Charging protection circuit and charging device

Abstract

The present application discloses a charging protection circuit and a charging device. The charging protection circuit includes: a battery for storing electric energy; a charging control module connected to the battery and used for outputting a charging signal to the battery; a protection module including a control unit and a field-effect transistor, the source electrode of the field-effect transistor is connected to the battery, the drain electrode of the field-effect transistor is connected to the charging control module, and the gate electrode of the field-effect transistor is connected to the control unit. The control unit is used for controlling the field-effect transistor to turn off when a surge voltage signal is generated by the charging control module. The charging protection circuit of the present application has at least the following beneficial effects: by arranging a protection module between the charging control module and the battery, the risk of the charging current flowing back into the battery when the charging control module is interfered by the outside is avoided, and the safety of battery use is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power supplies, and in particular, to a charging protection circuit and a charging device. Background Art

[0002] In the related art, in a conventional battery charging solution, when the charging control chip is interfered by an external surge, there is a risk of reverse charging current, which affects the safety of battery use. Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present application provides a charging protection circuit, which can prevent the impact of external surge interference on the battery and improve the safety of battery use.

[0004] The present application also provides a charging device having the above charging protection circuit.

[0005] The charging protection circuit according to the first aspect embodiment of the present application includes: a battery for storing electrical energy; a charging control module connected to the battery, the charging control module being configured to output a charging signal to the battery; a protection module including a control unit and a field effect transistor, the source electrode of the field effect transistor being connected to the battery, the drain electrode of the field effect transistor being connected to the charging control module, and the gate electrode of the field effect transistor being connected to the control unit, the control unit being configured to control the field effect transistor to cut off when a surge voltage signal is generated by the charging control module.

[0006] The charging protection circuit according to the embodiment of the present application has at least the following beneficial effects: By providing a protection module between the charging control module and the battery, the risk of reverse charging current flowing into the battery when the charging control module is interfered by an external source is avoided, and the safety of battery use is improved.

[0007] According to some embodiments of the present application, the battery includes a temperature signal output terminal connected to the source electrode of the field effect transistor, and the temperature signal output terminal is configured to output a temperature signal according to the temperature of the battery.

[0008] According to some embodiments of the present application, the charging control module includes a control chip, the control chip includes a temperature detection terminal connected to the temperature signal output terminal, the temperature detection terminal is configured to acquire the temperature signal, and the control chip is configured to control the charging signal according to the temperature signal.

[0009] According to some embodiments of the present application, the protection module further includes a first resistor. The source electrode of the field effect transistor is connected to the temperature signal output terminal, the gate electrode of the field effect transistor is connected to the temperature detection terminal, one end of the first resistor is connected to the source electrode of the field effect transistor, and the other end of the first resistor is grounded.

[0010] According to some embodiments of the present application, the control unit includes a second resistor. One end of the second resistor is connected to the gate electrode of the field effect transistor, and the other end of the second resistor is grounded.

[0011] According to some embodiments of the present application, the charging control module further includes a third resistor and a first capacitor. The control chip further includes a chip power supply terminal. One end of the first capacitor is connected to the chip power supply terminal, the other end of the first capacitor is grounded, one end of the third resistor is connected to the chip power supply terminal, and the other end of the third resistor is connected to the drain electrode of the field effect transistor.

[0012] According to some embodiments of the present application, it further includes a connector. The battery includes a connection head. The connector is respectively connected to the charging control module and the protection module. The connector is used for detachably electrically connecting to the battery through the connection head.

[0013] According to some embodiments of the present application, it further includes a power supply module. The power supply module is connected to the charging control module. The power supply module is used for supplying power to the charging control module.

[0014] According to some embodiments of the present application, the power supply module includes a USB interface. The USB interface is used for connecting to an external power supply.

[0015] The charging device according to the second aspect embodiment of the present application includes the charging protection circuit of the first aspect embodiment above.

[0016] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present application. Description of the Drawings

[0017] The following further describes the present application in conjunction with the drawings and embodiments, where:

[0018] Figure 1 It is a module diagram of an embodiment of the charging protection circuit of the present application;

[0019] Figure 2 It is a circuit diagram of an embodiment of the charging protection circuit of the present application;

[0020] Figure 3 It is a circuit diagram of another embodiment of the charging protection circuit of the present application;

[0021] Figure 4 This is a circuit diagram of an embodiment of the power supply module of the charging protection circuit of the present application.

