Simple multifunctional lithium battery charging circuit and charger

Abstract

The utility model discloses a simple multifunctional lithium battery charging circuit and a charger, and relates to the technical field of battery charging. The technical problem that an existing charging product is single in function is solved. The circuit comprises a charging voltage selection module used for acquiring a charging voltage corresponding to a to-be-charged battery; the voltage conversion module is provided with a positive end, a negative end, a power supply access end and a feedback voltage connection end, the positive end and the negative end are used for being connected with a battery to be charged, the charging voltage selection module is connected with the feedback voltage connection end, and the power supply access end is connected with a charging power supply; the current adjusting module is provided with a reference voltage input end, an input end and an output end, the input end of the current adjusting module is connected with the negative end of the voltage conversion module, the output end of the current adjusting module is connected with the feedback voltage connecting end, the reference voltage input end of the current adjusting module is connected with reference voltage, and the current adjusting module is used for obtaining charging current corresponding to the charging voltage. Functions of existing charging equipment are improved, use is convenient, and the charging experience of a user is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of battery charging technology, and in particular to a simple multifunctional lithium battery charging circuit and charger. Background Technology

[0002] Charging products have a wide range of applications, especially in daily life where they are widely used for charging consumer products such as mobile phones, cameras, electric vehicles, and new energy vehicles. In electrical applications where lithium batteries serve as the working or backup power source, charging products have broad application prospects.

[0003] However, commonly used lithium battery charging products can only charge one type of battery. For example, they can only provide a standard charging voltage of 5V, and cannot simultaneously charge fast charging voltages of 9V and above. Therefore, their charging function is limited, resulting in a poor user experience. Especially in large-scale integrated charging facilities, investing in a single battery charging device requires a significant investment and is costly. Therefore, there is an urgent need for a multi-functional charging technology to solve the technical problems of limited functionality and high investment costs of existing charging products. Utility Model Content

[0004] The purpose of this utility model is to provide a simple, multifunctional lithium battery charging circuit and charger to solve the technical problems of limited functionality and high investment costs in the prior art. The various technical effects of the preferred solutions among the many technical solutions provided by this utility model are detailed below.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] According to a first aspect of this utility model, a simple multifunctional lithium battery charging circuit is provided, comprising:

[0007] A charging voltage selection module is used to obtain the charging voltage corresponding to the battery to be charged; a voltage conversion module is provided with a positive terminal and a negative terminal for connecting to the battery to be charged, as well as a power input terminal and a feedback voltage connection terminal. The charging voltage selection module is connected to the feedback voltage connection terminal, and the power input terminal is connected to a charging power supply; a current adjustment module is provided with a reference voltage input terminal, an input terminal, and an output terminal. The input terminal of the current adjustment module is connected to the negative terminal of the voltage conversion module, its output terminal is connected to the feedback voltage connection terminal, and its reference voltage input terminal is connected to a reference voltage. The current adjustment module is used to obtain the charging current corresponding to the charging voltage.

[0008] In some embodiments, the voltage conversion module includes a step-down converter U1, an inductor L, a thermistor PTC, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4; the first diode D1 and the second diode D2 are connected in parallel, with their positive terminals connected to the circuit. The charging power supply has its negative terminal connected to one plate of the parallel-connected first capacitor C1, second capacitor C2, and third capacitor C3. The other plate of the parallel-connected first capacitor C1, second capacitor C2, and third capacitor C3 is grounded. One branch of one plate of the parallel-connected first capacitor C1, second capacitor C2, and third capacitor C3 is connected to pin 5 of the buck converter U1, and the other branch is connected to pin 4 of the buck converter U1 via a fourth capacitor C4. An inductor L is connected in series with a thermistor PTC. One end of the inductor L is connected to pin 3 of the buck converter U1, and one end of the thermistor PTC serves as the voltage conversion module. The positive terminal of the block is used to connect to the positive terminal of the battery to be charged; the third diode D3 and the fourth diode D4 are connected in parallel, with the negative terminal of the parallel connection connected to pin 3 of the buck converter U1, and the positive terminal of the parallel connection grounded; the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7 are connected in parallel, with one end connected between the series inductor L and the thermistor PTC, and the other end grounded; the fifth diode D5 and the sixth diode D6 are connected in parallel, with the positive terminal of the parallel connection connected to one end of the parallel fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7, and the negative terminal of the parallel connection connected to the other end of the thermistor PTC; the first resistor R1... One end is connected between the positive terminals of the third diode D3 and the fourth diode D4 connected in parallel and the other end of the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7 connected in parallel. The other end serves as the negative terminal of the voltage conversion module and is used to connect to the negative terminal of the battery to be charged. The second resistor R2 and the third resistor R3 are connected in series. One end of the second resistor R2 is connected to pin 2 of the buck converter U1, and one end of the third resistor R3 is grounded. The eighth capacitor C8 is connected in parallel with the fourth resistor R4. One end of the parallel connection is connected to pin 2 of the buck converter U1, and the other end is connected to one end of the thermistor PTC and grounded through the ninth capacitor C9.

