One-to-many charger circuit

Abstract

The utility model discloses a one-to-many charger circuit, comprising a power adapter connected with an external power supply and used for converting an AC voltage output by the power supply into a DC voltage; the power input protection circuit is connected with the power adapter and is used for protecting the input direct-current voltage; the step-down circuit is connected with the power supply input protection circuit and is used for reducing the direct-current voltage and outputting the reduced voltage; the single-chip microcomputer is connected with the step-down circuit, and the single-chip microcomputer is used for data processing; and the charger output circuit is connected with the step-down circuit and the single-chip microcomputer, and the single-chip microcomputer controls the charger output circuit to output charging voltage meeting the target battery. The charger can be used for charging different types of batteries, and is wide in applicability.

Description

Technical Field

[0001] The utility model relates to the technical field of chargers, in particular to a one-to-many charger circuit. Background Art

[0002] In the prior art, there are many types of lithium batteries. Different nominal voltages and different usage environments affect the output voltage of the charger. Cells of different capacities have different charging current limits. Therefore, a one-to-many charger is needed that can charge different types of batteries. Summary of the invention

[0003] According to an embodiment of the utility model, a one-to-many charger circuit is provided, comprising:

[0004] A power adapter, which is connected to an external power source and is used to convert the AC voltage output by the power source into a DC voltage;

[0005] A power input protection circuit, which is connected to the power adapter and is used to protect the input DC voltage;

[0006] A step-down circuit, the step-down circuit is connected to the power input protection circuit, steps down the DC voltage, and outputs a stepped-down voltage;

[0007] A single chip microcomputer is connected to the step-down circuit and is used for data processing;

[0008] The charger output circuit is connected to the step-down circuit and the single-chip microcomputer, and the single-chip microcomputer controls the charger output circuit to output a charging voltage that meets the target battery.

[0009] Furthermore, the power input protection circuit comprises:

[0010] A protection circuit, wherein an input end of the protection circuit is connected to a power adapter and is used to protect a DC voltage;

[0011] The RC delay circuit is connected to the output end of the protection circuit and the step-down circuit.

[0012] Further, the protection circuit comprises: a TVS tube, a fuse and a first diode;

[0013] The positive pole of the TVS tube is connected to the power adapter, and the negative pole of the TVS tube is grounded;

[0014] One end of the fuse is connected to the positive pole of the TVS tube;

[0015] The anode of the first diode is connected to the other end of the fuse, and the cathode of the first diode is connected to the RC delay circuit.

[0016] Furthermore, the RC delay circuit comprises: a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a triode and a MOS tube;

[0017] One end of the first resistor, one end of the third resistor, the emitter of the transistor and the source of the MOS transistor are all connected to the output end of the protection circuit;

[0018] The other end of the first resistor is connected to one end of the first capacitor and one end of the second resistor;

[0019] The other end of the first capacitor is grounded, and the other end of the second resistor is connected to the base of the transistor;

[0020] One end of the fourth resistor is connected to the collector of the triode, the other end of the third resistor is connected to the gate of the MOS tube, and the other end of the fourth resistor is grounded;

[0021] The drain of the MOS tube is connected to the step-down circuit.

[0022] Further, the step-down circuit comprises: a power chip, a first electrolytic capacitor, a second electrolytic capacitor, a second capacitor, a fifth resistor, a sixth resistor, a first inductor, a second diode and a linear regulator circuit;

[0023] The input end of the power chip, the positive electrode of the first electrolytic capacitor, one end of the second capacitor and the power input protection circuit are connected;

[0024] The negative electrode of the first electrolytic capacitor and the other end of the second capacitor are grounded;

[0025] The feedback end of the power chip is connected to one end of the fifth resistor and one end of the sixth resistor, and the other end of the fifth resistor is grounded;

[0026] The other end of the sixth resistor is connected to one end of the first inductor and the positive electrode of the second electrolytic capacitor, and the negative electrode of the second electrolytic capacitor is grounded;

[0027] The other end of the first inductor is connected to the output end of the power chip and the positive electrode of the second diode, and the negative electrode of the second diode is grounded;

[0028] One end of the first inductor is connected to the charger output circuit, and the power chip outputs a first step-down voltage to the single-chip microcomputer and the charger output circuit;

[0029] The input end of the linear voltage regulator circuit is connected to one end of the first inductor, and the output end of the linear voltage regulator circuit is connected to the single chip microcomputer to output the second step-down voltage to the single chip microcomputer.

