Charging circuit and charger

Abstract

A first end of the buffer module is connected with a battery pack and is used for supplying power to the battery pack, a second end of the buffer module is connected with a charging control module, and a third end of the buffer module is connected with a first power supply; the charging control module comprises an acquisition end and a control end, the acquisition end is connected with the battery pack and used for acquiring current of the battery pack, and the control end is connected with the buffer module and used for controlling output current of the buffer module. Through the mode, the current information of the battery pack can be obtained in real time, the control end is connected with the buffer module, and the charging control module can adjust the output current of the buffer module according to the collected current information, so that direct impact of power supply fluctuation on the battery pack in the charging process is avoided, the charging safety of the battery pack is improved, and meanwhile, the charging efficiency is improved. And necessary time is provided for the charging control module to configure a current loop, so that the active control of the charging current is realized. The charging efficiency is improved, and the service life of the battery pack is prolonged.

Description

Technical Field

[0001] This application relates to the field of charging circuit technology, and in particular to a charging circuit and charger. Background Technology

[0002] With the rapid development of lithium battery technology, lithium batteries have been widely used in various electronic products, drones, automobiles, and portable tools. In particular, power tools, with their cordless, miniaturized, and lightweight designs, have become an industry trend and are gradually becoming common in every household.

[0003] Currently available chargers may damage the battery pack due to excessive current surges when connecting it. Utility Model Content

[0004] The main technical problem addressed by this application is to provide a charging circuit and charger that controls the output current of the buffer module based on the collected information, thereby improving the charging safety of the battery pack.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application is: to provide a charging circuit, including: a buffer module: the first end of the buffer module is connected to the battery pack for supplying power to the battery pack, the second end is connected to the charging control module, and the third end is connected to the first power source; the charging control module includes a data acquisition end and a control end, the data acquisition end is connected to the battery pack for acquiring the current of the battery pack, and the control end is connected to the buffer module for controlling the output current of the buffer module.

[0006] The buffer module includes: a first voltage divider resistor, a second voltage divider resistor, a first switching transistor, and a first Zener diode; one end of the first voltage divider resistor is connected to the battery pack, the other end of the first voltage divider resistor is connected to one end of the second voltage divider resistor, the other end of the first voltage divider resistor is connected to the reference terminal of the first Zener diode, the anode of the first Zener diode is grounded, the cathode of the first Zener diode is connected to the charging control module, the collector of the first switching transistor is connected to the other end of the first voltage divider resistor through a first resistor unit, the base of the first switching transistor is connected to a first power supply, the base of the first switching transistor is connected to one end of a first capacitor, the other end of the first capacitor is grounded, the emitter of the first switching transistor is grounded, and the other end of the first voltage divider resistor is connected to the control terminal of the charging control module.

[0007] The charging control module includes a processing unit and a control unit. The input of the processing unit is connected to the acquisition unit, and the output of the processing unit outputs a current control signal. The input of the control unit is communicatively connected to the output of the processing unit, and the output of the control unit serves as the output of the charging control module.

[0008] The processing unit includes a first operational amplifier and a second operational amplifier. The positive input terminal of the first operational amplifier is connected to the battery pack through a sampling resistor. The output terminal of the first operational amplifier is grounded through a second resistor unit. The negative input terminal of the first operational amplifier is grounded through a third resistor unit. The positive input terminal of the second operational amplifier is connected to the anode of the Zener diode through a fourth resistor unit. The negative input terminal of the second operational amplifier is connected to the battery pack through a sampling resistor. The output terminal of the second operational amplifier is connected to the negative terminal of the Zener diode through a sixth resistor unit.

[0009] The input terminal of the control unit is connected to the output terminal of the processing unit via an optocoupler isolation unit, and the control unit includes an AC-DC chip.

[0010] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a charger that includes the charging circuit of any of the above-mentioned items.

[0011] The beneficial effects of this application are as follows: Unlike the prior art, the charging circuit of this application is connected to the battery pack through the acquisition end of the charging control module, which can obtain the current information of the battery pack in real time. The control end is connected to the buffer module. According to the acquired current information, the charging control module can adjust the output current of the buffer module to avoid the direct impact of power fluctuations on the battery pack during the charging process, thereby improving the charging safety of the battery pack. Attached Figure Description

[0012] Figure 1 This is a circuit diagram of one embodiment of the charging circuit of this application.