[0009] In some embodiments, the charging voltage selection module includes a switch selection unit, multiple charging voltage lines, and multiple indicator light lines corresponding to the operating states of the multiple charging voltage lines. The switch selection unit selects the charging voltage corresponding to the battery to be charged in the multiple charging voltage lines, and the selected charging voltage line is indicated by the corresponding indicator light line. One end of each charging voltage line is connected to the switch selection unit, and the other end is connected to the feedback voltage connection terminal. One end of each indicator light line is connected to the switch selection unit, and the other end is grounded.

[0010] In some embodiments, the switch selection unit is a first counter U2, and the charging voltage line and indicator light line are both 5-channel; each charging voltage line includes three resistors connected in series, with a MOSFET connected between the middle and last two series resistors. The drain of the MOSFET is connected to one end of the middle resistor, its gate is connected to one end of the last resistor, and its source is grounded; the other end of the last resistor of each charging voltage line is connected to one of the pins 1, 2, 4, 7, and 10 of the first counter U2, and one end of the resistor connected in series at the beginning is connected to the feedback voltage connection terminal; each indicator light line includes a resistor and a light-emitting diode, the negative terminal of the light-emitting diode is grounded, its positive terminal is connected to one end of the resistor, and the other end of the resistor is connected to the same pin of the first counter U2 as the other end of the last resistor of the corresponding charging voltage line.

[0011] In some embodiments, the simplified multi-functional lithium battery charging circuit further includes a first inverter U5 for preventing the charging voltage selection module switch button from being accidentally triggered. Pin 2 of the first inverter U5 is connected to the operating power supply through a double-pole single-throw switch, and pin 4 is connected to pin 14 of the first counter U2.

[0012] In some embodiments, the current regulation module includes an operational amplifier module, an amplification factor switching unit, multiple current regulation lines, and multiple adjustment indicator light lines corresponding to the working states of the multiple current regulation lines. The amplification factor switching unit selects the charging current of the battery to be charged in the multiple current regulation lines, and the selected current regulation line is indicated by the corresponding adjustment indicator light line. One end of each current regulation line is connected to the operational amplifier module, and the other end is connected to the amplification factor switching unit. One end of each adjustment indicator light line is connected to the amplification factor switching unit, and the other end is grounded.

[0013] In some embodiments, the operational amplifier module is an operational amplifier U4, the amplification factor switching unit is a second counter U3, and the current adjustment circuit and the adjustment indicator circuit are both three-channel. Each current adjustment circuit has three resistors connected in series. A MOSFET is connected between the middle and the last two series resistors. The drain of the MOSFET is connected to one end of the middle resistor, its gate is connected to one end of the last resistor, and its source is grounded. The other end of the last resistor of each current adjustment circuit is connected to one of the pins 1, 2, and 3 of the second counter U3. One end of the resistor connected in series at the beginning is connected to pins 1, 2, and 5 of the operational amplifier U4. Each indicator circuit includes a resistor and a light-emitting diode. The negative terminal of the light-emitting diode is grounded, its positive terminal is connected to one end of the resistor, and the other end of the resistor is connected to the other end of the last resistor of the corresponding current adjustment circuit and to the same pin of the second counter U3. Pin 1 of the operational amplifier U4 is connected to its pin 5, its pin 3 is connected to the negative terminal of the voltage conversion module, its pin 6 is connected to the reference voltage, and its pin 7 is connected to the feedback voltage connection terminal of the voltage conversion module.

[0014] In some embodiments, the simplified multi-functional lithium battery charging circuit further includes a second inverter U6 for preventing accidental triggering of the switch button of the current regulation module. Pin 2 of the second inverter U6 is connected to the working power supply through a double-pole single-throw switch, and pin 4 is connected to pin 14 of the second counter U3.

[0015] In some embodiments, the simplified multifunctional lithium battery charging circuit further includes a low-dropout voltage regulator module, which is connected to both the charging voltage selection module and the current regulation module. The low-dropout voltage regulator module converts the charging power supply into the operating voltage required by the charging voltage selection module and the current regulation module.

[0016] According to another aspect of the present invention, a charger is also provided, the charger including the simple multi-functional lithium battery charging circuit described above.

[0017] Implementing one of the above-described technical solutions of this utility model has the following advantages or beneficial effects:

[0018] This invention achieves simple and multifunctional charging of lithium batteries through a charging voltage selection module, a voltage conversion module, and a current regulation module, enhancing the functionality of existing charging equipment and providing ease of use, thus effectively improving the user charging experience. The entire charging process is implemented using only electrical components, allowing for the configuration of corresponding low-cost electrical components to reduce related costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0020] Figure 1 A simplified multifunctional lithium battery charging circuit structure block diagram according to an embodiment of this utility model;

[0021] Figure 2 A schematic diagram of the voltage conversion module circuit of this utility model embodiment;

[0022] Figure 3 Schematic diagram of the charging voltage selection module, current regulation module circuit and low dropout voltage regulator module of this utility model embodiment;

[0023] Figure 4 This utility model provides a schematic diagram of the operational amplifier and its peripheral circuitry according to an embodiment. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, various exemplary embodiments described below will be referenced to the accompanying drawings, which form part of the exemplary embodiments, illustrating various exemplary embodiments that may be adopted to implement this utility model. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. It should be understood that they are merely examples of processes, methods, and apparatuses consistent with some aspects of this utility model disclosed as detailed in the appended claims, and other embodiments may be used, or structural and functional modifications may be made to the embodiments listed herein without departing from the scope and spirit of this utility model.

