Unibus communication circuit, battery management system, battery pack and electric equipment

Abstract

A single bus communication circuit configured to electrically connect a second control circuit, the single bus communication circuit comprising: a first control circuit; a first power supply; a second power supply; the first isolation element and the second isolation element are electrically connected with the second control circuit at the first node; the single-bus communication circuit is configured to respond to the fact that the first control circuit sends a first communication signal to the second isolation element, the second isolation element is turned on or turned off, a second communication signal with the same level as the first communication signal is generated at the first node, and the second control circuit receives the second communication signal. In response to the first control circuit sending the first control signal to the second isolation element, the second isolation element is turned off, in response to the second control circuit sending the third communication signal to the first isolation element, the first isolation element is turned on or turned off, and the first control circuit receives a fourth communication signal having the same level as the third communication signal.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and in particular to a single bus communication circuit, a battery management system, a battery pack, and an electrical device. Background Art

[0002] The electrical device includes a battery pack, which provides power to the load within the device. For a battery pack in which a discharge switch is positioned between the negative electrode of the battery module and the negative output terminal of the battery pack, to achieve single-bus communication between the first and second control circuits, the discharge switch, or both the discharge switch and the charge switch, must be closed to short-circuit the negative electrode of the battery module and the negative output terminal of the battery pack. It is understood that the first control circuit is a component within the battery pack, while the second control circuit is a component within the electrical device. Summary of the Invention

[0003] The embodiments of the present application provide a single-bus communication circuit, a battery management system, a battery pack, and an electrical device, which can improve the reliability, stability, and safety of the system.

[0004] In the first aspect, an embodiment of the present application provides a single-bus communication circuit, which is configured to be electrically connected to a second control circuit, and the single-bus communication circuit includes: a first control circuit; a first power supply, electrically connected to the first control circuit; a second power supply, configured to be electrically connected to the second control circuit; a first isolation element and a second isolation element, the first isolation element and the second isolation element are configured to be electrically connected to the second control circuit at a first node, the first isolation element is electrically connected to the first power supply, the second power supply, the first control circuit and the first ground terminal, and the second isolation element is electrically connected to the first power supply, the first control circuit and the second ground terminal; the single-bus communication circuit is configured to: in response to the first control circuit sending a first communication signal to the second isolation element, the second isolation element is turned on or off, a second communication signal with the same level as the first communication signal is generated at the first node, and the second control circuit receives the second communication signal; in response to the first control circuit sending a first control signal to the second isolation element, the second isolation element is turned off, in response to the second control circuit sending a third communication signal to the first isolation element, the first isolation element is turned on or off, and the first control circuit receives a fourth communication signal with the same level as the third communication signal.

[0005] In summary, when the battery pack and the electrical equipment are transmitting and interacting data, they are no longer affected by the on-off state of the discharge switch, which is conducive to ensuring stable communication between the battery pack and the electrical equipment. When the single-bus communication circuit is used in a battery parallel system, there is no need to control the closure of the discharge switch, so that data transmission between the battery pack and the battery pack, and between the battery pack and the electrical equipment can be achieved, avoiding the circulation problem caused by the closing of the discharge switch. When the electrical equipment transmits a signal to the battery pack, the pull-up and pull-down functions are realized through the first power supply and the first ground terminal, so that the first control circuit receives a signal with a level consistent with that sent by the electrical equipment. When the battery pack transmits a signal to the electrical equipment, the pull-up and pull-down functions are realized through the second power supply and the second ground terminal, so that the second control circuit receives a signal with a level consistent with that sent by the battery pack. In this way, the single-bus communication circuit of the present application does not need to adapt the parameters of the external circuit, and the adaptability and compatibility of the single-bus communication circuit are strong. In addition, the single-bus communication circuit can be used for both negative control schemes and positive control schemes, which is conducive to improving the adaptability and compatibility of the single-bus communication circuit.

[0006] In one or more embodiments, the single bus communication circuit is further configured to: in response to the first control circuit and the second control circuit not communicating, the first control circuit controls the second isolation element to be turned off.

[0007] When the first control circuit and the second control circuit are not communicating, the second isolation element is controlled to be turned off. At this time, there is no leakage path in the single bus communication circuit, and the power consumption is low.

[0008] In one or more embodiments, the first control circuit includes a receiving pin and a transmitting pin; the first power supply is electrically connected to the receiving pin, and the first power supply is electrically connected to the transmitting pin through the second isolation element.

[0009] In one or more embodiments, the first ground terminal serves as a reference ground for the first power supply, and the second ground terminal serves as a reference ground for the second power supply.

[0010] In this way, the first power supply and the second power supply are two power supplies without direct electrical connection, which is beneficial to prevent current from flowing between the first power supply and the second power supply, so as to have a better isolation effect and improve the stability and reliability of communication between the first control circuit and the second control circuit.

[0011] In one or more embodiments, the first isolation element includes a first optocoupler, and the second isolation element includes a second optocoupler; the first optocoupler includes a first input terminal and a first output terminal, the first pin of the first input terminal is electrically connected to the second power supply, the second pin of the first input terminal is electrically connected to the first node, the third pin of the first output terminal is electrically connected to the receiving pin, and the fourth pin of the first output terminal is electrically connected to the first ground terminal; the second optocoupler includes a second input terminal and a second output terminal, the first pin of the second input terminal is electrically connected to the first power supply, the second pin of the second input terminal is electrically connected to the sending pin, the third pin of the second output terminal is electrically connected to the first node, and the fourth pin of the second output terminal is electrically connected to the second ground terminal.

[0012] In one or more embodiments, the single bus communication circuit also includes: a first switching circuit, electrically connected to the first node, the second power supply and the first isolation element, the first switching circuit and the first isolation element are configured to: in response to the second control circuit sending a third communication signal to the first switching circuit, the first switching circuit forms a path or a break, and the first isolation element is turned on or off; and / or, a second switching circuit, electrically connected to the first node, the second isolation element and the second ground terminal, the second isolation element is also electrically connected to the second power supply, the second switching circuit and the second isolation element are configured to: in response to the first control circuit sending a first communication signal to the second isolation element, the second isolation element is turned on or off, and the second switching circuit forms a path or a break.

[0013] A first switching circuit is added so that the current flowing from the second current through the first switching circuit and into the first isolation element is derived solely from the second power supply and is independent of the third communication signal, thereby facilitating stable conduction of the first isolation element. A second switching circuit is added so that the current flowing from the second current through the second isolation element and into the second switching circuit is derived solely from the second power supply and is independent of the current at the first node, thereby facilitating stable conduction of the second isolation element.

