Terminal resistor matching circuit based on CAN communication and electric equipment

Abstract

The utility model relates to the technical field of battery overcurrent protection, and discloses a terminal resistor matching circuit based on CAN communication and electric equipment. The terminal resistor matching circuit based on CAN communication comprises a terminal resistor R5 arranged in a charger, a terminal resistor R8 arranged in a battery module, a first switch tube and a second switch tube. According to the utility model, the terminal resistor R5 arranged in the charger and the terminal resistor R8 arranged in the battery module are respectively controlled by the first switch tube and the second switch tube to be connected to the CAN bus, so that when the battery is independently charged, the phenomenon of information disorder is avoided, and the reliability of CAN communication is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of terminal resistance application, in particular to a terminal resistance matching circuit based on CAN communication and an electrical equipment. Background Art

[0002] With the increasing trend of green energy in life, electric bicycles are becoming more and more popular, and the functional modules on electric bicycles are also increasing and becoming more perfect, such as meters, controllers, motors and batteries. Each module interacts with each other, resulting in more and more wires connecting between the modules. At this time, CAN (Controller Area Network) communication gradually replaces the previous point-to-point communication due to the advantages of bus technology. The CAN bus has a priority arbitration mode and a high communication rate, and is safe and reliable.

[0003] In order to ensure the reliability of CAN bus communication and make its anti-interference ability stronger, terminal resistors are generally added at both the head and tail ends of the communication line when designing the circuit to ensure the reliability of system operation. In the field of electric bicycles, generally, the system comes with two terminal resistors, and no terminal resistors are added to the other components; however, this arrangement will cause a problem, that is, there is no abnormality when the battery is running online. Once the user wants to remove the battery separately and the battery is in an offline state, at this time, if the charger is used for charging, because the terminal resistors of the CAN bus are on the whole vehicle system and there are no terminal resistors on the battery and the charger, this will cause information disorder when the charger and the battery interact with each other, resulting in the inability to charge or abnormal charging.

[0004] In the prior art, for example, the patent application number is "201720882825.X", and the name is "A vehicle-mounted charger with a CAN terminal resistor switching function". It adds a terminal resistor separately on the charger side. However, this patented technology requires the vehicle controller to judge the reflected wave interference in the CAN communication line in real time, that is, only when an abnormality (reflected wave interference) appears in the CAN communication line, the terminal resistor is connected; this approach has obvious defects, that is, only when the charging abnormality occurs in the circuit, the charger adds the terminal resistor, and moreover, the abnormal phenomena in the CAN communication line are not all caused by the terminal resistor. Therefore, the above-mentioned way of adding the terminal resistor has obvious defects.

[0005] In view of this, how to accurately match the corresponding terminal resistor to ensure the reliability of CAN communication is a technical problem that needs to be solved urgently by those skilled in the art.

[0006] The above information is given as background information only to assist in understanding the present disclosure, and it is not determined or admitted whether any of the above content can be used as the prior art relative to the present disclosure. Summary of the Invention

[0007] The purpose of the present utility model is to provide a terminal resistance matching circuit and an electrical equipment based on CAN communication, so as to solve or at least partially solve the technical problems existing in the prior art.

[0008] To achieve this purpose, the present utility model adopts the following technical solutions:

[0009] In the first aspect, the present utility model provides a terminal resistance matching circuit based on CAN communication, including: a terminal resistance R5 disposed in a charger and a terminal resistance R8 disposed in a battery module;

[0010] The CAN bus includes a low-level signal line CAN_L and a high-level signal line CAN_H; the first end of the terminal resistance R5 is electrically connected to the positive connection terminal of a first switching tube, the negative connection terminal of the first switching tube is electrically connected to the low-level signal line CAN_L, and the second end of the terminal resistance R5 is electrically connected to the high-level signal line CAN_H; the first end of the terminal resistance R8 is electrically connected to the positive connection terminal of a second switching tube, the negative connection terminal of the second switching tube is electrically connected to the low-level signal line CAN_L, and the second end of the terminal resistance R8 is electrically connected to the high-level signal line CAN_H;

