Adhesion detection circuit, adhesion detection method, control device and air conditioning equipment

Abstract

The invention provides an adhesion detection circuit, an adhesion detection method, a control device and air conditioning equipment. The adhesion detection circuit comprises a detected three-phase circuit and a detection circuit, in the detection circuit, the positive electrode of the transmitting end of the photoelectric coupler is electrically connected between the relay and the load of the first phase circuit, and the negative electrode of the transmitting end is electrically connected between the relay and the load of the second phase circuit. Therefore, the detection circuit can detect the voltage from the emitting electrode of the receiving end of the photoelectric coupler, and then the adhesion condition of the relay in the detected three-phase circuit can be determined based on the voltage detected from the emitting electrode of the receiving end in combination with the connection relation of the circuit. Namely, the adhesion detection of the relay in the detected three-phase circuit can be met through one detection circuit, the normal operation of the detected three-phase circuit can be better ensured, the cost is reduced, the occupied space is small, and the use experience can be well improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of air conditioning, and in particular to an adhesion detection circuit, an adhesion detection method, a control device and air conditioning equipment. Background Art

[0002] In today's era, air conditioning technology has experienced rapid development, which is mainly attributed to the continuous improvement of people's pursuit of quality of life. With the diversity of global climate and the wide range of people's living areas, air conditioning units are no longer limited to cooling functions, and the demand for heating in cold areas is becoming increasingly prominent. In order to meet this demand, air conditioners and other related home appliances have been equipped with heating measures, among which high-power heating devices have become the key components for achieving efficient heating.

[0003] In the process of controlling loads such as high-power heating devices, electromagnetic control elements such as relays are widely used. These devices realize the on-off control of the heating circuit by closing and opening the internal contacts, thereby adjusting the heating power or turning the heating function on and off. However, when the relay works in a high current environment, it faces many severe challenges. Because a large amount of heat is generated when a large current passes through its internal contacts, the contacts are prone to oxidation, ablation and other phenomena. Once these problems occur in the contacts, their contact resistance will increase significantly, further aggravating the heating effect, and may eventually cause the contacts to stick. When the contacts stick, the relay will not be able to execute the control instructions normally, that is, the circuit that should have been disconnected cannot be disconnected, and the heating device will continue to work and is uncontrolled. This situation will not only cause a huge waste of energy, but may also cause serious safety accidents, such as fires, damage to electrical equipment, etc., posing a huge threat to the safety of users' lives and property.

[0004] In order to ensure the safe and reliable operation of air-conditioning equipment, it is necessary to detect the state of relay contacts. In traditional detection methods, a one-to-one detection circuit design is usually adopted, that is, each set of load and relay circuits needs to be equipped with an independent detection circuit. Although this detection method can monitor the state of each relay contact more accurately, it also brings a series of significant problems. First, from a cost perspective, as the number of detection circuits increases, the number of electronic components required also increases significantly, including various sensors, signal conditioning circuits, microcontroller interface circuits, etc. The procurement cost of these components, the manufacturing cost of circuit boards, and the assembly and debugging costs will accumulate, significantly increasing the total cost of the product. This is undoubtedly a heavy burden for the home appliance manufacturing industry that pursues cost-effectiveness, reducing the competitiveness of products in the market. Secondly, from the perspective of space resource utilization, numerous detection circuits need to occupy a large amount of circuit board space. In home appliances such as air conditioners, the space layout is relatively compact. The presence of a large number of detection circuits will limit the layout and design freedom of other functional modules, which may lead to an increase in product volume or difficulty in achieving more complex and advanced functional expansion within a limited space. For example, it may affect the layout and installation of the air conditioner's intelligent control module, air purification module, etc., which is not conducive to the product's multifunctional integration and miniaturization development trend. Summary of the invention

[0005] In view of this, in order to solve the technical problems of high cost and large space occupation caused by the use of a one-to-one adhesion detection circuit for relay adhesion detection in the prior art, the present disclosure provides an adhesion detection circuit, an adhesion detection method, a control device and air-conditioning equipment.

[0006] According to a first aspect of an embodiment of the present disclosure, there is provided a sticking detection circuit, the sticking detection circuit comprising a three-phase circuit to be detected and a detection circuit;

[0007] The detected three-phase circuit includes a three-phase power supply, and a first phase circuit, a second phase circuit and a third phase circuit electrically connected to the three-phase power supply respectively, an end of the first phase circuit away from the three-phase power supply is electrically connected between the relay of the second phase circuit and the load, an end of the second phase circuit away from the three-phase power supply is electrically connected between the relay of the third phase circuit and the load, and an end of the third phase circuit away from the three-phase power supply is electrically connected between the relay of the first phase circuit and the load;

[0008] The detection circuit includes a photocoupler, a positive electrode of a transmitting end of the photocoupler is electrically connected between the relay and the load of the first phase circuit, and a negative electrode of the transmitting end is electrically connected between the relay and the load of the second phase circuit.