[0013] Figure 2 This is a schematic diagram of the structure of an embodiment of the charger of this application. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0015] It should be understood that the features described in the specification and claims of this application, specifically the terms "first" and "second," may explicitly or implicitly include one or more of those features. Furthermore, the terms "comprising," "including," or any other variations thereof as used herein are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0016] To make the purpose, technical solution and effects of this application clearer and more explicit, the following describes this application in further detail with reference to the accompanying drawings and embodiments.

[0017] This application provides a charging circuit, see reference. Figure 1 , Figure 1 This is a schematic diagram of a charging circuit according to an embodiment of the present application. The charging circuit includes: a buffer module: the first end of the buffer module is connected to the battery pack for supplying power to the battery pack, the second end is connected to the charging control module, and the third end is connected to the first power source; the charging control module includes a data acquisition end and a control end, the data acquisition end is connected to the battery pack for acquiring the current of the battery pack, and the control end is connected to the buffer module for controlling the output current of the buffer module.

[0018] The above solution connects the charging control module to the battery pack via its acquisition terminal, enabling real-time acquisition of the battery pack's current information. The control terminal connects to the buffer module, allowing the charging control module to adjust the buffer module's output current based on the acquired current information. This helps prevent power fluctuations during charging from directly impacting the battery pack and improves charging safety.

[0019] In some embodiments, the buffer module includes: a first voltage divider resistor R18, a second voltage divider resistor R34, a first switch Q8, and a first Zener diode IC1; one end of the first voltage divider resistor R18 is connected to the battery pack, the other end of the first voltage divider resistor R18 is connected to one end of the second voltage divider resistor R34, the other end of the first voltage divider resistor R18 is connected to the reference terminal of the first Zener diode IC1, the anode of the first Zener diode IC1 is grounded, the cathode of the first Zener diode IC1 is connected to the charging control module, the collector of the first switch Q8 is connected to the other end of the first voltage divider resistor R18 through a first resistor unit, the base of the first switch Q8 is connected to a first power supply, the base of the first switch Q8 is connected to one end of a first capacitor C26, the other end of the first capacitor C26 is grounded, the emitter of the first switch Q8 is grounded, and the other end of the first voltage divider resistor R18 is connected to the control terminal of the charging control module.

[0020] Specifically, when the charger is connected to the battery pack, the battery pack voltage is divided by the first voltage divider resistor R18 and the second voltage divider resistor R34, and then supplied to the reference terminal of the first Zener diode IC1. Zener diode IC1 outputs a stable voltage to the charging control module based on the provided reference voltage. Simultaneously, the first capacitor C26 begins charging. When the voltage of capacitor C26 reaches a certain level, it will turn on the first switching transistor Q8. After the first switching transistor Q8 turns on, it changes the voltage division ratio of the voltage divider circuit, thereby increasing the output voltage Vout. During this period, the charging control module adjusts the output current of the buffer module according to preset control logic.

[0021] In some specific embodiments, the first resistor unit includes resistors R35 and R58. One end of resistor R35 is connected to the collector of the first switching transistor Q8, and the other end of resistor R35 is connected to the other end of the first voltage divider resistor R18. The base of the first switching transistor Q8 is connected to the first power supply through resistor R59. In some application scenarios, the first power supply can be 5V. A resistor R60 is connected in parallel across capacitor C26. The cathode of Zener diode IC1 is connected to one end of resistor R49, and the other end of resistor R49 is connected to one end of capacitor C11. The other end of capacitor C11 is connected to the reference terminal of Zener diode IC1. Through the combined action of the voltage divider circuit, Zener diode, switching transistor, and capacitor, a buffer function is provided when the charger is connected to the battery pack. At the same time, it also provides the necessary time for the charging control module to configure the current loop, thereby realizing active control of the charging current. This improves charging efficiency and extends the battery pack life.