[0022] Reference numerals:

[0023] Battery 100, connector 110, charging control module 200, protection module 300, control unit 310, field effect transistor 320;

[0024] Connection socket 400, power supply module 500. Detailed implementation manners

[0025] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application.

[0026] In the description of the present application, the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood as not including the present number, above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0027] In the description of the present application, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present application in combination with the specific content of the technical solution.

[0028] The solution of the present application can be used for storage batteries, including lithium batteries with temperature detection functions. Lithium batteries are a type of battery with lithium metal or lithium alloy as the positive / negative electrode material and using a non-aqueous electrolyte solution. Due to the very active chemical properties of lithium metal, the processing, storage, and use of lithium metal have very high requirements for the environment. With the development of science and technology, lithium batteries have become the mainstream. Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium ion batteries. Lithium ion batteries do not contain metallic lithium and are rechargeable. The fifth-generation product of rechargeable batteries, lithium metal batteries, was born in 1996, and their safety, specific capacity, self-discharge rate, and performance-price ratio are all superior to those of lithium ion batteries.

[0029] Since the temperature of the battery gradually increases during continuous charging and discharging cycles, the battery performance will decline. Therefore, some battery products are equipped with a temperature detection function module to detect, control, and compensate for the temperature during battery charging. A common solution is to use an NTC (Negative Temperature Coefficient) thermistor to detect the battery temperature and cooperate with a charging control chip to adjust the charging voltage for the battery in real time to avoid excessive battery temperature.

[0030] In some embodiments, referring to Figure 1 , the charging protection circuit includes: a battery 100, a charging control module 200, and a protection module 300. The battery 100 is used to store electrical energy; the charging control module 200 is connected to the battery 100 and is used to output a charging signal to the battery 100; the protection module 300 includes a control unit 310 and a field effect transistor 320. The source of the field effect transistor 320 is connected to the battery 100, the drain of the field effect transistor 320 is connected to the charging control module 200, and the gate of the field effect transistor 320 is connected to the control unit 310. The control unit 310 is used to control the field effect transistor 320 to turn off when a surge voltage signal is generated by the charging control module 200.

[0031] Among them, the charging signal is the charging voltage for charging the battery 100. After receiving it, the battery 100 converts its electrical energy into chemical energy and stores it. The field effect transistor 320 is a field effect transistor, which is a semiconductor device that uses the electric field effect of the input circuit to control the current of the output circuit. It has the advantages of high input resistance, low noise, low power consumption, large dynamic range, easy integration, no secondary breakdown phenomenon, and wide safe operating area. The application scope of the field effect transistor 320 includes: 1. Applied to amplifiers. Since the input impedance of the field effect transistor 320 amplifier is very high, a ceramic capacitor with a small capacitance value can be selected for the coupling capacitor, and there is no need to use an electrolytic capacitor; 2. Applied to impedance transformation circuits; 3. Used as a variable resistor; 4. Used as a constant current source; 5. Used as an electronic switch.

[0032] In the embodiments of the present application, the field effect transistor 320 is used as an electronic switch. When the circuit is working normally, the field effect transistor 320 works in the on state, equivalent to a closed switch, and the charging control module 200 and the battery 100 are normally electrically connected. When affected by external interference, a surge voltage may be generated inside the charging control module 200, causing the charging current to flow backward. The control unit 310 in the present application can detect the surge voltage signal and then control the field effect transistor 320 to work in the off state. At this time, the field effect transistor 320 is equivalent to an open switch, and the electrical connection between the charging control module 200 and the battery 100 is disconnected, thereby avoiding the influence of the reverse current on the battery 100.

[0033] The charging protection circuit according to the embodiments of the present application has at least the following beneficial effects: By arranging a protection module 300 between the charging control module 200 and the battery 100, the risk of reverse charging current flowing into the battery 100 when the charging control module 200 is interfered by the outside is avoided, and the use safety of the battery 100 is improved.

