Protection circuit, battery and electronic equipment

Abstract

The invention provides a protection circuit, a battery and electronic equipment, and relates to the technical field of electronic circuits, and the circuit is structurally characterized in that the first ends of a first safety device and a second safety device are connected with a protected object; the first end of the first switch is connected with the second end of the first safety device, and the second end is grounded; the first end of the second switch is connected with the second end of the second safety device, and the second end is grounded; the first end of the third switch is connected with the three ends of the second safety device, the first end of the fourth switch is connected with the second end of the third switch, and the second end is connected with the positive port; the switch controller is used for controlling the first switch to be switched on when it is judged that protection needs to be provided for the protected object, controlling the third switch to be switched on after the fault of the protected object is eliminated, and continuing to provide protection for the protected object after the protection circuit completes one-time protection action and automatically recovers, so that the protected object continues to work. And the use efficiency of the protected object is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a protection circuit, a battery and an electronic device. Background Art

[0002] Lithium battery packs have been widely used in various consumer electronic products due to their high specific capacity and stability. To ensure user safety, protection circuits should be designed for the cells to form a battery pack to prevent the cells from burning or exploding due to reverse connection, overheating, etc. The current common protection solutions have problems such as short service life and irreversibility.

[0003] The mainstream battery protection board in the battery pack is composed of two-stage protection circuits in series. The first-level protection IC control unit controls the opening and closing of the charge and discharge NMOS (Negative channel-Metal-Oxide-Semiconductor) to perform recoverable protection actions. To avoid failure of NMOS, the second-level protection unit controls the three-terminal fuse to perform irreversible protection actions, that is, once the fuse blows, the battery pack cannot be used any more.

[0004] It can be seen that in the existing technology, in order to avoid the failure of the primary protection NMOS on the protection board, the conventional battery protection circuit generally uses a disposable fuse as the key component of the secondary protection, that is, when overtemperature or overcurrent occurs, the secondary protection circuit actively blows the disposable fuse to disconnect the battery cell from the load or charger. If the secondary protection mechanism is triggered by only occasional high temperature in the environment or the wrong charger is used, causing the disposable fuse to blow, then when the working environment is restored, the battery pack still cannot be used, greatly reducing the efficiency of the battery pack.

[0005] In some other battery protection circuits, as shown in the patent with publication number CN119340929A, NMOS tubes are used in the secondary protection instead of disposable fuses. The disadvantage of this solution is that the NMOS in the secondary protection may cause common cause failure with the NMOS tube in the primary protection circuit under high temperature and high current conditions, increasing the probability of battery explosion or combustion. Summary of the invention

[0006] In view of this, embodiments of the present invention provide a protection circuit, a battery, and an electronic device to improve the use efficiency of a protected object.

[0007] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0008] A protection circuit, comprising:

[0009] A first fuse device, wherein a first end of the first fuse device is connected to a first end of a protected object;

[0010] a second fuse device, wherein a first end of the second fuse device is connected to a first end of a protected object;

[0011] A first switch, wherein a first end of the first switch is connected to a second end of the first fuse, and a second end of the first switch is grounded;

[0012] a second switch, wherein a first end of the second switch is connected to a second end of the second fuse, and a second end of the second switch is grounded;

[0013] a third switch, wherein a first end of the third switch is connected to a third end of the second fuse;

[0014] a fourth switch, wherein a first end of the fourth switch is connected to the second end of the third switch and the third end of the first fuse device, and a second end of the fourth switch is connected to the positive electrode port;

[0015] The switch controller is used to control the first switch to be turned on and the fourth switch to be turned off when it is determined that protection is needed for the protected object, and to determine whether the fault of the protected object is eliminated. After the fault of the protected object is eliminated, the third switch and the fourth switch are controlled to be turned on, and when it is determined again that protection is needed for the protected object, the second switch is controlled to be turned on and the third switch and the fourth switch are controlled to be turned off.

