BMS (Battery Management System) activation circuit based on CAN (Controller Area Network) communication and electric equipment

Abstract

The utility model relates to the technical field of battery management, and discloses a BMS (Battery Management System) activation circuit based on CAN (Controller Area Network) communication and electric equipment. The BMS activation circuit comprises a CAN communication signal identification circuit, a BMS activation circuit and a BMS turn-off circuit. According to the BMS activation circuit provided by the utility model, the function of activating the BMS by a CAN signal can be realized by only depending on the design of passive devices such as the optocoupler and the semiconductor switch tube, and an MCU with a CAN activation function or a chip with a CAN activation function does not need to be externally hung, so that the circuit is simple and reliable, and the design cost is greatly reduced; after the BMS is activated, the activation signal can be cut off in time through the enable signal output pin of the MCU, the power consumption of the activation signal loop is cut off, the self power consumption of the battery is not additionally increased, and meanwhile the endurance time of the battery is effectively prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of battery management, in particular to a BMS activation circuit and electrical equipment based on CAN communication. Background Art

[0002] An electric assisted bicycle is a mechatronic vehicle that uses batteries as auxiliary energy and is based on an ordinary small car and is equipped with motors, controllers, batteries and other components. The battery is an important component of the electric assisted bicycle, and the battery of the electric assisted bicycle must be charged before use.

[0003] In recent years, with the continuous development of the electric bicycle industry and increasing customer demand, after use, the battery management system (BMS) is generally required to consume less than microamperes of power to maximize battery life and efficiency. This requires the BMS to enter low-power mode. However, when the BMS enters low-power mode, the charger typically activates the BMS by relying on the voltage between the positive and negative electrodes of the charger. This means that the charger remains charged. This approach poses a safety hazard and cannot pass safety certification.

[0004] The CAN bus (Controller Area Network) is an important bus transmission solution with a wide range of applications. Activating the BMS based on CAN communication eliminates the need for the charger to be constantly charged; the BMS can be activated simply through the charger's CAN signal. However, in the prior art, CAN activation for BMSs generally involves an external MCU with CAN activation or a chip with built-in CAN activation functionality. For example, the Chinese patent application number "CN201720812228.X," titled "A BMS Charging Detection Circuit with Activation Function," uses an external MCU to activate the BMS. Both of these methods require the battery to constantly power the chip, which increases the BMS's self-consumption and significantly increases manufacturing costs.

[0005] In view of this, how to further reduce the self-consumption of the BMS while reliably activating the BMS has become a technical problem that needs to be solved urgently in this field.

[0006] The above information is presented as background information only to assist with an understanding of the present disclosure and is not a determination or admission that any of the above may be applicable as prior art with respect to the present disclosure. Utility Model Content

[0007] The purpose of the present utility model is to provide a BMS activation circuit and 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 invention adopts the following technical solutions:

[0009] In a first aspect, the utility model provides a BMS activation circuit based on CAN communication, comprising: a CAN communication signal recognition circuit, a BMS activation circuit, and a BMS shutdown circuit;

[0010] The CAN communication signal recognition circuit includes an optocoupler U1, wherein the anode pin of the optocoupler U1 is electrically connected to the high-level CAN bus, the cathode pin of the optocoupler U1 is electrically connected to the low-level CAN bus, the collector pin of the optocoupler U1 is electrically connected to the positive electrode of the battery, and the emitter pin of the optocoupler U1 is electrically connected to the switch control terminal of the BMS activation circuit;

[0011] The BMS activation circuit includes a switch tube Q1 and a resistor R2. The first end of the resistor R2 is electrically connected to the switch control terminal of the switch tube Q1 and the shutdown signal terminal of the BMS shutdown circuit respectively. The second end of the resistor R2 is electrically connected to the emitter pin of the optocoupler U1. The positive terminal of the switch tube Q1 is electrically connected to the activation signal input terminal of the BMS, and the negative terminal of the switch tube Q1 is electrically connected to the negative terminal of the battery.