[0014] In one or more embodiments, the first isolation element includes a first optocoupler, the first optocoupler including a first input terminal and a first output terminal; the second isolation element includes a second optocoupler, the second optocoupler including a second input terminal and a second output terminal; the first switching circuit includes a first switch and a first resistor, the control terminal of the first switch is electrically connected to the first node, the first resistor is arranged between the control terminal of the first switch and the first terminal of the first switch, the first terminal of the first switch is electrically connected to the second power supply, the second terminal of the first switch is electrically connected to the first pin of the first input terminal, the second pin of the first input terminal is electrically connected to the second ground terminal, the third pin of the first output terminal is electrically connected to the receiving pin, the fourth pin of the first output terminal is electrically connected to the first ground terminal, the first pin of the second input terminal is electrically connected to the first power supply, the second pin of the second input terminal is electrically connected to the sending pin, the third pin of the second output terminal is electrically connected to the first node, and the fourth pin of the second output terminal is electrically connected to the second ground terminal; or the second switching circuit includes a second switch and a second resistor, the control terminal of the second switch is electrically connected to the fourth pin of the second output terminal, the second resistor is arranged between the control terminal of the second switch and the first terminal of the second switch, the first terminal of the second switch is electrically connected to the second ground terminal, the second terminal of the second switch is electrically connected to the first node, and the third pin of the second output terminal is electrically connected to the second ground terminal. The first switching circuit includes a first switch and a first resistor, a control terminal of the first switch is electrically connected to the first node, the first resistor is arranged between the control terminal of the first switch and the first terminal of the first switch, the first terminal of the first switch is electrically connected to the second power supply, the second terminal of the first input terminal is electrically connected to the sending pin, the first terminal of the first input terminal is electrically connected to the second power supply, the second terminal of the first input terminal is electrically connected to the first node, the third terminal of the first output terminal is electrically connected to the receiving pin, and the fourth terminal of the first output terminal is electrically connected to the first ground terminal; or the first switching circuit includes a first switch and a first resistor, the control terminal of the first switch is electrically connected to the first node, the first resistor is arranged between the control terminal of the first switch and the first terminal of the first switch, the first terminal of the first switch is electrically connected to the second power supply, the second terminal of the first switch is electrically connected to the first pin of the first input terminal, the second pin of the first input terminal is electrically connected to the second ground terminal, the third terminal of the first output terminal is electrically connected to the receiving pin, and the fourth terminal of the first output terminal is electrically connected to the first ground terminal; the second switching circuit includes a second switch and a second resistor, the control terminal of the second switch is electrically connected to the fourth pin of the second output terminal, the second resistor is arranged between the control terminal of the second switch and the first terminal of the second switch, the first terminal of the second switch is electrically connected to the second ground terminal, the second terminal of the second switch is electrically connected to the first node, the third terminal of the second output terminal is electrically connected to the second power supply, the first pin of the second input terminal is electrically connected to the first power supply, and the second pin of the second input terminal is electrically connected to the sending pin.

[0015] By adding a first switch, the current flowing through the first input terminal is derived from the second power supply and is independent of the third communication signal, which facilitates stable conduction of the first photocoupler. Furthermore, when the first switch is a P-type FET, since the P-type FET is a voltage-driven device, the resistance of the first resistor can be increased to reduce the current flowing through the first resistor, while ensuring that the voltage across the first resistor can determine the conduction of the first switch, thereby reducing power consumption. By adding a second switch, the current flowing through the second output terminal is derived from the second power supply and is independent of the current at the first node, which facilitates stable conduction of the second photocoupler.

[0016] In one or more embodiments, the single bus communication circuit further includes: a third resistor, the third resistor being arranged between the second end of the first switch and the first pin of the first input end; and / or, a first diode, the anode of the first diode being electrically connected to the second pin of the first input end, and the cathode of the first diode being electrically connected to the second ground end; and / or, a fourth resistor, the fourth resistor being arranged between the third pin of the second output end and the second power supply.

[0017] In one or more embodiments, the first switch includes a P-type FET or a PNP-type transistor; and / or the second switch includes an N-type FET or an NPN-type transistor.

[0018] In one or more embodiments, the single bus communication circuit further includes: a unidirectional conductive element; the unidirectional conductive element is disposed between the first node and the second pin of the first input terminal; or the unidirectional conductive element is disposed between the first node and the control terminal of the first switch.

[0019] The unidirectional conductive element is cut off when a higher voltage exists on the first node. For example, the unidirectional conductive element is cut off when the first node is not electrically connected to the second control circuit but is electrically connected to a higher voltage. This helps to reduce the risk of damage to the first isolation element due to the higher voltage input to the first isolation element.

[0020] In one or more embodiments, the unidirectional conductive element includes: a second diode; the anode of the second diode is electrically connected to the second pin of the first input terminal, and the cathode of the second diode is electrically connected to the first node; or, the anode of the second diode is electrically connected to the control terminal of the first switch, and the cathode of the second diode is electrically connected to the first node.

[0021] In one or more embodiments, the single bus communication circuit further includes: a fifth resistor, a first end of the fifth resistor electrically connected to the first power supply, and a second end of the fifth resistor electrically connected to the third pin and the receiving pin of the first output terminal; and / or, a sixth resistor, a first end of the sixth resistor electrically connected to the first power supply, and a second end of the sixth resistor electrically connected to the first pin of the second input terminal; and / or, a seventh resistor, the seventh resistor is arranged between the second pin of the first input terminal and the first node, or the seventh resistor is arranged between the control end of the first switch and the first node.

[0022] In one or more embodiments, the single bus communication circuit further includes: an eighth resistor, a first end of the eighth resistor being electrically connected to the first node, and a second end of the eighth resistor being configured to be electrically connected to the second control circuit; and / or a transient voltage suppression diode being arranged between the first node and the second ground terminal.

[0023] The eighth resistor is configured as a thermistor with a positive temperature coefficient. When a large current flows through it, the eighth resistor heats up, increasing its impedance and acting as a current limiter, thereby reducing the risk of damage to the second isolation element. The transient voltage suppressor diode (TVS) can respond to sudden voltage changes in a very short time, clamping excessive voltage to a safe level, thereby protecting subsequent electronic components from damage. Furthermore, the simultaneous installation of the eighth resistor and the TVS diode ensures that if the TVS diode fails and shorts, the eighth resistor is triggered to act as a current limiter, thus preventing single-point failure.

[0024] In a second aspect, an embodiment of the present application provides a battery management system, including a discharge switch and a single bus communication circuit as in the first aspect; the discharge switch is configured to be located between the negative pole of the battery module and the second reference ground.

[0025] In one or more embodiments, the battery management system further includes: a charging switch; the charging switch is connected in series with the discharging switch, and the charging switch and the discharging switch are configured to be disposed between the negative electrode of the battery module and the second reference ground.

[0026] In a third aspect, an embodiment of the present application provides a battery pack, including a first connector, a wiring harness, a battery module and a battery management system as in the second aspect; the first connector is electrically connected to the battery management system through the wiring harness, and the battery module is electrically connected to the battery management system.

[0027] In a fourth aspect, an embodiment of the present application provides an electrical device, including a second connector, a second control circuit, a load and a battery pack as in the third aspect; the second connector is electrically connected to the first connector, and the second control circuit is electrically connected to the first control circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] One or more embodiments are exemplarily described by the figures in the accompanying drawings, which are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0029] Figure 1 This is a schematic diagram of the electrical equipment provided in the embodiment of the present application. Figure 1 ; Figure 2 This is a schematic diagram of the electrical equipment provided in the embodiment of the present application. Figure 2 ; Figure 3 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 1 ; Figure 4 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 2 ; Figure 5 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 3 ; Figure 6 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 4 ; Figure 7 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 5 ; Figure 8 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 6 ; Figure 9 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 7 ; Figure 10 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 8 ; Figure 11 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 9 ; Figure 12 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 10 ; Figure 13 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 10 one; Figure 14 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 10 two; Figure 15 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 10 three; Figure 16 This is a schematic diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 10 Four. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0031] It should be noted that, when an element is referred to as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0032] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0033] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the electrical equipment provided in the embodiment of the present application. Figure 1 As shown, the electric device 1 includes a battery pack 10 , a second connector 20 , a second control circuit 30 and a load 40 .

[0034] Load 40 includes electrical components such as motors, lights, speakers, and meters on electrical equipment 1. Electrical equipment 1 is a device that requires power from battery pack 10. Examples of these electrical equipment include unmanned aerial vehicles (UAVs), energy storage products, power tools, and electric vehicles (electric two-wheelers and electric three-wheelers).

