Switching device fault diagnosis circuit, switching device and vehicle

Abstract

The present application relates to the field of electronic circuits. Disclosed are a switching device fault diagnosis circuit, a switching device and a vehicle. The switching device fault diagnosis circuit comprises a first resistor, a second resistor, a third resistor and a high-resistance element, wherein a first end of the first resistor is connected to an output end of an external power source, a first end of the second resistor is connected to a second end of the first resistor, a second end of the second resistor is connected to an output end of a first switching device under test and to the ground, a second end of the high-resistance element is connected to a common end of the first and second resistors, a first end of the third resistor is connected to a first end of the high-resistance element, and a second end of the third resistor is connected to an input end of the switching device under test. The switching device fault diagnosis circuit further comprises a clamping element, wherein a first end of the clamping element is connected to the first end of the high-resistance element, a second end of the clamping element is connected to the second end of the second resistor, and the common end of the first and second resistors serves as an output end of the switching device fault diagnosis circuit. When the ON states of switching devices under test are different, the switching device fault diagnosis circuit outputs different sampling signals, such that fault detection can be implemented for the switching devices under test by using only one sampling point. Therefore, the reliability of the switching device fault diagnosis circuit is higher than that of an existing solution.

Description

Fault diagnosis circuits for switching devices, switching equipment, and automobiles

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202520278072.6, filed on February 20, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of electronic circuit technology, and in particular to a fault diagnosis circuit for switching devices, switching equipment, and automobiles. Background Technology

[0004] The negative relay in a power battery is a crucial component of the charging and discharging control actuators within the power battery system. Controlled by the vehicle control unit (VCU), the negative relay controls the connection and disconnection of the power battery's negative terminal circuit. When the power battery system needs power or charging, the VCU controls the negative relay to close, connecting the negative terminal circuit; when power needs to be disconnected, the VCU controls the negative relay to open, ensuring the safety of the power battery system. The negative relay also plays a protective role in the power battery system. When the power battery system experiences abnormal conditions such as overcurrent or short circuits, the negative relay can quickly disconnect the circuit, preventing battery damage or safety accidents.

[0005] To ensure the safe and reliable operation of the negative relay, fault diagnosis of the negative relay is required. The installation method of the negative relay in the circuit is shown in Figures 1 and 2. In the existing solution, the voltage across the negative relay is sampled by two voltage divider circuits set at the two ends of the negative relay. In Figure 1, S1 and S2 are the sampling points of the two voltage divider circuits. By comparing the voltage difference between the sampling voltages at sampling points S1 and S2, the fault diagnosis of the negative relay is performed.

[0006] This fault diagnosis method requires two sampling points to diagnose the fault of the negative relay. If either of the two sampling points malfunctions (e.g., poor contact), it will affect the diagnosis results. Therefore, there is an urgent need for a more reliable relay fault diagnosis solution. Summary of the Invention

[0007] In view of the above problems, this application provides a fault diagnosis circuit for switching devices, a switching device, and an automobile, to provide a relay fault diagnosis solution with high reliability. The specific solution is as follows:

[0008] The first aspect of this application provides a fault diagnosis circuit for switching devices, comprising:

[0009] First resistor (R1), second resistor (R2), third resistor (R3), high-resistance component (D1), and clamping component (D2)

[0010] The first terminal of the first resistor (R1) is connected to the output terminal of the external power supply;

[0011] The first end of the second resistor (R2) is connected to the second end of the first resistor (R1), and the second end of the second resistor (R2) is connected to the output terminal of the first switch device under test.

[0012] The second terminal of the high-resistance element (D1) is connected to the common terminal of the first resistor (R1) and the second resistor (R2);

[0013] The first end of the third resistor (R3) is connected to the first end of the high-resistance element (D1), and the second end of the third resistor (R3) is connected to the input end of the first switch device under test.

[0014] The first end of the clamping element (D2) is connected to the first end of the high-resistance element (D1), and the second end of the clamping element (D2) is connected to the second end of the second resistor (R2).

[0015] The common terminal of the first resistor (R1) and the second resistor (R2) serves as the output terminal of the switching device fault diagnosis circuit, and the output terminal is used to provide the sampling results of the switching device fault diagnosis circuit.

[0016] Optionally, in the above-mentioned fault diagnosis circuit for switching devices, the high-resistance element (D1) is a reverse cutoff protection diode; and the clamping element (D2) is a clamping protection diode.

