectional conductivity of the diode, the second diode is in a cut-off state, and the 220V voltage between the first bus and the second bus will not act on the second varistor. The 220V voltage between the first bus and the second bus acts on the first varistor, which is greater than the threshold of the first varistor. At this time, the first varistor is equivalent to a resistor with an infinitesimal resistance, and the current flowing through the first varistor surges. A path is formed from the first bus to the fuse, the first varistor, the first diode, and then to the second bus. Since the first varistor is equivalent to a resistor with an infinitesimal resistance, the current flowing through the first varistor surges, the fuse is blown, and there is no longer a path between the communication chip and the first bus and the second bus, preventing the 220V voltage between the first bus and the second bus from acting on the communication chip and burning the chip.

[0052] Although the combination of a varistor and a diode can effectively protect the communication circuit from overvoltage, the distributed capacitance of the two varistors and the two diodes themselves may cause distortion of the communication waveform in the case of high-frequency communication.

[0053] For example, Figure 4 and Figure 5 As shown, Figure 4 The waveform of high frequency communication under the influence of varistor and diode distributed capacitance is shown. Figure 5 The ideal output waveform under high frequency communication is shown. Figure 4 and Figure 5 It can be seen that in Figure 4 The area surrounded by the dotted circle in the figure is distorted, which will eventually lead to poor communication quality and a bad user experience. Therefore, how to maintain high fidelity in high-frequency communication while ensuring the overvoltage protection function has become an urgent problem to be solved.

[0054] The reason why the overvoltage protection circuit composed of a varistor and a diode causes waveform distortion in high-frequency communication is that the distributed capacitance of the varistor and the diode is large. For example, the distributed capacitance of the varistor with product number TNR7G220K is 1800pF.

[0055] For example, Figure 6 As shown, Figure 6 shows the distributed capacitance of the diode. Figure 6 , Figure 6 The horizontal axis represents the reverse voltage of the diode, and the vertical axis represents the distributed capacitance of the diode. Figure 6It can be seen that when the reverse voltage of the diode is higher, the distributed capacitance corresponding to the diode is smaller. In the air conditioner with H-link high-frequency communication, the reverse voltage through the diode is usually around 5V, corresponding to Figure 6 The distributed capacitance of the diode in is 15pF.

[0056] Combination Figure 3 The composition of the overvoltage protection circuit, Figure 7 The equivalent capacitance diagram of the overvoltage protection circuit composed of a varistor and a diode is shown. Figure 7 , taking the distributed capacitance of the first varistor CZ1 and the second varistor CZ2 as 1800pF, and the distributed capacitance of the first diode CD2 and the second diode CD3 as 15pF as an example for calculation, the total distributed capacitance of the overvoltage protection circuit is:

[0057]

[0058] When the communication frequency is low, such as 9.6KHz, the distributed capacitance has little effect on the communication waveform of the air conditioner, and waveform distortion will not occur. However, in order to solve the ticking sound heard by users when the air conditioner is running, the communication frequency of the air conditioner needs to be increased, for example, to 48KHz. In this case, the 29.74pF distributed capacitance of the overvoltage protection circuit is relatively large, which will cause distortion of the communication waveform.

[0059] For example, Fig. 9 As shown, Fig. 9 An overvoltage protection circuit provided by the present application is shown. Fig. 9 The overvoltage protection circuit 2 includes: a transient suppression diode 26, a first fuse 27 and a second fuse 27. The first end of the transient suppression diode 26 is connected to the first port of the communication chip 1 and is also connected to the first bus 3. The second end of the transient suppression diode 26 is connected to the second port of the communication chip 1 and is also connected to the second bus 4. The first fuse 27 is connected between the first end of the transient suppression diode 26 and the first bus 3, and / or the second fuse 27 is connected between the second end of the transient suppression diode 26 and the second bus 4. The first fuse 27 and the second fuse 27 are configured to disconnect the communication chip 1 from the first bus 3 and the communication chip 1 from the second bus 4 when the voltage applied between the first bus 3 and the second bus 4 is greater than the highest clamping voltage of the transient suppression diode 26.