[0009] In an optional implementation, the relay of the first phase circuit is recorded as a first relay, the relay of the second phase circuit is recorded as a second relay, and the relay of the third phase circuit is recorded as a third relay;

[0010] The detection circuit includes a detection power supply and a control device, the collector of the receiving end of the photocoupler is electrically connected to the detection power supply, and the emitter of the receiving end is electrically connected to the control device;

[0011] The control device determines the sticking conditions of the first relay, the second relay, and the third relay based on the voltage detected from the emitter of the receiving end.

[0012] In an optional implementation, the load of the first phase circuit is recorded as a first load, the load of the second phase circuit is recorded as a second load, and the load of the third phase circuit is recorded as a third load;

[0013] The first end of the first relay is electrically connected to the first phase output end of the three-phase power supply, the second end of the first relay is electrically connected to the first end of the first load, and the second end of the first relay is electrically connected to the first end of the third load, the first end of the second relay is electrically connected to the second phase output end of the three-phase power supply, the second end of the second relay is electrically connected to the first end of the second load, and the second end of the second relay is electrically connected to the second end of the first load, the first end of the third relay is electrically connected to the third phase output end of the three-phase power supply, the second end of the third relay is electrically connected to the second end of the second load, and the second end of the third relay is electrically connected to the second end of the third load.

[0014] In an optional embodiment, the detection circuit includes a first branch, a second branch and a protection diode, and the second branch is provided with a first current limiting unit;

[0015] The positive electrode of the transmitting end is electrically connected between the relay and the load of the first phase circuit through the first branch, and the negative electrode of the transmitting end is electrically connected between the relay and the load of the second phase circuit through the second branch;

[0016] Wherein, the anode of the protection diode is electrically connected to the cathode of the transmitting end, and the cathode of the protection diode is electrically connected to the anode of the transmitting end.

[0017] In an optional embodiment, the detection circuit includes a third branch, a second current limiting unit is arranged on the third branch, and the emitter of the receiving end is electrically connected to the control device through the third branch, wherein the first end of the third branch is electrically connected to the emitter of the receiving end, the second end of the third branch is electrically connected to the control device, and the second end of the third branch is grounded through a filter capacitor.

[0018] In an alternative embodiment,

[0019] The load of the first phase circuit includes a first electric heating unit; and / or,

[0020] The load of the second phase circuit includes a second electric heating unit; and / or,

[0021] The load of the third phase circuit includes a third electric heating unit.

[0022] According to a second aspect of an embodiment of the present disclosure, there is provided a method for detecting adhesion, the method for detecting adhesion being applied to the adhesion detection circuit according to any one of claims 1 to 6, the adhesion detection circuit comprising a three-phase circuit to be detected and a detection circuit, the detection circuit comprising a photoelectric coupler, the method for detecting adhesion comprising:

[0023] Based on the voltage detected from the emitter of the receiving end of the photocoupler, the sticking conditions of the relay of the first phase circuit, the relay of the second phase circuit, and the relay of the third phase circuit are determined.

[0024] In an optional implementation, determining the adhesion conditions of the relay of the first phase circuit, the relay of the second phase circuit, and the relay of the third phase circuit based on the voltage detected from the emitter of the receiving end of the photoelectric coupler includes:

[0025] After the load of the first phase circuit is controlled to be disconnected, if it is detected that the voltage of the emitter of the receiving end is at a high level, it is determined that the relay of the first phase circuit and the relay of the second phase circuit are stuck.

[0026] In an optional implementation, determining the adhesion conditions of the relay of the first phase circuit, the relay of the second phase circuit, and the relay of the third phase circuit based on the voltage detected from the emitter of the receiving end of the photoelectric coupler includes:

[0027] After the load of the second phase circuit is controlled to be disconnected, if it is detected that the voltage of the emitter of the receiving end is at a high level, it is determined that the relay of the second phase circuit and the relay of the third phase circuit are stuck.

[0028] In an optional implementation, determining the adhesion conditions of the relay of the first phase circuit, the relay of the second phase circuit, and the relay of the third phase circuit based on the voltage detected from the emitter of the receiving end of the photoelectric coupler includes:

[0029] After the load of the third phase circuit is controlled to be disconnected, if it is detected that the voltage of the emitter of the receiving end is at a high level, it is determined that the relay of the first phase circuit and the relay of the third phase circuit are stuck.

[0030] According to a third aspect of an embodiment of the present disclosure, a control device is provided, wherein the control device is used to implement the detection method as described in any one of the second aspects.

[0031] According to a fourth aspect of an embodiment of the present disclosure, an air conditioning device is provided, comprising a adhesion detection circuit as described in any one of the first aspects.