[0017] Optionally, the above-mentioned fault diagnosis circuit for switching devices further includes:

[0018] An inductor (L) is disposed between the input terminal of the first switch device under test and the third resistor (R3).

[0019] Optionally, the above-mentioned fault diagnosis circuit for switching devices further includes:

[0020] First switching switch (K1) and second switching switch (K2);

[0021] The first terminal of the first switching switch (K1) is connected to the input terminal of the first switch device under test, and the second terminal of the first switching switch (K1) is connected to the second terminal of the third resistor (R3).

[0022] The first terminal of the second switching switch (K2) is connected to the input terminal of the second switch device under test, and the second terminal of the second switching switch (K2) is connected to the second terminal of the third resistor (R3).

[0023] Optionally, the above-mentioned fault diagnosis circuit for switching devices further includes:

[0024] Switch controller;

[0025] The control signal output terminal of the switch controller is connected to the control terminals of the first switching switch (K1) and the second switching switch (K2);

[0026] The switch controller is used to provide control signals to the first switch (K1) and the second switch (K2). The control signals are used to control the conduction state of the first switch (K1) and the second switch (K2). Under the control of the control signals, when the first switch (K1) is on, the second switch (K2) is off, and when the first switch (K1) is off, the second switch (K2) is on.

[0027] Optionally, the above-mentioned fault diagnosis circuit for switching devices includes:

[0028] The first switch device under test is a negative relay, and the second switch device under test is a positive relay corresponding to the negative relay.

[0029] Optionally, the above-mentioned fault diagnosis circuit for switching devices includes:

[0030] The first resistor (R1), the second resistor (R2), and / or the third resistor (R3) are formed by connecting at least two sub-resistors in parallel.

[0031] A second aspect of this application provides a switching device, including a switching device body and a fault diagnosis circuit for the switching device as described in any one of the above claims, wherein the switching device body is the first switching device under test.

[0032] Optionally, in the above-mentioned switching device, the switching device is a relay device.

[0033] A third aspect of this application provides an automobile that includes a fault diagnosis circuit for switching devices as described in any one of the foregoing claims or a switching device as described in any one of the foregoing claims.

[0034] The switching device fault diagnosis circuit provided in this application, using the above technical solution, includes: a first resistor, a second resistor, a third resistor, a high-resistance element, and a clamping element. The first end of the first resistor is connected to the output terminal of an external power supply; the first end of the second resistor is connected to the second end of the first resistor; the second end of the second resistor is connected to the output terminal of a first switching device under test; the second end of the high-resistance element is connected to the common terminal of the first resistor and the second resistor; the first end of the third resistor is connected to the first end of the high-resistance element; the second end of the third resistor is connected to the input terminal of the first switching device under test; the first end of the clamping element is connected to the first end of the high-resistance element; the second end of the clamping element is connected to the second end of the second resistor; the common terminal of the first resistor and the second resistor serves as the output terminal of the switching device fault diagnosis circuit, and the output terminal is used to provide the sampling results of the switching device fault diagnosis circuit.

[0035] When the conduction state of the first tested switch device is different, the sampling signal output by the output terminal of the switch device fault diagnosis circuit is different. By comparing the sampling signal output by the output terminal of the switch device fault diagnosis circuit with the reference signal that matches the conduction state of the first tested switch device, it can be determined whether the current state of the first tested switch device is faulty. It can be seen that this application only needs to use one sampling point (the output terminal of the switch device fault diagnosis circuit) to realize the fault detection of the first tested switch device. The probability of a fault occurring at one sampling node is less than the probability of at least one of the two nodes failing. Therefore, the reliability of the switch device fault diagnosis circuit disclosed in this application is higher than that of the existing solutions. Attached Figure Description

[0036] The above and other features, advantages, and aspects of the embodiments disclosed in this application will become more apparent when taken in conjunction with the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0037] Figure 1 is a structural schematic diagram of a relay fault diagnosis scheme provided in an embodiment of this application;

[0038] Figure 2 is a schematic diagram of a relay fault diagnosis scheme provided in another embodiment of this application;

[0039] Figure 3 is a schematic diagram of a fault diagnosis circuit for a switching device provided in an embodiment of this application;

[0040] Figure 4 is a schematic diagram of a fault diagnosis circuit for a switching device provided in another embodiment of this application;

[0041] Figure 5 is a schematic diagram of the current path in a fault diagnosis circuit for a switching device in a specific scenario provided in an embodiment of this application.

