Charging protection circuit, charging protection device and electric appliance

Abstract

The utility model discloses a charging protection circuit, a charging protection device and an electric appliance, the charging protection circuit comprises a first-layer protection circuit and a second-layer protection circuit, the input end of the first-layer protection circuit is connected with a power supply, the output end of the first-layer protection circuit is connected with the input end of the second-layer protection circuit, and the output end of the second-layer protection circuit is connected with the power supply. The output end of the second-layer protection circuit is connected with an electric appliance; the first-layer protection circuit comprises a first protection chip and a first field effect transistor; and the second-layer protection circuit comprises a second protection chip and a second field effect transistor. According to the utility model, two layers of protection circuits are arranged, so that secondary safety protection of the power supply on electric appliance charging can be realized, and the charging safety performance of the electric appliance can be ensured to the greatest extent.

Description

Technical Field

[0001] The utility model relates to the technical field of charging protection circuits, and in particular to a charging protection circuit, a charging protection device and an electrical appliance. Background Art

[0002] With the continuous development of science and technology, charging equipment has occupied an important position in our daily life. Mobile phones, tablets, laptops, headphones, watches, etc. need to be charged regularly for daily use. However, if the charging equipment is not properly protected, there will be certain safety hazards, and even cause serious incidents such as fire. Therefore, the protection measures for charging equipment have become a topic of great concern, and charging protection circuits have come into being.

[0003] Charging protection circuit refers to a circuit designed in the circuit system to protect the battery from automatic charging, discharging, protection and other functions. Its main function is to control the charging and discharging of the battery to avoid overcharging, overdischarging, overcurrent, overtemperature and other situations, thereby effectively improving the safety of charging equipment. However, the existing charging protection circuits are often only equipped with a single-layer protection circuit. In some high-risk use places, once a fault occurs, it cannot achieve the desired protection function and the reliability is insufficient. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies of the prior art. The utility model provides a charging protection circuit, a charging protection device and an electrical appliance. A two-layer protection circuit is provided to realize secondary safety protection of the power supply for charging the electrical appliance, thereby ensuring the charging safety performance of the electrical appliance to the greatest extent.

[0005] The utility model provides a charging protection circuit, the charging protection circuit comprises a first layer protection circuit and a second layer protection circuit, the input end of the first layer protection circuit is connected to a power supply, the output end of the first layer protection circuit is connected to the input end of the second layer protection circuit, and the output end of the second layer protection circuit is connected to an electrical appliance;

[0006] The first layer protection circuit includes a first protection chip and a first field effect transistor, wherein pin 1 of the first protection chip is connected to pin G1 of the first field effect transistor, pin 3 of the first protection chip is connected to pin G2 of the first field effect transistor, and pin 6 of the first protection chip is connected to pin S1 of the first field effect transistor and the negative electrode of the power supply;

[0007] The second layer protection circuit includes a second protection chip and a second field effect transistor, wherein pin 1 of the second protection chip is connected to pin G1 of the second field effect transistor, pin 3 of the second protection chip is connected to pin G2 of the second field effect transistor, pin 6 of the second protection chip is connected to pin S1 of the second field effect transistor, and pin S2 of the second field effect transistor is connected to the negative electrode of the electrical appliance;

[0008] The S2 pin of the first field effect transistor is connected to the S1 pin of the second field effect transistor.

[0009] Furthermore, the first protection chip is an S-8261 protection chip.

[0010] Furthermore, the first layer protection circuit also includes a first resistor, a second resistor, and a first capacitor;

[0011] The first end of the first resistor is connected to the positive electrode of the power supply, the second end of the first resistor is connected to pin 5 of the first protection chip, the first end of the second resistor is connected to pin 2 of the first protection chip, the second end of the second resistor is connected to pin 2 of the first protection chip, the first end of the first capacitor is connected to pin 5 of the first protection chip, and the second end of the first capacitor is connected to pin 6 of the first protection chip.

[0012] Furthermore, the first field effect transistor is a CJS8820 dual N-channel field effect transistor.

[0013] Furthermore, the second protection chip is an S-8261 protection chip.

[0014] Furthermore, the second layer protection circuit also includes a third resistor, a fourth resistor, and a second capacitor;

[0015] The first end of the third resistor is connected to the positive electrode of the power supply, the second end of the third resistor is connected to pin 5 of the second protection chip, the first end of the fourth resistor is connected to pin 2 of the second protection chip, the second end of the fourth resistor is connected to pin 2 of the second protection chip, the first end of the second capacitor is connected to pin 5 of the second protection chip, and the second end of the second capacitor is connected to pin 6 of the second protection chip.