[0016] Optionally, in the above protection circuit, the switch controller includes:

[0017] Primary protection IC unit, secondary protection IC unit and auxiliary protection IC unit;

[0018] The output end of the secondary protection IC unit is connected to the control end of the first switch, and the secondary protection IC unit is used to control the first switch to be turned on when it is determined that protection needs to be provided to the protected object;

[0019] The first output end of the auxiliary protection IC unit is connected to the control end of the second switch, and the second output end of the auxiliary protection IC unit is connected to the control end of the third switch. The auxiliary protection IC unit is used to determine whether the fault of the protected object is eliminated after the secondary protection IC unit controls the first switch to be turned on, and if the fault is eliminated, control the third switch to be turned on;

[0020] The first output end of the first-level protection IC unit is connected to the control end of the fourth switch. The first-level protection IC unit is used to control the fourth switch to be disconnected when the second-level protection IC unit controls the first switch to be turned on, control the fourth switch to be turned on when the auxiliary protection IC unit controls the third switch to be turned on, and control the fourth switch to be turned off when the auxiliary protection IC unit controls the second switch to be turned on.

[0021] Optionally, in the above protection circuit, the determining whether the fault of the protected object is eliminated includes:

[0022] The state information of the protected object is obtained, and it is determined whether the fault of the protected object is eliminated based on the state information, wherein the state information includes at least one data item of voltage, current and temperature.

[0023] Optionally, in the above protection circuit, the switch controller is further used for:

[0024] Acquire and send the status information of the protected object to a display unit;

[0025] When the first switch is controlled to be turned on, a first prompt message is generated and sent to the display unit. When the second switch is controlled to be turned on, a second prompt message is generated and sent to the display unit. The first prompt message is used to indicate that the first fuse device is worn out, and the second prompt message is used to indicate that the second fuse device is worn out.

[0026] Optionally, in the above protection circuit, the first fuse device and the second fuse device are fuses.

[0027] Optionally, in the above protection circuit, the first switch, the second switch, the third switch and / or the fourth switch are back-to-back NMOS switch tubes or triodes.

[0028] Optionally, the above protection circuit further includes:

[0029] A sampling resistor, wherein a first end of the sampling resistor is grounded, and a second end of the sampling resistor is connected to a negative electrode port.

[0030] A battery comprises: a cell group and a protection circuit connected to the cell group, wherein the protection circuit is any one of the above protection circuits, and the cell group is the protected object.

[0031] An electronic device comprises: any one of the above protection circuits.

[0032] Based on the above technical solution, the above solution provided by the embodiment of the present invention is that when the protected object does not have overvoltage, overcurrent, abnormal capacity or overtemperature, the fourth switch is in a conducting state, and the first end of the protected object is connected to the positive port through the first fuse device and the fourth switch to form a path. When the protected object has overvoltage, overcurrent, abnormal capacity or overtemperature, a fuse instruction is generated. When the switch controller obtains the fuse instruction, the first switch is controlled to be turned on and the fourth switch is controlled to be turned off. After the first switch is turned on, the first fuse device is actuated to disconnect the path in the first fuse device. The controller continues to detect the working condition of the protected object. After the fault of the protected object is eliminated, the third switch and the fourth switch are controlled to be turned on. At this time, the first end of the protected object is connected to the positive port through the second fuse device, the third switch and the fourth switch to form a path. When the fuse instruction is obtained again, the second switch is controlled to be turned on and the third switch and the fourth switch are controlled to be turned off. It can be seen that in this solution, when the protection circuit completes a protection action, it can automatically recover and continue to provide protection to the protected object, so that the protected object continues to work, thereby improving the use efficiency of the protected object. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0034] Figure 1 A schematic diagram of the structure of a protection circuit provided in an embodiment of the present application;

[0035] Figure 2 A structural schematic diagram of a protection circuit provided in another embodiment of the present application. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] See also Figure 1 , the protection circuit disclosed in the embodiment of the present application may include:

[0038] A first fuse device F1, a second fuse device F2, a first switch K1, a second switch K2, a third switch K3 and a fourth switch K4, and a switch controller for controlling the on / off state of the first switch K1, the second switch K2, the third switch K3 and the fourth switch K4;

[0039] The first end of the first fuse device F1 is connected to the first end of the protected object;

[0040] The first end of the second fuse device F2 is connected to the first end of the protected object;

[0041] The first end of the first switch K1 is connected to the second end of the first fuse F1, and the second end of the first switch K1 is grounded;

[0042] The first end of the second switch K2 is connected to the second end of the second fuse F2, and the second end of the second switch K2 is grounded;

[0043] The first end of the third switch K3 is connected to the third end of the second fuse F2;

[0044] A first end of the fourth switch K4 is connected to a second end of the third switch K3 and a third end of the first fuse F1, and a second end of the fourth switch K4 is connected to a positive terminal of the protection circuit;

[0045] The switch controller is used to control the first switch K1 to be turned on and the fourth switch K4 to be turned off when it is determined that protection needs to be provided to the protected object, and to determine whether the fault of the protected object is eliminated. After the fault of the protected object is eliminated, the third switch K3 and the fourth switch K4 are controlled to be turned on, and when it is determined again that protection needs to be provided to the protected object, the second switch K2 is controlled to be turned on and the third switch K3 and the fourth switch K4 are controlled to be turned off.

[0046] When the protected object does not have overvoltage, overcurrent, abnormal capacity or overtemperature, the fourth switch K4 is in the on state, and the first end of the protected object is connected to the positive electrode port through the first fuse F1 and the fourth switch K4 to form a path. When the protected object has overvoltage, overcurrent, abnormal capacity or overtemperature, a fuse instruction is generated. When the switch controller obtains the fuse instruction, the first switch K1 is controlled to be turned on and the fourth switch K4 is controlled to be turned off. After the first switch K1 is turned on, the first fuse F1 is actuated to disconnect the path in the first fuse F1. The controller continues to detect the working condition of the protected object. After the fault of the protected object is eliminated, the third switch K3 and the fourth switch K4 are controlled to be turned on. At this time, the first end of the protected object is connected to the positive electrode port through the second fuse F2, the third switch K3 and the fourth switch K4 to form a path. When the fuse instruction is obtained again, the second switch K2 is controlled to be turned on and the third switch K3 and the fourth switch K4 are controlled to be turned off. It can be seen that in this solution, when the protection circuit completes a protection action, it can automatically recover and continue to provide protection to the protected object, so that the protected object continues to work, thereby improving the use efficiency of the protected object.

[0047] For further information, see Figure 1 , when an abnormality occurs in the protected object, the fourth switch K4 is controlled to be disconnected. If an overcurrent abnormality occurs, the first fuse F1 will be automatically blown; however, if other abnormalities such as overvoltage or battery capacity occur, sufficient heat for melting may not be generated on the first fuse F1. At this time, the controller needs to send a melting instruction to control the first switch K1 to be turned on. After the first switch K1 is turned on, the first fuse F1 is actuated, and the second end of the first fuse F1 is grounded, which will generate a large amount of heat on the first fuse F1. This heat is enough to make the first fuse F1 melt quickly, and then disconnect the path in the first fuse F1 at the first time. The controller continues to detect the working condition of the protected object. After the fault of the protected object is eliminated, the third switch K3 and the fourth switch K4 are controlled to be turned on. At this time, the first end of the protected object is connected to the positive port through the second fuse F2, the third switch K3, and the fourth switch K4 to form a path. When the melting instruction is obtained again, the second switch K2 is controlled to be turned on, the second fuse F2 is actively melted, and the third switch K3 and the fourth switch K4 are controlled to be disconnected. It can be seen that in this solution, when the protection circuit completes a protection action, it can automatically recover and continue to provide protection to the protected object, so that the protected object continues to work, thereby improving the use efficiency of the protected object.