[0042] Figure 6 is a schematic diagram of the current path in a fault diagnosis circuit for a switching device in a certain scenario, according to another embodiment of this application.

[0043] Figure 7 is a schematic diagram of a fault diagnosis circuit for a switching device provided in another embodiment of this application;

[0044] Figure 8 is a schematic diagram of a fault diagnosis circuit for a switching device provided in another embodiment of this application. Detailed Implementation

[0045] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0046] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0047] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a product or device comprising a series of units is not necessarily limited to those units, but may include other units not explicitly listed or inherent to such products or devices.

[0048] This application discloses a highly reliable fault diagnosis scheme for a switching device, which can be a relay. This scheme can determine whether the switching device has failed by using only the output signal of a single sampling point. Therefore, it reduces the probability of a failure in the sampling circuit and improves the reliability of the diagnosis results.

[0049] This application discloses a fault diagnosis circuit for switching devices. This circuit is used to diagnose faults in switching devices (relays are a type of switching device). Referring to Figure 3, the fault diagnosis circuit includes:

[0050] The first resistor is R1, the second resistor is R2, the third resistor is R3, and the high-resistance component is D1.

[0051] A first resistor R1 is connected at its first end to the output terminal of an external power supply. The external power supply refers to a DC power module located outside the switching device fault diagnosis circuit. The switching device fault diagnosis circuit can provide a power interface through which the first end of the first resistor R1 is connected to the external power supply. The output voltage of the external power supply can be selected according to design requirements. For example, in this embodiment, the external power supply can be a 5V DC power module, a 3V DC power module, or a DC power module of other amplitudes. Alternatively, the switching device fault diagnosis circuit may include a DC-DC conversion circuit. One end of the DC-DC conversion circuit is connected to the external power supply, and the other end is connected to the first end of the first resistor. This circuit converts the output voltage of the external power supply to a voltage compatible with the switching device fault diagnosis circuit, such as converting it to 5V DC or 3V DC.

[0052] The second resistor R2 has its first end connected to the second end of the first resistor R1, and its second end connected to the output terminal of the first switch device under test Q1. The first switch device under test Q1 has two terminals: an input terminal and an output terminal. The output terminal of the first switch device under test Q1 is connected to the negative terminal of the power supply, and the input terminal of the first switch device under test Q1 is connected to the positive terminal of the power supply. The power supply connected to the first switch device under test Q1 and the external power supply are two different power supplies: the former is a high-voltage power supply, and the latter is a low-voltage DC power supply.

[0053] A high-resistance element D1 is provided, with its second end connected to the common terminal of the first resistor R1 and the second resistor R2. The high-resistance element D1 prevents overvoltage damage to the processor connected to the output terminal S of the switching device fault diagnosis circuit due to the L-node voltage being higher than the negative terminal (the second end of the second resistor). The L-node is a circuit node connected to the input terminal of the first tested switching device Q1, which may exhibit a high-voltage signal. The negative terminal is the node connected to the second end of the second resistor R2, which can specifically be a grounded node. Without the high-resistance element D1, when a high voltage occurs at the L-node, the high-voltage signal will be applied to the output terminal S of the switching device fault diagnosis circuit through the third resistor R3. The output terminal S of the switching device fault diagnosis circuit is connected to a processor for fault analysis of the first tested switching device Q1. If the voltage applied to the output terminal S of the switching device fault diagnosis circuit is too high and exceeds the processor's withstand capacity, it will cause the processor to be damaged by overvoltage. When the high-resistance element D1 is set, the high-resistance element D1 can provide reverse cutoff protection to prevent the processor connected to the output terminal S of the switching device fault diagnosis circuit from being damaged by overvoltage when the voltage at the L-node is higher than the voltage at the output terminal S of the switching device fault diagnosis circuit.

[0054] The third resistor R3 has its first end connected to the first end of the high-resistance element D1, and its second end connected to the input end of the first tested switch device Q1.

[0055] The common terminal of the first resistor R1 and the second resistor R2 serves as the output terminal S of the switching device fault diagnosis circuit. The fault analysis device obtains the sampling signal of the switching device fault diagnosis circuit through the output terminal S of the switching device fault diagnosis circuit. Based on the sampling signal and the current state of the first switching device under test Q1, the device can quickly perform fault detection on the first switching device under test Q1.