[0022] In some embodiments, the charging control module includes a processing unit and a control unit. The input terminal of the processing unit is connected to the acquisition terminal, and the output terminal of the processing unit outputs a current control signal. The input terminal of the control unit is communicatively connected to the output terminal of the processing unit, and the output terminal of the control unit serves as the output terminal of the charging control module.

[0023] Specifically, during charging, the acquisition unit obtains the battery pack's current information in real time and transmits it to the processing unit. The processing unit processes the received current information and generates a current control signal based on the processing result. The control unit receives the current control signal output by the processing unit and adjusts the output current of the buffer module according to the signal to ensure the safety and efficiency of the charging process.

[0024] In some embodiments, the processing unit includes a first operational amplifier and a second operational amplifier. The positive input terminal U1-1 of the first operational amplifier is connected to the battery pack through a sampling resistor. The output terminal U1-10 of the first operational amplifier is grounded through a second resistor unit. The negative input terminal U1-11 of the first operational amplifier is grounded through a third resistor unit. The positive input terminal U1-12 of the second operational amplifier is connected to the anode of the Zener diode IC1 through a fourth resistor unit. The negative input terminal U1-13 of the second operational amplifier is connected to the battery pack through a sampling resistor. The output terminal U1-8 of the second operational amplifier is connected to the cathode of the Zener diode IC1 through a sixth resistor unit.

[0025] Specifically, the positive input terminal U1-1 of the first operational amplifier is connected to the battery pack via a sampling resistor to acquire the current or voltage information of the battery pack. The output terminal U1-10 is grounded via a second resistor unit, forming a negative feedback circuit to help stabilize the amplifier's output voltage. The negative input terminal U1-11 is grounded via a third resistor unit, serving as a reference potential point for comparison with the positive input terminal, thereby amplifying the input signal. The positive input terminal U1-12 of the second operational amplifier is connected to the anode of the Zener diode IC1 via a fourth resistor unit. The Zener diode provides a stable reference voltage for the second operational amplifier's comparison and amplification operations. The negative input terminal U1-13 is connected to the battery pack via a sampling resistor, and the output terminal U1-8 is connected to the negative terminal of the Zener diode via a sixth resistor unit, forming a feedback circuit to adjust the output voltage of the second operational amplifier.

[0026] In some specific embodiments, the first operational amplifier is used to directly amplify the current or voltage signal obtained from the battery pack. The second operational amplifier is used to compare it with the reference voltage provided by the Zener diode and output a corresponding control signal based on the comparison result, enabling the charger to use battery packs of various capacities and states. Different charging currents are used at different temperatures and voltage ranges, improving charging efficiency and extending battery pack life.

[0027] In some specific embodiments, the positive input terminal U1-1 of the first operational amplifier is connected to the battery pack through a first acquisition resistor R40, and the negative input terminal U1-13 of the second operational amplifier is connected to the battery pack through a second acquisition resistor R40. The second resistor unit includes resistors R30 and R33 connected in series, and the second resistor unit is resistor R33. The fourth resistor unit is resistor R37, and a capacitor C12 is connected in parallel across resistor R37. The positive input terminal U1-12 of the second operational amplifier is also connected to a first power supply through resistor R32. The positive input terminal U1-12 of the second operational amplifier is also connected to one end of resistor R41, and the other end of resistor R41 is connected to the negative terminal of diode D7. The positive terminal of diode D7 is connected to a reference voltage. The positive terminal of diode D7 is connected to one end of diode C14, the negative terminal of diode C14 is grounded, and a resistor R56 is connected in parallel across diode C14. The sixth resistor unit includes a resistor R29 and an inductor J20 connected in series. The output terminal U1-8 of the second operational amplifier is connected to one end of resistor R31, the other end of resistor R31 is connected to capacitor C9, and the other end of capacitor C9 is connected to the negative input terminal U1-13 of the second operational amplifier. The output terminal U1-8 of the second operational amplifier is connected to the negative terminal of diode D6 through the sixth resistor unit, and the positive terminal of diode D6 is connected to the cathode of Zener diode IC1.