[0048] Furthermore, the first fuse device F1 and the second fuse device F2 are heated by built-in heating wires. When the first switch K1 / the second switch K2 is turned on, the current flowing into the first fuse device F1 / the second fuse device F2 passes through the heating wire and is output from the third end. At this time, the heating wire will generate enough heat to melt the first fuse device F1 / the second fuse device F2. When the first switch K1 / the second switch K2 is not turned on, the current in the first fuse device F1 and the second fuse device F2 cannot flow through the heating wire.

[0049] The specific types of the first fuse F1, the second fuse F2, and each switch (i.e., the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4) can be flexibly selected in practical applications according to various factors such as system design requirements, working environment, current and voltage characteristics, and cost budget. For example, in scenarios involving higher current protection requirements, the first fuse F1 and the second fuse F2 can use disposable fuses, which can quickly blow when the current is overloaded, thereby effectively cutting off the circuit and protecting subsequent equipment from damage. Disposable fuses have been widely used in a variety of electronic devices due to their simplicity, reliability, and relatively low cost.

[0050] As for the selection of each switch, they can all be implemented based on semiconductor devices to meet the needs of modern electronic devices for high performance, low power consumption and fast response. Specifically, MOS tubes (metal oxide semiconductor field effect transistors) and triodes are common choices. MOS tubes are known for their low on-resistance, high input impedance and good switching characteristics, and are suitable for high-speed switching circuits. Triodes can be used in certain specific application scenarios due to their current amplification capabilities, such as see Figure 2 As shown, in the technical solution disclosed in the embodiment of the present application, the specific type of the selected switch can be a back-to-back NMOS switch tube.

[0051] See also Figure 2 In this embodiment, due to the influence of the body diode in a single MOS tube, bidirectional shutdown cannot be achieved, so it is necessary to use a back-to-back form of two MOS tubes to achieve bidirectional conduction and shutdown control. Based on the above reasons, the third switch K3 and the fourth switch K4 can be back-to-back NMOS switch tubes, such as Figure 2As shown, the back-to-back NMOS switch tube is composed of two NMOS switch tubes, and the source (S) and drain (D) of the two NMOS are connected in reverse series, that is, the drain of the first NMOS is connected to the drain of the second NMOS, forming a "back-to-back" structure. The source of the first NMOS switch tube in the back-to-back NMOS switch tube constituting the third switch K3 is connected to the third end of the second fuse F2, and the drain is connected to the drain of the second switch tube in the back-to-back NMOS switch tube, and the source of the second switch tube in the back-to-back NMOS switch tube is connected to the first end of the fourth switch K4. The source of the first NMOS switch tube in the back-to-back NMOS switch tube constituting the fourth switch K4 is connected to the second end of the third switch K3, and the drain is connected to the drain of the second switch tube in the back-to-back NMOS switch tube, and the source of the second switch tube in the back-to-back NMOS switch tube serves as the second end of the fourth switch. The gates of the two NMOS switch tubes in the back-to-back switch tube serve as the control ends of their corresponding switch tubes. It should be noted that when the NMOS switch tube is turned on, its source and drain can both serve as the input and output ends of the current.

[0052] In the preferred embodiment, in order to further improve the protection effect and switch performance of the circuit, each switch in the protection circuit is designed as an NMOS tube. The NMOS tube has the advantages of low turn-on voltage, small on-resistance, and fast switching speed, especially in low-voltage and low-power application scenarios, its advantages are more obvious. In addition, the NMOS tube is also easy to integrate into the CMOS circuit, which helps to achieve the miniaturization and integration of the circuit. Therefore, under the premise of meeting the design requirements, choosing the NMOS tube as the switching device can not only improve the overall performance of the circuit, but also reduce the design cost and complexity to a certain extent.