[0025] In the description of this utility model, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. The terms "connected" and "linked" should be interpreted broadly, for example, they can refer to fixed connections, detachable connections, integral connections, mechanical connections, electrical connections, communication connections, direct connections, indirect connections via an intermediate medium, or connections within two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] To illustrate the technical solution described in this utility model, specific embodiments are described below, showing only the parts related to the embodiments of this utility model.

[0027] Example 1:

[0028] like Figure 1 As shown in the figure, this embodiment provides a simple, multifunctional lithium battery charging circuit, including:

[0029] Charging voltage selection module 1 is used to obtain the charging voltage corresponding to the battery to be charged;

[0030] The voltage conversion module 2 is equipped with a positive terminal Batt+ and a negative terminal Batt- for connecting to the battery to be charged, as well as a power input terminal and a feedback voltage connection terminal. The charging voltage selection module 1 is connected to the feedback voltage connection terminal, and the power input terminal is connected to the charging power supply VIN.

[0031] The current regulation module 3 is provided with a reference voltage input terminal, an input terminal, and an output terminal. The input terminal of the current regulation module 3 is connected to the negative terminal of the voltage conversion module 2, its output terminal is connected to the feedback voltage connection terminal, and its reference voltage input terminal is connected to the reference voltage REF. The current regulation module 3 is used to obtain the charging current corresponding to the charging voltage.

[0032] Based on the above embodiments, the simplified multi-functional lithium battery charging circuit connects to the charging power supply VIN and the reference voltage REF. After the circuit starts, the voltage conversion module 2 converts the charging power supply VIN into DC power, forming a stable power supply voltage. The user selects the charging voltage corresponding to the battery to be charged through the charging voltage selection module 1, such as the standard charging voltage 5V, fast charging voltage 9V, fast charging voltage 12V, fast charging voltage 20V, and other charging voltages such as 4.5V and 10V. The current adjustment module 3 collects the voltage at the negative terminal of the voltage conversion module 2, amplifies it, and compares it with the reference voltage REF. After comparison, a high level or low level is output to the feedback voltage connection terminal of the voltage conversion module 2, thereby modulating the PWM duty cycle of the voltage conversion module 2 to obtain the charging current corresponding to the charging voltage, thus realizing simplified multi-functional charging of lithium batteries and improving the user's charging experience. It should be noted that the entire charging process is implemented only through electrical components, allowing for the configuration of corresponding low-cost electrical components to reduce related costs.

[0033] Based on the above embodiments, the voltage conversion module 2 includes a step-down converter U1, an inductor L, a thermistor PTC, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. Among these,

[0034] The first diode D1 and the second diode D2 are connected in parallel. The positive terminal of the parallel connection is connected to the charging power supply VIN, and the negative terminal of the parallel connection is connected to one plate of the first capacitor C1, the second capacitor C2, and the third capacitor C3 connected in parallel. The other plate of the first capacitor C1, the second capacitor C2, and the third capacitor C3 connected in parallel is grounded. One branch of one plate of the first capacitor C1, the second capacitor C2, and the third capacitor C3 connected in parallel is connected to pin 5 of the buck converter U1, and the other branch is connected to pin 4 of the buck converter U1 through the fourth capacitor C4.

[0035] Inductor L is connected in series with the thermistor PTC. One end of inductor L is connected to pin 3 of buck converter U1. One end of the thermistor PTC serves as the positive terminal of voltage conversion module 2 and is used to connect to the positive terminal Batt+ of the battery to be charged.

[0036] The third diode D3 and the fourth diode D4 are connected in parallel, with the negative terminal of the parallel connection connected to pin 3 of the buck converter U1 and the positive terminal grounded; the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7 are connected in parallel, with one end connected between the series inductor L and the thermistor PTC, and the other end grounded; the fifth diode D5 and the sixth diode D6 are connected in parallel, with the positive terminal of the parallel connection connected to one end of the parallel fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7, and the negative terminal connected to the other end of the thermistor PTC;

[0037] One end of the first resistor R1 is connected between the positive terminals of the third diode D3 and the fourth diode D4 connected in parallel and the other ends of the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7 connected in parallel. The other end serves as the negative terminal Batt- of the voltage conversion module 2, used to connect to the negative terminal of the battery to be charged. The second resistor R2 and the third resistor R3 are connected in series. One end of the second resistor R2 is connected to pin 2 of the buck converter U1, and one end of the third resistor R3 is grounded. The eighth capacitor C8 is connected in parallel with the fourth resistor R4. One end of the parallel connection is connected to pin 2 of the buck converter U1, and the other end is connected to one end of the thermistor PTC, and grounded through the ninth capacitor C9.