[0012] The BMS shutdown circuit includes a switch tube M1, the switch control terminal of the switch tube M1 is electrically connected to the enable signal output pin of the MCU; the positive terminal of the switch tube M1 is a shutdown signal terminal, which is electrically connected to the first end of the resistor R2; the negative terminal of the switch tube M1 is electrically connected to the negative electrode of the battery;

[0013] When the emitter pin and the collector pin of the optocoupler U1 are turned on, the switch tube Q1 is turned on and the BMS is activated; when the BMS is activated and starts working, the MCU controls the switch tube M1 to turn on through the enable signal output pin, thereby turning off or disconnecting the switch tube Q1.

[0014] Optionally, the CAN communication signal recognition circuit further includes a diode D2, a voltage-stabilizing diode ZD1 and a current-limiting resistor R3;

[0015] The anode of the diode D2 is electrically connected to the positive electrode of the battery, the cathode of the diode D2 is electrically connected to the cathode of the Zener diode ZD1, and the anode of the Zener diode ZD1 is electrically connected to the collector pin of the optocoupler U1;

[0016] A first end of the current limiting resistor R3 is electrically connected to the cathode pin of the optocoupler U1 , and a second end of the current limiting resistor R3 is electrically connected to the low-level CAN bus.

[0017] Optionally, the BMS activation circuit further includes a resistor R1, a resistor R4, a capacitor C1 and a diode D1;

[0018] The first end of the resistor R1 is electrically connected to the first end of the resistor R4 and the positive electrode of the capacitor C1, respectively, and the second end of the resistor R1 is electrically connected to the first end of the resistor R2; the second end of R4 and the negative electrode of the capacitor C1 are both electrically connected to the negative electrode of the battery; the anode of the diode D1 is electrically connected to the activation signal input terminal of the BMS, and the cathode of the diode D1 is electrically connected to the positive terminal of the switch tube Q1.

[0019] Optionally, the switch tube Q1 is an NPN transistor; the switch control terminal of the switch tube Q1 is the base of the NPN transistor; the positive terminal of the switch tube Q1 is the collector of the NPN transistor, and the negative terminal of the switch tube Q1 is the emitter of the NPN transistor.

[0020] Optionally, the switch tube Q1 is an enhancement type NMOS field effect tube; the switch control terminal of the switch tube Q1 is the gate of the enhancement type NMOS field effect tube, the positive terminal of the switch tube Q1 is the drain of the enhancement type NMOS field effect tube, and the negative terminal of the switch tube Q1 is the source of the enhancement type NMOS field effect tube.

[0021] Optionally, the BMS shutdown circuit further includes a resistor R5, a resistor R6 and a capacitor C2;

[0022] The first end of the resistor R5 is electrically connected to the first end of the resistor R6, the positive electrode of the capacitor C2 and the switch control end of the switch tube M1 respectively, and the second end of the resistor R6 and the negative electrode of the capacitor C2 are electrically connected to the negative electrode of the battery; the second end of the resistor R5 is electrically connected to the enable signal output pin of the MCU.

[0023] Optionally, the switch tube M1 is an enhancement type NMOS field effect tube; the switch control terminal of the switch tube M1 is the gate of the enhancement type NMOS field effect tube, the positive terminal of the switch tube M1 is the drain of the enhancement type NMOS field effect tube, and the negative terminal of the switch tube M1 is the source of the enhancement type NMOS field effect tube.

[0024] Optionally, the switch tube M1 is an NPN transistor; the switch control terminal of the switch tube M1 is the base of the NPN transistor; the positive terminal of the switch tube M1 is the collector of the NPN transistor, and the negative terminal of the switch tube M1 is the emitter of the NPN transistor.

[0025] In a second aspect, the utility model further provides an electrical device, including a battery, a BMS and an MCU, characterized in that it also includes a BMS activation circuit based on CAN communication as described above.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The BMS activation circuit provided by the utility model only relies on the design of passive devices such as optocouplers and semiconductor switch tubes, and can realize the function of activating the BMS by CAN signal. It does not require an external MCU with CAN activation or a chip with built-in CAN activation function. The circuit is simple and reliable, greatly reducing the design cost. After the BMS is activated, the activation signal can be cut off in time through the enable signal output pin of the MCU, thereby cutting off the power consumption of the activation signal circuit, without increasing the battery self-consumption and effectively improving the battery life.