[0035] The battery pack 10 includes a first connector 13, and the first connector 13 is provided with a plurality of terminals, such as Figure 1 The battery pack 10 shown has a positive output terminal P+, a signal terminal D1, and a negative output terminal P-. It will be appreciated that this embodiment shows only three terminals. In other embodiments, the first connector 13 may have other terminals, such as an indicator signal terminal for indicating that the first connector 13 and the second connector 20 are mated. In some embodiments, the first connector 13 and the second connector 20 are configured as aviation plugs.

[0036] The battery pack 10 also includes wiring harnesses, specifically a communication harness and a power harness. The communication harness is used for signal transmission; for example, the harness connected to the battery pack 10's signal terminal D1 is a communication harness. The power harness is used for power transmission; for example, the harness connected to the battery pack 10's positive output terminal P+ and negative output terminal P- is a power harness.

[0037] The battery pack 10 includes a battery management system 11 and a battery module 12. The battery module 12 consists of multiple cells connected in parallel, series, or hybrid mode to store and provide electrical energy. The hybrid mode includes both series and parallel connections. The battery management system (BMS) 11 is powered by the battery module 12 and manages the charging and / or discharging of the battery module 12. It also monitors, manages, and protects the performance and safety of the battery module 12.

[0038] The battery management system 11 includes a discharge switch K1 and a charge switch K2. The discharge switch K1 and the charge switch K2 are connected in series between the negative electrode B- and the negative output terminal P- of the battery module. In this embodiment, the discharge switch K1 and the charge switch K2 are both N-type FETs. In other embodiments, the discharge switch K1 and / or the charge switch K2 can be configured as other controllable switching elements.

[0039] The battery management system 11 also includes a first control circuit 111. The second connector 20 provided on the power-consuming device is connected to the first connector 13 provided on the battery pack to establish an electrical connection between the second control circuit 30 and the first control circuit 111. It is understood that the electrical connection in this application includes a communication connection. In this application, the first control circuit 111 and the second control circuit 30 are circuits with control functions. Data transmission is achieved between the battery pack 10 and the power-consuming device 1 by means of single bus communication or dual bus communication. Dual bus communication includes CAN bus communication, RS485 bus communication, etc. For the present application, the first control circuit 111 and the second control circuit 30 use a single bus communication to achieve data interaction between the battery pack 10 and the power-consuming device 1. Single bus communication, also known as one-line communication, is a communication data line connecting two communication devices. At a given moment, data can only be transmitted in one direction between the communication devices. For example, at the current moment, the first device sends data and the second device receives data. At the next moment, the second device sends data and the first device receives data. In some usage scenarios, the first control circuit 111 includes a microcontroller unit (MCU) and the second control circuit 30 includes an electronic control unit (ECU). For example, in a usage scenario where the battery pack is installed in an electric vehicle (power-consuming device), the second control circuit 30 is also called a vehicle controller.

[0040] Figure 1 The power consumption device 1 includes a battery pack 10. In other application scenarios, in order to expand power, the power consumption device 1 includes two or more battery packs 10. Figure 2As shown, the electric device 1 includes two battery packs 10, which are connected in parallel, also known as two battery packs 10 used in parallel. Figure 2 As shown, two battery packs 10 are connected in parallel to power a load 40 and communicate with a second control circuit 30. The positive output terminals P+ of the two battery packs 10 are short-circuited, the communication terminals D1 of the two battery packs 10 are short-circuited, and the negative output terminals P- of the two battery packs 10 are short-circuited. When two or more battery packs 10 are used in parallel, the first control circuits 111 of each battery pack 10 communicate with each other. One battery pack serves as the master battery pack, and the master battery pack's first control circuit 111 communicates with the second control circuit 30.

[0041] The applicant has discovered that for a battery pack in which the discharge switch is disposed between the negative electrode B- of the battery module and the negative output terminal P- of the battery pack: In scenarios where multiple such battery packs are used in parallel, on the one hand, when there is a voltage difference between the battery packs, when the discharge switch is closed to provide power to the load, if the load does not require high power, the high-voltage battery pack will power the load and may also charge the low-voltage battery pack, thereby forming a circulating current and causing unnecessary energy loss. If the voltage difference between the battery packs is large, the corresponding circulating current will also become larger. The large circulating current will impact the battery cells in the battery module and the switches installed on the battery management system, causing the battery cells and switches to heat up. When the circulating current is too large, it may damage the battery cells and cause the switches to break down and be unable to be turned off, thereby causing more serious risks (such as thermal runaway). On the other hand, for a battery pack with a discharge switch positioned between the negative electrode B- of the battery module and the negative output terminal P- of the battery pack, when communication between the battery pack and the power consumer utilizes a single-bus communication scheme, closing the discharge switch establishes single-bus communication between the battery pack and the power consumer, and opening the discharge switch disconnects single-bus communication between the battery pack and the power consumer. This is because the reference ground of the first control circuit 111 is the negative electrode B- of the battery module, while the corresponding reference ground of the second control circuit 30 is the negative output terminal P- of the battery pack. If the grounds of the first control circuit 111 and the second control circuit 30 are not connected together, electrically floating, a potential difference may exist between them. This potential difference can interfere with the interpretation of communication signals (e.g., incorrectly identifying high and low levels). Therefore, to ensure proper communication, B- and P- must be shorted to form a common reference potential, enabling accurate identification of the voltage difference between the transmitting and receiving ends.

[0042] Based on this, the applicant designed a single-bus communication circuit. For a solution where the discharge switch K1 is located between the negative electrode B- of the battery module and the negative output terminal P- of the battery pack, this single-bus communication circuit enables single-bus communication between the first control circuit 111 and the second control circuit 30 without closing the discharge switch K1. It is understandable that for a solution where the discharge switch K1 is located between the positive electrode B+ of the battery module and the positive output terminal P+ of the battery pack, single-bus communication between the battery pack and the power-consuming device can still be achieved through this single-bus communication circuit.

[0043] Please refer to Figure 3 , Figure 3 This is a block diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 3 As shown, the single bus communication circuit 110 includes a first control circuit 111 , a first power source V1 , a second power source V2 , a first isolation element U1 , and a second isolation element U2 .

[0044] The first power supply V1 is electrically connected to the first control circuit 111, and the second power supply V2 is configured to be electrically connected to the second control circuit 30. The first isolation element U1 and the second isolation element U2 are configured to be electrically connected to the second control circuit 30 at a first node P1. The first isolation element U1 is electrically connected to the first power supply V1, the second power supply V2, the first control circuit 111, and the first ground terminal, while the second isolation element U1 is electrically connected to the first power supply V1, the first control circuit 111, and the second ground terminal. The first isolation element U1 and the second isolation element U2 are elements used to achieve electrical isolation. It will be understood that the first ground terminal and the second ground terminal are two different reference grounds, and the first ground terminal is electrically connected to a first side of the first isolation element U1, and the second ground terminal is electrically connected to a second side of the first isolation element U1.

[0045] The following describes the principle of data interaction between the first control circuit 111 and the second control circuit 30 through the single bus communication circuit.