[0034] Some embodiments, referring to Figure 2 and Figure 3 , the battery 100 includes a temperature signal output terminal, the temperature signal output terminal is connected to the source electrode of the field effect transistor 320, and the temperature signal output terminal is used to output a temperature signal according to the temperature of the battery 100. The component number of the field effect transistor 320 in the figure is Q1. A battery management control circuit board is arranged inside the battery 100, and it includes an NTC thermistor element. During charging, the thermistor outputs a voltage signal to the charging control module 200 according to the temperature of the battery 100. In one embodiment, a temperature sensor can also be used to detect the temperature of the battery 100.

[0035] Some embodiments, referring to Figure 2 and Figure 3 , the charging control module 200 includes a control chip U1, the control chip U1 includes a temperature detection terminal (pin 3), the temperature detection terminal is connected to the temperature signal output terminal, the temperature detection terminal is used to obtain the temperature signal, and the control chip U1 is used to control the charging signal according to the temperature signal. The control chip U1 adjusts the voltage for charging the battery 100 in real time according to the temperature signal, avoiding excessive heating of the battery 100. On the one hand, when the temperature of the battery 100 is too high during charging, the performance of the battery 100 is likely to decline; on the other hand, when the temperature of the battery 100 is too high during charging, there may be a risk of explosion.

[0036] Some embodiments, referring to Figure 2 and Figure 3 , the protection module 300 further includes a first resistor R1, the source electrode of the field effect transistor 320 is connected to the temperature signal output terminal, the gate electrode of the field effect transistor 320 is connected to the temperature detection terminal, one end of the first resistor R1 is connected to the source electrode of the field effect transistor 320, and the other end of the first resistor R1 is grounded. The first resistor R1 is used for voltage division to protect the field effect transistor 320. When a surge voltage is generated due to external interference in the charging control module 200, the reverse current mainly flows back into the battery 100 through the temperature detection circuit, and the influence of the surge voltage on the charging circuit is small. Therefore, usually only by arranging the field effect transistor 320 for preventing reverse flow in the temperature detection circuit can the battery 100 be better protected. In a schematic embodiment, field effect transistors 320 can also be arranged in each circuit between the charging control module 200 and the battery 100 to protect the battery 100.

[0037] Some embodiments, referring to Figure 2 and Figure 3, the control unit 310 includes a second resistor R2. One end of the second resistor R2 is connected to the gate of the field effect transistor 320, and the other end of the second resistor R2 is grounded. The gate of the field effect transistor 320 is connected to the charging input terminal of the control chip U1. The conduction and cutoff of the field effect transistor 320 are controlled by the gate voltage. Therefore, the second resistor R2 is actually a voltage dividing resistor. The gate voltage of the field effect transistor 320 is adjusted through the voltage dividing function of the resistor. When the circuit works normally, the voltage dividing resistor controls the gate voltage of the field effect transistor 320 to meet the conduction condition, and the source and drain of the field effect transistor 320 are conducted. At this time, the field effect transistor 320 is equivalent to a closed switch, and the temperature detection terminal of the charging control module 200 is electrically connected to the temperature signal output terminal of the battery 100. When the charging control module 200 is interfered externally, the internal circuit thereof (especially the internal circuit of the control chip U1) may generate a surge voltage, causing the charging current to flow back into the battery 100 through the field effect transistor 320. However, the surge voltage will change the gate voltage of the field effect transistor 320. When the gate voltage no longer meets the conduction condition, the field effect transistor 320 is cut off, and the temperature detection terminal of the charging control module 200 is disconnected from the temperature signal output terminal of the battery 100, thereby avoiding the charging current flowing back into the battery 100 through the temperature detection circuit.

[0038] In some embodiments, referring to Figure 2 and Figure 3 , the charging control module 200 further includes a third resistor R3 and a first capacitor C1. The control chip U1 further includes a chip power supply terminal (pin 2). One end of the first capacitor C1 is connected to the chip power supply terminal, and the other end of the first capacitor C1 is grounded. One end of the third resistor R3 is connected to the chip power supply terminal, and the other end of the third resistor R3 is connected to the drain of the field effect transistor 320. The third resistor R3 is used for current limiting protection of the chip power supply terminal of the control chip U1, and the first capacitor C1 is used for stabilizing the voltage of the chip power supply terminal.

