A charging protection circuit, a circuit board and a charging protection device

Abstract

The utility model is suitable for charging protection technical field provides a kind of charging protection circuit, circuit board and charging protection device, charging protection circuit is connected on the charging loop of charging device, and it includes: power detection module, its input end connects charging loop, for detecting the charging power of charging loop;Control module, its input end connects the output end of power detection module, for receiving the charging power of charging loop, and when the charging power of charging loop is below threshold value, output control signal;Switch module is connected between the output end of control module and charging loop, for cutting off charging loop when receiving control signal.The utility model detects the charging power of charging loop, and automatically cuts off charging when the charging power is below threshold value, to avoid the security risk brought by long time keeping connection after being full of electricity.

Description

Technical Field

[0001] This utility model belongs to the field of charging protection technology, and in particular relates to a charging protection circuit, circuit board and charging protection device. Background Technology

[0002] With the rapid development of new energy technologies and mobile communication technologies, charging devices such as electric vehicles and smartphones have become indispensable tools in people's daily lives. Correspondingly, the associated charging equipment and charging activities have become extremely frequent.

[0003] However, a common and unresolved safety hazard exists in existing charging technologies. Specifically, because users are accustomed to charging at night or for extended periods without supervision, the charger's power adapter, charging cable, and even the charging module inside the charging device remain connected to the mains power after charging is complete, posing a certain safety risk. Utility Model Content

[0004] This utility model provides a charging protection circuit, a circuit board, and a charging protection device, aiming to solve at least one technical problem in the prior art.

[0005] This utility model embodiment is implemented as follows: a charging protection circuit is connected to the charging circuit of the charging device to provide charging protection for the charging device. The charging protection circuit includes: A power detection module, whose input terminal is connected to the charging circuit, is used to detect the charging power of the charging circuit; The control module, whose input terminal is connected to the output terminal of the power detection module, is used to receive the charging power of the charging circuit and output a control signal when the charging power of the charging circuit is lower than a threshold. A switch module is connected between the output terminal of the control module and the charging circuit, and is used to cut off the charging circuit when the control signal is received.

[0006] Preferably, the switching module includes a relay switch and a transistor, wherein the relay switch is connected in series in the charging circuit; The base of the transistor is connected to the output terminal of the control module, the collector of the transistor is connected to the negative terminal of the relay switch, the positive terminal of the relay switch is connected to the power supply, and the emitter of the transistor is grounded.

[0007] Preferably, the switching module further includes a diode connected in parallel with the relay switch, wherein the anode of the diode is connected to the cathode of the relay switch, and the cathode of the diode is connected to the power supply.

[0008] Preferably, the power detection module includes: A voltage detection unit, connected to the charging circuit, is used to detect the charging voltage of the charging circuit; A current detection unit, connected to the charging circuit, is used to detect the charging current of the charging circuit; An energy metering chip is connected to the voltage detection unit and the current detection unit, and is used to obtain the charging power of the charging circuit based on the charging voltage and the charging current. The output pin of the energy metering chip is connected to the input terminal of the control module.

[0009] Preferably, the voltage detection unit includes at least two power resistors, which are connected in series between the charging circuit and ground, and the first input pin of the power metering chip is connected between two adjacent power resistors. The current detection unit includes a sampling resistor connected in series in the charging circuit. The two ends of the sampling resistor are connected to the second input pin and the third input pin of the power metering chip through current limiting resistors, respectively.

[0010] Preferably, the control module includes an MCU chip, the input pin of which is connected to the output pin of the power metering chip, and the output pin of which is connected to the base of the transistor.

[0011] Preferably, the charging protection circuit further includes: An indicator module, which is connected to the indicator pin of the MCU chip, is used to display different circuit states according to the signals output by the indicator pin of the MCU chip.

[0012] Preferably, the indicator module includes a current-limiting resistor and an LED connected in series from the indicator pin of the MCU chip.

[0013] This utility model embodiment also proposes a circuit board, which includes the charging protection circuit as described above.