[0038] It should be noted that diodes D1, D2, D3, D4, D5, and D6 can be surface-mount Schottky diodes. The buck converter U1 can be an XL4015. Buck converter U1 and its peripheral circuitry convert the input voltage into the required charging voltage, thereby enabling simple and multi-functional charging of lithium batteries and improving the user's charging experience.

[0039] The diodes connected in parallel form a rectifier circuit, converting AC power into DC power. The capacitors connected in parallel form a DC protection circuit, which can stabilize the power supply voltage.

[0040] The aforementioned thermistor PTC can suppress or even block current, thereby protecting components or downstream circuits in the circuit.

[0041] Based on the above embodiments, the charging voltage selection module 1 includes a switch selection unit, multiple charging voltage lines, and multiple indicator light lines corresponding to the operating states of the multiple charging voltage lines. The switch selection unit selects the corresponding charging voltage for the battery to be charged from among the multiple charging voltage lines, and the selected charging voltage line is indicated by the corresponding indicator light line illuminating. Further, one end of each charging voltage line is connected to the switch selection unit, and the other end is connected to a feedback voltage connection terminal; one end of each indicator light line is connected to the switch selection unit, and the other end is grounded.

[0042] like Figure 3 As shown in the illustration, as a specific example, the switch selection unit is the first counter U2, and there are 5 charging voltage lines and 5 indicator light lines. Specifically, each charging voltage line includes three resistors connected in series. A MOSFET is connected between the middle and last two series resistors. The drain of the MOSFET is connected to one end of the middle resistor, its gate is connected to one end of the last resistor, and its source is grounded. The other end of the last resistor of each charging voltage line is connected to one of the pins 1, 2, 4, 7, and 10 of the first counter U2 (i.e., pins 1, 2, 4, 7, and 10 of the first counter U2 are connected to the other ends of the last resistors of the five charging voltage lines one by one). One end of the resistor connected in series at the beginning is connected to the feedback voltage connection terminal (pin 2 of the buck converter U1 mentioned above). Each indicator light line includes a resistor and a light-emitting diode. The negative terminal of the light-emitting diode is grounded, and its positive terminal is connected to one end of the resistor. The other end of the resistor is connected to the same pin of the first counter U2, which is the other end of the corresponding charging voltage line's last resistor.

[0043] Furthermore, the fifth resistor R5, the sixth resistor R6, the first MOSFET Q1, and the seventh resistor R7, connected in series, constitute the first charging voltage line. One end of the fifth resistor R5, connected in series at the beginning, is connected to pin 2 of the buck converter U1, and one end of the seventh resistor R7, connected in series at the end, is connected to pin 2 of the first counter U2. The indicator light circuit corresponding to the first charging voltage line consists of the twentieth resistor R20 and the LED D7, connected in series. One end of the twentieth resistor R20 is connected to pin 2 of the first counter U2, and the negative terminal of the LED D7 is grounded. Similarly,

[0044] The eighth resistor R8, the ninth resistor R9, the second MOSFET Q2, and the tenth resistor R10, connected in series, constitute the second charging voltage line. One end of the eighth resistor R8, connected in series at the beginning, is connected to pin 2 of the buck converter U1, and one end of the tenth resistor R10, connected in series at the end, is connected to pin 4 of the first counter U2. The corresponding indicator light line for the second charging voltage line consists of the twenty-first resistor R21 and the LED D8, connected in series. One end of the twenty-first resistor R21 is connected to pin 4 of the first counter U2, and the negative terminal of the LED D8 is grounded.

[0045] The eleventh resistor R11, the twelfth resistor R12, the third MOSFET Q3, and the thirteenth resistor R13, connected in series, constitute the third charging voltage line. One end of the eleventh resistor R11, connected in series at the beginning, is connected to pin 2 of the buck converter U1. One end of the thirteenth resistor R13, connected in series at the end, is connected to pin 7 of the first counter U2. The indicator light circuit corresponding to the third charging voltage line consists of the twenty-second resistor R22 and the LED D9, connected in series. One end of the twenty-second resistor R22 is connected to pin 7 of the first counter U2, and the negative terminal of the LED D9 is grounded.

[0046] The fourteenth resistor R14, the fifteenth resistor R15, the fourth MOSFET Q4, and the sixteenth resistor R16, connected in series, form the fourth charging voltage line. One end of the fourteenth resistor R14, connected in series at the beginning, is connected to pin 2 of the buck converter U1, and one end of the sixteenth resistor R16, connected in series at the end, is connected to pin 10 of the first counter U2. The indicator light circuit corresponding to the fourth charging voltage line consists of the twenty-third resistor R23 and the light-emitting diode D10, connected in series. One end of the twenty-third resistor R23 is connected to pin 10 of the first counter U2, and the negative terminal of the light-emitting diode D10 is grounded.