[0039] In some embodiments, referring to Figure 2 , it further includes a connection base 400. The battery 100 includes a connection head 110. The connection base 400 is respectively connected to the charging control module 200 and the protection module 300. The connection base 400 is used for detachably electrically connecting to the battery 100 through the connection head 110. By providing the connection base 400, it is convenient for users to disassemble and replace the battery 100 to meet the application requirements in more scenarios. The connection head 110 of the battery 100 is also called a terminal or a wiring terminal, which is a component for connecting the storage battery to an external conductor. The types of terminals include single-hole, double-hole, socket, hook, etc., and are mainly used for transmitting electrical signals or conducting electricity.

[0040] In some embodiments, referring to Figure 2 and Figure 4 , it further includes a power supply module 500. The power supply module 500 is connected to the charging control module 200, and the power supply module 500 is used for supplying power to the charging control module 200.

[0041] In some embodiments, with reference to Figure 4 , the power supply module 500 includes a USB interface for connecting to an external power supply.

[0042] In some embodiments, the charging device includes the charging protection circuit of the first aspect embodiment described above. The charging device of the embodiment of the present application has at least the following beneficial effects: by setting the protection module 300 between the charging control module 200 and the battery 100, the risk of reverse charging current flowing into the battery 100 when the charging control module 200 is interfered by the outside is avoided, and the safety of using the battery 100 is improved.

[0043] In the description of the present application, the description with reference to terms such as "one embodiment", "some embodiments" or "illustrative embodiments" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0044] The embodiments of the present application have been described in detail above in conjunction with the accompanying drawings. However, the present application is not limited to the above embodiments. Various changes can be made without departing from the spirit of the present application within the scope of knowledge possessed by those of ordinary skill in the art. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. Charging protection circuit, Characterized in that, Comprising: A battery for storing electrical energy; the battery includes a temperature signal output terminal, the temperature signal output terminal is connected to the source electrode of the field effect transistor, and the temperature signal output terminal is used to output a temperature signal according to the temperature of the battery; A charging control module connected to the battery, the charging control module is used to output a charging signal to the battery; the charging control module includes a control chip, the control chip includes a temperature detection terminal, the temperature detection terminal is connected to the temperature signal output terminal, the temperature detection terminal is used to obtain the temperature signal, and the control chip is used to control the charging signal according to the temperature signal; A protection module, the protection module includes a control unit and a field effect transistor, the source electrode of the field effect transistor is connected to the battery, the drain electrode of the field effect transistor is connected to the charging control module, the gate electrode of the field effect transistor is connected to the control unit, and the control unit is used to control the field effect transistor to cut off when a surge voltage signal is generated by the charging control module; the protection module further includes a first resistor, the source electrode of the field effect transistor is connected to the temperature signal output terminal, the gate electrode of the field effect transistor is connected to the temperature detection terminal, one end of the first resistor is connected to the source electrode of the field effect transistor, and the other end of the first resistor is grounded; the first resistor is used for voltage division to protect the field effect transistor; When a surge voltage is generated due to external interference in the charging control module, the control unit controls the field effect transistor to cut off, and the temperature detection terminal is disconnected from the temperature signal output terminal to prevent the charging current in the charging control module from flowing back into the battery.

2. The charging protection circuit according to claim 1, Characterized in that, The control unit includes a second resistor, one end of the second resistor is connected to the gate electrode of the field effect transistor, and the other end of the second resistor is grounded.

3. The charging protection circuit according to claim 1, Characterized in that, The charging control module further includes a third resistor and a first capacitor, the control chip further includes a chip power supply terminal, one end of the first capacitor is connected to the chip power supply terminal, the other end of the first capacitor is grounded, one end of the third resistor is connected to the chip power supply terminal, and the other end of the third resistor is connected to the drain electrode of the field effect transistor.

4. The charging protection circuit according to claim 1, Characterized in that, It further includes a connection seat, the battery includes a connection head, the connection seat is respectively connected to the charging control module and the protection module, and the connection seat is used for detachably electrically connecting to the battery through the connection head.

5. The charging protection circuit according to claim 1, Characterized in that, It further includes a power supply module, the power supply module is connected to the charging control module, and the power supply module is used to supply power to the charging control module.

6. The charging protection circuit according to claim 5, Characterized in that, The power supply module includes a USB interface, and the USB interface is used to connect to an external power supply.

7. Charging device, Characterized in that, It includes the charging protection circuit according to any one of claims 1 to 6.

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