[0016] Furthermore, the second field effect transistor is a CJS8820 dual N-channel field effect transistor.

[0017] Furthermore, the power source is a 18650 lithium battery.

[0018] The utility model also provides a charging protection device, which includes the charging protection circuit mentioned above.

[0019] The utility model also provides an electrical appliance, wherein the electrical appliance is provided with the above-mentioned charging protection device.

[0020] The utility model provides a charging protection circuit, a charging protection device and an electrical appliance. By setting up a two-layer protection circuit and adopting an S-8261 protection chip and a CJS8820 dual N-channel field effect transistor, the protection effect is better, and the secondary safety protection of the power supply for charging the electrical appliance can be realized, thereby ensuring the charging safety performance of the electrical appliance to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model 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 some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the module principle of the charging protection circuit in the embodiment of the utility model;

[0023] Figure 2 It is a circuit principle schematic diagram of the charging protection circuit in the embodiment of the utility model. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] Embodiment 1

[0026] The first embodiment of the utility model provides a charging protection circuit, such as Figure 1 and Figure 2 As shown, Figure 1 The module principle schematic diagram of the charging protection circuit in the embodiment of the utility model is shown. Figure 2 The schematic diagram of the circuit principle of the charging protection circuit in the embodiment of the utility model is shown.

[0027] In an optional implementation of the present embodiment, the charging protection circuit includes a first-layer protection circuit and a second-layer protection circuit, the input end of the first-layer protection circuit is connected to a power supply, the output end of the first-layer protection circuit is connected to the input end of the second-layer protection circuit, and the output end of the second-layer protection circuit is connected to an electrical appliance.

[0028] In an optional implementation of this embodiment, the positive electrode B+ of the power source is connected to the positive electrode P+ of the electrical appliance, and the negative electrode B- of the power source is connected to the negative electrode P- of the electrical appliance.

[0029] In an optional implementation of this embodiment, the first-layer protection circuit includes a first protection chip IC1 and a first field effect transistor Q1.

[0030] Specifically, pin 1 of the first protection chip IC1 is connected to the G1 pin of the first field effect transistor Q1, pin 3 of the first protection chip IC1 is connected to the G2 pin of the first field effect transistor Q1, and pin 6 of the first protection chip IC1 is connected to the S1 pin of the first field effect transistor Q1 and the negative electrode B- of the power supply.

[0031] In an optional implementation of this embodiment, the first protection chip IC1 is an S-8261 protection chip.

[0032] Specifically, the S-8261 protection chip is a battery protection IC chip for batteries, with a built-in high-precision voltage detection circuit and a delay circuit, which can protect the rechargeable lithium battery pack from overcharging, overdischarging and overcurrent. In this embodiment, it can protect the power supply.

[0033] Furthermore, the first protection chip IC1 has built-in over-discharge detection comparator, over-charge detection comparator, discharge over-current detection comparator, load short-circuit detection comparator, and charge over-current detection comparator, which are combined with control logic circuit, delay circuit, and oscillation circuit to realize overall control of the first layer protection circuit.

[0034] Furthermore, the first protection chip IC1 includes five pins, wherein pin 1 is a DO pin, pin 2 is a VM pin, pin 3 is a CO pin, pin 5 is a VDD pin, and pin 6 is a VSS pin, wherein pin 1 is a FET gate control terminal (CMOS output terminal) for discharge control, pin 2 is a voltage detection terminal between the VM terminal and the VSS terminal (i.e., an overcurrent / charger detection terminal), pin 3 is a FET gate connection terminal (CMOS output terminal) for charging control, pin 5 is a positive power input terminal, and pin 6 is a negative power input terminal.

[0035] It should be noted that pin 4 is a blank pin and will not be described here.

[0036] In an optional implementation of this embodiment, the first field effect transistor Q1 is a CJS8820 dual N-channel field effect transistor.

[0037] Specifically, the CJS8820 dual N-channel field effect transistor is composed of two N-channel sub-field effect transistors and a Zener diode. The N-channel field effect transistor provides a stable drain-source on-resistance and low gate charge in the on state, and cooperates with the protection chip to provide ESD (Electro-Static discharge) protection function, effectively reducing overvoltage and overcurrent, and realizing the protection of the charging circuit. Its two N-channel sub-field effect transistors use a common drain, which is convenient for quick configuration and use.

[0038] In an optional implementation of this embodiment, the first layer protection circuit further includes a first resistor R1, a second resistor R2, and a first capacitor C1.