[0011] The switch control signal output pin of the MCU of the charger is electrically connected to the control end of the first switching tube; the switch control signal output pin of the MCU of the battery module is electrically connected to the control end of the second switching tube; the reference power supply of the charger is electrically connected to the first end of a resistor R2, and the second end of the resistor R2 is respectively electrically connected to the first end of a resistor R3 and the ADC sampling end of the MCU of the charger; the first end of a voltage-dividing resistor R1 disposed in a controller is electrically connected to the second end of a resistor R15 disposed in the battery module, and the first end of the resistor R15 is electrically connected to the reference power supply of the battery module; the second end of the resistor R15 is also electrically connected to the ADC sampling end of the MCU of the battery module; the second end of the resistor R15 is also used for electrically connecting to the second end of the resistor R2; the second end of the voltage-dividing resistor R1 and the second end of the resistor R3 are both electrically connected to the negative electrode of the battery module;

[0012] When the ADC sampling end of the MCU of the charger recognizes the voltage-dividing resistor R1, the first switching tube is controlled to disconnect; when the ADC sampling end of the MCU of the battery module recognizes the voltage-dividing resistor R1, the second switching tube is controlled to disconnect.

[0013] Optionally, the terminal resistance matching circuit further includes: a terminal resistance R4 disposed in an instrument and a terminal resistance R14 disposed in a controller;

[0014] The first end of the terminal resistor R4 is electrically connected to the low-level signal line CAN_L, and the second end of the terminal resistor R4 is electrically connected to the high-level signal line CAN_H; the first end of the terminal resistor R14 is electrically connected to the low-level signal line CAN_L, and the second end of the terminal resistor R14 is electrically connected to the high-level signal line CAN_H.

[0015] Optionally, the first switching transistor and the second switching transistor are enhancement-type NMOS transistors;

[0016] The positive connection terminal of the first switching transistor is the drain of the NMOS transistor, the negative connection terminal of the first switching transistor is the source of the NMOS transistor, and the control terminal of the first switching transistor is the gate of the NMOS transistor;

[0017] The positive connection terminal of the second switching transistor is the drain of the NMOS transistor, the negative connection terminal of the second switching transistor is the source of the NMOS transistor, and the control terminal of the second switching transistor is the gate of the NMOS transistor.

[0018] Optionally, the first switching transistor and the second switching transistor are NPN triodes;

[0019] The positive connection terminal of the first switching transistor is the collector of the NPN triode, the negative connection terminal of the first switching transistor is the emitter of the NPN triode, and the control terminal of the first switching transistor is the base of the NPN triode;

[0020] The positive connection terminal of the second switching transistor is the collector of the NPN triode, the negative connection terminal of the second switching transistor is the emitter of the NPN triode, and the control terminal of the second switching transistor is the base of the NPN triode.

[0021] Optionally, the first end of the voltage-dividing resistor R1 is electrically connected to the negative connection terminal of the mode switching switch SW, the positive connection terminal of the mode switching switch SW is electrically connected to the resistor R15 respectively; the positive connection terminal of the mode switching switch SW is also used to be electrically connected to the second end of the resistor R2.

[0022] Optionally, the terminal resistor R4, the terminal resistor R14, the terminal resistor R5, and the terminal resistor R8 are resistors with the same resistance value.

[0023] In a second aspect, the present invention further provides a battery module, a controller, and an instrument. The battery module is electrically connected to the controller and the instrument respectively through a CAN bus; the battery module is also detachably electrically connected to a charger; and it further includes a terminal resistor matching circuit based on CAN communication as described above.

[0024] Optionally, the electrical device is an electric bicycle.

[0025] Optionally, the resistance values of the terminal resistor R4, the terminal resistor R14, the terminal resistor R5, and the terminal resistor R8 are all 120 ohms.