[0028] The present invention has other features and advantages, which will be apparent from the accompanying drawings and subsequent detailed descriptions incorporated herein, or will be described in detail in the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a structural principle diagram of a BMS activation circuit based on CAN communication provided by an embodiment of the utility model.

[0031] In the figure: 100, CAN communication signal recognition circuit; 200, BMS activation circuit; 300, BMS shutdown circuit. DETAILED DESCRIPTION

[0032] In order to explain in detail the possible application scenarios, technical principles, specific solutions that can be implemented, and the purpose and effects of this application, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of this application and are therefore only examples and are not intended to limit the scope of protection of this application.

[0033] References to "embodiments" herein mean that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the word "embodiment" 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 this application, as long as there are no technical contradictions or conflicts, the various technical features mentioned in the embodiments can be combined in any manner to form a corresponding implementable technical solution.

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

[0035] In the description of this application, the term "and / or" is used to describe a logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and both A and B exist. In addition, the character " / " in this document generally indicates that the objects before and after are in a logical "or" relationship.

[0036] In this application, terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantity, priority or sequence relationship between these entities or operations.

[0037] Without further limitations, in this application, the words "include", "comprise", "have" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those defined elements, but also other elements not explicitly listed, or elements inherent to such process, method or product.

[0038] Consistent with the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceed" are understood to exclude the number itself; expressions such as "above," "below," and "within" are understood to include the number itself. Furthermore, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this manner, such as "multiple groups," "multiple times," etc., unless otherwise specifically defined.

[0039] In the description of the embodiments of the present application, the 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 device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it should not 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 "installed", "connected", "connected", "fixed", "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 an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art of the present application, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0041] Example 1:

[0042] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of a BMS activation circuit based on CAN communication provided by an embodiment of the present invention. The BMS activation circuit includes:

[0043] CAN communication signal recognition circuit 100, BMS activation circuit 200 and BMS shutdown circuit 300;

[0044] The CAN communication signal recognition circuit 100 includes an optocoupler U1, an anode pin of the optocoupler U1 ( Figure 1 The 1 pin of the optocoupler U1 in the middle is electrically connected to the high-level CAN bus, and the cathode pin of the optocoupler U1 ( Figure 1 Pin 2 of the optocoupler U1 in the middle) is electrically connected to the low-level CAN bus, and the collector pin of the optocoupler U1 ( Figure 1 Pin 4 of the optocoupler U1 is electrically connected to the positive terminal of the battery (i.e. Figure 1 The "BAT+" pin in the figure), the emitter pin of the optocoupler U1 ( Figure 1 Pin 3 of the optocoupler U1 is electrically connected to the switch control terminal of the BMS activation circuit;

[0045] For the convenience of description, in this embodiment, Figure 1 In the resistor element, the left end or the upper end is uniformly named the first end, and the right end or the lower end is uniformly named the second end;

[0046] Specifically, the BMS activation circuit 200 includes a switch tube Q1 and a resistor R2, wherein the first end of the resistor R2 is electrically connected to the switch control terminal of the switch tube Q1 and the shutdown signal terminal of the BMS shutdown circuit, respectively; the second end of the resistor R2 is electrically connected to the emitter pin of the optocoupler U1; the positive terminal of the switch tube Q1 is electrically connected to the activation signal input terminal of the BMS (i.e., Figure 1 The negative terminal of the switch tube Q1 is electrically connected to the negative terminal of the battery (i.e. Figure 1 "BAT-" pin in the PCB);

[0047] The BMS shutdown circuit 300 includes a switch tube M1, a switch control terminal of the switch tube M1 ( Figure 1 The right end pin of the middle switch tube M1 is electrically connected to the enable signal output pin of the MCU (i.e. Figure 1 "EN_BAT+" pin in the circuit); the positive terminal of the switch tube M1 ( Figure 1 The upper pin of the switch tube M1 is the shutdown signal terminal, which is electrically connected to the first end of the resistor R2; the negative terminal of the switch tube M1 ( Figure 1 The lower pin of the middle switch tube M1 is electrically connected to the negative electrode of the battery;