[0014] This utility model embodiment also proposes a charging protection device, which includes the circuit board as described above.

[0015] The beneficial effects achieved by this utility model are as follows: Based on the characteristics of the charging power change of the charging device when it is fully charged, a charging protection circuit is designed. The charging power is detected by the power detection module and the detected power is output to the control module. When the control module recognizes that the charging power is lower than the threshold, it means that the charging is full and outputs a control signal to control the switch module to cut off the charging circuit, thereby disconnecting the charging and avoiding the safety hazards caused by maintaining the connection for a long time after the device is fully charged. Attached Figure Description

[0016] Figure 1 This is a structural block diagram of the charging protection circuit in Embodiment 1 of this utility model; Figure 2 This is a detailed circuit diagram of the charging protection circuit in Embodiment 1 of this utility model; Figure 3 This is a specific circuit diagram of a power supply circuit provided in an embodiment of this utility model.

[0017] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0019] In existing technologies, because users are accustomed to charging at night or for extended periods without supervision, the charger's power adapter, charging cable, and even the charging module inside the charging device remain connected to the mains power after charging is complete, posing a certain safety hazard. Therefore, the purpose of this invention is to design a charging protection circuit based on the changes in the charging power (i.e., the charger's output power) during the charging process. By detecting the charging power of the charging circuit and automatically cutting off the charging circuit when the charging power falls below a threshold, this avoids the safety hazards caused by maintaining connection for extended periods after the device is fully charged.

[0020] The charging devices described in the following embodiments include, but are not limited to, electric vehicles, smartphones, laptops, smartwatches, electric fans, and any other devices that require charging. These devices can all utilize the charging protection circuit described in any of the following embodiments for charging protection. Furthermore, the charging protection circuit described in any of the following embodiments can be integrated into the existing charger of these charging devices, or it can be an independent module externally connected to the charger or charging circuit, or even integrated into the internal charging circuitry of the charging device. The present invention will be described in detail below with reference to specific embodiments.

[0021] Example 1 Please see Figures 1-3 The diagram shows a charging protection circuit in Embodiment 1 of this utility model. It is connected to the charging circuit 200 of the charging device and is used to protect the charging device during charging. The charging protection circuit includes a power detection module 10, a control module 20, and a switch module 30, wherein: The input terminal of the power detection module 10 is connected to the charging circuit 200 to detect the charging power of the charging circuit 200. The input terminal of the control module 20 is connected to the output terminal of the power detection module 10 to receive the charging power of the charging circuit 200 detected by the power detection module 10. When the charging power of the charging circuit 200 is lower than a threshold (which can be preset), the control module 20 outputs a control signal. The switch module 30 is connected between the output terminal of the control module 20 and the charging circuit 200 to cut off the charging circuit 200 when the control signal is received, thereby disconnecting the charging and providing protection. By understanding the battery charging characteristics, it is found that the charging current is relatively small after the battery is fully charged. Therefore, it can be concluded that the output power of the charger is relatively small after the battery is fully charged, that is, the charging power of the charging circuit 200 is lower than the threshold.

[0022] Specifically, the switching module 30 includes a relay switch K1 and a transistor Q1. The relay switch K1 is connected in series in the charging circuit 200. The base B of the transistor Q1 is connected to the output terminal of the control module 20, the collector C of the transistor Q1 is connected to the negative terminal of the relay switch K1, the positive terminal of the relay switch K1 is connected to the power supply, and the emitter E of the transistor Q1 is grounded. Specifically, when the charging power of the charging circuit 200 is higher than or equal to the threshold, the output terminal of the control module 20 outputs a high level to the base B of the transistor Q1 to turn on the transistor Q1, thereby keeping the relay switch K1 in a closed conducting state. When the charging power of the charging circuit 200 is lower than the threshold, the output terminal of the control module 20 outputs a low level to the base B of the transistor Q1 to turn off the transistor Q1, thereby opening the relay switch K1.