[0053] In the technical solution disclosed in this embodiment, the switch controller may be a processor, or may be composed of three control chips for controlling the switch, see Figure 2In this embodiment, the switch controller may include a primary protection IC unit, a secondary protection IC unit and an auxiliary protection IC unit. The output end of the secondary protection IC unit is connected to the control end of the first switch K1. The secondary protection IC unit is used to control the first switch K1 to be turned on when a fuse instruction is obtained; the first output end of the auxiliary protection IC unit is connected to the control end of the second switch K2, and the second output end of the auxiliary protection IC unit is connected to the control end of the third switch K3. The auxiliary protection IC unit is used to determine whether the fault of the protected object is eliminated after the secondary protection IC unit controls the first switch K1 to be turned on. If the fault is eliminated, the third switch K3 is controlled to be turned on; the first output end of the primary protection IC unit is connected to the control end of the fourth switch K4. The primary protection IC unit is used to control the fourth switch K4 to be turned off when the secondary protection IC unit controls the first switch K1 to be turned on, control the fourth switch K4 to be turned on when the auxiliary protection IC unit controls the third switch K3 to be turned on, and control the fourth switch K4 to be turned off when the auxiliary protection IC unit controls the second switch K2 to be turned on.

[0054] In this embodiment, the determination of the need to provide protection to the protected object and the determination of whether the fault of the protected object has been eliminated include: obtaining the state information of the protected object, and determining whether the fault of the protected object has been eliminated based on the state information, wherein the state information includes at least one data item of voltage, current and temperature. For example, if any one of the voltage, current and temperature of the protected object is greater than a preset voltage, preset current and preset temperature, it indicates that the protected object is in an overcurrent, overvoltage or overheating state, and short-circuit protection needs to be provided to the protected object, and the fault of the protected object (overcurrent fault, overvoltage fault, overheating fault) has not been eliminated, wherein the voltage and current can be measured by Figure 2 The temperature is measured by the sampling resistor R in the circuit shown. The temperature can be obtained by a temperature sensor on the protected object or other temperature detection elements.

[0055] In this embodiment, the protection circuit is composed of a primary protection part, a secondary protection part and an auxiliary protection part, and the primary protection part is composed of a fourth switch K4 and a primary protection IC unit. The primary protection IC unit may have a built-in charge pump, which can provide sufficient start-up voltage for the fourth switch K4, so as to control the connection and disconnection between the protected object and the external connection object. The secondary protection part is composed of the first switch K1, the first fuse device F1 and the secondary protection IC unit. The secondary protection IC unit is used to detect the status data of the protected object. When the protected object has overvoltage, overcurrent, abnormal capacity or overtemperature, a fuse instruction is generated, and the first switch K1 is controlled to be turned on based on the fuse instruction. At this time, a large current flows through the first fuse device F1, and its built-in heater heats and melts the built-in disposable fuse of the first fuse device F1, thereby powering off the protected circuit. At the same time, the secondary protection IC unit also sends the fuse instruction to the primary protection IC unit. When the primary protection IC unit obtains the fuse instruction, it controls the fourth switch K4 to be disconnected, further ensuring that the protection circuit can provide reliable power-off protection for the protected object. The auxiliary protection part is composed of an auxiliary protection IC unit, a second switch K2, a third switch K3 and a second fuse F2. The auxiliary protection IC unit is connected to the secondary protection IC unit and the protected object, and is used to communicate with the protected object when it is detected that the secondary protection IC unit generates a fuse instruction, obtain the status information of the protected object, and judge whether the fault (overcurrent fault, overvoltage fault, overheating fault) of the protected object is eliminated based on the status information of the protected object. If the fault is eliminated and lasts for a set time (for example, 1 minute, 5 minutes or 10 minutes, etc.), the third switch K3 is controlled to be turned on, and at the same time, a prompt message is output to the primary protection IC unit, so that the primary protection IC unit controls the fourth switch K4 to be turned on. If the fault is not eliminated, or the elimination time does not reach the set time, the third switch K3 is kept in an open state. When the third switch K3 is turned on, if the auxiliary protection IC unit determines that the protected object has overvoltage, overcurrent, abnormal capacity or overtemperature, a fuse instruction will also be generated, and the second switch K2 will be controlled to be turned on based on the fuse instruction. At the same time, a prompt message is output to the first-level protection IC unit, so that the first-level protection IC unit controls the fourth switch K4 to be disconnected.