[0060] Transient voltage suppressor diodes are referred to as TVS tubes. The electrical characteristics of TVS tubes are determined by the PN junction area, doping concentration and wafer resistance. Its ability to withstand surge current is proportional to its PN junction area. Transient voltage suppressor diodes are usually connected in parallel in the circuit to protect the circuit from abnormal instantaneous high voltage. When the circuit is working normally, it is in the cut-off state (high impedance state) and does not affect the normal operation of the circuit. When the circuit has abnormal overvoltage and reaches its highest clamping voltage, it quickly changes from high impedance state to low impedance state, providing a low impedance conduction path for the transient current, while clamping the abnormal high voltage within a safe level, thereby protecting the protected IC or circuit. When the abnormal overvoltage disappears, the transient voltage suppressor diode returns to the high impedance state and the circuit works normally.

[0061] In actual applications, due to operational errors of construction workers, a high voltage of 220V may be connected between the first bus and the second bus. Since the voltage connected between the first bus and the second bus during air-conditioning communication is much smaller than 220V, for example, 10V, the excessively high voltage connected between the first bus and the second bus may cause the communication chip to burn out, thereby making it impossible to achieve normal communication of the air conditioner.

[0062] An overvoltage protection circuit composed of a transient suppression diode and a fuse is used. When the voltage between the first bus and the second bus exceeds the highest clamping voltage of the transient suppression diode, it indicates that an abnormal overvoltage condition occurs. The impedance of the transient suppression diode changes rapidly from a high resistance state to a low resistance state. The current flowing through the transient suppression diode increases instantaneously, causing the fuse to disconnect. There is no longer a path between the communication chip and the first bus and the second bus, preventing the 220V voltage between the first bus and the second bus from acting on the communication chip and burning the chip.

[0063] Compared with the overvoltage protection circuit composed of two varistors, two diodes and a fuse, the overvoltage protection circuit composed of a transient suppression diode and a fuse has a smaller distributed capacitance and can also effectively protect the communication circuit under overvoltage conditions.

[0064] It should be noted that the transient suppression diode provided in the embodiment of the present application is a bidirectional transient suppression diode. When the unidirectional transient suppression diode works in a reverse biased state, it will be in a cut-off state (high impedance state) when the circuit is working normally, and it will not affect the normal operation of the circuit. When the circuit has an abnormal overvoltage and reaches its highest clamping voltage, it quickly changes from a high impedance state to a low impedance state, providing a low impedance conduction path for the instantaneous current, and at the same time clamping the abnormal high voltage within a safe level. The potential of the first bus and the second bus is not fixed, that is, if only one unidirectional transient suppression diode is used as the core component of the overvoltage protection circuit, then only the overvoltage protection when the potential of the first bus is higher than the potential of the second bus or the overvoltage protection when the potential of the first bus is lower than the potential of the second bus can be realized. Therefore, if you want to realize the overvoltage protection function, you need to set two unidirectional transient suppression diodes.

[0065] Considering that unidirectional TVS diodes are usually used in DC circuits, while bidirectional TVS diodes are usually used in AC circuits, as well as the size of the distributed capacitance of two unidirectional TVS diodes and one bidirectional TVS diode, the embodiment of the present application uses bidirectional TVS diodes as the preferred component.

[0066] Transient suppression diode is a new product developed on the basis of voltage regulator technology. When the two ends of transient suppression diode are subjected to instantaneous high energy impact, it can reduce its impedance suddenly at a very high speed (up to 1*10^-12 seconds), while absorbing a large current, clamping the voltage between its two ends to a predetermined value, thereby ensuring that the subsequent communication chip is protected from damage by transient high energy impact. As a possible implementation method, the maximum clamping voltage of transient suppression diode is 80~100V. Due to the small distributed capacitance of transient suppression diode, it is highly suitable as a component of overvoltage protection circuit under high frequency of air conditioner.