[0056] When the fault diagnosis circuit of the switching device is applied to a real-world scenario, the connection relationship between each component in the fault diagnosis circuit and the battery pack and the first switch device under test Q1 can be seen in Figure 4. The high-resistance component D1 and the clamping component D2 in Figures 3 and 4 can be considered as a single resistor with a very high resistance. Let the resistance of the high-resistance component D1 be Rd. When the first switch device under test Q1 is closed, the L-node and the negative terminal are connected together through the first switch device under test Q1. At this time, the output current direction of the external power supply is as shown in Figure 5. The potentials of the L-node and the negative terminal are equal. At this time, the output voltage of the output terminal S of the fault diagnosis circuit of the switching device is: Where Vcc is the output voltage of the external power supply, R1, R2 and R3 in the formula are the resistance values ​​of the first resistor R1, the second resistor R2 and the third resistor R3 respectively, and Rd is the equivalent resistance value of the high-resistance element D1.

[0057] When the first tested switching device Q1 is disconnected, the L-node is equivalent to a floating state. At this time, the output current direction of the external power supply is as shown in Figure 6, and the output voltage of the output terminal S of the switching device fault diagnosis circuit is:

[0058] In this scheme, when the first switch device under test Q1 is closed, the output voltage of the output terminal S of the switch device fault diagnosis circuit is recorded as V1. When the first switch device under test Q1 is open, the output voltage of the output terminal S of the switch device fault diagnosis circuit is recorded as V2. After the processor obtains the output voltage of the output terminal S of the switch device fault diagnosis circuit and the state of the first switch device under test Q1, it can quickly determine whether the first switch device under test Q1 has a fault by comparing and analyzing the output voltage of the output terminal with the corresponding reference voltage.

[0059] For example, when the first tested switch Q1 is in the closed state, the output voltage V1 of the switch device fault diagnosis circuit's output terminal S is compared with a first reference voltage to determine whether they are equal or whether their error is within the allowable range. If they are equal or their error is within the allowable range, it indicates that the first tested switch can be reliably closed. When the first tested switch Q1 is in the open state, the output voltage V2 of the switch device fault diagnosis circuit's output terminal S is compared with a second reference voltage to determine whether they are equal or whether their error is within the allowable range. If they are equal or their error is within the allowable range, it indicates that the first tested switch can be reliably opened. Here, the first reference voltage is the output voltage of the switch device fault diagnosis circuit's output terminal S when the first tested switch Q1 is reliably closed, and the second reference voltage is the output voltage of the switch device fault diagnosis circuit's output terminal S when the first tested switch Q1 is reliably opened.

[0060] As can be seen from the above scheme, the fault diagnosis circuit for switching devices disclosed in this application can realize the fault diagnosis of the first switch device Q1 under test through only one sampling node. The probability of a fault occurring at one sampling node is less than the probability of at least one of the two nodes failing. Therefore, the reliability of the fault diagnosis circuit for switching devices disclosed in this application is higher than that of the existing schemes.

[0061] Furthermore, referring to Figure 1, the switching device fault diagnosis circuit disclosed in this embodiment may further include a clamping element D2. The first terminal of the clamping element D2 is connected to the first terminal of the high-resistance element D1, and the second terminal of the clamping element D2 is connected to the second terminal of the second resistor R2. Similar to the high-resistance element D1, the clamping element D2 is used to implement a clamping protection function, which can prevent the processor connected to the output terminal S of the switching device fault diagnosis circuit from being damaged due to overvoltage when the voltage at the output terminal S of the switching device fault diagnosis circuit is higher than the voltage at the L-node.