[0032] The technical solution provided by the embodiment of the present disclosure may include the following beneficial effects: the three-phase circuit to be detected in the present disclosure includes a three-phase power supply, and a first phase circuit, a second phase circuit and a first phase circuit electrically connected to the three-phase power supply respectively, one end of the first phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the second phase circuit, one end of the second phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the third phase circuit, and one end of the third phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the first phase circuit; in the detection circuit, the positive pole of the transmitting end of the photocoupler is electrically connected between the relay and the load of the first phase circuit, and the negative pole of the transmitting end is electrically connected between the relay and the load of the second phase circuit. The detection circuit can detect the voltage from the emitter of the receiving end of the photocoupler, and then, combined with the connection relationship of the circuit, based on the voltage detected from the emitter of the receiving end, the adhesion of the relay in the three-phase circuit to be detected can be determined. That is, the present invention can satisfy the adhesion detection of relays in the three-phase circuit being detected through a detection circuit, which can better ensure the normal operation of the three-phase circuit being detected, reduce costs, occupy less space, and can greatly improve the user experience.

[0033] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0036] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0037] Figure 1 is a schematic diagram of a sticking detection circuit according to an exemplary embodiment.

[0038] Figure 2 The figure is a schematic diagram of a control flow of an air-conditioning device according to an exemplary embodiment.

[0039] Figure 3 is a block diagram of an air conditioning device according to an exemplary embodiment. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0041] The disclosure below provides many different embodiments or examples to implement different schemes of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0042] For ease of description, spatial relative terms may be used herein to describe the relative positional relationship or movement of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", "front", "back", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure undergoes a position flip or a posture change or a motion state change, then these directional indications also change accordingly, for example: an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative descriptors used herein are interpreted accordingly.

[0043] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0044] The following will describe the implementation methods of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, not for limiting the scope of protection of the present application.

[0045] In order to solve the technical problems of high cost and large space occupation caused by the use of a one-to-one adhesion detection circuit for relay adhesion detection in the prior art, the present disclosure provides an adhesion detection circuit, an adhesion detection method, a control device and an air conditioning device.

[0046] Among them, the three-phase circuit to be detected in the present disclosure includes a three-phase power supply, and a first phase circuit, a second phase circuit and a first phase circuit electrically connected to the three-phase power supply respectively, one end of the first phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the second phase circuit, one end of the second phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the third phase circuit, and one end of the third phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the first phase circuit; in the detection circuit, the positive pole of the transmitting end of the photoelectric coupler is electrically connected between the relay and the load of the first phase circuit, and the negative pole of the transmitting end is electrically connected between the relay and the load of the second phase circuit. The detection circuit can detect the voltage from the emitter of the receiving end of the photoelectric coupler, and then combined with the connection relationship of the circuit, based on the voltage detected from the emitter of the receiving end, the adhesion of the relay in the detected three-phase circuit can be determined. That is, the present disclosure can meet the adhesion detection of the relay in the detected three-phase circuit through a detection circuit, which can better ensure the normal operation of the detected three-phase circuit, reduce costs, and occupy less space, which can well improve the user experience.

[0047] In an exemplary embodiment, a sticking detection circuit, a sticking detection method applied to the sticking detection circuit, a control device for implementing the sticking detection method, and an air conditioning device provided with the sticking detection circuit are provided. Figures 1 to 3 As shown, the adhesion detection circuit includes a three-phase circuit to be detected and a detection circuit.

[0048] Among them, the three-phase circuit to be detected includes a three-phase power supply, and a first phase circuit, a second phase circuit and a first phase circuit electrically connected to the three-phase power supply respectively, an end of the first phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the second phase circuit, an end of the second phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the third phase circuit, and an end of the third phase circuit away from the three-phase power supply is electrically connected between the relay and the load of the first phase circuit.

[0049] Wherein, the detection circuit includes a photocoupler U1, and the photocoupler U1 may include a transmitting end and a receiving end. The transmitting end may include, for example, a light emitting diode, and the receiving end may include, for example, a photodetector, and the photodetector may be, for example, a phototransistor. The positive pole of the transmitting end of the photocoupler U1 is electrically connected between the relay and the load of the first phase circuit, and the negative pole of the transmitting end is electrically connected between the relay and the load of the second phase circuit. Based on this, the detection circuit can detect the voltage from the emitter of the receiving end of the photocoupler U1, and then, combined with the connection relationship of the circuit, based on the voltage detected from the emitter of the receiving end, it is possible to determine the adhesion of the relays in the three-phase circuit being detected, that is, determine the adhesion of the relays of the first phase circuit, the relays of the second phase circuit, and the relays of the third phase circuit.

[0050] Among them, the relay of the first phase circuit can be recorded as the first relay KM1, the load of the first phase circuit can be recorded as the first load EH1, the relay of the second phase circuit can be recorded as the second relay KM2, the load of the second phase circuit can be recorded as the second load EH2, the relay of the third phase circuit can be recorded as the third relay KM3, and the load of the third phase circuit can be recorded as the third load EH3.