[0047] The five charging voltage lines are formed by connecting the seventeenth resistor R17, the eighteenth resistor R18, the fifth MOSFET Q5, and the nineteenth resistor R19 in series. One end of the seventeenth resistor R17, connected in series at the beginning, is connected to pin 2 of the buck converter U1, and one end of the nineteenth resistor R19, connected in series at the end, is connected to pin 1 of the first counter U2. The indicator light circuit corresponding to the fifth charging voltage line consists of the twenty-fourth resistor R24 ​​and the LED D11, connected in series. One end of the twenty-fourth resistor R24 ​​is connected to pin 1 of the first counter U2, and the negative terminal of the LED D11 is grounded.

[0048] Furthermore, pin 5 of the first counter U2 is connected to pin 15, and pin 16 is connected to ground through the ninth capacitor C9. Pin 16 is also connected to the operating voltage (e.g., 5V).

[0049] It should be noted that pin 3 of the first counter U2 is connected to one end of the 25th resistor R25, and the other end of the 25th resistor R25 is the positive terminal of the LED D12. The negative terminal of the LED D12 is grounded. The series connection of the 25th resistor R25 and the LED D12 can serve as an indicator and warning of whether the first counter U2 is in a normal or abnormal operating state in a simple multi-functional lithium battery charging circuit. The above five charging voltage lines correspond to one type of charging voltage. Users can select the corresponding charging voltage using the first MOSFET Q1 to the fifth MOSFET Q5. Alternatively, an intelligent identification device can be used to intelligently identify the charging voltage of the battery.

[0050] Based on the above embodiments, the current regulation module 3 includes an operational amplifier module, an amplification factor switching unit, multiple current regulation circuits, and multiple adjustment indicator light circuits corresponding to the operating status of the multiple current regulation circuits. The amplification factor switching unit selects the charging current of the battery to be charged in the multiple current regulation circuits, and the selected current regulation circuit is indicated by the corresponding adjustment indicator light. Specifically, one end of each current regulation circuit is connected to the operational amplifier module, and the other end is connected to the amplification factor switching unit; one end of each adjustment indicator light circuit is connected to the amplification factor switching unit, and the other end is grounded.

[0051] like Figure 3As shown in the illustration, as a specific example, the operational amplifier module is operational amplifier U4, the amplification factor switching unit is the second counter U3, and there are three current adjustment circuits and three indicator light circuits. Specifically, each current adjustment circuit has three resistors connected in series. A MOSFET is connected between the middle and last series resistors. The drain of the MOSFET is connected to one end of the middle resistor, its gate is connected to one end of the last resistor, and its source is grounded. The other end of the last resistor of each current adjustment circuit is connected to one of the pins 1, 2, and 3 of the second counter U3 (i.e., pins 1, 2, and 3 of the second counter U3 are connected to the other ends of the three current adjustment circuits' last resistors one by one). One end of the resistors connected in series at the beginning is connected to pins 1, 2, and 5 of the operational amplifier U4. Each indicator light circuit includes a resistor and a light-emitting diode (LED). The negative terminal of the LED is grounded, its positive terminal is connected to one end of the resistor, and the other end of the resistor is connected to the same pin of the second counter U3, which is also connected to the other end of the corresponding current adjustment circuit's last resistor.

[0052] Furthermore, the 26th resistor R26, the 27th resistor R27, the 6th MOSFET Q6, and the 28th resistor R28, connected in series, constitute the first current adjustment circuit. One end of the 26th resistor R26, which is connected first, is connected to pins 1, 2, and 5 of the operational amplifier U4, and one end of the 28th resistor R28, which is connected to pin 3 of the second counter U3. The indicator light circuit corresponding to the first current adjustment circuit consists of the 35th resistor R35 and the light-emitting diode D13. One end of the 35th resistor R35 is connected to pin 3 of the second counter U3, and the negative terminal of the light-emitting diode D13 is grounded.

[0053] The second current adjustment circuit is formed by connecting the 29th resistor R29, the 30th resistor R30, the 7th MOSFET Q7, and the 31st resistor R31 in series. One end of the 29th resistor R29, which is connected first, is connected to pins 1, 2, and 5 of the operational amplifier U4. One end of the 31st resistor R31, which is connected to the second counter U3, is connected to pin 2. The corresponding indicator light circuit for the second current adjustment circuit consists of the 36th resistor R36 and the LED D14. One end of the 36th resistor R36 is connected to pin 2 of the second counter U3, and the negative terminal of the LED D14 is grounded.

[0054] The third current adjustment circuit is formed by connecting the 32nd resistor R32, the 33rd resistor R33, the 8th MOSFET Q8, and the 34th resistor R34 in series. One end of the 32nd resistor R32, which is connected first, is connected to pins 1, 2, and 5 of the operational amplifier U4. One end of the 34th resistor R34, which is last, is connected to pin 4 of the second counter U3. The indicator light circuit corresponding to the third current adjustment circuit consists of the 37th resistor R37 and the LED D15. One end of the 37th resistor R37 is connected to pin 4 of the second counter U3, and the negative terminal of the LED D15 is grounded.