[0023] In a preferred embodiment, the switch module 30 further includes a diode D2 connected in parallel with the relay switch K1. The anode of diode D2 is connected to the cathode of the relay switch K1, and the cathode of diode D2 is connected to the power supply. Specifically, diode D2 is a freewheeling diode. By connecting the freewheeling diode in parallel with the relay switch K1, a low-impedance discharge path is provided for the induced current in the relay coil when the relay switch K1 is turned off, thereby protecting the circuit. The power supply can specifically be 5V, and can be derived from... Figure 3 The power supply circuit shown is used to provide it.

[0024] Among them, such as Figure 2As shown, the power detection module 10 includes a voltage detection unit 11, a current detection unit 12, and an energy metering chip 13. The voltage detection unit 11 is connected to the charging circuit 200 and is used to detect the charging voltage of the charging circuit 200. The current detection unit 12 is connected to the charging circuit 200 and is used to detect the charging current of the charging circuit 200. The energy metering chip 13 is connected to the voltage detection unit 11 and the current detection unit 12 and is used to obtain the charging power of the charging circuit 200 based on the charging voltage and the charging current. The output pin of the energy metering chip is connected to the input terminal of the control module 20.

[0025] Specifically, the voltage detection unit 11 includes at least two power resistors, which are connected in series between the charging circuit 200 and ground. The first input pin VP of the energy metering chip 13 is connected between two adjacent power resistors. In this embodiment, four power resistors are connected in series: power resistors R10, R11, R12, and R13. The input pin VP of the energy metering chip is connected between power resistors R12 and R13, thereby acquiring the voltage of power resistor R13. The current flowing through power resistor R13 can then be calculated, and the charging voltage of the charging circuit 200 can be obtained. The current detection unit includes a sampling resistor RW1 connected in series in the charging circuit 200. The two ends of the sampling resistor RW1 are connected to the second input pin IP and the third input pin IN of the energy metering chip through current-limiting resistors (R19 and R20), respectively. The potential across the sampling resistor is input, the voltage of the sampling resistor is obtained, and the charging current of the charging circuit 200 is calculated, ultimately obtaining the charging power of the charging circuit 200.

[0026] In addition, to ensure stable and accurate voltage acquisition, power resistor R13, current-limiting resistor R19, and current-limiting resistor R20 are connected in parallel with filter capacitors (C9, C10, and C11, respectively).

[0027] Specifically, the control module 20 includes an MCU chip U3. The input pins of the MCU chip U3 are connected to the output pins of the energy metering chip, and the output pins of the MCU chip U3 are connected to the base B of the transistor Q1. That is, in this embodiment, an MCU is preferably used for control, specifically the MCU chip controls the conduction and cutoff of the transistor Q1 to control the on / off state of the charging circuit 200.

[0028] Furthermore, in some other preferred embodiments, the charging protection circuit may further include an indicator module 40, which is connected to the indicator pin of the MCU chip and is used to display different circuit states according to the signal output by the indicator pin of the MCU chip. For example, the indicator module can be controlled to light up when the charging circuit 200 is disconnected to indicate that charging is currently disconnected, or the indicator module can be controlled to light up when the charging circuit 200 is connected to indicate that charging is currently in progress, or different colors can be used to distinguish them. In specific implementations, the indicator module may include a current-limiting resistor R7 and an LED LED1 connected in series from the indicator pin of the MCU chip.

[0029] In practical use, when the charger is connected to charge the charging device, the power detection module 10 detects the charging power of the charging circuit 200. During normal power-on, the charging power of the charging circuit 200 is greater than or equal to the threshold. At this time, the switch module 30 is in the closed state of the charging circuit 200. When the battery is fully charged, the charging power of the charging circuit 200 will decrease to less than the threshold. At this time, the control module 20 starts to act and controls the switch module 30 to cut off the charging circuit 200. This is an example, not a limitation, that a mobile phone is considered fully charged when its charging power is less than 0.8W (a conclusion drawn from testing multiple mainstream mobile phones on the market), and an electric vehicle is considered fully charged when its charging power is less than 20W (a conclusion drawn from testing multiple mainstream electric vehicles on the market).