[0051] Wherein, the first end of the first relay KM1 is electrically connected to the first phase output end of the three-phase power supply, the second end of the first relay KM1 (i.e., the end away from the three-phase power supply) is electrically connected to the first end of the first load EH1, and the second end of the first relay KM1 is electrically connected to the first end of the third load EH3. The first end of the second relay KM2 is electrically connected to the second phase output end of the three-phase power supply, the second end of the second relay KM2 (i.e., the end away from the three-phase power supply) is electrically connected to the first end of the second load EH2, and the second end of the second relay KM2 is electrically connected to the second end of the first load EH1. The first end of the third relay KM3 is electrically connected to the third phase output end of the three-phase power supply, the second end of the third relay KM3 (i.e., the end away from the three-phase power supply) is electrically connected to the second end of the second load EH2, and the second end of the third relay KM3 is electrically connected to the second end of the third load EH3.

[0052] It should be noted that the reference Figure 1 As shown, the three phases of the three-phase power supply can be recorded as L1, L2 and L3, that is, the three-phase power supply can include the connection terminal QF1 of the three-phase power supplies L1, L2 and L3. In addition, the above-mentioned first load EH1, second load EH2 and third load EH3 can include heating units, and can also include other loads, which are not limited to this. For example, the first load EH1 can include a first electric heating unit, the second load EH2 can include a second electric heating unit, and the third load EH3 can include a third electric heating unit. The three electric heating units can be electric heating wires, or other electric heating units, which are not limited to this. The connection method of this embodiment makes it possible to power different combinations of the three loads by controlling the on and off of the three relays, thereby meeting the heating requirements of the air conditioner under different working conditions.

[0053] In addition, the detection circuit may also include a detection power supply and a control device. Among them, the positive pole of the transmitting end of the photoelectric coupler U1 is electrically connected to the second end of the first relay KM1, the negative pole of the transmitting end is electrically connected to the second end of the second relay KM2, the collector of the receiving end of the photoelectric coupler U1 is electrically connected to the detection power supply, and the emitter of the receiving end is electrically connected to the control device. The specifications of the detection power supply can be set according to actual needs and are not limited to this. For example, the detection power supply can be a 12V power supply. It should be noted that the detection power supply can also be understood as a control power supply.

[0054] Among them, the transmitting end of the photocoupler U1 includes a photodiode and the receiving end includes a phototransistor. When current flows through the photocoupler U1 and the conduction condition of the light-emitting diode is met, the light-emitting diode emits light. The collector of the phototransistor of the photocoupler U1 is connected to a 12V detection power supply, and the emitter is connected to a control device (such as an MCU). When the light-emitting diode emits light, the phototransistor receives light, the resistance between its collector and emitter decreases, and the current increases, thereby generating a corresponding voltage change at the emitter.

[0055] Based on this, in this embodiment, the control device can determine the adhesion conditions of the first relay KM1, the second relay KM2 and the third relay KM3 based on the voltage detected from the emitter of the receiving end.

[0056] The control device may have multiple input and output interfaces. The interface connected between the control device and the emitter of the receiving end of the photocoupler U1 is used to collect voltage signals. A special adhesion detection program can be run inside the control device, which can perform logical judgment based on the collected voltage signals to determine the adhesion conditions of the first relay KM1, the second relay KM2, and the third relay KM3.

[0057] Among them, when the first relay KM1 and the second relay KM2 are stuck, the three-phase power supply is directly added to the first load EH1, and the voltage of the transmitting end of the photoelectric coupler U1 is consistent with the above power supply voltage. At this time, the photoelectric coupler U1 is turned on, and the voltage of the emitter of the receiving end of the photoelectric coupler U1 is high. In other words, if the control device detects that the emitter of the receiving end is still high after the first load EH1 is disconnected, it can be determined that the first relay KM1 and the second relay KM2 are stuck.

[0058] It should be noted that, in this embodiment, "controlling the first load EH1 to disconnect" means controlling the first load EH1 to disconnect through a control instruction, that is, issuing a demand instruction to control the first load EH1 to disconnect. However, if it is detected that the emitter of the receiving end is still at a high level, it means that the first relay KM1 and the second relay KM2 are stuck. In this case, it means that the first load EH1 has not been actually disconnected.

[0059] When the second relay KM2 and the third relay KM3 are stuck, the three-phase power supply is directly added to the first load EH1, the third load EH3 and the second load EH2, and one pole of the emitter of the photocoupler U1 is connected between the first load EH1 and the third load EH3. When the first load EH1 and the third load EH3 have the same specifications, the voltage of the emitter of the photocoupler U1 is half of the above power supply voltage. At this time, the photocoupler U1 is turned on, and the voltage of the emitter of the receiving end of the photocoupler U1 is high. Based on this, if the control device detects that the emitter of the receiving end is still high after the third load EH3 is disconnected, it can be determined that the second relay KM2 and the third relay KM3 are stuck.