[0028] In some embodiments, the input terminal of the control unit is communicatively connected to the output terminal of the processing unit via an optocoupler isolation unit, and the control unit includes an AC-DC chip.

[0029] Specifically, after processing the acquired battery pack current signal, the control unit sends the control signal to the AC-DC chip via the optocoupler isolation unit. The main function of the optocoupler isolation unit is to isolate the high-voltage circuit and the low-voltage circuit, preventing the voltage and current in the high-voltage circuit from interfering with or damaging the low-voltage circuit. After receiving the control signal from the MCU, the AC-DC chip adjusts its internal PWM (Pulse Width Modulation) or PFM (Pulse Frequency Modulation) control signal according to the magnitude and direction of the signal, thereby changing the output voltage and current to achieve precise control of the charging current. When the battery pack requires a larger charging current, the MCU outputs a larger control signal, causing the AC-DC chip to increase the output voltage and current; conversely, when the battery pack requires a smaller charging current, the MCU outputs a smaller control signal, causing the AC-DC chip to decrease the output voltage and current.

[0030] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of one embodiment of the charger of this application. The charger 20 includes the charging circuit 21 of any of the above embodiments.

[0031] In the above scheme, the charging circuit 21 used in this application is connected to the battery pack through the acquisition terminal of the charging control module, which can obtain the current information of the battery pack in real time. The control terminal is connected to the buffer module. According to the acquired current information, the charging control module can adjust the output current of the buffer module to ensure that the power fluctuation during the charging process does not directly impact the battery pack, thereby improving the charging safety of the battery pack.

[0032] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A charging circuit, characterized in that, include: Buffer module: The first end of the buffer module is connected to the battery pack to supply power to the battery pack, the second end is connected to the charging control module, and the third end is connected to the first power source; The charging control module includes a data acquisition terminal and a control terminal. The data acquisition terminal is connected to the battery pack and is used to acquire the current of the battery pack. The control terminal is connected to the buffer module and is used to control the output current of the buffer module.

2. The charging circuit according to claim 1, characterized in that, The buffer module includes: a first voltage divider resistor, a second voltage divider resistor, a first switching transistor, and a first Zener diode; one end of the first voltage divider resistor is connected to the battery pack, the other end of the first voltage divider resistor is connected to one end of the second voltage divider resistor, the other end of the first voltage divider resistor is connected to the reference terminal of the first Zener diode, the anode of the first Zener diode is grounded, the cathode of the first Zener diode is connected to the charging control module, the collector of the first switching transistor is connected to the other end of the first voltage divider resistor through a first resistor unit, the base of the first switching transistor is connected to the first power supply, the base of the first switching transistor is connected to one end of a first capacitor, the other end of the first capacitor is grounded, the emitter of the first switching transistor is grounded, and the other end of the first voltage divider resistor is connected to the control terminal of the charging control module.

3. The charging circuit according to claim 2, characterized in that, The charging control module includes: Processing unit: The input terminal of the processing unit is connected to the acquisition terminal, and the output terminal of the processing unit outputs a current control signal; Control unit: The input terminal of the control unit is communicatively connected to the output terminal of the processing unit, and the output terminal of the control unit serves as the output terminal of the charging control module.

4. The charging circuit according to claim 3, characterized in that, The processing unit includes a first operational amplifier and a second operational amplifier. The positive input terminal of the first operational amplifier is connected to the battery pack through a sampling resistor. The output terminal of the first operational amplifier is grounded through a second resistor unit. The negative input terminal of the first operational amplifier is grounded through a third resistor unit. The positive input terminal of the second operational amplifier is connected to the anode of the Zener diode through a fourth resistor unit. The negative input terminal of the second operational amplifier is connected to the battery pack through the sampling resistor. The output terminal of the second operational amplifier is connected to the negative terminal of the Zener diode through a sixth resistor unit.

5. The charging circuit according to claim 3, characterized in that, The input terminal of the control unit is communicatively connected to the output terminal of the processing unit through an optocoupler isolation unit, and the control unit includes an AC-DC chip.

6. A charger, characterized in that, The charger includes the charging circuit as described in any one of claims 1-5.

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