[0056] When the first switch K1 is an NMOS tube, the drain of the first switch K1 is connected to the second end of the first fuse device F1, the source of the first switch K1 is grounded, and the gate of the first switch K1 is connected to the output end of the secondary protection IC unit; when the second switch K2 is an NMOS tube, the drain of the second switch K2 is connected to the second end of the second fuse device F2, the source of the second switch K2 is grounded, and the gate of the second switch K2 is connected to the output end of the auxiliary protection IC unit.

[0057] In this embodiment, the protected object may be a battery cell group, the positive electrode of the battery cell group is the first end of the protected object, and the negative electrode of the battery cell group is grounded.

[0058] In this embodiment, the protection circuit can provide two fuse protections for the protected object. In this embodiment, in order to show the remaining number of protections that can be provided to the user and to facilitate the user to understand the status information of the protected object, see Figure 2 The protection circuit is also used to provide an IIC communication interface. The switch controller can also obtain and send the status information of the protected object to the display unit through the IIC communication interface. When the first switch K1 is controlled to be turned on, a first prompt message is generated and the first prompt message is sent to the display unit through the IIC communication interface. When the second switch K2 is controlled to be turned on, a second prompt message is generated and the second prompt message is sent to the display unit through the IIC communication interface. The first prompt message is used to indicate that the first fuse device F1 is worn out, and the second prompt message is used to indicate that the second fuse device F2 is worn out.

[0059] In this embodiment, see Figure 2 The protection circuit is provided with a sampling resistor, a first end of the sampling resistor is grounded, and a second end of the sampling resistor is connected to the negative terminal of the protection circuit. The sampling resistor is used to collect the current and voltage of the protected object, and the primary protection IC unit, the secondary protection IC unit, and the auxiliary protection IC unit are used to read the collected value of the sampling resistor.

[0060] Based on the above technical solutions, the protection circuit provided by the present application example has the following characteristics:

[0061] 1. High safety: The fuse components in the traditional protection circuit are retained to avoid the danger of overvoltage and overcurrent of the protected object caused by single-point failure of the protection IC unit or short circuit of the switch of the primary protection part.

[0062] 2. Flexible communication interface: Through the IIC communication interface, the status information, security events and other information of the protected object can be easily transmitted to the external display device. If the first fuse F1 of the primary protection part is blown and the second fuse F2 of the secondary protection part is blown, the specific cause of the blown can also be sent to the external display device through the IIC communication interface to prevent the user from exposing the protected object to an unsafe environment for a long time and provide data support for fault diagnosis.

[0063] 3. Long service life: Compared with the traditional electrical protection circuit, the additional auxiliary protection part can take over the secondary protection part after the first fuse F1 of the primary protection part is blown. After the current, voltage and temperature of the protected object return to suitable conditions and maintain for a period of time, it provides an opportunity for active recovery, thereby extending the service life of the protected object.

[0064] Therefore, the protection circuit disclosed in the present application has the advantages of high safety, flexibility and longer service life, and provides data support for the safe operation of the protected object and the diagnosis after a fault occurs.

[0065] In this embodiment, corresponding to the above protection circuit, the present application discloses a battery, the battery may include a cell group and a protection circuit connected to the cell group, the protection circuit is any one of the above protection circuits, and the cell group is the protected object.