[0067] The packaging of different transient suppression diodes will also have an impact on the size of the distributed capacitance. Taking the above-mentioned embodiment as an example, the packaging selection of the transient suppression diode is explained. When the air conditioner communication frequency is 9.6KHz, the distributed capacitance of the overvoltage protection circuit is 29.74pF, which does not affect the normal communication of the air conditioner, nor does it cause distortion of the communication waveform. Then, when the air conditioner communication frequency is increased to 48KHz, that is, increased by 5 times, the distributed capacitance of the overvoltage protection circuit should be reduced to at least one-fifth of the original, that is, 5.894pF. The packaging of the transient suppression diode is selected based on the calculated maximum value of the distributed capacitance of the overvoltage protection circuit.

[0068] As a possible implementation, the embodiments of the present application provide packaging methods for transient voltage suppressor diodes, including: 0603 packaging, 0402 packaging, 0805 packaging and 1206 packaging.

[0069] For example, Figure 8 As shown, Figure 8 A schematic diagram of a transient suppression diode package provided in an embodiment of the present application is shown. Figure 8 , Figure 8 L1 represents the extent after packaging, and L2 represents the width after packaging. The packaging of transient suppression diodes can not only strengthen the support and protection of components, but also improve the heat dissipation of components to a certain extent. Using different packaging methods to package transient suppression diodes will obtain packaging shells of different sizes. The 0603 package provided in the embodiment of the present application has a length of 0.6 inches and a width of 0.3 inches, the length of the 0402 package is 0.4 inches and a width of 0.2 inches, the length of the 0805 package is 0.8 inches and a width of 0.5 inches, and the length of the 1206 package is 1.2 inches and a width of 0.6 inches.

[0070] As a possible implementation, the first fuse and the second fuse include copper foil, and the overcurrent capacity of the copper foil is smaller than the overcurrent capacity of the transient suppression diode. When the fuse is copper foil, the connection of the overvoltage protection circuit can refer to Fig. 9 That is, the first fuse 27 (first copper foil) is connected between the first end of the transient suppression diode and the first bus, and the second fuse 28 (second copper foil) is connected between the second end of the transient suppression diode 26 and the second bus.

[0071] The overcurrent capacity of copper foil is smaller than that of transient suppression diode. When the circuit is under abnormal overvoltage, the copper foil will be disconnected quickly. The response speed of copper foil is fast, the cost is low, and it can effectively protect the communication circuit.

[0072] As a possible implementation, the fuse includes a fuse. In the case where the fuse is a fuse, the connection of the overvoltage protection circuit can refer to Fig.10 and Fig.11 .

[0073] Combination Fig.10 As shown, the overvoltage protection circuit 2 includes: a transient suppression diode 26 and a fuse 25, wherein a first end of the transient suppression diode 26 is connected to a first port of the communication chip 1 and is also connected to a first bus 3, and a second end of the transient suppression diode 26 is connected to a second port of the communication chip 1 and is also connected to a second bus 4. The fuse 25 is connected between the first end of the transient suppression diode 26 and the first bus 3.

[0074] Combination Fig.11 As shown, the overvoltage protection circuit 2 includes: a transient suppression diode 26 and a fuse 25, wherein a first end of the transient suppression diode 26 is connected to a first port of the communication chip 1 and is also connected to a first bus 3, and a second end of the transient suppression diode 26 is connected to a second port of the communication chip 1 and is also connected to a second bus 4. The fuse 25 is connected between the second end of the transient suppression diode 26 and the second bus 4.

[0075] In some embodiments, Fig.12 As shown, Fig.12 A communication circuit provided by an embodiment of the present application is shown. Fig.12 The communication circuit also includes a first resistor 5, a second resistor 6, a first capacitor 7 and a second capacitor 8. The first end of the first resistor 5 is electrically connected to the first port of the communication chip 1, the second end of the first resistor 5 is electrically connected to the first electrode of the first capacitor 7, and the second electrode of the first capacitor 7 is electrically connected to the first end of the transient suppression diode 26. The first end of the second resistor 6 is electrically connected to the second port of the communication chip 1, the second end of the second resistor 6 is electrically connected to the first electrode of the second capacitor 8, and the second electrode of the second capacitor 8 is electrically connected to the second end of the transient suppression diode 26.