[0055] The second counter U3 has pins 10 and 15 connected, pin 8 grounded, and pin 16 grounded through the tenth capacitor. Pin 16 is also connected to the operating voltage (e.g., 5V).

[0056] It should be noted that pin 7 of the second counter U3 is connected to one end of the 38th resistor R38, and the other end of the 38th resistor R38 is the positive terminal of LED D16, while the negative terminal of LED D16 is grounded. The series connection of the 38th resistor R38 and LED D16 can serve as an indicator and warning of whether the second counter U3 is in a normal or abnormal operating state in a simple multi-functional lithium battery charging circuit. The above three current adjustment circuits correspond to one amplification factor of operational amplifier U4. Users can select the corresponding amplification factor (i.e., the charging current corresponding to the charging voltage) through the sixth MOSFET Q6 to the eighth MOSFET Q8, or through intelligent identification.

[0057] The first counter U2 and the second counter U3 mentioned above can be CD4017-5th order Johnson counters. The operational amplifier U4 can be an LM358.

[0058] Based on the above embodiments, this simple multifunctional lithium battery charging circuit also includes a first inverter U5 for preventing accidental triggering of the switch button of the charging voltage selection module 1. Pin 2 of the first inverter U5 is connected to the working power supply through a double-pole single-throw switch, and pin 4 is connected to pin 14 of the first counter U2.

[0059] like Figure 3 As shown, as a specific example, pin 2 of the first inverter U5 is connected to one end of the double-pole single-throw switch S1 through the thirty-ninth resistor R39, and the other end of the double-pole single-throw switch S1 is connected to the operating voltage (e.g., 5V); pin 3 of the first inverter U5 is grounded, and the eleventh capacitor C11 is connected between pins 2 and 3; the fortieth resistor R40 is grounded between the thirty-ninth resistor R39 and one end of the double-pole single-throw switch; pin 4 of the first inverter U5 is connected to pin 14 of the first counter U2.

[0060] Based on the above embodiments, this simple multifunctional lithium battery charging circuit also includes a second inverter U6 for preventing the switch button of the current regulation module 3 from being accidentally triggered. Pin 2 of the second inverter U6 is connected to the working power supply through a double-pole single-throw switch, and pin 4 is connected to pin 14 of the second counter U3.

[0061] like Figure 3 As shown, as a specific example, pin 2 of the second inverter U6 is connected to one end of the double-pole single-throw switch S2 through resistor R41 (41), and the other end of the double-pole single-throw switch S2 is connected to the operating voltage (e.g., 5V); pin 3 of the second inverter U6 is grounded, and capacitor C12 is connected between pins 2 and 3. Resistor R42 is connected to ground between resistor R41 (41) and one end of the double-pole single-throw switch; pin 4 of the second inverter U5 is connected to pin 14 of the second counter U3.

[0062] It should be noted that the model number of the first inverter U5 and the second inverter U6 can be Aip74lvc1.

[0063] like Figure 4 As shown, based on the above embodiment, pin 1 of operational amplifier U4 is connected to pin 5. Pin 1 is also connected to one end of resistors R26, R29, and R32 via resistor R43 (forty-third resistor). Pin 2 of operational amplifier U4 is connected to one end of resistors R26, R29, and R32, and is grounded via resistor R44 (forty-fourth resistor). Pin 3 of operational amplifier U4 is connected to the negative terminal of voltage conversion module 2 (i.e., one end of the first resistor). The 4th pin of the operational amplifier U4 is grounded through the 13th capacitor C13; the operating voltage of the operational amplifier U4 (e.g., 5V) is grounded through the 45th resistor R45 to form a reference voltage and connected to the 6th pin of the operational amplifier U4. At the same time, the 6th pin is grounded through the 46th resistor R46; the 7th pin of the operational amplifier U4 is connected to the feedback voltage connection terminal of the voltage conversion module 2 (i.e., the 2nd pin of the buck converter U1) through the 16th diode D16; the 8th pin of the operational amplifier U4 is grounded through the 14th capacitor C14.

[0064] Based on the above embodiments, this simple multifunctional lithium battery charging circuit also includes a low-dropout voltage regulator module. The low-dropout voltage regulator module is connected to both the charging voltage selection module 1 and the current regulation module 3. The low-dropout voltage regulator module converts the charging power supply into the operating voltage required by the charging voltage selection module 1 and the current regulation module 3.

[0065] As a concrete example, further as Figure 3As shown, the low-dropout voltage regulator module includes a low-dropout voltage regulator U7, a seventeenth diode D17, a fifteenth capacitor C15, and a sixteenth capacitor C16. The charging power supply VIN is connected to the Vin (input) pin of the low-dropout voltage regulator U7 via the seventeenth diode D17. One plate of the fifteenth capacitor C15 and the sixteenth capacitor C16 are connected to the GND pin of the low-dropout voltage regulator U7 and to ground. The other plate of the fifteenth capacitor C15 is connected between the negative terminal of the seventeenth diode D17 and the Vin pin of the low-dropout voltage regulator U7. The other plate of the sixteenth capacitor C16 is connected to the out (output) pin of the low-dropout voltage regulator U7. The out (output) pin of the low-dropout voltage regulator U7 is connected to pin 16 of the first counter U2, pin 16 of the second counter U3, one end of the double-pole single-throw switch S1, one end of the double-pole single-throw switch S2, and one end of the forty-fifth resistor R45, respectively.