[0046] The first control circuit 111 sends data to the second control circuit 30 including: (1) The first control circuit 111 sends a high-level signal to the second control circuit 30. The high-level signal controls the second isolation element U2 to be turned off. The electrical connection between the second control circuit 30 and the second ground terminal is not established. The first node P1 is pulled up by the second power supply, thereby generating a high-level signal at the first node P1. The second control circuit 30 receives the high-level signal. Based on this, the first control circuit 111 sends a high-level signal to the outside, and the second control circuit 30 receives a high-level signal. (2) The first control circuit 111 sends a low-level signal to the second control circuit 30. The low-level signal controls the second isolation element U2 to open, and an electrical connection is established between the second control circuit 30 and the second ground terminal. The first node P1 is pulled down by the second ground terminal, thereby generating a low-level signal at the first node P1. The second control circuit 30 receives the low-level signal. Based on this, the first control circuit 111 sends a low-level signal to the outside, and the second control circuit 30 receives a low-level signal.

[0047] The second control circuit 30 sends data to the first control circuit 111, and the first control circuit 111 sends a first control signal to the second isolation element U2 to turn off the second isolation element U2, so as to prevent the on and off of the second isolation element U2 from affecting the communication between the second control circuit 30 and the first control circuit 111: (1) The second control circuit 30 sends a high-level signal to the first control circuit 111. The high-level signal controls the first isolation element U1 to turn off. The electrical connection between the first power supply V1 and the first ground terminal is not established. The first control circuit 111 is pulled up by the first power supply, thereby enabling the first control circuit 30 to receive the high-level signal. Based on this, the second control circuit 30 sends a high-level signal to the first control circuit 111, and the first control circuit 111 receives the high-level signal. (2) The second control circuit 30 sends a low-level signal to the first control circuit 111. The low-level control turns on the first isolation element U1, and an electrical connection is established between the first power supply V1 and the first ground terminal. The first control circuit 111 is pulled down by the first ground terminal, thereby enabling the first control circuit 30 to receive the low-level signal. Based on this, the second control circuit 30 sends a low-level signal to the first control circuit 111, and the first control circuit 111 receives the low-level signal.

[0048] The single-bus communication circuit designed in this application is no longer affected by the on / off state of the discharge switch when the battery pack and the power-consuming device transmit and interact data, which helps ensure stable communication between the battery pack and the power-consuming device. When the single-bus communication circuit is used in a battery parallel system (the system includes two or more battery packs connected in parallel), data transmission between battery packs and between battery packs and power-consuming devices can be achieved without controlling the closure of the discharge switch, thus avoiding the circulation problem caused by the closure of the discharge switch. In addition, when the power-consuming device transmits a signal to the battery pack, the pull-up and pull-down functions are implemented through the first power supply V1 and the first ground terminal, so that the first control circuit receives a signal with the same level as that sent by the power-consuming device. When the battery pack transmits a signal to the power-consuming device, the pull-up and pull-down functions are implemented through the second power supply and the second ground terminal, so that the second control circuit receives a signal with the same level as that sent by the battery pack. As such, the single-bus communication circuit of the present application does not need to adapt to the parameters of an external circuit (e.g., a circuit disposed within an electrical device). That is, regardless of whether the voltage used by the second control circuit 30 is the same as that of the single-bus communication circuit 110, communication between the first control circuit 111 and the second control circuit 30 can be achieved. This single-bus communication circuit 110 has strong adaptability and compatibility. Furthermore, the single-bus communication circuit 110 can be used for both negative control (where the discharge switch and the charge switch are disposed between the negative electrode B- of the battery module and the negative output terminal P- of the battery pack) and positive control (where the discharge switch and the charge switch are disposed between the positive electrode B+ of the battery module and the positive output terminal P+ of the battery pack), thereby enhancing the adaptability and compatibility of the single-bus communication circuit 110.

[0049] In one or more embodiments of the present application, the first control circuit 111 includes a receive pin RX and a transmit pin TX. A first power source V1 is electrically connected to the receive pin RX, which is electrically connected to the transmit pin TX via a second isolation element U2. The receive pin RX is used to receive external input signals, and the transmit pin TX is used to transmit external signals.

[0050] In one or more embodiments of the present application, the first ground terminal serves as a reference ground for the first power supply V1, and the second ground terminal serves as a reference ground for the second power supply V2. Thus, the first power supply V1 and the second power supply V2 are not directly electrically connected, which helps prevent current from flowing between the first power supply V1 and the second power supply V2, thereby providing better isolation and improving the stability and reliability of communication between the first control circuit 111 and the second control circuit 30.

[0051] In some embodiments, the voltage of the first power supply V1 and the voltage of the second power supply V2 have the same amplitude. For example, the voltage amplitude of the first power supply V1 is 3.3V, and the voltage amplitude of the second power supply V2 is also 3.3V. The second power supply V2 is obtained from the first power supply V1 via an isolated power supply chip. In addition, the isolated power supply chip is electrically connected to a first ground terminal and a second ground terminal, respectively, so that the first ground terminal serves as a reference ground for the first power supply V1 and the second ground terminal serves as a reference ground for the second power supply V2. The first ground terminal is electrically connected to the negative electrode B- of the battery module, and the second ground terminal is electrically connected to the negative output terminal P- of the battery pack.

[0052] In one or more embodiments of the present application, the single bus communication circuit 110 is further configured to: in response to the first control circuit 111 not communicating with the second control circuit 30 , the first control circuit 111 controls the second isolation element U2 to be turned off.

[0053] When the first control circuit 111 and the second control circuit 30 are not communicating, the first control circuit 111 controls the second isolation element U2 to be turned off. In this way, on the one hand, the electrical connection between the pull-up power supply provided in the electrical device and the second ground terminal is disconnected, and on the other hand, the electrical connection between the second power supply V2 and the second ground terminal is disconnected. At this time, there is no leakage path in the single bus communication circuit 110, and the power consumption is low.

[0054] In one or more embodiments of the present application, Figure 4 As shown, the first isolation element U1 includes a first photocoupler, and the second isolation element U2 includes a second photocoupler.

[0055] The first optocoupler includes a first input terminal and a first output terminal, the first pin of the first input terminal is electrically connected to the second power supply V2, the second pin of the first input terminal is electrically connected to the first node P1, the third pin of the first output terminal is electrically connected to the receiving pin RX, and the fourth pin of the first output terminal is electrically connected to the first ground terminal.

[0056] The second optocoupler includes a second input terminal and a second output terminal, the first pin of the second input terminal is electrically connected to the first power supply V1, the second pin of the second input terminal is electrically connected to the transmitting pin TX, the third pin of the second output terminal is electrically connected to the first node P1, and the fourth pin of the second output terminal is electrically connected to the second ground terminal.

[0057] When the transmit pin TX of the first control circuit 111 sends the first communication signal to the second optocoupler, if the first communication signal is a low-level signal, the light emitter of the second optocoupler is turned on, that is, the first pin and the second pin of the second input terminal are turned on, and the light receiver of the second optocoupler is turned on, that is, the third pin and the fourth pin of the second output terminal V are turned on. The first node P1 is electrically connected to the second ground terminal through the third pin and the fourth pin of the second output terminal. The signal of the first node P1 is a low-level signal. At this time, the second communication signal received by the second control circuit 30 is a low-level signal. If the first communication signal is a high-level signal, the light emitter of the second optocoupler is turned off, that is, the first pin and the second pin of the second input terminal are disconnected, and the light receiver of the second optocoupler is turned off, that is, the third pin and the fourth pin of the second output terminal are disconnected. The first node P1 is pulled up by the second power supply V2 through the light emitter of the first optocoupler, and the signal corresponding to the first node P1 is a high-level signal. At this time, the second communication signal received by the second control circuit 30 is a high-level signal.