[0062] In the technical solution disclosed in this embodiment, the types of the high-resistance element D1 and the clamping element D2 can be selected according to the setting requirements. In this embodiment, the high-resistance element D1 can be used as a reverse protection diode, and the clamping element D2 is used to implement the clamping protection function. Therefore, the clamping element D2 can be a clamping diode. A reverse protection diode, also known as a reverse polarity diode or a self-resetting diode, is mainly used to protect the circuit from damage by reverse voltage. When the input voltage is positive, the reverse protection diode is in the off state and will not affect the circuit; however, when the input voltage is reverse, the reverse protection diode will become conductive, thereby isolating the circuit from the reverse voltage and protecting the circuit from voltage damage. A clamping protection diode, also known as a clamping diode or clamping diode, is a diode used in a circuit to limit the potential at a certain point. The clamping protection diode utilizes the unidirectional conductivity of the diode to limit the potential at a certain point in the circuit. When the potential at that point exceeds or falls below a set threshold, the clamping diode will conduct, thereby pulling or pushing the potential towards a predetermined DC level. This feature helps protect other components in the circuit from damage caused by excessively high or low voltage.

[0063] In this embodiment, when the first tested switch Q1 is closed, its output terminal is connected to the negative terminal of the power supply, and its input terminal is connected to the positive terminal. At this time, a large current flows through the first tested switch Q1. When the first tested switch Q1 is opened, if the contact separation speed is too slow, an arc will form between the contacts during the disconnection process. This is because at the instant the current is disconnected, due to electromagnetic induction and inductance, a self-induced high voltage will be generated between the contacts, thereby breaking down the air and forming an arc. This arc will act on the third resistor R3. If the arc intensity is too large, it may burn out the third resistor R3 or the circuitry in the switch device fault diagnosis circuit. To suppress this arc, the aforementioned switch device fault diagnosis circuit may also include an inductor L. The inductor L is disposed between the input terminal of the first tested switch Q1 and the third resistor R3. The inductor L has the function of passing DC and blocking AC, and can prevent the instantaneously generated arc from entering the switch device fault diagnosis circuit, thus preventing damage to the switch device fault diagnosis circuit due to the high-voltage arc.

[0064] In this embodiment, the switching device fault diagnosis circuit can diagnose two switching devices simultaneously. In this application, one of the switching devices is designated as the first tested switching device Q1, and the other switching device is designated as the second tested switching device Q2. Referring to Figure 7, the switching device fault diagnosis circuit further includes a first switching switch K1 and a second switching switch K2. The first switching switch K1 is disposed between the input terminal of the first tested switching device Q1 and the third resistor R3; the second switching switch K2 is disposed between the input terminal of the second tested switching device Q2 and the third resistor R3. When the fault diagnosis circuit for the first tested switch device Q1 needs to be used for fault diagnosis, the first switch K1 is kept closed and the second switch K2 is kept open. Similarly, when the fault diagnosis circuit for the second tested switch device Q2 needs to be used, the first switch K1 is kept open and the second switch K2 is kept closed. This solution can determine whether the diagnosed switch device is the first tested switch device Q1 or the second tested switch device Q2 by controlling the conduction state of the first switch K1 and the second switch K2. Then, based on the output result of the output terminal S of the fault diagnosis circuit, it is determined whether the diagnosed switch device has a fault. As can be seen from this embodiment, this application can achieve abnormal state diagnosis of two switch devices through a single sampling point (the output terminal S of the fault diagnosis circuit).

[0065] Referring to Figure 8, two switching devices are usually connected to the two ends of the power supply, one of which is connected to the positive terminal of the power supply and the other is connected to the negative terminal of the power supply. In this embodiment, the switching device connected to the negative terminal of the power supply is referred to as the first switch device under test Q1, and the switching device connected to the positive terminal of the power supply is referred to as the second switch device under test Q2.

[0066] In this embodiment, the conduction states of both the first switching switch K1 and the second switching switch K2 can be controlled by a switch controller. The switch controller is connected to the control terminals of the first switching switch K1 and the second switching switch K2. The switch controller provides switch control signals to the first switching switch K1 and the second switching switch K2 to control their alternating conduction. Specifically, the switch controller provides control signals to the first switching switch K1 and the second switching switch K2 to control their conduction states. Under the control of these control signals, when the first switching switch K1 is on, the second switching switch K2 is off; when the first switching switch K1 is off, the second switching switch K2 is on. When the second switching switch K2 is on, the load between the high-voltage output port and the high-voltage input port is equivalent to a resistor. In this case, it can be considered that the output terminal of the second tested switching device Q2 is connected to the second terminal of the second resistor after passing through the first tested switching device Q1. The switch controller can be integrated into a processor connected to the output terminal S of the switching device fault diagnosis circuit. Furthermore, the processor can be integrated into the battery management system, in which case no additional processor is required in this application.