[0066] This embodiment achieves simple and multifunctional charging of lithium batteries through a charging voltage selection module, a voltage conversion module, and a current regulation module. This enhances the functionality of existing charging equipment, is easy to use, and effectively improves the user's charging experience. The entire charging process is implemented using only electrical components, allowing for the configuration of corresponding low-cost electrical components and reducing related costs.

[0067] Example 2:

[0068] This embodiment provides a charger, including the simple multi-functional lithium battery charging circuit described in Embodiment 1. The charger in this embodiment can include small chargers, such as those for mobile smart devices like smartphones, cameras, laptops, and tablets, and can also be applied to the multi-functional charging needs of large-scale charging facilities such as large integrated testing cabinets and new energy vehicles. The circuit of this charger is consistent with that in Embodiment 1, and will not be described again here.

[0069] The above embodiments are merely specific examples and do not indicate that this utility model is implemented in only one way. The above descriptions are only preferred embodiments of this utility model. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A simple multi-functional lithium battery charging circuit, characterized in that, The application relates to a charging device for a battery, which comprises: a charging voltage selection module for obtaining a charging voltage corresponding to a battery to be charged, a voltage conversion module provided with a positive end and a negative end for connecting the battery to be charged, a power supply access end and a feedback voltage connection end, the charging voltage selection module being connected with the feedback voltage connection end, and the power supply access end being connected with a charging power supply, a current regulation module provided with a reference voltage input end, an input end and an output end, the input end of the current regulation module being connected with the negative end of the voltage conversion module, the output end of the current regulation module being connected with the feedback voltage connection end, the reference voltage input end of the current regulation module being connected with a reference voltage, and the current regulation module being used for obtaining a charging current corresponding to the charging voltage.

2. The simple multi-functional lithium battery charging circuit according to claim 1, characterized in that, The voltage conversion module comprises a step-down converter U1, an inductor L and a thermistor PTC, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a first resistor R1, a second resistor R2 and a third resistor R3. The first diode D1 and the second diode D2 are connected in parallel, the positive end of the parallel connection is connected with the charging power supply, the negative end of the parallel connection is connected with one plate of the first capacitor C1, the second capacitor C2 and the third capacitor C3, the other plate of the first capacitor C1, the second capacitor C2 and the third capacitor C3 is grounded, and one branch of the one plate of the first capacitor C1, the second capacitor C2 and the third capacitor C3 is connected with the No.5 pin of the step-down converter U1, and the other branch is connected with the No.4 pin of the step-down converter U1 through the fourth capacitor C4. The inductor L and the thermistor PTC are connected in series, one end of the inductor L is connected with the No.3 pin of the step-down converter U1, and one end of the thermistor PTC is used as the positive end of the voltage conversion module and is used for connecting the positive pole of the battery to be charged. The third diode D3 and the fourth diode D4 are connected in parallel, the negative end of the parallel connection is connected with the No.3 pin of the step-down converter U1, and the positive end of the parallel connection is grounded. The fifth capacitor C5, the sixth capacitor C6 and the seventh capacitor C7 are connected in parallel, one end of the parallel connection is connected between the inductor L and the thermistor PTC in series, and the other end of the parallel connection is grounded. The fifth diode D5 and the sixth diode D6 are connected in parallel, the positive end of the parallel connection is connected with one end of the fifth capacitor C5, the sixth capacitor C6 and the seventh capacitor C7 in parallel, and the negative end of the parallel connection is connected with the other end of the thermistor PTC. One end of the first resistor R1 is connected between the positive end of the parallel connection of the third diode D3 and the fourth diode D4 and the other end of the fifth capacitor C5, the sixth capacitor C6 and the seventh capacitor C7 in parallel, and the other end of the first resistor R1 is used as the negative end of the voltage conversion module and is used for connecting the negative pole of the battery to be charged. The second resistor R2 and the third resistor R3 are connected in series, one end of the second resistor R2 is connected with the No.2 pin of the step-down converter U1, and one end of the third resistor R3 is grounded. The eighth capacitor C8 is connected with the fourth resistor R4 in parallel, one end of the parallel connection is connected with the pin 2 of the voltage reducer U1, the other end is connected with one end of the thermistor PTC, and the other end is connected with the ninth capacitor C9.

3. The simple multi-functional lithium battery charging circuit according to claim 1, characterized in that, The charging voltage selection module comprises a switch selection unit, a plurality of charging voltage lines, and a plurality of display lamp lines corresponding to the working states of the plurality of charging voltage lines; the corresponding charging voltage of the battery to be charged in the plurality of charging voltage lines is selected through the switch selection unit, and the selected charging voltage line is indicated by lighting the corresponding display lamp line; One end of each charging voltage line is connected with the switch selection unit, and the other end is connected with the feedback voltage connection end. One end of each display lamp line is connected with the switch selection unit, and the other end is grounded.