[0030] Further, the charger output circuit includes: a pair of power switches, a voltage detection circuit and a pair of current detection circuits;

[0031] A pair of power switches are connected to the step-down circuit, and output ends of the pair of power switches are connected to the voltage detection circuit;

[0032] The voltage detection circuit is connected to the single chip microcomputer and the target battery to detect the charging voltage of the target battery;

[0033] One end of a pair of current detection circuits is connected to current sampling ends of a pair of power switches respectively, and the other end of the current detection circuit is connected to a single chip microcomputer to detect the charging current of the target battery;

[0034] The single chip microcomputer controls the on and off of a pair of power switches according to the charging voltage and charging current to output a charging voltage that meets the target battery.

[0035] Furthermore, it also includes: a display circuit, which is connected to the single-chip microcomputer and the step-down circuit, and the display circuit displays the charging status.

[0036] The one-to-many charger circuit according to the embodiment of the utility model can charge different types of batteries and has wide applicability.

[0037] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A circuit diagram of a power input protection circuit of a one-to-many charger circuit according to an embodiment of the utility model;

[0039] Figure 2 A circuit diagram of a step-down circuit of a one-to-many charger circuit according to an embodiment of the utility model;

[0040] Figure 3 A circuit diagram of a single chip microcomputer of a one-to-many charger circuit according to an embodiment of the utility model;

[0041] Figure 4 A circuit diagram of a charger output circuit of a one-to-many charger circuit according to an embodiment of the utility model;

[0042] Figure 5 4 is a circuit diagram of a display circuit of a one-to-many charger circuit according to an embodiment of the utility model. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings to further illustrate the present invention.

[0044] First, combine Figures 1 to 5 A one-to-many charger circuit according to an embodiment of the present invention is described, which is used to adapt to different types of batteries and has a wide range of application scenarios.

[0045] like Figures 1 to 5 As shown, the one-to-many charger circuit of the embodiment of the utility model includes: a power adapter, a power input protection circuit, a step-down circuit, a single-chip microcomputer 1U1 and a charger output circuit.

[0046] Specifically, Figures 1 to 5 As shown, in this embodiment, the power adapter is connected to an external power supply, and is used to convert the AC voltage output by the power supply into a DC voltage, and convert 220V AC power into 24V DC power; the power input protection circuit is connected to the power adapter, and is used to protect the input DC voltage; the step-down circuit is connected to the power input protection circuit, and steps down the DC voltage, outputs the stepped-down voltage, and steps down the 24V DC power into 9V and 3.3V, 9V is provided to the charger output circuit, and 3.3V is provided to the single-chip microcomputer 1U1 and the display circuit; the single-chip microcomputer 1U1 is connected to the step-down circuit, and the single-chip microcomputer 1U1 is connected to the step-down circuit. The microcontroller 1U1 is used for data processing and circuit control. The microcontroller 1U1 may be an STM32L071RBT6 chip. The PA13 and PA14 pins of the microcontroller 1U1 are used by JTMS and JTCK respectively and connected to the terminal block 1JP1 for microcontroller 1U1 program burning. The floating charge voltage and constant current charge current are controlled by the program. The charger output circuit is connected to the step-down circuit and the microcontroller 1U1. The microcontroller 1U1 controls the charger output circuit to output a charging voltage that meets the target battery, thereby achieving adaptation to a variety of batteries and having wide applicability.

[0047] Further, if Figure 1 As shown, in this embodiment, the power input protection circuit includes: a protection circuit, the input end of the protection circuit is connected to the power adapter, and is used to protect the DC voltage; an RC delay circuit, the RC delay circuit is connected to the output end of the protection circuit and the step-down circuit. Since different power adapters need to be adapted, sparks will be generated if there is a gap, and double protection is performed through the protection circuit and the RC delay circuit.