[0039] Specifically, the first end of the first resistor R1 is connected to the positive electrode B+ of the power supply, the second end of the first resistor R1 is connected to pin 5 of the first protection chip IC1, the first end of the second resistor R2 is connected to pin 2 of the first protection chip IC1, the second end of the second resistor R2 is connected to pin 2 of the first protection chip IC1, the first end of the first capacitor C1 is connected to pin 5 of the first protection chip IC1, and the second end of the first capacitor C1 is connected to pin 6 of the first protection chip IC1.

[0040] Furthermore, the resistance value of the first resistor R1 is 471 ohms, the resistance value of the second resistor R2 is 2K ohms, and the first capacitor C1 is a 104 capacitor with a capacitance value of 0.1 uF.

[0041] In an optional implementation of this embodiment, the second layer protection circuit includes a second protection chip IC2 and a second field effect transistor Q2.

[0042] Specifically, pin 1 of the second protection chip IC2 is connected to the G1 pin of the second field effect transistor Q2, pin 3 of the second protection chip IC2 is connected to the G2 pin of the second field effect transistor Q2, pin 6 of the second protection chip IC2 is connected to the S1 pin of the second field effect transistor Q2, and the S2 pin of the second field effect transistor Q2 is connected to the negative pole P- of the electrical appliance.

[0043] In an optional implementation of this embodiment, the second protection chip IC2 is an S-8261 protection chip.

[0044] Specifically, the second protection chip IC2 has built-in over-discharge detection comparator, over-charge detection comparator, discharge over-current detection comparator, load short-circuit detection comparator, and charge over-current detection comparator, combined with control logic circuit, delay circuit, and oscillation circuit to achieve overall control of the second-layer protection circuit.

[0045] Furthermore, the second protection chip IC2 includes five pins, wherein pin 1 is a DO pin, pin 2 is a VM pin, pin 3 is a CO pin, pin 5 is a VDD pin, and pin 6 is a VSS pin, wherein pin 1 is a FET gate control terminal (CMOS output terminal) for discharge control, pin 2 is a voltage detection terminal between the VM terminal and the VSS terminal (i.e., an overcurrent / charger detection terminal), pin 3 is a FET gate connection terminal (CMOS output terminal) for charging control, pin 5 is a positive power input terminal, and pin 6 is a negative power input terminal.

[0046] It should be noted that pin 4 is a blank pin and will not be described here.

[0047] In an optional implementation of this embodiment, the second field effect transistor Q2 is a CJS8820 dual N-channel field effect transistor.

[0048] In an optional implementation of this embodiment, the second layer protection circuit further includes a third resistor R3, a fourth resistor R4, and a second capacitor C2.

[0049] Specifically, the first end of the third resistor R3 is connected to the positive electrode B+ of the power supply, the second end of the third resistor R3 is connected to pin 5 of the second protection chip IC2, the first end of the fourth resistor R4 is connected to pin 2 of the second protection chip IC2, the second end of the fourth resistor R4 is connected to pin 2 of the second protection chip IC2, the first end of the second capacitor C2 is connected to pin 5 of the second protection chip IC2, and the second end of the second capacitor C2 is connected to pin 6 of the second protection chip IC2.

[0050] Furthermore, the resistance value of the third resistor R3 is 471 ohms, the resistance value of the fourth resistor R4 is 2K ohms, and the second capacitor C2 is a 104 capacitor with a capacitance value of 0.1 uF.

[0051] In an optional implementation of this embodiment, the power source is a 18650 lithium battery.

[0052] Working principle: When the power supply charges the electrical appliance, it first passes through the first layer of protection circuit. The first protection chip protects the power supply from overcharging, over-discharging and over-current through the built-in high-precision voltage detection circuit and delay circuit. The N-channel sub-field effect transistor connected to the pin 1 of the first protection chip in the first field effect transistor realizes discharge control. The N-channel sub-field effect transistor connected to the pin 3 of the first protection chip in the first field effect transistor realizes charging control. The first resistor and the second resistor are used for ESD countermeasures and power supply variation countermeasures. The first capacitor is used for power supply variation countermeasures to realize the protection of the first layer of protection circuit on the power supply and electrical appliances. The second layer of protection circuit is the same.

[0053] In summary, the first embodiment of the utility model proposes a charging protection circuit, which sets up two layers of protection circuits, adopts the S-8261 protection chip and the CJS8820 dual N-channel field effect transistor, and applies electrostatic release protection to achieve overcharging and over-discharging control, with better protection effect. It can realize secondary safety protection of the power supply for charging electrical appliances, and ensure the charging safety performance of electrical appliances to the greatest extent.