[0030] In summary, the charging protection circuit in this embodiment is designed based on the characteristics of the charging power change when the charging device is fully charged. The charging power is detected by the power detection module 10 and the detected power is output to the control module 20. When the control module 20 detects that the charging power is lower than the threshold, it means that the charging is full and outputs a control signal to control the switch module 30 to cut off the charging circuit 200, thereby disconnecting the charging and avoiding the safety hazards caused by maintaining the connection for a long time after the device is fully charged.

[0031] Example 2 Embodiment 2 of this utility model also proposes a circuit board, which includes a substrate and a charging protection circuit disposed on the substrate. The charging protection circuit is the charging protection circuit described in any of the above embodiments.

[0032] In practical implementation, the charging protection circuit can be laid on the substrate using circuit board fabrication techniques such as printing and soldering to form the circuit board.

[0033] Example 3 This utility model embodiment three also proposes a charging protection device, which includes the circuit board described in embodiment three above.

[0034] In specific implementations, the charging protection device can be a charger integrated with the charging protection circuit described in this embodiment, or it can be a separate module unit used in conjunction with the charger during the charging process to provide protection. Alternatively, the charging protection device can also be a part of the charging circuit within the charging device.

[0035] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0036] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A charge protection circuit, characterized by, It is connected to the charging circuit of the charging device and is used to protect the charging device during charging. The charging protection circuit includes: A power detection module, whose input terminal is connected to the charging circuit, is used to detect the charging power of the charging circuit; The control module, whose input terminal is connected to the output terminal of the power detection module, is used to receive the charging power of the charging circuit and output a control signal when the charging power of the charging circuit is lower than a threshold. A switch module is connected between the output terminal of the control module and the charging circuit, and is used to cut off the charging circuit when the control signal is received.

2. The charging protection circuit as described in claim 1, characterized in that, The switching module includes a relay switch and a transistor, with the relay switch connected in series in the charging circuit. The base of the transistor is connected to the output terminal of the control module, the collector of the transistor is connected to the negative terminal of the relay switch, the positive terminal of the relay switch is connected to the power supply, and the emitter of the transistor is grounded.

3. The charge protection circuit of claim 2, wherein, The switching module also includes a diode connected in parallel with the relay switch, the anode of the diode being connected to the cathode of the relay switch, and the cathode of the diode being connected to the power supply.

4. The charge protection circuit of claim 2, wherein, The power detection module includes: A voltage detection unit, connected to the charging circuit, is used to detect the charging voltage of the charging circuit; A current detection unit, connected to the charging circuit, is used to detect the charging current of the charging circuit; An energy metering chip is connected to the voltage detection unit and the current detection unit, and is used to obtain the charging power of the charging circuit based on the charging voltage and the charging current. The output pin of the energy metering chip is connected to the input terminal of the control module.

5. The charge protection circuit of claim 4, wherein, The voltage detection unit includes at least two power resistors, which are connected in series between the charging circuit and ground. The first input pin of the power metering chip is connected between two adjacent power resistors. The current detection unit includes a sampling resistor connected in series in the charging circuit. The two ends of the sampling resistor are connected to the second input pin and the third input pin of the power metering chip through current limiting resistors, respectively.

6. The charge protection circuit of claim 4 or 5, wherein, The control module includes an MCU chip, the input pin of which is connected to the output pin of the power metering chip, and the output pin of which is connected to the base of the transistor.

7. The charging protection circuit as described in claim 6, characterized in that, The charging protection circuit also includes: An indicator module, which is connected to the indicator pin of the MCU chip, is used to display different circuit states according to the signals output by the indicator pin of the MCU chip.

8. The charging protection circuit as described in claim 7, characterized in that, The indicator module includes a current-limiting resistor and an LED connected in series from the indicator pin of the MCU chip.

9. A circuit board, characterized by The circuit board includes a charging protection circuit as described in any one of claims 1 to 7.

10. A charging protection device, characterized by, The charging protection device includes the circuit board as described in claim 9.

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