[0048] When the emitter pin and the collector pin of the optocoupler U1 are turned on, the switch tube Q1 is turned on, the positive terminal and the negative terminal of the switch tube Q1 are turned on, the "Activate" pin signal is pulled low, and the BMS is activated accordingly; when the BMS is activated and starts working, the MCU can enable the "EN_BAT+" pin as a high-level signal, and the high-level signal will control the switch tube M1 to turn on, that is, to turn on the positive terminal and the negative terminal of the switch tube M1, pull down the voltage of the first end of the resistor R2, so that the switch tube Q1 is turned off or disconnected, and the BMS activation circuit 200 does not work.

[0049] The BMS activation circuit provided in this embodiment relies solely on passive components such as the optocoupler U1 and semiconductor switch tubes to implement the function of activating the BMS using a CAN signal. It does not require an external MCU with CAN activation or a chip with its own CAN activation function. The circuit is simple and reliable, greatly reducing design costs. After the BMS is activated, the activation signal can be promptly cut off through the enable signal output pin of the MCU, thereby cutting off the power consumption of the activation signal circuit. This does not increase the battery's self-consumption while effectively improving battery life.

[0050] Specifically, the CAN communication signal recognition circuit 100 further includes a diode D2, a voltage-stabilizing diode ZD1, and a current-limiting resistor R3;

[0051] The anode of the diode D2 is electrically connected to the positive electrode of the battery, the cathode of the diode D2 is electrically connected to the cathode of the Zener diode ZD1, and the anode of the Zener diode ZD1 is electrically connected to the collector pin of the optocoupler U1;

[0052] A first end of the current limiting resistor R3 is electrically connected to the cathode pin of the optocoupler U1 , and a second end of the current limiting resistor R3 is electrically connected to the low-level CAN bus.

[0053] It should be noted that the value of the Zener diode ZD1 needs to confirm the minimum activation voltage of the BMS. For example, for a 36V battery pack, the operating range is generally 25V to 42V. If the minimum activation voltage is set to 20V, the Zener diode ZD1 value can be 18V. When the positive voltage is lower than 20V, the diode D2 and the transistor Q1 will consume a certain voltage.

[0054] Specifically, the BMS activation circuit 200 further includes a resistor R1, a resistor R4, a capacitor C1, and a diode D1;

[0055] The first end of the resistor R1 is electrically connected to the first end of the resistor R4 and the positive electrode of the capacitor C1, respectively, and the second end of the resistor R1 is electrically connected to the first end of the resistor R2; the second end of R4 and the negative electrode of the capacitor C1 are both electrically connected to the negative electrode of the battery; the anode of the diode D1 is electrically connected to the activation signal input terminal of the BMS, and the cathode of the diode D1 is electrically connected to the positive terminal of the switch tube Q1.

[0056] Among them, the resistor R4 and the capacitor C1 can prevent the switch tube Q1 from being mis-turned on due to interference, and can enhance the anti-interference ability of the circuit to a certain extent.

[0057] As an optional implementation of this embodiment, the switch tube Q1 is an NPN transistor; the switch control terminal of the switch tube Q1 is the base of the NPN transistor; the positive terminal of the switch tube Q1 is the collector of the NPN transistor, and the negative terminal of the switch tube Q1 is the emitter of the NPN transistor.

[0058] As another optional implementation of this embodiment, the switch tube Q1 is an enhancement type NMOS field effect transistor; the switch control terminal of the switch tube Q1 is the gate of the enhancement type NMOS field effect transistor, the positive terminal of the switch tube Q1 is the drain of the enhancement type NMOS field effect transistor, and the negative terminal of the switch tube Q1 is the source of the enhancement type NMOS field effect transistor.