[0026] Compared with the prior art, the utility model has the following beneficial effects:

[0027] In the utility model, the first switching tube and the second switching tube are respectively used to control the terminal resistor R5 arranged in the charger and the terminal resistor R8 arranged in the battery module to access the CAN bus, so that when the battery is charged separately, the phenomenon of information disorder will not occur; moreover, when the battery module resumes online work or the battery module and the charger work online together, the states of the first switching tube and the second switching tube can be automatically switched by identifying the voltage dividing resistor R1, and then the terminal resistor R5 arranged in the charger and the terminal resistor R8 arranged in the battery module are controlled to be disconnected from the CAN bus, so that the CAN bus always has a terminal resistor, ensuring the reliability of CAN communication.

[0028] The utility model has other characteristics and advantages, which will be obvious from the accompanying drawings incorporated herein and the subsequent detailed description, or will be described in detail in the accompanying drawings incorporated herein and the subsequent detailed description. These accompanying drawings and detailed description are used together to explain the specific principles of the utility model. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0030] Figure 1 It is the structural schematic diagram of a terminal resistor matching circuit based on CAN communication provided by an embodiment of the present utility model.

[0031] In the figure: 10, battery module; 20, controller; 30, instrument; 40, charger; Detailed Embodiments

[0032] In order to illustrate in detail the possible application scenarios, technical principles, implementable specific solutions, achievable purposes and effects, etc. of the present application, the following will be described in detail in combination with the listed specific embodiments and the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, so they are only examples and cannot be used to limit the protection scope of the present application.

[0033] As used herein, the term "embodiment" means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The term "embodiment" that appears in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0034] Unless otherwise defined, the meanings of the technical terms used herein are the same as those commonly understood by those skilled in the technical field to which the present application belongs; the use of the relevant terms herein is only for describing specific embodiments and is not intended to limit the present application.

[0035] In the description of the present application, the phrase "and / or" is an expression used to describe the logical relationship between objects, indicating that there can be three relationships, for example, A and / or B, which means: there is A, there is B, and there is both A and B at the same time. In addition, the character " / " in this article generally represents an "or" logical relationship between the associated objects before and after.

[0036] In the present application, 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 actual quantitative, primary-secondary, or sequential relationships between these entities or operations.

[0037] Without further limitation, in the present application, the terms "comprising", "including", "having", or other similar expressions used in a statement are intended to cover non-exclusive inclusion. These expressions do not exclude the possibility that there may be additional elements in the process, method, or product that includes the said elements, such that the process, method, or product that includes a series of elements may not only include those defined elements, but also include other elements not explicitly listed, or elements inherent to such process, method, or product.

[0038] The same as the understanding in the "Examination Guidelines", in the present application, expressions such as "greater than", "less than", "exceeding", etc. are understood not to include the number itself; expressions such as "above", "below", "within", etc. are understood to include the number itself. In addition, in the description of the embodiments of the present application, the meaning of "multiple" is two or more (including two), and similar expressions related to "many" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise specifically defined.

[0039] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0040] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0041] Embodiment 1:

[0042] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of a terminal resistance matching circuit based on CAN communication provided by an embodiment of the utility model. The terminal resistance matching circuit includes:

[0043] A terminal resistor R5 disposed in the charger 40 and a terminal resistor R8 disposed in the battery module 10;

[0044] like Figure 1 As shown, the CAN bus includes a low-level signal line CAN_L and a high-level signal line CAN_H;

[0045] The first end of the terminal resistor R5 is electrically connected to the first switch tube ( Figure 1 The positive terminal of SW1 in Figure 1 The left end of SW1 in the figure), the negative terminal of the first switch tube ( Figure 1 The right end of SW1 in the figure) is electrically connected to the low-level signal line CAN_L, and the second end of the terminal resistor R5 is electrically connected to the high-level signal line CAN_H; the first end of the terminal resistor R8 is electrically connected to the second switch tube ( Figure 1 The positive terminal of SW2 in Figure 1 The right end of SW1 in the figure), the negative terminal of the second switch tube (Figure 1 The left end of SW1 (in

[0046] the R5_CTL pin of the MCU of the charger 40) is electrically connected to the low-level signal line CAN_L, and the second end of the terminal resistor R8 is electrically connected to the high-level signal line CAN_H; Figure 1 The switch control signal output pin of the MCU of the battery module 10 (in Figure 1 the R8_CTL pin) is electrically connected to the control end of the second switch tube; the reference power supply of the charger 40 (in Figure 1 the 5V power supply on the upper side of R2) is electrically connected to the first end of the resistor R2, and the second end of the resistor R2 is electrically connected to the first end of the resistor R3 and the ADC sampling end of the MCU of the charger 10 respectively;