[0058] Before the second control circuit 30 sends the third communication signal to the first control circuit 111, the transmit pin TX of the first control circuit 111 sends a first control signal (a high-level signal) to the second photocoupler, thereby turning off both the light emitter and the light receiver of the second photocoupler. This prevents the signal at the first node P1 from being interfered with by the second photocoupler. It is understood that if the second photocoupler is not turned off and is turned on, the first node P1 will be electrically connected to the second ground terminal via the light receiver of the second photocoupler, causing the signal at the first node P1 to remain at a low level. This will prevent the second control circuit 30 and the first control circuit 111 from communicating normally.

[0059] After the second photocoupler is turned off, when the second control circuit 30 sends the third communication signal to the first control circuit 111, if the third communication signal is a low-level signal, the light emitter of the first photocoupler is turned on, that is, the first pin of the first input terminal is conductively connected to the second pin, and the light receiver of the first photocoupler is turned on, that is, the third pin of the first output terminal is conductively connected to the fourth pin, and the receiving pin RX of the first control circuit 111 is electrically connected to the first ground terminal through the third pin and the fourth pin of the first output terminal. Accordingly, the fourth communication signal received by the receiving pin RX of the first control circuit 111 is a low-level signal. If the third communication signal is a high-level signal, the light emitter of the first photocoupler is turned off, the light receiver of the first photocoupler is turned off, and the receiving pin RX of the first control circuit 111 is electrically connected to the first power supply V1. Accordingly, the fourth communication signal received by the receiving pin RX of the first control circuit 111 is a high-level signal.

[0060] In the above embodiment, the first isolation element U1 and the second isolation element U2 are both optocouplers. In other embodiments, the first isolation element U1 and the second isolation element U2 may also be other elements that achieve electrical isolation, such as optical MOS.

[0061] In some embodiments, as Figure 5 As shown, the single-bus communication circuit 110 further includes a unidirectional conductive element D2. The unidirectional conductive element D2 is disposed between the first node P1 and the second pin of the first input terminal. The unidirectional conductive element D2 is configured to be cut off when a higher voltage is present at the first node P1, thereby limiting the unidirectional flow of current from the second power source V2 to the first node P1. For example, the unidirectional conductive element D2 is cut off when the first node P1 is not electrically connected to the second control circuit 30 but is instead electrically connected to a higher voltage. This helps reduce the risk of damage to the first isolation element U1 due to the higher voltage input.

[0062] In some embodiments, as Figure 6 As shown, the unidirectional conductive element D2 includes a second diode.

[0063] The anode of the second diode is electrically connected to the second pin of the first input terminal, and the cathode of the second diode is electrically connected to the first node P1. When a higher voltage exists on the first node P1 and the voltage is greater than the voltage of the cathode of the second diode, the reverse direction of the second diode is cut off.

[0064] In some embodiments, as Figure 7 As shown, the single bus communication circuit 110 further includes a fifth resistor R5. A first end of the fifth resistor R5 is electrically connected to the first power source V1, and a second end of the fifth resistor R5 is electrically connected to the third pin of the first output terminal and the receiving pin RX. The fifth resistor R5 is a pull-up resistor.

[0065] In some embodiments, the single-bus communication circuit 110 further includes a sixth resistor R6. A first end of the sixth resistor R6 is electrically connected to the first power source V1, and a second end of the sixth resistor R6 is electrically connected to the first pin of the second input terminal. The sixth resistor R6 is a current-limiting resistor to prevent a short circuit between the first power source V1 and the ground terminal within the first control circuit 111 when the second optocoupler is turned on.

[0066] In some embodiments, the single bus communication circuit 110 further includes a seventh resistor R7 . The seventh resistor R7 is disposed between the second pin of the first input terminal and the first node P1 . The seventh resistor R7 is a current limiting resistor.

[0067] In some embodiments, the single-bus communication circuit 110 further includes an eighth resistor R8. A first end of the eighth resistor R8 is electrically connected to the first node P1, and a second end of the eighth resistor R8 is configured to be electrically connected to the second control circuit 30. In one specific embodiment, the eighth resistor R8 is a positive temperature coefficient (PTC) thermistor. When a large current flows through the eighth resistor R8, the eighth resistor R8 generates heat, increasing its impedance and thus acting as a current limiter to reduce the risk of damage to the second isolation element U2.

[0068] In some embodiments, the single-bus communication circuit 110 further includes a transient voltage suppressor diode Z1. The transient voltage suppressor diode Z1 is disposed between the first node P1 and the second ground terminal. The transient voltage suppressor diode (TVS diode) Z1 can respond to sudden voltage changes in a very short time, clamping excessive voltage to a safe level, thereby protecting subsequent electronic components from damage. Furthermore, the simultaneous provision of an eighth resistor R8 and the transient voltage suppressor diode Z1 ensures that, if the transient voltage suppressor diode Z1 fails and short-circuits, the eighth resistor R8 is triggered to limit current, thereby preventing single-point failure.

[0069] Please refer to Figure 8 , Figure 8 This is another block diagram of the single bus communication circuit provided in the embodiment of the present application. Figure 8 As shown, the single bus communication circuit 110 includes a first control circuit 111 , a first power supply V1 , a second power supply V2 , a first isolation element U1 , a second isolation element U2 , and a first switch circuit 112 . Figure 8 The structure of Figure 3 The first control circuit 111, the first power supply V1, the second power supply V2, the first isolation element U1, and the second isolation element U2 are specifically implemented in the same manner as shown in FIG. Figure 3 same.

[0070] like Figure 8 As shown, the single bus communication circuit 110 further includes a first switch circuit 112 , which is electrically connected to the first node P1 , the second power supply V2 , and the first isolation element U1 , wherein the first isolation element U1 is electrically connected to the second power supply V2 through the first switch circuit 112 .

[0071] The first switch circuit 112 and the first isolation element U1 are configured such that, in response to the second control circuit 30 sending a third communication signal to the first switch circuit 112, the first switch circuit 112 forms a path or a path, and the first isolation element U1 is turned on or off. As a result, the first control circuit 111 receives a fourth communication signal having the same level as the third communication signal.

[0072] When using Figures 3 to 7 In any of the circuit structures shown, if there is a voltage difference between the low level output by the second control circuit and the second ground terminal, the current flowing from the second power supply V2 through the first isolation element U1 and toward the first node P1 will decrease, thereby causing the first isolation element U1 to be unable to stably conduct.

[0073] Based on this, Figure 8 As shown, a first switch circuit 112 is further added, so that the current flowing from the second power supply V2 through the first switch circuit 112 and to the first isolation element U1 is obtained according to the second power supply V2, which is conducive to achieving stable conduction of the first isolation element U1.

[0074] It is understandable that Figure 8 The circuit structure shown implements the process of the first control circuit 111 sending the first communication signal and the second control circuit 30 receiving the second communication signal, which is the same as the content recorded above, and, except for the beneficial effects brought about by adding the first switching circuit 112, other beneficial effects are the same as the beneficial effects recorded above.

[0075] In some embodiments, as Figure 9 As shown, the first switch circuit 112 includes a first switch Q1 and a first resistor R1. The first isolation element U1 includes a first photocoupler, and the second isolation element U2 includes a second photocoupler. The first photocoupler includes a first input terminal and a first output terminal, and the second photocoupler includes a second input terminal and a second output terminal.

[0076] A control end of the first switch Q1 is electrically connected to a first node P1. A first resistor R1 is disposed between the control end of the first switch Q1 and the first end of the first switch Q1. The first end of the first switch Q1 is electrically connected to a second power supply V2. The second end of the first switch Q1 is electrically connected to a first pin of the first input end, a second pin of the first input end is electrically connected to a second ground end, a third pin of the first output end is electrically connected to a receive pin RX, a fourth pin of the first output end is electrically connected to the first ground end, a first pin of the second input end is electrically connected to the first power supply V1, a second pin of the second input end is electrically connected to a transmit pin TX, a third pin of the second output end is electrically connected to the first node P1, and a fourth pin of the second output end is electrically connected to the second ground end.