[0048] Further, if Figure 1 As shown, in this embodiment, the protection circuit includes: TVS tube 2D0, fuse 2FS1 and first diode 2D1; the positive electrode of TVS tube 2D0 is connected to the power adapter, and the negative electrode of TVS tube 2D0 is grounded; one end of fuse 2FS1 is connected to the positive electrode of TVS tube 2D0; the positive electrode of first diode 2D1 is connected to the other end of fuse 2FS1, and the negative electrode of first diode 2D1 is connected to RC delay circuit. In this embodiment, TVS tube 2D0 is an electrostatic and surge protection device, which is used to absorb transient high voltage that may appear on the power line and protect subsequent circuits. TVS tube 2D0 can use SM8S36A, fuse 2FS1 can prevent overcurrent, and first diode 2D1 is used for reverse connection protection, so as to achieve comprehensive protection of the circuit.

[0049] Further, if Figure 1 As shown, in this embodiment, the RC delay circuit includes: a first resistor 2R4, a second resistor 2R5, a third resistor 2R6, a fourth resistor 2R7, a first capacitor 2C8, a transistor 1Q1 and a MOS transistor 2Q2; one end of the first resistor 2R4, one end of the third resistor 2R6, the emitter of the transistor 1Q1 and the source of the MOS transistor 2Q2 are all connected to the output end of the protection circuit; the other end of the first resistor 2R4 is connected to one end of the first capacitor 2C8 and one end of the second resistor 2R5; the other end of the first capacitor 2C8 is grounded, and the other end of the second resistor 2R5 is connected to the base of the transistor 1Q1; one end of the fourth resistor 2R7 is connected to the collector of the transistor 1Q1, the other end of the third resistor 2R6 and the gate of the MOS transistor 2Q2, and the other end of the fourth resistor 2R7 is grounded; the drain of the MOS transistor 2Q2 is connected to the step-down circuit; in this embodiment, the RC delay circuit includes: a first resistor 2R4, a second resistor 2R5, a third resistor 2R6, a third resistor 2R6, a fourth resistor 2R7, a first capacitor 2C8, a transistor 1Q1, a third resistor 2R6, a third resistor 2Q2, and a fourth resistor 2R7. The drain of the MOS transistor 2Q2 is connected to the step-down circuit; In the embodiment, the voltage of the base of the transistor 1Q1 is in a conducting state due to RC charging after power-on, and the transistor 1Q1 is in a conducting state, and the emitter and the collector are conducting. Because the collector of the transistor 1Q1 is connected to the gate of the MOS tube 2Q2, the gate voltage 24V of the MOS tube 2Q2 is equal to the source voltage 24V, and the source and the drain of the MOS tube 2Q2 are in a non-conducting state. After the RC charging is completed, the transistor 1Q1 is turned off, and the emitter and the collector are turned on and off. The other end of the third resistor 2R6 is connected to the fourth resistor 2R7, and the other end of the fourth resistor 2R7 is grounded. At this time, the gate voltage of the MOS tube 2Q2 is a 12V voltage after the voltage is divided by the third resistor 2R6 and the fourth resistor 2R7. At this time, the source voltage 24V> the gate voltage 12V, so that the source and the drain are conducting. The RC delay circuit provides a delay process when powering on to prevent instantaneous large current from damaging the circuit.