[0047] The first end of the voltage-dividing resistor R1 provided in the controller 20 is electrically connected to the second end of the resistor R15 provided in the battery module 10, and the first end of the resistor R15 is electrically connected to the reference power supply of the battery module 10 (in Figure 1 the VCC power supply); the second end of the resistor R15 is also electrically connected to the ADC sampling end of the MCU of the battery module 10; the second end of the resistor R15 is also used for electrically connecting to the second end of the resistor R2; the second end of the voltage-dividing resistor R1 and the second end of the resistor R3 are both electrically connected to the negative electrode of the battery module 10.

[0048] For ease of understanding, as an optional implementation manner, the first switch tube and the second switch tube are enhancement-type NMOS tubes;

[0049] The positive connection end of the first switch tube is the drain of the NMOS tube, the negative connection end of the first switch tube is the source of the NMOS tube, and the control end of the first switch tube is the gate of the NMOS tube;

[0050] The positive connection end of the second switch tube is the drain of the NMOS tube, the negative connection end of the second switch tube is the source of the NMOS tube, and the control end of the second switch tube is the gate of the NMOS tube;

[0051] As another optional implementation manner, the first switch tube and the second switch tube are NPN triodes;

[0052] The positive connection end of the first switch tube is the collector of the NPN triode, the negative connection end of the first switch tube is the emitter of the NPN triode, and the control end of the first switch tube is the base of the NPN triode;

[0053] The positive connection end of the second switch tube is the collector of the NPN triode, the negative connection end of the second switch tube is the emitter of the NPN triode, and the control end of the second switch tube is the base of the NPN triode.

[0054] For ease of understanding, in this embodiment, the MCU selects the microcontroller chip with the model number S9KEAZ128 from NXP Semiconductors, and this chip has the ADC sampling function.

[0055] Specifically, the terminal resistance matching circuit further includes a terminal resistance R4 disposed in the instrument and a terminal resistance R14 disposed in the controller;

[0056] The first end of the terminal resistance R4 is electrically connected to the low-level signal line CAN_L, and the second end of the terminal resistance R4 is electrically connected to the high-level signal line CAN_H; the first end of the terminal resistance R14 is electrically connected to the low-level signal line CAN_L, and the second end of the terminal resistance R14 is electrically connected to the high-level signal line CAN_H.

[0057] Specifically, the first end of the voltage-dividing resistor R1 is electrically connected to the negative terminal of the mode switching switch SW, and the positive terminal of the mode switching switch SW is electrically connected to the resistor R15 respectively; the positive terminal of the mode switching switch SW is also used to be electrically connected to the second end of the resistor R2.

[0058] Specifically, the terminal resistance R4, the terminal resistance R14, the terminal resistance R5, and the terminal resistance R8 are resistors with the same resistance value. In this embodiment, the terminal resistance selects a resistor with a resistance value of 120 ohms.

[0059] In this embodiment, in various application scenarios, the CAN bus always maintains two 120-ohm terminal resistors, and each module can freely switch the configuration of the terminal resistors to prevent abnormal communication waveforms and data loss caused by too many or too few terminal resistors, so that the system appears in an unstable state; the specific principle is described as follows:

[0060] The first working mode, that is, when the battery module 10 is working online, the battery module 10 connects the controller 20 and the instrument 30. At this time, the battery module 10 is not connected to the charger 40 or the charger 40 is in an offline state, and the mode switching switch SW is closed;

[0061] In the first working mode, the ADC sampling terminal of the MCU of the battery module 10 recognizes the voltage-dividing resistor R1, and then controls the second switching tube to turn off;

[0062] At this time, only two 120-ohm terminal resistors, namely the terminal resistance R4 and the terminal resistance R14, remain on the CAN bus.