[0077] Before the second control circuit 30 sends the third communication signal to the first control circuit 111, the sending pin TX of the first control circuit 111 sends the first control signal (a high-level signal) to the second photocoupler, so that the light emitter and the light receiver of the second photocoupler are both turned off, and the signal of the first node P1 is not interfered with by the second photocoupler.

[0078] After the second optocoupler is turned off, when the second control circuit 30 sends the third communication signal to the first control circuit 111, if the third communication signal is a low-level signal, the first switch tube Q1 is turned on, the second power supply V2 is electrically connected to the first pin of the first input terminal through the first switch tube Q1, the light emitter of the first optocoupler is turned on, the light receiver of the first optocoupler is turned on, and the receiving pin RX of the first control circuit 111 is electrically connected to the first ground terminal via the third pin and the fourth pin of the first output terminal, corresponding to the fourth communication signal received by the receiving pin RX of the first control circuit 111 being a low-level signal. If the third communication signal is a high-level signal, the first switch tube Q1 is turned off, the electrical connection between the second power supply V2 and the first optocoupler is disconnected, the light emitter of the first optocoupler is turned off, the light receiver of the first optocoupler is turned off, and the receiving pin RX of the first control circuit 111 is electrically connected to the first power supply V1. Accordingly, the fourth communication signal received by the receiving pin RX of the first control circuit 111 is a high-level signal.

[0079] It is understandable that Figure 9 The circuit structure shown implements the process of the first control circuit 111 sending the first communication signal and the second control circuit 30 receiving the second communication signal in the same manner as described above. In addition, except for the beneficial effects brought about by the addition of the first switch circuit 112, other beneficial effects are the same as those described above.

[0080] exist Figures 4 to 7 In any of the circuit structures shown, to ensure that the first photocoupler is stably turned on, it is necessary to match the current flowing through the first input terminal with the current that turns on the first output terminal to ensure that the first photocoupler is stably turned on. Figure 9 As shown, by adding the first switch circuit 112, the current flowing through the first input terminal is obtained according to the second power supply V2, which is conducive to achieving stable conduction of the first photoelectric coupler.

[0081] In addition, Figure 4 In the structure shown, in order to ensure that the first photocoupler is stably turned on, the current flowing through the first input terminal needs to be set to be large, which will result in large power consumption. Figure 9In the structure shown, since the P-type FET is a voltage-driven switch, on the premise of ensuring that the voltage across the first resistor R1 drives the first switch Q1 to turn on, the resistance value of the first resistor R1 can be appropriately increased to reduce the current flowing through the first resistor R1, thereby reducing power consumption.

[0082] In this embodiment, the first switch Q1 is a P-type FET, where the control terminal of the first switch Q1 is the gate of the P-type FET, the first terminal of the first switch Q1 is the source of the P-type FET, and the second terminal of the first switch Q1 is the drain of the P-type FET. In other embodiments, the first switch Q1 is a PNP transistor, where the control terminal of the first switch Q1 is the base of the PNP transistor, the first terminal of the first switch Q1 is the emitter of the PNP transistor, and the second terminal of the first switch Q1 is the collector of the PNP transistor.

[0083] In some embodiments, as Figure 10 As shown, the single bus communication circuit 110 includes at least one of a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first diode D1, a unidirectional conductive element D2 and a transient voltage suppression diode Z1. Figure 10 Take the single bus communication circuit 110 as an example, which includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first diode D1, a unidirectional conductive element D2 and a transient voltage suppressor diode Z1. Figure 10 The specific implementation of the fifth resistor R5, the sixth resistor R6, the eighth resistor R8 and the transient voltage suppression diode Z1 shown in FIG. Figure 7 The structures shown are the same.

[0084] like Figure 10 As shown, the unidirectional conductive element D2 is disposed between the first node P1 and the control terminal of the first switch Q1. Specifically, the anode of the second diode is electrically connected to the control terminal of the first switch Q1, and the cathode of the second diode is electrically connected to the first node P1. The seventh resistor R7 is disposed between the control terminal of the first switch Q1 and the first node P1. The third resistor R3 is disposed between the second terminal of the first switch Q1 and the first pin of the first input terminal. The anode of the first diode D1 is electrically connected to the second pin of the first input terminal, and the cathode of the first diode D1 is electrically connected to the second ground terminal.

[0085] The functions of the unidirectional conductive element D2 and the seventh resistor R7 are similar to Figure 4 The structure shown is the same and will not be described again here. The third resistor R3 is a current limiting resistor.

[0086] Please refer to Figure 11 , Figure 11 This is another block diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 11As shown, the single bus communication circuit 110 includes a first control circuit 111 , a first power supply V1 , a second power supply V2 , a first isolation element U1 , a second isolation element U2 , and a second switch circuit 113 . Figure 8 The structure of Figure 3 The specific implementation of the first control circuit 111, the first power supply V1, the second power supply V2, and the first isolation element U1 is the same as that of the first control circuit 111. Figure 3 same.

[0087] like Figure 11 As shown, the single bus communication circuit 110 also includes a second switch circuit 113, which is electrically connected to the first node P1, the second isolation element U2 and the second ground terminal. The second isolation element U2 is also electrically connected to the second power supply V2, wherein the second isolation element U2 is electrically connected to the first node P1 through the second switch circuit 113.

[0088] The second switch circuit 113 and the second isolation element U2 are configured such that, in response to the first control circuit 111 sending a first communication signal to the second isolation element U2, the second isolation element U2 is turned on or off, and the second switch circuit 113 is connected or disconnected. Subsequently, a second communication signal having the same level as the first communication signal is generated at the first node P1, and the second control circuit 30 receives the second communication signal.

[0089] When using Figures 3 to 7 In any of the circuit structures shown in FIG, the current flowing from the first node P1 through the second isolation element U2 and to the second ground terminal is determined by the current flowing from the second control circuit 30 to the first node P1. If a pull-up power supply (for example, a pull-up power supply provided in an electrical device, which can output a voltage of 3.3V or 5V) exists between the second control circuit 30 and the first node P1, the current flowing from the second control circuit 30 to the first node P1 may increase, and the current flowing from the first node P1 through the second isolation element U2 and to the second ground terminal may increase, thereby causing the second isolation element U2 to be unable to stably conduct. Based on this, as Figure 11 As shown, a second switch circuit 113 is further added, so that the current flowing from the second power supply V2 through the second isolation element U2 and to the second switch circuit 113 is obtained according to the second power supply V2, which is conducive to achieving stable conduction of the second isolation element U2.

[0090] It is understandable that Figure 11 The structure shown implements the process of the second control circuit 30 sending the third communication signal and the first control circuit 111 receiving the fourth communication signal, which is the same as the content recorded above. In addition, except for the beneficial effects brought by adding the second switching circuit 113, other beneficial effects are the same as the content recorded above.

[0091] In some embodiments, as Figure 12 As shown, the second switch circuit 113 includes a second switch Q2 and a second resistor R2. The first isolation element U1 includes a first photocoupler, and the second isolation element U2 includes a second photocoupler. The first photocoupler includes a first input terminal and a first output terminal, and the second photocoupler includes a second input terminal and a second output terminal.