[0066] An electronic device comprises any one of the above-mentioned protection circuits, wherein the electronic device is any electronic device that needs to be equipped with a protection circuit, such as a charger, a mobile phone, a computer or a household appliance.

[0067] For the convenience of description, the above system is described as being divided into various modules according to their functions. Of course, when implementing the present invention, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0068] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. A person of ordinary skill in the art may understand and implement it without creative work.

[0069] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0070] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0071] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0072] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A protection circuit, characterized in that: include: A first fuse device, wherein a first end of the first fuse device is connected to a first end of a protected object; a second fuse device, wherein a first end of the second fuse device is connected to a first end of a protected object; A first switch, wherein a first end of the first switch is connected to a second end of the first fuse, and a second end of the first switch is grounded; a second switch, wherein a first end of the second switch is connected to a second end of the second fuse, and a second end of the second switch is grounded; a third switch, wherein a first end of the third switch is connected to a third end of the second fuse; a fourth switch, wherein a first end of the fourth switch is connected to the second end of the third switch and the third end of the first fuse device, and a second end of the fourth switch is connected to the positive electrode port; The switch controller is used to control the first switch to be turned on and the fourth switch to be turned off when it is determined that protection is needed for the protected object, and to determine whether the fault of the protected object is eliminated. After the fault of the protected object is eliminated, the third switch and the fourth switch are controlled to be turned on, and when it is determined again that protection is needed for the protected object, the second switch is controlled to be turned on and the third switch and the fourth switch are controlled to be turned off.

2. The protection circuit according to claim 1, characterized in that: The switch controller comprises: Primary protection IC unit, secondary protection IC unit and auxiliary protection IC unit; The output end of the secondary protection IC unit is connected to the control end of the first switch, and the secondary protection IC unit is used to control the first switch to be turned on when it is determined that protection needs to be provided to the protected object; The first output end of the auxiliary protection IC unit is connected to the control end of the second switch, and the second output end of the auxiliary protection IC unit is connected to the control end of the third switch. The auxiliary protection IC unit is used to determine whether the fault of the protected object is eliminated after the secondary protection IC unit controls the first switch to be turned on, and if the fault is eliminated, control the third switch to be turned on; The first output end of the first-level protection IC unit is connected to the control end of the fourth switch. The first-level protection IC unit is used to control the fourth switch to be disconnected when the second-level protection IC unit controls the first switch to be turned on, control the fourth switch to be turned on when the auxiliary protection IC unit controls the third switch to be turned on, and control the fourth switch to be turned off when the auxiliary protection IC unit controls the second switch to be turned on.

3. The protection circuit according to claim 1, characterized in that: Determining whether the fault of the protected object is eliminated includes: The state information of the protected object is obtained, and it is determined whether the fault of the protected object is eliminated based on the state information, wherein the state information includes at least one data item of voltage, current and temperature.

4. The protection circuit according to claim 1, characterized in that: The switch controller is also used for: Acquire and send the status information of the protected object to a display unit; When the first switch is controlled to be turned on, a first prompt message is generated and sent to the display unit. When the second switch is controlled to be turned on, a second prompt message is generated and sent to the display unit. The first prompt message is used to indicate that the first fuse device is worn out, and the second prompt message is used to indicate that the second fuse device is worn out.

5. The protection circuit according to claim 1, characterized in that: The first fuse device and the second fuse device are fuses.

6. The protection circuit according to claim 1, characterized in that: The first switch, the second switch, the third switch and / or the fourth switch are back-to-back NMOS switch tubes or triodes.

7. The protection circuit according to claim 1, characterized in that: Also includes: A sampling resistor, wherein a first end of the sampling resistor is grounded, and a second end of the sampling resistor is connected to a negative electrode port.

8. A battery, characterized in that: include: A battery cell group and a protection circuit according to any one of claims 1 to 7 connected to the battery cell group, wherein the battery cell group is the protected object.

9. An electronic device, characterized in that: include: The protection circuit according to any one of claims 1 to 7.

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