[0060] When the first relay KM1 and the third relay KM3 are stuck, the three-phase power supply is directly added to the first load EH1, the second load EH2 and the third load EH3, and one pole of the emitter of the photocoupler U1 is connected between the first load EH1 and the second load EH2. When the first load EH1 and the second load EH2 have the same specifications, the voltage of the emitter of the photocoupler U1 is half of the above power supply voltage. At this time, the photocoupler U1 is turned on, and the voltage of the emitter of the receiving end of the photocoupler U1 is high. Based on this, if the control device detects that the emitter of the receiving end is still high after the second load EH2 is disconnected, it can be determined that the first relay KM1 and the third relay KM3 are stuck.

[0061] This embodiment can satisfy the adhesion detection of the relay in the three-phase circuit being detected through a detection circuit, which can better ensure the normal operation of the three-phase circuit being detected, reduce costs, and enhance the competitiveness of the product in the market. Secondly, from the perspective of space resource utilization, this embodiment only sets up a single detection circuit, which only needs to occupy a small amount of circuit board space. Inside home appliances such as air conditioners, the spatial layout is relatively compact. This embodiment can enhance the layout and design freedom of other functional modules, making it easier to achieve more complex and advanced functional expansions that are difficult to achieve within a limited space. For example, it is more convenient to layout and install the intelligent control module, air purification module, etc. of the air conditioner, which is conducive to the multi-functional integration and miniaturization development trend of the product.

[0062] In an exemplary embodiment, a sticking detection circuit, a sticking detection method applied to the sticking detection circuit, a control device for implementing the sticking detection method, and an air conditioning device provided with the sticking detection circuit are provided. Figures 1 to 3As shown, the detection circuit may include a first branch, a second branch and a protection diode D1, and a first current limiting unit R1 (for example, a current limiting resistor) is provided on the second branch. The resistance value of the first current limiting unit R1 can be set according to actual needs and is not limited thereto. The positive electrode of the transmitter is electrically connected between the relay and the load of the first phase circuit through the first branch, that is, the positive electrode of the transmitter is electrically connected to the second end of the first relay KM1 through the first branch. Among them, the first end of the first branch is electrically connected to the second end of the first relay KM1, and the second end of the first branch is electrically connected to the positive electrode of the transmitter. Based on this, the positive electrode of the transmitter can be electrically connected to the second end of the first relay KM1 through the first branch.

[0063] The negative electrode of the transmitter is electrically connected to the relay of the second phase circuit and the load through the second branch, that is, the negative electrode of the transmitter is electrically connected to the second end of the second relay KM2 through the second branch. The first end of the second branch is electrically connected to the second end of the second relay KM2, and the second end of the second branch is electrically connected to the negative electrode of the transmitter. Based on this, the negative electrode of the transmitter can be electrically connected to the second end of the second relay KM2 through the second branch.

[0064] The anode of the protection diode D1 is electrically connected to the cathode of the transmitting end, and the cathode of the protection diode D1 is electrically connected to the anode of the transmitting end. That is, the anode of the protection diode D1 is electrically connected to the second end of the second branch, and the cathode of the protection diode D1 is electrically connected to the second end of the first branch.

[0065] In this embodiment, when current flows through the circuit, the first current limiting unit R1 can limit the current through the emitter of the photocoupler U1 to prevent excessive current from damaging the light-emitting diode at the emitter. The function of the protection diode D1 is to prevent the reverse voltage from damaging the emitter of the photocoupler U1. When a reverse voltage appears in the circuit, such as the induced electromotive force generated at the moment of relay switching, the protection diode D1 will be turned on, clamping the reverse voltage to about its forward conduction voltage, thereby protecting the light-emitting diode at the emitter of the photocoupler U1 from breakdown.

[0066] That is to say, this embodiment further improves the safety of the detection circuit by setting the protection diode D1 and the current limiting resistor. The protection diode D1 effectively prevents the damage of the reverse voltage to the photocoupler U1, and the current limiting resistor avoids the situation where the light-emitting diode is damaged due to excessive current. In the face of various complex electrical environment interferences, such as power supply fluctuations, induced electromotive force generated by relay switching, etc., the circuit can still work stably and accurately detect the adhesion of the relay, greatly reducing the safety hazards caused by the failure of the detection circuit itself. Moreover, the design of the first branch and the second branch and the application of the current limiting resistor make it possible to more accurately judge the adhesion situation according to the subtle changes in the emitter voltage at the receiving end of the photocoupler U1 when detecting the adhesion of the relay.

[0067] Among them, the detection circuit may include a third branch, and a second current limiting unit R2 (for example, a current limiting resistor) is provided on the third branch. The resistance value of the second current limiting unit R2 can be set according to actual needs and is not limited to this. The first end of the third branch is electrically connected to the emitter of the receiving end, and the second end of the third branch is electrically connected to the control device. Based on this, the emitter of the receiving end can be electrically connected to the control device through the third branch. In addition, the second end of the third branch can be connected to the ground through the filter capacitor C1.