[0092] The second switch circuit 113 includes a second switch Q2 and a second resistor R2. The control terminal of the second switch Q2 is electrically connected to the fourth pin of the second output terminal. The second resistor R2 is arranged between the control terminal of the second switch Q2 and the first terminal of the second switch Q2. The first terminal of the second switch Q2 is electrically connected to the second ground terminal. The second terminal of the second switch Q2 is electrically connected to the first node P1. The third pin of the second output terminal is electrically connected to the second power supply V2. The first pin of the second input terminal is electrically connected to the first power supply V1. The second pin of the second input terminal is electrically connected to the transmit pin TX. The first pin of the first input terminal is electrically connected to the second power supply V2. The second pin of the first input terminal is electrically connected to the first node P1. The third pin of the first output terminal is electrically connected to the receive pin RX. The fourth pin of the first output terminal is electrically connected to the first ground terminal.

[0093] When the transmit pin TX of the first control circuit 111 transmits a first communication signal to the second optocoupler, if the first communication signal is a low-level signal, the light emitter of the second optocoupler is turned on, and the light receiver of the second optocoupler is turned on. The second power supply V2 is electrically connected to the control terminal of the second switch Q2 via the second optocoupler, turning on the second switch Q2. The first node P1 is electrically connected to the first ground terminal via the second switch Q2. Accordingly, the signal at the first node P1 is a low-level signal, i.e., the second communication signal is a low-level signal at this time. If the first communication signal is a high-level signal, the light emitter of the second optocoupler is turned off, the light receiver of the second optocoupler is turned off, the electrical connection between the second power supply V2 and the control terminal of the second switch Q2 is disconnected, the second switch Q2 is turned off, and the first node P1 is pulled up by the second power supply V2 via the light emitter of the first optocoupler. Accordingly, the signal at the first node P1 is a high-level signal, i.e., the second communication signal is a high-level signal at this time. The second communication signal is received by the second control circuit 30, thus completing the process of the first control circuit 111 sending the signal and the second control circuit 30 receiving the signal.

[0094] It is understandable that Figure 12 The structure shown implements the process of the second control circuit 30 sending the third communication signal and the first control circuit 111 receiving the fourth communication signal, which is the same as the content recorded above. In addition, except for the beneficial effects brought by adding the second switching circuit 113, other beneficial effects are the same as the content recorded above.

[0095] In addition, Figures 4 to 7In any of the circuit structures shown in , to ensure that the second photocoupler is stably turned on, it is necessary to match the current flowing through the second input terminal with the current that turns on the second output terminal to ensure that the second photocoupler is stably turned on. Figure 12 As shown, by adding the second switch circuit 113, the current flowing through the second output terminal is obtained according to the second power supply V2, which is conducive to achieving stable conduction of the second photoelectric coupler.

[0096] In this embodiment, the second switch Q2 is an N-type FET, where the control terminal of the second switch Q2 is the gate of the N-type FET, the first terminal of the second switch Q2 is the source of the N-type FET, and the second terminal of the second switch Q2 is the drain of the N-type FET. In other embodiments, the second switch Q2 is an NPN transistor, where the control terminal of the second switch Q2 is the base of the NPN transistor, the first terminal of the second switch Q2 is the emitter of the NPN transistor, and the second terminal of the second switch Q2 is the collector of the NPN transistor.

[0097] In some embodiments, as Figure 13 As shown, the single bus communication circuit 110 includes at least one of a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a unidirectional conductive element D2, and a transient voltage suppressor diode Z1. Figure 13 Take the single bus communication circuit 110 as an example, which includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a unidirectional conductive element D2 and a transient voltage suppressor diode Z1. Figure 13 The specific implementation of the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the unidirectional conductive element D2 and the transient voltage suppression diode Z1 is shown in FIG. Figure 7 The structures shown are the same.

[0098] like Figure 13 As shown, the fourth resistor R4 is provided between the third pin of the second output terminal and the second power supply V2. The fourth resistor R4 is a current limiting resistor.

[0099] Please refer to Figure 14 , Figure 14 This is another block diagram of a single bus communication circuit provided in an embodiment of the present application. Figure 14 As shown, the single bus communication circuit 110 includes a first control circuit 111 , a first power supply V1 , a second power supply V2 , a first isolation element U1 , a second isolation element U2 , a first switch circuit 112 , and a second switch circuit 113 . Figure 14 The structure of Figure 3The structure shown in FIG1 is obtained by adding the first switch circuit 112 and the second switch circuit 113. The specific implementation of the first control circuit 111, the first power supply V1 and the second power supply V2 is the same as that of FIG1. Figure 3 The specific implementation of the first isolation element U1 and the first switch circuit 112 is the same as Figure 8 The specific implementation of the second isolation element U2 and the second switch circuit 113 is the same as Figure 11 same.

[0100] Reference Figure 9 and Figure 12 The circuit structure shown in the figure can be obtained as follows Figure 15 The circuit structure shown, Figure 15 The working principle and beneficial effects achieved can be referred to Figure 9 and Figure 12 Description.

[0101] Reference Figure 10 and Figure 13 The circuit structure shown in the figure can be obtained as follows Figure 16 The circuit structure shown, Figure 16 The working principle and beneficial effects achieved can be referred to Figure 10 and Figure 13 Description.

[0102] The present invention also provides a battery management system, which includes a discharge switch and the single bus communication circuit 110 in any embodiment of the present invention. The discharge switch is configured to be disposed between the negative electrode of the battery module and the negative output terminal of the battery pack.

[0103] In some embodiments, the battery management system further includes a charging switch connected in series with the discharging switch, and the charging switch and the discharging switch are configured to be disposed between the negative electrode of the battery module and the negative output terminal of the battery pack.

[0104] The present application also provides a battery pack, comprising a first connector, a wiring harness, a battery module, and a battery management system according to any embodiment of the present application. The first connector is electrically connected to the battery management system via the wiring harness, and the battery module is electrically connected to the battery management system.

[0105] An embodiment of the present application also provides an electrical device, which includes a second connector, a second control circuit, a load and a battery pack in any embodiment of the present application, the second connector is electrically connected to the first connector, and the second control circuit is electrically connected to the first control circuit.

[0106] The above description is merely an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0107] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, and the steps may be implemented in any order. A person skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some of the technical features may be replaced by equivalents. However, such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single bus communication circuit, configured to be electrically connected to a second control circuit, characterized in that: The single bus communication circuit comprises: a first control circuit; a first power supply, electrically connected to the first control circuit; a second power supply configured to be electrically connected to the second control circuit; a first isolation element and a second isolation element, wherein the first isolation element and the second isolation element are configured to be electrically connected to the second control circuit at a first node; The first isolation element is electrically connected to the first power supply, the second power supply, the first control circuit, and a first ground terminal, and the second isolation element is electrically connected to the first power supply, the first control circuit, and a second ground terminal; The single bus communication circuit is configured as follows: In response to the first control circuit sending a first communication signal to the second isolation element, the second isolation element is turned on or off, a second communication signal having the same level as the first communication signal is generated at the first node, and the second control circuit receives the second communication signal; In response to the first control circuit sending a first control signal to the second isolation element, the second isolation element is turned off. In response to the second control circuit sending a third communication signal to the first isolation element, the first isolation element is turned on or off. The first control circuit receives a fourth communication signal with the same level as the third communication signal.

2. The single bus communication circuit according to claim 1, characterized in that: The single bus communication circuit is further configured to: in response to the first control circuit and the second control circuit not communicating with each other, the first control circuit controls the second isolation element to be turned off.