[0076] For example, Fig.13 As shown, Fig.13 The composition of a communication circuit provided by an embodiment of the present application is shown. Fig.13 The communication circuit includes a communication chip 1, an overvoltage protection circuit 2 and a negative voltage protection circuit 9. The negative voltage protection circuit 9 is used to protect the communication chip 1, prevent the communication chip 1 from being damaged by a high negative voltage, and ensure the stability and safety of the communication circuit.

[0077] Since the protection circuit inside the communication chip 1 is not protected against negative voltage, once a slightly larger current is applied to the port of the communication chip 1, the communication chip 1 can be burned and the communication circuit can be paralyzed without a very high negative voltage. Therefore, in order to ensure the reliability of the communication chip 1 and prevent the communication chip 1 from being damaged by negative voltage, the embodiment of the present application also provides a method for implementing a negative voltage protection circuit.

[0078] For example, Fig.14 As shown, Fig.14 The composition of a negative voltage protection circuit provided by an embodiment of the present application is shown. Fig.14 The negative voltage protection circuit 9 includes a first diode 91, a second diode 92, a third diode 93 and a fourth diode 94. The communication chip 1 also includes a third port and a fourth port, wherein the third port is Fig.14 The ninth pin of the communication chip, the fourth port is Fig.14 The tenth pin of the communication chip.

[0079] The anode of the first diode 91 is electrically connected to the fourth port of the communication chip 1, and the anode of the first diode 91 is also electrically connected to the first bus 3; the cathode of the first diode 91 is electrically connected to the cathode of the second diode 92, and the anode of the second diode 92 is grounded. The anode of the third diode 93 is electrically connected to the third port of the communication chip 1, and the anode of the third diode 93 is also electrically connected to the second bus 4. The cathode of the third diode 93 is also electrically connected to the cathode of the fourth diode 94, and the anode of the fourth diode 94 is grounded.

[0080] As a possible implementation, the first diode 91, the second diode 92, the third diode 93 and the fourth diode 94 can be voltage regulator diodes. The voltage regulator diode works in the reverse breakdown region. When the reverse voltage increases to the breakdown voltage, the voltage change at both ends of the voltage regulator diode is very small, which is equivalent to being clamped within a certain range. Fig.13 The Zener diode connection method shown can ensure the safety of the communication circuit regardless of whether the positive voltage or negative voltage is abnormal. For example, when the negative voltage of the communication circuit is too large, the first diode 91 is forward-conducted and the second diode 92 is reverse-broken, clamping the voltage within a safe range.

[0081] It should be understood that the forward conduction voltage of a diode is usually 0.7V, and the forward conduction voltage of n diodes connected in series is 0.7nV. After conduction, the voltage across the diode remains basically unchanged. The diode can only be turned on when the conduction condition of the diode is met (that is, the external forward voltage is greater than the conduction voltage of the diode), otherwise the diode is cut off.

[0082] For example, Fig.15 As shown, Fig.15 Another communication circuit composition diagram provided by an embodiment of the present application is shown. Fig.15 and Fig.13 It can be found that compared to Fig.15 , Fig.15 The communication circuit shown includes not only the communication chip 1 , the overvoltage protection circuit 2 and the negative voltage protection circuit 9 , but also a driving circuit 10 .

[0083] The drive circuit is often located between the main circuit and the control circuit. It is an intermediate circuit used to amplify the signal of the control circuit. The function of the drive circuit is to control the working state of other electronic devices and convert the electrical signal into a signal that can drive the load. By adding a drive circuit, the efficiency of the system can be improved. Taking the air conditioning communication circuit as an example, adding a drive circuit in the communication circuit can enhance the communication efficiency between different air conditioners, between the indoor and outdoor units of the air conditioner, and between the indoor unit and the wired controller. Since the characteristics of each component in the circuit are different, adding a drive circuit can accurately adjust and control it to overcome the nonlinear effects of circuit components, thereby reducing noise and other problems caused by switch jumps. The stability of the system can be improved through the drive circuit. The system's overvoltage, undervoltage, overload and other conditions can be monitored through the drive circuit, and feedback control can be performed in a timely manner, thereby ensuring the stability and safety of the communication circuit.