[0063] The second working mode, that is, when the battery module 10 is working online, the battery module 10 connects the controller 20 and the instrument 30, and the battery module 10 is simultaneously connected to the charger 40, the mode switching switch SW is closed;

[0064] In the second working mode, the ADC sampling terminal of the MCU of the charger 40 recognizes the voltage-dividing resistor R1, and then controls the first switching tube to turn off; the ADC sampling terminal of the MCU of the battery module 10 recognizes the voltage-dividing resistor R1, and then controls the second switching tube to turn off;

[0065] At this time, only two 120-ohm termination resistors, the termination resistor R4 and the termination resistor R14, remain on the CAN bus.

[0066] In the third working mode, that is, when the battery module 10 and the charger 40 are used separately, the battery module 10 is not connected to the controller 20 and the instrument 30, the mode switching switch SW is turned off, and the voltage-dividing resistor R1 is disconnected;

[0067] In the third working mode, the ADC sampling terminal of the MCU of the charger 40 cannot recognize the voltage-dividing resistor R1, and then controls the first switching tube to conduct or turn off; the ADC sampling terminal of the MCU of the battery module 10 cannot recognize the voltage-dividing resistor R1, and then controls the second switching tube to conduct or turn off; at this time, only two 120-ohm termination resistors, the termination resistor R5 and the termination resistor R8, remain on the CAN bus.

[0068] In summary, during the application of the above-mentioned termination resistor matching circuit based on CAN communication, the CAN bus always adheres to the principle of having two 120R termination resistors; when the charger 40 and the battery module 10 recognize the system resistor R1, they timely disconnect the termination resistors on their own CAN buses; when the charger 40 charges the battery module 10 alone (offline charging), it can timely close the termination resistors on its own CAN bus; both the charger 40 and the battery module 10 need to perform ADC recognition through the voltage-dividing resistor R1.

[0069] The present utility model controls the termination resistor R5 provided in the charger and the termination resistor R8 provided in the battery module to be connected to the CAN bus through the first switching tube and the second switching tube respectively, so that when the battery is charged alone, there will be no phenomenon of information disorder; and, when the battery module resumes online work or the battery module and the charger work online together, by recognizing the voltage-dividing resistor R1, the states of the first switching tube and the second switching tube can be automatically switched, and then the termination resistor R5 provided in the charger and the termination resistor R8 provided in the battery module are controlled to be disconnected from the CAN bus, so that the CAN bus always has termination resistors, ensuring the reliability of CAN communication.

[0070] Embodiment 2:

[0071] The present utility model further provides an electrical equipment, comprising a battery module, a controller and an instrument, wherein the battery module is electrically connected to the controller and the instrument respectively through a CAN bus; the battery module is also detachably electrically connected with a charger; and it further comprises a terminal resistor matching circuit based on CAN communication as described above.

[0072] Since in the first embodiment, the relevant structures and principles of the terminal resistor matching circuit based on CAN communication have been explained in detail, they will not be elaborated in this embodiment.

[0073] In this embodiment, the electrical equipment is an electric bicycle; correspondingly, the resistance values of the terminal resistor R4, the terminal resistor R14, the terminal resistor R5 and the terminal resistor R8 are all 120 ohms.

[0074] It can be understood that in this embodiment, the mode switching switch SW can be selected from a key switch, a mechanical switch and other switches. The user can freely switch the working mode of the electrical equipment by operating the mode switching switch SW, which is very convenient for charging. When the battery module 10 is charged offline, there will be no phenomenon of information disorder, resulting in failure to charge or abnormal charging.

[0075] As described above, the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims

1. A terminal resistance matching circuit based on CAN communication, characterized in that: include: A terminal resistor R5 provided in the charger and a terminal resistor R8 provided in the battery module; The CAN bus includes a low-level signal line CAN_L and a high-level signal line CAN_H; a first end of the terminal resistor R5 is electrically connected to the positive terminal of the first switch tube, a negative terminal of the first switch tube is electrically connected to the low-level signal line CAN_L, and a second end of the terminal resistor R5 is electrically connected to the high-level signal line CAN_H; a first end of the terminal resistor R8 is electrically connected to the positive terminal of the second switch tube, a negative terminal of the second switch tube is electrically connected to the low-level signal line CAN_L, and a second end of the terminal resistor R8 is electrically connected to the high-level signal line CAN_H; The switch control signal output pin of the charger's MCU is electrically connected to the control end of the first switch tube; the switch control signal output pin of the battery module's MCU is electrically connected to the control end of the second switch tube; the charger's reference power supply is electrically connected to the first end of the resistor R2, and the second end of the resistor R2 is electrically connected to the first end of the resistor R3 and the ADC sampling end of the charger's MCU respectively; the first end of the voltage-dividing resistor R1 provided in the controller is electrically connected to the second end of the resistor R15 provided in the battery module, and the first end of the resistor R15 is electrically connected to the reference power supply of the battery module; the second end of the resistor R15 is also electrically connected to the ADC sampling end of the MCU of the battery module; the second end of the resistor R15 is also used to electrically connect the second end of the resistor R2; the second end of the voltage-dividing resistor R1 and the second end of the resistor R3 are both electrically connected to the negative electrode of the battery module; When the ADC sampling end of the charger's MCU recognizes the voltage-dividing resistor R1, the first switch tube is controlled to be disconnected; when the ADC sampling end of the battery module's MCU recognizes the voltage-dividing resistor R1, the second switch tube is controlled to be disconnected.

2. A terminal resistance matching circuit based on CAN communication according to claim 1, characterized in that: Also includes: A terminal resistor R4 provided in the instrument and a terminal resistor R14 provided in the controller; The first end of the terminal resistor R4 is electrically connected to the low level signal line CAN_L, and the second end of the terminal resistor R4 is electrically connected to the high level signal line CAN_H; the first end of the terminal resistor R14 is electrically connected to the low level signal line CAN_L, and the second end of the terminal resistor R14 is electrically connected to the high level signal line CAN_H.

3. A terminal resistance matching circuit based on CAN communication according to claim 1, characterized in that: The first switch tube and the second switch tube are enhanced NMOS tubes; The positive terminal of the first switch tube is the drain of the NMOS tube, the negative terminal of the first switch tube is the source of the NMOS tube, and the control terminal of the first switch tube is the gate of the NMOS tube; The positive terminal of the second switch tube is the drain of the NMOS tube, the negative terminal of the second switch tube is the source of the NMOS tube, and the control terminal of the second switch tube is the gate of the NMOS tube.

4. A terminal resistance matching circuit based on CAN communication according to claim 1, characterized in that: The first switch tube and the second switch tube are NPN transistors; The positive terminal of the first switch tube is the collector of the NPN transistor, the negative terminal of the first switch tube is the emitter of the NPN transistor, and the control terminal of the first switch tube is the base of the NPN transistor; The positive terminal of the second switch tube is the collector of the NPN transistor, the negative terminal of the second switch tube is the emitter of the NPN transistor, and the control terminal of the second switch tube is the base of the NPN transistor.

5. A terminal resistance matching circuit based on CAN communication according to claim 1, characterized in that: The first end of the voltage dividing resistor R1 is electrically connected to the negative terminal of the mode switching switch SW, and the positive terminal of the mode switching switch SW is electrically connected to the resistor R15; the positive terminal of the mode switching switch SW is also used to electrically connect the second end of the resistor R2.

6. A terminal resistance matching circuit based on CAN communication according to claim 1, characterized in that: The terminal resistor R4 , the terminal resistor R14 , the terminal resistor R5 , and the terminal resistor R8 are resistors having the same resistance value.

7. An electrical device, comprising a battery module, a controller and an instrument, wherein the battery module is electrically connected to the controller and the instrument respectively through a CAN bus; the battery module is also detachably electrically connected to a charger; characterized in that: It also includes a terminal resistance matching circuit based on CAN communication as described in any one of claims 1-6.

8. The electrical equipment according to claim 7, characterized in that: The electrical equipment is an electric bicycle.

9. An electrical equipment according to claim 8, characterized in that: The resistance values ​​of the terminal resistor R4, the terminal resistor R14, the terminal resistor R5 and the terminal resistor R8 are all 120 ohms.

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