3. The single bus communication circuit according to claim 1 or 2, characterized in that: The first control circuit includes a receiving pin and a transmitting pin; The first power supply is electrically connected to the receiving pin, and the first power supply is electrically connected to the transmitting pin through the second isolation element.

4. The single bus communication circuit according to any one of claims 1 to 3, characterized in that: The first ground terminal serves as a reference ground for the first power supply, and the second ground terminal serves as a reference ground for the second power supply.

5. The single bus communication circuit according to claim 3 or 4, characterized in that: The first isolation element includes a first photocoupler, and the second isolation element includes a second photocoupler; The first optocoupler includes a first input terminal and a first output terminal, a first pin of the first input terminal is electrically connected to the second power supply, a second pin of the first input terminal is electrically connected to the first node, a third pin of the first output terminal is electrically connected to the receiving pin, and a fourth pin of the first output terminal is electrically connected to the first ground terminal; The second optocoupler includes a second input terminal and a second output terminal, the first pin of the second input terminal is electrically connected to the first power supply, the second pin of the second input terminal is electrically connected to the sending pin, the third pin of the second output terminal is electrically connected to the first node, and the fourth pin of the second output terminal is electrically connected to the second ground terminal.

6. The single bus communication circuit according to claim 3 or 4, characterized in that: The single bus communication circuit further includes: a first switch circuit electrically connecting the first node, the second power supply, and the first isolation element; The first switch circuit and the first isolation element are configured such that: in response to the second control circuit sending the third communication signal to the first switch circuit, the first switch circuit forms a path or a path, and the first isolation element is turned on or off; and / or, a second switch circuit electrically connecting the first node, the second isolation element and the second ground terminal; The second isolation element is also electrically connected to the second power supply, The second switch circuit and the second isolation element are configured such that: in response to the first control circuit sending a first communication signal to the second isolation element, the second isolation element is turned on or off, and the second switch circuit forms a circuit or an open circuit.

7. The single bus communication circuit according to claim 6, characterized in that: The first isolation element includes a first photocoupler, and the first photocoupler includes a first input terminal and a first output terminal; The second isolation element includes a second photocoupler, and the second photocoupler includes a second input terminal and a second output terminal; The first switch circuit includes a first switch and a first resistor, wherein a control end of the first switch is electrically connected to the first node, the first resistor is arranged between the control end of the first switch and the first end of the first switch, the first end of the first switch is electrically connected to the second power supply, and the second end of the first switch is electrically connected to the first pin of the first input end. The second pin of the first input terminal is electrically connected to the second ground terminal, the third pin of the first output terminal is electrically connected to the receiving pin, and the fourth pin of the first output terminal is electrically connected to the first ground terminal. The first pin of the second input terminal is electrically connected to the first power supply, the second pin of the second input terminal is electrically connected to the sending pin, the third pin of the second output terminal is electrically connected to the first node, and the fourth pin of the second output terminal is electrically connected to the second ground terminal; or The second switch circuit includes a second switch and a second resistor, wherein the control end of the second switch is electrically connected to the fourth pin of the second output end, the second resistor is arranged between the control end of the second switch and the first end of the second switch, the first end of the second switch is electrically connected to the second ground end, and the second end of the second switch is electrically connected to the first node. The third pin of the second output terminal is electrically connected to the second power supply, the first pin of the second input terminal is electrically connected to the first power supply, and the second pin of the second input terminal is electrically connected to the sending pin. The first pin of the first input terminal is electrically connected to the second power supply, the second pin of the first input terminal is electrically connected to the first node, the third pin of the first output terminal is electrically connected to the receiving pin, and the fourth pin of the first output terminal is electrically connected to the first ground terminal; or The first switch circuit includes a first switch and a first resistor, wherein a control end of the first switch is electrically connected to the first node, the first resistor is arranged between the control end of the first switch and the first end of the first switch, the first end of the first switch is electrically connected to the second power supply, and the second end of the first switch is electrically connected to the first pin of the first input end. The second pin of the first input terminal is electrically connected to the second ground terminal, the third pin of the first output terminal is electrically connected to the receiving pin, and the fourth pin of the first output terminal is electrically connected to the first ground terminal. The second switch circuit includes a second switch and a second resistor, wherein the control end of the second switch is electrically connected to the fourth pin of the second output end, the second resistor is arranged between the control end of the second switch and the first end of the second switch, the first end of the second switch is electrically connected to the second ground end, and the second end of the second switch is electrically connected to the first node. The third pin of the second output end is electrically connected to the second power supply, the first pin of the second input end is electrically connected to the first power supply, and the second pin of the second input end is electrically connected to the sending pin.

8. The single bus communication circuit according to claim 7, characterized in that: The single bus communication circuit further includes: a third resistor, the third resistor being provided between the second end of the first switch and the first pin of the first input end; and / or, a first diode, wherein an anode of the first diode is electrically connected to the second pin of the first input terminal, and a cathode of the first diode is electrically connected to the second ground terminal; and / or, A fourth resistor is provided between the third pin of the second output end and the second power supply.

9. The single bus communication circuit according to claim 7 or 8, characterized in that: The first switch includes a P-type FET or a PNP-type transistor; and / or, The second switch includes an N-type FET or an NPN-type transistor.

10. The single bus communication circuit according to any one of claims 5, 7 to 9, characterized in that: Also includes: One-way conductive element; The unidirectional conductive element is provided between the first node and the second pin of the first input terminal; or, The unidirectional conductive element is arranged between the first node and the control end of the first switch.

11. The single bus communication circuit according to claim 10, characterized in that: The unidirectional conductive element includes: a second diode; The anode of the second diode is electrically connected to the second pin of the first input terminal, and the cathode of the second diode is electrically connected to the first node; or, An anode of the second diode is electrically connected to the control end of the first switch, and a cathode of the second diode is electrically connected to the first node.

12. The single bus communication circuit according to any one of claims 5, 7 to 11, characterized in that: Also includes: a fifth resistor, wherein a first end of the fifth resistor is electrically connected to the first power supply, and a second end of the fifth resistor is electrically connected to the third pin of the first output terminal and the receiving pin; and / or, a sixth resistor, wherein a first end of the sixth resistor is electrically connected to the first power supply, and a second end of the sixth resistor is electrically connected to the first pin of the second input terminal; and / or, A seventh resistor is provided between the second pin of the first input terminal and the first node, or the seventh resistor is provided between the control terminal of the first switch and the first node.

13. The single bus communication circuit according to any one of claims 1 to 12, characterized in that: Also includes: an eighth resistor, a first end of the eighth resistor being electrically connected to the first node, and a second end of the eighth resistor being configured to be electrically connected to the second control circuit; and / or, A transient voltage suppression diode is provided between the first node and the second ground terminal.

14. A battery management system, characterized in that: comprising a discharge switch and a single bus communication circuit according to any one of claims 1 to 13; The discharge switch is configured to be disposed between the negative electrode of the battery module and the second reference ground.

15. The battery management system according to claim 14, characterized in that: Also includes: Charging switch; The charging switch and the discharging switch are connected in series, and the charging switch and the discharging switch are configured to be disposed between the negative electrode of the battery module and the second reference ground.

16. A battery pack, characterized in that: comprising a first connector, a wiring harness, a battery module, and a battery management system as claimed in claim 14 or 15; The first connector is electrically connected to the battery management system through the wiring harness, and the battery module is electrically connected to the battery management system.

17. An electrical device, characterized in that: comprising a second connector, a second control circuit, a load, and the battery pack as claimed in claim 16; The second connector is electrically connected to the first connector, and the second control circuit is electrically connected to the first control circuit.

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