[0084] In some embodiments, Fig.16 As shown, Fig.16 The composition diagram of the driving circuit provided in the embodiment of the present application is shown. Fig.16 The communication chip 1 also includes a fifth port and a sixth port, wherein the fifth port is Fig.16 The seventh pin of the communication chip 1 and the sixth port are Fig.16 The driving circuit 10 includes: a first switch tube 101 and a second switch tube 102, wherein the control electrode of the first switch tube 101 is electrically connected to the fifth port of the communication chip 1, the first electrode of the first switch tube 101 is electrically connected to the fourth port of the communication chip 1, and the second electrode of the first switch tube 101 is grounded. The control electrode of the second switch tube 102 is electrically connected to the sixth port of the communication chip 1, the first electrode of the second switch tube 102 is electrically connected to the third port of the communication chip 1, and the second electrode of the second switch tube 102 is grounded.

[0085] It should be noted that the switch tube can be a triode or a field effect tube. When the switch tube is a triode, the first end of the switch tube is the base of the triode, the second end of the switch tube is one of the emitter and the collector of the triode, and the third end of the switch tube is the other of the emitter and the collector of the triode. When the switch tube is a field effect tube, the first end of the switch tube is the gate of the field effect tube, the second end of the switch tube is one of the source and the drain of the field effect tube, and the third end of the switch tube is the other of the source and the drain of the field effect tube.

[0086] As a possible implementation, Fig.17 As shown, Fig.17 FIG. 1 shows another communication circuit diagram provided in an embodiment of the present application, referring to FIG. Fig.17The communication circuit includes a communication chip 1, a negative voltage protection circuit 2, an overvoltage protection circuit 9, a driving circuit 10, a modulation circuit 11 and a demodulation circuit 12.

[0087] There will be timing problems in the communication between different air conditioners, between the indoor and outdoor units of air conditioners, and between indoor units and wire controllers. That is to say, when information is being transmitted, different air conditioners, between the indoor and outdoor units of air conditioners, and between indoor units and wire controllers cannot achieve synchronous control. For example, the user issues instructions to multiple indoor units of air conditioners through the wire controller, and the instruction content is to increase the temperature of each indoor unit to 26 degrees Celsius. The time when each indoor unit receives the instruction through the communication loop is different. For example, the indoor unit of the master bedroom receives the instruction 3 seconds after the user issues the instruction through the wire controller, while the indoor unit of the living room receives the instruction 6 seconds after the user issues the instruction through the wire controller, and the indoor unit of the second bedroom receives the instruction 10 seconds after the user issues the instruction through the wire controller.

[0088] In order to ensure the synchronization of communication between different air conditioners, between the indoor and outdoor units of air conditioners, and between the indoor units and wire controllers, the addition of modulation loops and demodulation loops is particularly important. Exemplarily, the communication chip also includes a seventh port and an eighth port. The modulation loop includes a first input end, a second input end, and an output end, wherein the first input end of the modulation loop is connected to the first signal end, the second input end of the modulation loop is connected to the second signal end, and the output end of the modulation loop is electrically connected to the seventh port of the communication chip. The demodulation loop includes an input end and an output end, the input end of the demodulation loop is connected to the third signal end, and the output end of the demodulation loop is electrically connected to the eighth port of the communication chip. The modulation loop is configured to receive a signal input by the first signal end through the first input end, receive a signal input by the second signal end through the second input end, and output a signal synthesized by the signal input by the first signal end and the signal input by the second signal end through the output end.