[0054] Embodiment 2

[0055] Embodiment 2 of the present invention provides a charging protection device, which includes the charging protection circuit in embodiment 1.

[0056] In summary, the second embodiment of the utility model proposes a charging protection device, which is provided with the charging protection circuit in the first embodiment. By setting up two layers of protection circuits, adopting the S-8261 protection chip and the CJS8820 dual N-channel field effect transistor, electrostatic release protection is applied to achieve overcharging and over-discharging control, and the protection effect is better. It can realize secondary safety protection of the power supply for charging electrical appliances, and ensure the charging safety performance of electrical appliances to the greatest extent.

[0057] Embodiment 3

[0058] A third embodiment of the present invention provides an electrical appliance, wherein the electrical appliance is provided with the charging protection device of the second embodiment.

[0059] In summary, embodiment 3 of the present invention proposes an electrical appliance, which is provided with the charging protection device in embodiment 2, and the charging protection device is provided with the charging protection circuit in embodiment 1. By setting up two layers of protection circuits, adopting the S-8261 protection chip and the CJS8820 dual N-channel field effect transistor, electrostatic release protection is applied to achieve overcharging and over-discharging control, and the protection effect is better. It can realize secondary safety protection of the power supply for charging the electrical appliance, and ensure the charging safety performance of the electrical appliance to the greatest extent.

[0060] A charging protection circuit, a charging protection device and an electrical appliance provided by an embodiment of the utility model are introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the utility model. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model; at the same time, for general technical personnel in this field, according to the idea of ​​the utility model, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the utility model.

Claims

1. A charging protection circuit, characterized in that: The charging protection circuit comprises a first layer protection circuit and a second layer protection circuit, the input end of the first layer protection circuit is connected to a power source, the output end of the first layer protection circuit is connected to the input end of the second layer protection circuit, and the output end of the second layer protection circuit is connected to an electrical appliance; The first layer protection circuit includes a first protection chip and a first field effect transistor, wherein pin 1 of the first protection chip is connected to pin G1 of the first field effect transistor, pin 3 of the first protection chip is connected to pin G2 of the first field effect transistor, and pin 6 of the first protection chip is connected to pin S1 of the first field effect transistor and the negative electrode of the power supply; The second layer protection circuit includes a second protection chip and a second field effect transistor, wherein pin 1 of the second protection chip is connected to pin G1 of the second field effect transistor, pin 3 of the second protection chip is connected to pin G2 of the second field effect transistor, pin 6 of the second protection chip is connected to pin S1 of the second field effect transistor, and pin S2 of the second field effect transistor is connected to the negative electrode of the electrical appliance; The S2 pin of the first field effect transistor is connected to the S1 pin of the second field effect transistor.

2. The charging protection circuit according to claim 1, characterized in that: The first protection chip is an S-8261 protection chip.

3. The charging protection circuit according to claim 1, characterized in that: The first layer protection circuit also includes a first resistor, a second resistor, and a first capacitor; The first end of the first resistor is connected to the positive electrode of the power supply, the second end of the first resistor is connected to pin 5 of the first protection chip, the first end of the second resistor is connected to pin 2 of the first protection chip, the second end of the second resistor is connected to pin 2 of the first protection chip, the first end of the first capacitor is connected to pin 5 of the first protection chip, and the second end of the first capacitor is connected to pin 6 of the first protection chip.

4. The charging protection circuit according to claim 1, characterized in that: The first field effect transistor is a CJS8820 dual N-channel field effect transistor.

5. The charging protection circuit according to claim 1, characterized in that: The second protection chip is an S-8261 protection chip.

6. The charging protection circuit according to claim 1, characterized in that: The second layer protection circuit also includes a third resistor, a fourth resistor, and a second capacitor; The first end of the third resistor is connected to the positive electrode of the power supply, the second end of the third resistor is connected to pin 5 of the second protection chip, the first end of the fourth resistor is connected to pin 2 of the second protection chip, the second end of the fourth resistor is connected to pin 2 of the second protection chip, the first end of the second capacitor is connected to pin 5 of the second protection chip, and the second end of the second capacitor is connected to pin 6 of the second protection chip.

7. The charging protection circuit according to claim 1, characterized in that: The second field effect transistor is a CJS8820 dual N-channel field effect transistor.

8. The charging protection circuit according to claim 1, characterized in that: The power source is a 18650 lithium battery.

9. A charging protection device, characterized in that: The charging protection device comprises the charging protection circuit according to any one of claims 1-8.

10. An electrical appliance, characterized in that: The electrical appliance is provided with the charging protection device according to claim 9.

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