4. The simple multi-functional lithium battery charging circuit according to claim 3, characterized in that, The switch selection unit is a first counter U2, and the charging voltage lines and the display lamp lines are both 5 lines; Each charging voltage line comprises three resistors connected in series, and a MOS tube is connected between the middle and the end of the two series resistors; the drain of the MOS tube is connected with one end of the middle resistor, the gate of the MOS tube is connected with one end of the end resistor, and the source of the MOS tube is grounded; the other end of the end resistor of each charging voltage line is connected with one of the pins 1, 2, 4, 7 and 10 of the first counter U2, and one end of the resistor connected in series at the head is connected with the feedback voltage connection end; Each display lamp line comprises a resistor and a light emitting diode; the negative electrode of the light emitting diode is grounded, the positive electrode of the light emitting diode is connected with one end of the resistor, and the other end of the resistor is connected with the same pin of the first counter U2 as the other end of the end resistor of the corresponding charging voltage line.

5. The simple multi-functional lithium battery charging circuit according to claim 4, characterized in that, The first inverter U5 is further arranged to prevent the switch key of the charging voltage selection module from being triggered by mistake; the pin 2 of the first inverter U5 is connected with the working power supply through a double-pole single-throw switch, and the pin 4 of the first inverter U5 is connected with the pin 14 of the first counter U2.

6. The simple multi-functional lithium battery charging circuit according to claim 1, characterized in that, The current regulation module comprises an operational amplification module, an amplification multiple switch unit, a plurality of current regulation lines, and a plurality of regulation indicator lamp lines corresponding to the working states of the plurality of current regulation lines; the corresponding charging current of the battery to be charged in the plurality of current regulation lines is selected through the amplification multiple switch unit, and the selected current regulation line is indicated by lighting the corresponding regulation indicator lamp line; One end of each current regulation line is connected with the operational amplification module, and the other end is connected with the amplification multiple switch unit. One end of each regulation indicator lamp line is connected with the amplification multiple switch unit, and the other end is grounded.

7. The simple multi-functional lithium battery charging circuit according to claim 6, characterized in that, The operational amplification module is an operational amplifier U4, the amplification multiple switch unit is a second counter U3, and the current regulation lines and the regulation indicator lamp lines are both 3 lines. Each current regulation line comprises three resistors connected in series, and a MOS tube is connected between the middle and the end of the two series resistors; the drain of the MOS tube is connected with one end of the middle resistor, the gate of the MOS tube is connected with one end of the end resistor, and the source of the MOS tube is grounded; the other end of the end resistor of each current regulation line is connected with one of the pins 1, 2, 4, 7 and 10 of the first counter U2, and one end of the resistor connected in series at the head is connected with the feedback voltage connection end. Each regulation indicator lamp line comprises a resistor and a light emitting diode; the negative electrode of the light emitting diode is grounded, the positive electrode of the light emitting diode is connected with one end of the resistor, and the other end of the resistor is connected with the same pin of the first counter U2 as the other end of the end resistor of the corresponding charging voltage line. Three resistors are connected in series in each current regulating circuit, a MOS transistor is connected between the middle resistor and the last resistor, the drain of the MOS transistor is connected to one end of the middle resistor, the gate of the MOS transistor is connected to one end of the last resistor, and the source of the MOS transistor is grounded; the other end of the last resistor of each current regulating circuit is connected to one of the 1st pin, 2nd pin and 3rd pin of the second counter U3, and one end of the first resistor is connected to the 1st pin, 2nd pin and 5th pin of the operational amplifier U4; Each display lamp circuit includes a resistor and a light emitting diode, the negative electrode of the light emitting diode is grounded, the positive electrode of the light emitting diode is connected to one end of the resistor, and the other end of the resistor is connected to the same pin of the second counter U3 as the other end of the last resistor of the corresponding current regulating circuit; The 1st pin of the operational amplifier U4 is connected to the 5th pin of the operational amplifier U4, the 3rd pin of the operational amplifier U4 is connected to the negative end of the voltage conversion module, the 6th pin of the operational amplifier U4 is connected to the reference voltage, and the 7th pin of the operational amplifier U4 is connected to the feedback voltage connection end of the voltage conversion module.

8. The simple multi-functional lithium battery charging circuit according to claim 7, characterized in that, The second inverter U6 is further included for preventing the switch button of the current regulating module from being triggered by mistake, the 2nd pin of the second inverter U6 is connected to the working power supply through a double-pole single-throw switch, and the 4th pin of the second inverter U6 is connected to the 14th pin of the second counter U3.

9. The simple multi-functional lithium battery charging circuit according to any one of claims 1-8, characterized in that, The low dropout voltage regulator module is further included, which is connected to the charging voltage selection module and the current regulating module, and converts the charging power supply into the working voltage required by the charging voltage selection module and the current regulating module.

10. A charger characterized by comprising: The charger includes the simple multifunctional lithium battery charging circuit according to any one of claims 1-9.

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