[0089] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An air conditioner, characterized in that: include: A communication circuit, the communication circuit comprising: A communication chip, the communication chip comprising: a first port and a second port a first bus connected to the first port; a second bus connected to the second port; an overvoltage protection circuit, connected to the first bus and the second bus, the overvoltage protection circuit comprising: A transient suppression diode, wherein a first end of the transient suppression diode is connected to the first port of the communication chip and is also connected to the first bus, and a second end of the transient suppression diode is connected to the first port of the communication chip and is also connected to the second bus; A fuse, comprising: a first fuse connected between a first end of the transient suppression diode and the first bus; and / or; a second fuse connected between a second end of the transient suppression diode and the second bus; The fuse is configured to disconnect the communication chip from the first bus and the communication chip from the second bus when a voltage applied between the first bus and the second bus is greater than a maximum clamping voltage of the transient suppression diode.

2. The air conditioner according to claim 1, characterized in that: The transient voltage suppression diode is a bidirectional transient voltage suppression diode.

3. The air conditioner according to claim 1, characterized in that: The maximum clamping voltage of the transient suppression diode is 80-100V.

4. The air conditioner according to claim 1, characterized in that: The first fuse and the second fuse include copper foils, and an overcurrent capability of the copper foils is smaller than an overcurrent capability of the TVS diode.

5. The air conditioner according to claim 1, characterized in that: The packaging methods of the transient suppression diode include: 0603 packaging, 0402 packaging, 0805 packaging and 1206 packaging.

6. The air conditioner according to claim 1, characterized in that: The fuse includes a fuse.

7. The air conditioner according to claim 1, characterized in that: The communication circuit also includes a first resistor, a second resistor, a first capacitor and a second capacitor; The first end of the first resistor is electrically connected to the first port of the communication chip, the second end of the first resistor is electrically connected to the first electrode of the first capacitor, and the second electrode of the first capacitor is electrically connected to the first end of the transient suppression diode; The first end of the second resistor is electrically connected to the second port of the communication chip, the second end of the second resistor is electrically connected to the first electrode of the second capacitor, and the second electrode of the second capacitor is electrically connected to the second end of the transient suppression diode.

8. The air conditioner according to claim 1, characterized in that: The communication circuit also includes a negative pressure protection circuit, and the communication chip also includes a third port and a fourth port; The negative voltage protection circuit includes a first diode, a second diode, a third diode and a fourth diode; the anode of the first diode is electrically connected to the fourth port of the communication chip, and the anode of the first diode is also electrically connected to the first bus; the cathode of the first diode is electrically connected to the cathode of the second diode, and the anode of the second diode is grounded; The anode of the third diode is electrically connected to the third port of the communication chip, the anode of the third diode is also electrically connected to the second bus, the cathode of the third diode is also electrically connected to the cathode of the fourth diode, and the anode of the fourth diode is grounded.

9. The air conditioner according to claim 1, characterized in that: The communication circuit further includes a driving circuit, and the communication chip further includes a fifth port and a sixth port; The driving circuit includes: a first switch tube and a second switch tube; the control electrode of the first switch tube is electrically connected to the fifth port of the communication chip, the first electrode of the first switch tube is electrically connected to the fourth port of the communication chip, and the second electrode of the first switch tube is grounded; The control electrode of the second switch tube is electrically connected to the sixth port of the communication chip, the first electrode of the second switch tube is electrically connected to the third port of the communication chip, and the second electrode of the second switch tube is grounded.

10. The air conditioner according to claim 1, characterized in that: The communication circuit also includes a modulation circuit and a demodulation circuit; the communication chip also includes a seventh port and an eighth port; The modulation circuit comprises a first input terminal, a second input terminal and an output terminal, wherein the first input terminal of the modulation circuit is connected to the first signal terminal, the second input terminal of the modulation circuit is connected to the second signal terminal, and the output terminal of the modulation circuit is electrically connected to the seventh port of the communication chip; The demodulation circuit comprises an input end and an output end, the input end of the demodulation circuit is connected to the third signal end, and the output end of the demodulation circuit is electrically connected to the eighth port of the communication chip; The modulation circuit is configured to receive a signal input from the first signal terminal through the first input terminal, receive a signal input from the second signal terminal through the second input terminal, and output a signal synthesized by the signal input from the first signal terminal and the signal input from the second signal terminal through the output terminal.

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