[0059] It should be noted that, in practical applications, the value of resistor R2 needs to be coordinated with resistors R4 and R1 to ensure that the switch tube Q1 is turned on, and to ensure that the self-power consumption of the entire circuit is not too large after the BMS shutdown circuit 300 is enabled.

[0060] Specifically, the BMS shutdown circuit 300 further includes a resistor R5, a resistor R6 and a capacitor C2;

[0061] The first end of the resistor R5 is electrically connected to the first end of the resistor R6, the positive electrode of the capacitor C2 and the switch control end of the switch tube M1 respectively, and the second end of the resistor R6 and the negative electrode of the capacitor C2 are electrically connected to the negative electrode of the battery; the second end of the resistor R5 is electrically connected to the enable signal output pin of the MCU.

[0062] Likewise, the capacitor C2 among the above components is a filter capacitor, which is used to enhance the anti-interference capability of the BMS shutdown circuit 300 .

[0063] As an optional implementation of this embodiment, the switch tube M1 is an enhancement NMOS field-effect transistor; the switch control terminal of the switch tube M1 is the gate of the enhancement NMOS field-effect transistor, the positive terminal of the switch tube M1 is the drain of the enhancement NMOS field-effect transistor, and the negative terminal of the switch tube M1 is the source of the enhancement NMOS field-effect transistor.

[0064] As another optional implementation of this embodiment, the switch tube M1 is an NPN transistor; the switch control terminal of the switch tube M1 is the base of the NPN transistor; the positive terminal of the switch tube M1 is the collector of the NPN transistor, and the negative terminal of the switch tube M1 is the emitter of the NPN transistor.

[0065] It should be noted that, in this embodiment, the value of the resistor R2 needs to coordinate with the resistor R4 and the resistor R1 to ensure that the transistor Q1 is turned on, and to ensure that the self-power consumption of the entire circuit is not too large after the third part of the circuit is enabled.

[0066] In summary, the BMS activation circuit based on CAN communication provided in this embodiment relies only on passive device design such as optocouplers and transistors. The circuit is simple and reliable, which greatly reduces the design cost. After the BMS is activated, the activation signal is promptly cut off through EN_BAT+ to cut off the power consumption of the activation signal loop. By utilizing the characteristics of the voltage regulator diode, the battery will no longer be activated when the voltage is lower than a certain threshold, and the low-voltage charging prohibition function can also be realized.

[0067] Example 2:

[0068] Based on the same concept, the present invention also provides an electrical device, including a battery, a BMS and an MCU, and also includes a BMS activation circuit based on CAN communication as described in the first embodiment.

[0069] Since the structure of the BMS activation circuit and the connection relationship between the components have been described in detail in the first embodiment, they will not be repeated in this embodiment.

[0070] Compared with traditional electric assisted bicycles, the electric equipment provided in this embodiment further reduces the self-consumption of the BMS while reliably activating the BMS, and greatly reduces the manufacturing cost of the electric assisted bicycle.

[0071] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A BMS activation circuit based on CAN communication, characterized in that: include: CAN communication signal recognition circuit, BMS activation circuit and BMS shutdown circuit; The CAN communication signal recognition circuit includes an optocoupler U1, wherein the anode pin of the optocoupler U1 is electrically connected to the high-level CAN bus, the cathode pin of the optocoupler U1 is electrically connected to the low-level CAN bus, the collector pin of the optocoupler U1 is electrically connected to the positive electrode of the battery, and the emitter pin of the optocoupler U1 is electrically connected to the switch control terminal of the BMS activation circuit; The BMS activation circuit includes a switch tube Q1 and a resistor R2. The first end of the resistor R2 is electrically connected to the switch control terminal of the switch tube Q1 and the shutdown signal terminal of the BMS shutdown circuit respectively. The second end of the resistor R2 is electrically connected to the emitter pin of the optocoupler U1. The positive terminal of the switch tube Q1 is electrically connected to the activation signal input terminal of the BMS, and the negative terminal of the switch tube Q1 is electrically connected to the negative terminal of the battery. The BMS shutdown circuit includes a switch tube M1, the switch control terminal of the switch tube M1 is electrically connected to the enable signal output pin of the MCU; the positive terminal of the switch tube M1 is a shutdown signal terminal, which is electrically connected to the first end of the resistor R2; the negative terminal of the switch tube M1 is electrically connected to the negative electrode of the battery; When the emitter pin and the collector pin of the optocoupler U1 are turned on, the switch tube Q1 is turned on and the BMS is activated; when the BMS is activated and starts working, the MCU controls the switch tube M1 to turn on through the enable signal output pin, thereby turning off or disconnecting the switch tube Q1.