[0068] Among them, the second current limiting unit R2 can limit the current flowing from the emitter of the receiving end to the control device to prevent damage to the input port of the control device due to excessive current. For example, when the emitter of the receiving end produces a large current change trend due to light, according to Ohm's law, the current limiting resistor can limit the current within a safe range to ensure that the control device stably receives the signal. The filter capacitor C1 can filter out the high-frequency clutter components in the signal. When electromagnetic interference and other conditions exist in the circuit to generate high-frequency signals, the filter capacitor C1 provides a low-impedance path for these high-frequency signals, allowing them to flow into the ground, thereby making the signal received by the control device smoother and more stable, reducing misjudgments caused by interference signals.

[0069] In addition, in the process of detecting relay adhesion, the current limiting unit and the filter capacitor C1 work together to make the signal changes received by the control device more stable and orderly, which is convenient for the control device to make accurate logical judgments, improves the stability and reliability of the entire adhesion detection system, reduces system failures or misoperations caused by problems in the detection circuit itself, and ensures the safe and stable operation of electrical systems such as air-conditioning equipment.

[0070] In an exemplary embodiment, a sticking detection circuit, a sticking detection method applied to the sticking detection circuit, a control device for implementing the sticking detection method, and an air conditioning device provided with the sticking detection circuit are provided. Figures 1 to 3As shown, the first load EH1 in the detected three-phase circuit may include a first electric heating unit, the second load EH2 may include a second electric heating unit, the third load EH3 may include a third electric heating unit, and the three electric heating units may be electric heating wires, and the specifications of the three electric heating wires may be the same.

[0071] Among them, the first end of the first relay KM1 is electrically connected to the first phase output end of the three-phase power supply, the second end of the first relay KM1 is electrically connected to the first end of the first electric heating unit, and the second end of the first relay KM1 is electrically connected to the first end of the third electric heating unit. The first end of the second relay KM2 is electrically connected to the second phase output end of the three-phase power supply, the second end of the second relay KM2 is electrically connected to the first end of the second electric heating unit, and the second end of the second relay KM2 is electrically connected to the second end of the first electric heating unit. The first end of the third relay KM3 is electrically connected to the third phase output end of the three-phase power supply, the second end of the third relay KM3 is electrically connected to the second end of the second electric heating unit, and the second end of the third relay KM3 is electrically connected to the second end of the third electric heating unit.

[0072] The detection circuit may include a photocoupler U1, a detection power supply and a control device. The detection power supply may be a 12V power supply. The photocoupler U1 may include a transmitting end and a receiving end. The transmitting end may include a light emitting diode, and the receiving end may include a phototransistor.

[0073] Among them, the positive pole of the transmitting end of the photoelectric coupler U1 is electrically connected to the second end of the first relay KM1, the negative pole of the transmitting end is electrically connected to the second end of the second relay KM2, the collector of the receiving end of the photoelectric coupler U1 is electrically connected to the detection power supply, and the emitter of the receiving end is electrically connected to the control device.

[0074] When current flows through the photocoupler U1 and the conduction condition of the light-emitting diode is met, the light-emitting diode emits light. The collector of the phototransistor of the photocoupler U1 is connected to the 12V detection power supply, and the emitter is connected to the control device (such as MCU). When the light-emitting diode emits light, the phototransistor receives light, the resistance between its collector and emitter decreases, and the current increases, thereby generating a corresponding voltage change at the emitter.

[0075] In this embodiment, when a single relay among the first relay KM1, the second relay KM2 and the third relay KM3 is adhered, the electric heating control in the detected three-phase circuit cannot form a complete loop, so there is no need to detect the adhesion of a single relay.

[0076] When two of the relays are stuck together, the detection method can be as follows:

[0077] When the first relay KM1 and the second relay KM2 are both adhered, the three-phase power supply is directly added to the first electric heating unit. At this time, the voltage of the three-phase power supply can be 220VAC, and the voltage detected by the transmitter of the photoelectric coupler U1 is consistent with the voltage of the three-phase power supply. At this time, the photoelectric coupler U1 is turned on. Because there is a capacitor on the secondary of the photoelectric coupler U1, after a charging cycle of the capacitor, the voltage of the emitter of the receiving end can be stabilized at about 3.3V. At this time, the control device compares the actual control logic (that is, the established process set by the designer). When the first electric heating unit is controlled to be turned on, it is judged to be consistent with the control logic, and it is a normal working state; when the first electric heating unit is controlled to be disconnected, the control device still detects a high level at the emitter of the receiving end. At this time, the actual situation is inconsistent with the control logic, and it is determined that the first relay KM1 and the second relay KM2 are adhered, and the control device can report an adhesion protection fault.