[0050] Further, if Figure 2As shown, in this embodiment, the step-down circuit includes: a power chip 2N1, a first electrolytic capacitor 2C2, a second electrolytic capacitor 2C4, a second capacitor 2C1, a fifth resistor 2R1, a sixth resistor 2R2, a first inductor 1L1, a second diode 2D3 and a linear regulator circuit; the power chip 2N1 can adopt an LM2596ADJ chip, and the input end (input pin Vin) of the power chip 2N1, the positive electrode of the first electrolytic capacitor 2C2, and one end of the second capacitor 2C1 are connected to the power input protection circuit; the negative electrode of the first electrolytic capacitor 2C2 and the other end of the second capacitor 2C1 are grounded; the feedback end (FB feedback pin) of the power chip 2N1 is connected to one end of the fifth resistor 2R1 and one end of the sixth resistor 2R2, and the other end of the fifth resistor 2R1 is grounded; the other end of the sixth resistor 2R2 is connected to one end of the first inductor 1L1 and the second electrolytic capacitor 2C 4, and the negative electrode of the second electrolytic capacitor 2C4 is grounded; the other end of the first inductor 1L1 is connected to the output end of the power chip 2N1 and the positive electrode of the second diode 2D3, and the negative electrode of the second diode 2D3 is grounded; one end of the first inductor 1L1 is connected to the charger output circuit, and the power chip 2N1 outputs a first step-down voltage to the microcontroller 1U1 and the charger output circuit. At this time, the output end voltage of the power chip 2N1 is Vout=1.23*(1+2R2 / 2R1)=9.87V; the input end of the linear regulator circuit is connected to one end of the first inductor 1L1, and the output end of the linear regulator circuit is connected to the microcontroller 1U1, and the second step-down voltage is output to the microcontroller 1U1. The output voltage of the power chip 2N1 is converted into a 3.3V output after passing through a -3.3V step-down circuit of a linear regulator 2W2 (model LM1117-IMPX).

[0051] Further, if Figure 4As shown, in this embodiment, the charger output circuit includes: a pair of power switches (4U1 and 4U2), a voltage detection circuit and a pair of current detection circuits; the pair of power switches (4U1 and 4U2) are connected to the step-down circuit, and the output ends of the pair of power switches (4U1 and 4U2) are connected to the voltage detection circuit; the voltage detection circuit is connected to the single-chip microcomputer 1U1 and the target battery to detect the charging voltage of the target battery; one end of the pair of current detection circuits is connected to the current sampling ends of the pair of power switches (4U1 and 4U2) respectively, and the other end of the current detection circuit is connected to the single-chip microcomputer 1U1 to detect the charging current of the target battery; the single-chip microcomputer 1U1 controls the on and off of the pair of power switches according to the charging voltage and the charging current to output the charging voltage that meets the target battery. In this embodiment, the power switch model is VN5016, the V-ADin network connects the voltage detection circuit to the single-chip microcomputer 1U1, and the ADC detection pin PA1 of the single-chip microcomputer 1U1 detects the battery charging voltage; A-ADin1 and A-ADin2 connect the SENSE pin of the power switch VN5016 to the single-chip microcomputer 1U1, and the ADC value detected by the ADC detection pins PA0 and PA2 of the single-chip microcomputer 1U1, and the single-chip microcomputer 1U1 controls the duty cycle of PWM1 to change the current working mode of the charger, that is, the charging current during constant current charging, and the floating current. Charging voltage; in the constant current charging stage, the microcontroller 1U1 adjusts the duty cycle of PWM1 to maintain a constant charging current. By detecting the ADC value of the current (PA0 and PA2), the microcontroller 1U1 continuously adjusts the PWM signal to ensure that the charging current is stable at the set value; when charging is nearly completed, the microcontroller 1U1 will adjust the duty cycle of PWM1 to increase the output voltage to the floating charge voltage value to keep the battery within a safe charging voltage range. Diodes 4D5 and 4D6 at the output end prevent the battery capacity from being consumed when the battery is not removed from the charger and the charger is not powered on.

[0052] Further, if Figure 5As shown, in this embodiment, it also includes: a display circuit, which is connected to the single-chip microcomputer 1U1 and the buck circuit, and the display circuit displays the charging status. Specifically, the display circuit includes three LED indicator lights (LED1, LED2, LED3); one end of the three LED indicator lights (LED1, LED2, LED3) is connected to the buck circuit, and the other end is connected to the single-chip microcomputer 1U1. When the charger is powered on, the single-chip microcomputer 1U1 works normally, and the pin PC0 of the single-chip microcomputer 1U1 outputs a low level by default when powered on, and the red light of LED1 is lit; due to the power switch (4U1 and 4U2) V The SENSE pin of N5016 has the function of providing a current proportional to the load current. When charging is in progress, that is, the charging current is greater than a certain value, the microcontroller 1U1 pulls down the output level of the pin PC1, the yellow light of LED2 is lit, and the output level of the pin PC2 of the microcontroller 1U1 is pulled up, and the green light of LED3 is off. This state indicates that charging is in progress; when charging is about to be completed, that is, the charging current is less than a certain value, the microcontroller 1U1 pulls up the output level of the pin PC1, the yellow light of LED2 is off, the microcontroller 1U1 pulls down the output level of the pin PC2, and the green light of LED3 is lit. This state indicates that it is fully charged.