2. A BMS activation circuit based on CAN communication according to claim 1, characterized in that: The CAN communication signal recognition circuit also includes a diode D2, a voltage-stabilizing diode ZD1, and a current-limiting resistor R3; The anode of the diode D2 is electrically connected to the positive electrode of the battery, the cathode of the diode D2 is electrically connected to the cathode of the Zener diode ZD1, and the anode of the Zener diode ZD1 is electrically connected to the collector pin of the optocoupler U1; A first end of the current limiting resistor R3 is electrically connected to the cathode pin of the optocoupler U1 , and a second end of the current limiting resistor R3 is electrically connected to the low-level CAN bus.

3. The BMS activation circuit based on CAN communication according to claim 1, characterized in that: The BMS activation circuit also includes resistor R1, resistor R4, capacitor C1 and diode D1; The first end of the resistor R1 is electrically connected to the first end of the resistor R4 and the positive electrode of the capacitor C1, respectively, and the second end of the resistor R1 is electrically connected to the first end of the resistor R2; the second end of R4 and the negative electrode of the capacitor C1 are both electrically connected to the negative electrode of the battery; the anode of the diode D1 is electrically connected to the activation signal input terminal of the BMS, and the cathode of the diode D1 is electrically connected to the positive terminal of the switch tube Q1.

4. A BMS activation circuit based on CAN communication according to claim 3, characterized in that: The switch tube Q1 is an NPN transistor; the switch control terminal of the switch tube Q1 is the base of the NPN transistor; the positive terminal of the switch tube Q1 is the collector of the NPN transistor, and the negative terminal of the switch tube Q1 is the emitter of the NPN transistor.

5. The BMS activation circuit based on CAN communication according to claim 3, characterized in that: The switch tube Q1 is an enhancement type NMOS field effect tube; the switch control terminal of the switch tube Q1 is the gate of the enhancement type NMOS field effect tube, the positive terminal of the switch tube Q1 is the drain of the enhancement type NMOS field effect tube, and the negative terminal of the switch tube Q1 is the source of the enhancement type NMOS field effect tube.

6. The BMS activation circuit based on CAN communication according to claim 1, characterized in that: The BMS shutdown circuit also includes resistor R5, resistor R6 and capacitor C2; The first end of the resistor R5 is electrically connected to the first end of the resistor R6, the positive electrode of the capacitor C2 and the switch control end of the switch tube M1 respectively, and the second end of the resistor R6 and the negative electrode of the capacitor C2 are electrically connected to the negative electrode of the battery; the second end of the resistor R5 is electrically connected to the enable signal output pin of the MCU.

7. The BMS activation circuit based on CAN communication according to claim 6, characterized in that: The switch tube M1 is an enhancement type NMOS field effect tube; the switch control terminal of the switch tube M1 is the gate of the enhancement type NMOS field effect tube, the positive terminal of the switch tube M1 is the drain of the enhancement type NMOS field effect tube, and the negative terminal of the switch tube M1 is the source of the enhancement type NMOS field effect tube.

8. The BMS activation circuit based on CAN communication according to claim 6, characterized in that: The switch tube M1 is an NPN transistor; the switch control terminal of the switch tube M1 is the base of the NPN transistor; the positive terminal of the switch tube M1 is the collector of the NPN transistor, and the negative terminal of the switch tube M1 is the emitter of the NPN transistor.

9. An electrical device, comprising a battery, a BMS and an MCU, characterized in that: It also includes a BMS activation circuit based on CAN communication as described in any one of claims 1-8.

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