[0078] When the first relay KM1 and the third relay KM3 are adhered, the three-phase power supply is added to the first electric heating unit, the second electric heating unit and the third electric heating unit. At this time, one pole of the emitter of the photoelectric coupler U1 is connected at the middle position of the first electric heating unit and the second electric heating unit. At this time, the voltage of the three-phase power supply is 220VAC, and the voltage detected by the emitter of the photoelectric coupler U1 is 220VAC / 2. At this time, the photoelectric coupler U1 is turned on. Because the primary voltage of the photoelectric coupler U1 is reduced and the charging time of the secondary capacitor is prolonged, it takes about two charging cycles of the capacitor for the voltage of the emitter of the receiving end to stabilize at about 3.3V. At this time, the control device compares the actual control logic. When the third electric heating unit is controlled to be turned on, the judgment is consistent with the control logic, and it is a normal working state at this time; when the third electric heating unit is controlled to be disconnected, the control device still detects that the emitter of the receiving end is at a high level. At this time, the actual situation is inconsistent with the control logic, and it is determined that the first relay KM1 and the third relay KM3 are adhered, and the control device reports an adhesion protection fault.

[0079] When the second relay KM2 and the third relay KM3 are adhered, the three-phase power supply is added to the first electric heating unit, the third electric heating unit and the second electric heating unit. At this time, one pole of the emitter of the photoelectric coupler U1 is connected at the middle position of the first electric heating unit and the third electric heating unit. At this time, the voltage of the three-phase power supply is 220VAC, and the voltage detected by the emitter of the photoelectric coupler U1 is 220VAC / 2. At this time, the photoelectric coupler U1 is turned on. Because the primary voltage of the photoelectric coupler U1 is reduced and the charging time of the secondary capacitor is prolonged, it takes about two charging cycles of the capacitor for the voltage of the emitter of the receiving end to stabilize at about 3.3V. At this time, the control device compares with the actual control logic. When the second electric heating unit is controlled to be turned on, the judgment is consistent with the control logic, and it is a normal working state at this time; when the second electric heating unit is controlled to be disconnected, the control device still detects that the emitter of the receiving end is at a high level. At this time, the actual situation is inconsistent with the control logic, and it is determined that the second relay KM2 and the third relay KM3 are adhered, and the control device reports an adhesion protection fault.

[0080] During the adhesion detection process of the adhesion detection circuit of this embodiment, the following data are obtained through experiments:

[0081]

[0082] Among them, for KM1-KM3 adhesion detection, the LL voltage refers to the voltage between L1 and L3; for KM2-KM3 adhesion detection, the LL voltage refers to the voltage between L2 and L3; for KM1-KM2 adhesion detection, the LL voltage refers to the voltage between L1 and L2.

[0083] It should be noted that the above-mentioned adhesion detection scheme includes but is not limited to relay adhesion detection of the electric heating unit, and is also applicable to circuit detection schemes with similar functional requirements, without limitation thereto.

[0084] In addition, for air-conditioning equipment provided with the above-mentioned adhesion detection circuit, the air-conditioning equipment may include fans corresponding to the above-mentioned electric heating units for dissipating heat for the electric heating units. That is, the first electric heating unit may be configured with a first fan, the second electric heating unit may be configured with a second fan, and the third electric heating unit may be configured with a third fan. When it is detected that the first relay KM1 and the second relay KM2 are adhered, the air-conditioning equipment can be controlled to shut down, and the adhesion protection fault can be reported, and the first fan can be controlled to turn on to dissipate heat for the first electric heating unit, so as to protect the first electric heating unit and its surroundings from being burned out due to being in the on state for a long time. The control logic of the second fan and the third fan can refer to the first fan, which will not be repeated here.

[0085] This embodiment can satisfy the adhesion detection of the relay in the three-phase circuit being detected through a detection circuit, which can better ensure the normal operation of the three-phase circuit being detected, reduce costs, and enhance the competitiveness of the product in the market. Secondly, from the perspective of space resource utilization, this embodiment only sets up a single detection circuit, which only needs to occupy a small amount of circuit board space. Inside home appliances such as air conditioners, the spatial layout is relatively compact. This embodiment can enhance the layout and design freedom of other functional modules, making it easier to achieve more complex and advanced functional expansions that are difficult to achieve within a limited space. For example, it is more convenient to layout and install the intelligent control module, air purification module, etc. of the air conditioner, which is conducive to the multi-functional integration and miniaturization development trend of the product.

[0086] The professionals should also be further aware that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0087] It should be noted that the phrases "one implementation", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include certain features, structures or characteristics, but not every embodiment may include the certain features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing certain features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0088] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more limiting values, the elements defined by the sentence "comprise a..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0089] The above embodiments are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present application is within the protection scope of the present application.

Claims

1. A adhesion detection circuit, characterized in that: The adhesion detection circuit includes a three-phase circuit to be detected and a detection circuit; The detected three-phase circuit includes a three-phase power supply, and a first phase circuit, a second phase circuit and a third phase circuit electrically connected to the three-phase power supply respectively, an end of the first phase circuit away from the three-phase power supply is electrically connected between the relay of the second phase circuit and the load, an end of the second phase circuit away from the three-phase power supply is electrically connected between the relay of the third phase circuit and the load, and an end of the third phase circuit away from the three-phase power supply is electrically connected between the relay of the first phase circuit and the load; The detection circuit includes a photocoupler, a positive electrode of a transmitting end of the photocoupler is electrically connected between the relay and the load of the first phase circuit, and a negative electrode of the transmitting end is electrically connected between the relay and the load of the second phase circuit.