[0067] In this embodiment, the type and structure of the first resistor R1, the second resistor R2, and / or the third resistor R3 can be selected according to design and cost requirements. For example, the first resistor R1, the second resistor R2, and / or the third resistor R3 can be composed of at least two sub-resistors connected in parallel. This parallel design of multiple sub-resistors can distribute the current in the circuit, allowing each resistor to carry a portion of the current. Thus, even if one resistor fails or carries excessive current, the other resistors can still function normally, improving the reliability and stability of the circuit.

[0068] In response to the above-mentioned circuit, this application also discloses a switching device, which includes a switching device body and a switching device fault diagnosis circuit. The switching device fault diagnosis circuit can be the switching device fault diagnosis circuit described in any of the above embodiments of this application. The switching device body in the switching device serves as the first switch device under test Q1. The switching device has a data interface, which is connected to the output terminal S of the switching device fault diagnosis circuit.

[0069] In this embodiment, the switching device has two switching device bodies, one of which is designated as the first switch device under test Q1, and the other switch device body is designated as the second switch device under test Q2.

[0070] In this embodiment, the switching device can be a relay device.

[0071] This embodiment also discloses an automobile, a home appliance, and engineering equipment that utilize the switching device fault diagnosis circuit or the switching device described in any of the above embodiments of this application.

[0072] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0073] In this utility model, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0074] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0075] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0076] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0077] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fault diagnosis circuit for a switching device, comprising: The first resistor (R1), the second resistor (R2), the third resistor (R3), and the high-resistance component (D1); The first terminal of the first resistor (R1) is connected to the output terminal of the external power supply; The first end of the second resistor (R2) is connected to the second end of the first resistor (R1), and the second end of the second resistor (R2) is connected to the output terminal of the first switch device under test and ground. The second terminal of the high-resistance element (D1) is connected to the second terminal of the first resistor (R1); The first end of the third resistor (R3) is connected to the first end of the high-resistance element (D1), and the second end of the third resistor (R3) is connected to the input end of the first switch device under test. The common terminal of the first resistor (R1) and the second resistor (R2) serves as the output terminal of the switching device fault diagnosis circuit, and the output terminal is used to provide the sampling results of the switching device fault diagnosis circuit.

2. The switch device failure diagnosis circuit according to claim 1, further comprising: Clamping element (D2); The first end of the clamping element (D2) is connected to the first end of the high-resistance element (D1), and the second end of the clamping element (D2) is connected to the second end of the second resistor (R2).

3. The switching device fault diagnosis circuit according to any one of claims 1-2 further includes: An inductor (L) is disposed between the input terminal of the first switch device under test and the third resistor (R3).

4. The switching device fault diagnosis circuit according to any one of claims 1-3 further includes: First switching switch (K1) and second switching switch (K2); The first terminal of the first switching switch (K1) is connected to the input terminal of the first switch device under test, and the second terminal of the first switching switch (K1) is connected to the second terminal of the third resistor (R3). The first terminal of the second switching switch (K2) is connected to the input terminal of the second switch device under test, and the second terminal of the second switching switch (K2) is connected to the second terminal of the third resistor (R3).

5. The switching device fault diagnosis circuit according to claim 4 further includes: Switch controller; The control signal output terminal of the switch controller is connected to the control terminals of the first switching switch (K1) and the second switching switch (K2); The switch controller is used to provide control signals to the first switch (K1) and the second switch (K2). The control signals are used to control the conduction state of the first switch (K1) and the second switch (K2). Under the control of the control signals, when the first switch (K1) is on, the second switch (K2) is off, and when the first switch (K1) is off, the second switch (K2) is on.

6. The switching device fault diagnosis circuit according to claim 4 or 5, wherein, The first switch device under test is a negative relay, and the second switch device under test is a positive relay corresponding to the negative relay.

7. The switching device fault diagnosis circuit according to claim 2, wherein, The high-resistance element (D1) is a reverse protection diode, and the clamping element (D2) is a clamping diode.

8. A switching device, comprising a switching device body and a fault diagnosis circuit for a switching device as described in any one of claims 1-7, wherein the switching device body is the first switching device under test.

9. The switching device according to claim 8, wherein the switching device is a relay device.

10. An automobile comprising a switching device fault diagnosis circuit according to any one of claims 1-7 or a switching device according to any one of claims 8-9.

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