2. The adhesion detection circuit according to claim 1, characterized in that: The relay of the first phase circuit is denoted as a first relay, the relay of the second phase circuit is denoted as a second relay, and the relay of the third phase circuit is denoted as a third relay; The detection circuit includes a detection power supply and a control device, the collector of the receiving end of the photocoupler is electrically connected to the detection power supply, and the emitter of the receiving end is electrically connected to the control device; The control device determines the sticking conditions of the first relay, the second relay, and the third relay based on the voltage detected from the emitter of the receiving end.

3. The adhesion detection circuit according to claim 2, characterized in that: The load of the first phase circuit is recorded as a first load, the load of the second phase circuit is recorded as a second load, and the load of the third phase circuit is recorded as a third load; The first end of the first relay is electrically connected to the first phase output end of the three-phase power supply, the second end of the first relay is electrically connected to the first end of the first load, and the second end of the first relay is electrically connected to the first end of the third load, the first end of the second relay is electrically connected to the second phase output end of the three-phase power supply, the second end of the second relay is electrically connected to the first end of the second load, and the second end of the second relay is electrically connected to the second end of the first load, the first end of the third relay is electrically connected to the third phase output end of the three-phase power supply, the second end of the third relay is electrically connected to the second end of the second load, and the second end of the third relay is electrically connected to the second end of the third load.

4. The adhesion detection circuit according to claim 1, characterized in that: The detection circuit comprises a first branch, a second branch and a protection diode, and the second branch is provided with a first current limiting unit; The positive electrode of the transmitting end is electrically connected between the relay and the load of the first phase circuit through the first branch, and the negative electrode of the transmitting end is electrically connected between the relay and the load of the second phase circuit through the second branch; Wherein, the anode of the protection diode is electrically connected to the cathode of the transmitting end, and the cathode of the protection diode is electrically connected to the anode of the transmitting end.

5. The adhesion detection circuit according to claim 2, characterized in that: The detection circuit includes a third branch, a second current limiting unit is arranged on the third branch, and the emitter of the receiving end is electrically connected to the control device through the third branch, wherein the first end of the third branch is electrically connected to the emitter of the receiving end, the second end of the third branch is electrically connected to the control device, and the second end of the third branch is grounded through a filter capacitor.

6. The adhesion detection circuit according to any one of claims 1 to 5, characterized in that: The load of the first phase circuit includes a first electric heating unit; and / or, The load of the second phase circuit includes a second electric heating unit; and / or, The load of the third phase circuit includes a third electric heating unit.

7. A method for detecting adhesion, characterized in that: The adhesion detection method is applied to the adhesion detection circuit according to any one of claims 1 to 6, the adhesion detection circuit includes a three-phase circuit to be detected and a detection circuit, the detection circuit includes a photocoupler, and the adhesion detection method includes: Based on the voltage detected from the emitter of the receiving end of the photocoupler, the sticking conditions of the relay of the first phase circuit, the relay of the second phase circuit, and the relay of the third phase circuit are determined.

8. The adhesion detection method according to claim 7, characterized in that: The method of determining the adhesion of the relay of the first phase circuit, the relay of the second phase circuit, and the relay of the third phase circuit based on the voltage detected from the emitter of the receiving end of the photoelectric coupler comprises: After the load of the first phase circuit is controlled to be disconnected, if it is detected that the voltage of the emitter of the receiving end is at a high level, it is determined that the relay of the first phase circuit and the relay of the second phase circuit are stuck.

9. The adhesion detection method according to claim 7, characterized in that: The method of determining the adhesion of the relay of the first phase circuit, the relay of the second phase circuit, and the relay of the third phase circuit based on the voltage detected from the emitter of the receiving end of the photoelectric coupler comprises: After the load of the second phase circuit is controlled to be disconnected, if it is detected that the voltage of the emitter of the receiving end is at a high level, it is determined that the relay of the second phase circuit and the relay of the third phase circuit are stuck.

10. The adhesion detection method according to claim 7, characterized in that: The method of determining the adhesion of the relay of the first phase circuit, the relay of the second phase circuit, and the relay of the third phase circuit based on the voltage detected from the emitter of the receiving end of the photoelectric coupler comprises: After the load of the third phase circuit is controlled to be disconnected, if it is detected that the voltage of the emitter of the receiving end is at a high level, it is determined that the relay of the first phase circuit and the relay of the third phase circuit are stuck.

11. A control device, characterized in that: The control device is used to implement the detection method as described in any one of claims 7-10.

12. An air conditioning device, characterized in that: The air conditioning device comprises a sticking detection circuit as claimed in any one of claims 1-6.

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