[0053] When working, the power adapter converts the external power supply into 24V DC, and provides a stable DC voltage after anti-static protection and RC delay; the step-down circuit then converts the voltage into 9V and 3.3V, 9V powers the charger output circuit, and 3.3V powers the microcontroller 1U1 and the display circuit; the microcontroller 1U1 program controls PWM1 and PWM2 to control the power switch, and outputs a charging voltage that meets the target battery.

[0054] Above, refer to Figures 1 to 5 A one-to-many charger circuit according to an embodiment of the utility model is described, which can charge different types of batteries and has wide applicability.

[0055] It should be noted that, in this specification, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0056] Although the content of the utility model has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. A one-to-many charger circuit, characterized in that: Include: A power adapter, which is connected to an external power source and is used to convert the AC voltage output by the power source into a DC voltage; A power input protection circuit, which is connected to the power adapter and is used to protect the input DC voltage; A step-down circuit, the step-down circuit is connected to the power input protection circuit, steps down the DC voltage and outputs a stepped-down voltage; A single chip microcomputer, the single chip microcomputer is connected to the step-down circuit, and the single chip microcomputer is used for data processing; A charger output circuit, wherein the charger output circuit is connected to the step-down circuit and the single-chip microcomputer, and the single-chip microcomputer controls the charger output circuit to output a charging voltage that meets the target battery; The charger output circuit comprises: a pair of power switches, a voltage detection circuit and a pair of current detection circuits; The pair of power switches are connected to the step-down circuit, and the output ends of the pair of power switches are connected to the voltage detection circuit; The voltage detection circuit is connected to the single chip microcomputer and the target battery to detect the charging voltage of the target battery; One end of the pair of current detection circuits is connected to the current sampling ends of the pair of power switches respectively, and the other end of the current detection circuit is connected to the single chip microcomputer to detect the charging current of the target battery; The single chip microcomputer controls the on and off of the pair of power switches according to the charging voltage and the charging current to output a charging voltage that meets the target battery.

2. The one-to-many charger circuit as claimed in claim 1, characterized in that: The power input protection circuit comprises: A protection circuit, the input end of which is connected to the power adapter and is used to protect the DC voltage; An RC delay circuit is connected to the output end of the protection circuit and the step-down circuit.

3. The one-to-many charger circuit as claimed in claim 2, characterized in that: The protection circuit comprises: a TVS tube, a fuse and a first diode; The positive electrode of the TVS tube is connected to the power adapter, and the negative electrode of the TVS tube is grounded; One end of the fuse is connected to the positive electrode of the TVS tube; The anode of the first diode is connected to the other end of the fuse, and the cathode of the first diode is connected to the RC delay circuit.

4. The one-to-many charger circuit as claimed in claim 2 or 3, characterized in that: The RC delay circuit comprises: a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a triode and a MOS tube; One end of the first resistor, one end of the third resistor, the emitter of the transistor and the source of the MOS transistor are all connected to the output end of the protection circuit; The other end of the first resistor is connected to one end of the first capacitor and one end of the second resistor; The other end of the first capacitor is grounded, and the other end of the second resistor is connected to the base of the transistor; One end of the fourth resistor is connected to the collector of the triode, the other end of the third resistor is connected to the gate of the MOS transistor, and the other end of the fourth resistor is grounded; The drain of the MOS tube is connected to the step-down circuit.

5. The one-to-many charger circuit as claimed in claim 1, characterized in that: The step-down circuit comprises: a power chip, a first electrolytic capacitor, a second electrolytic capacitor, a second capacitor, a fifth resistor, a sixth resistor, a first inductor, a second diode and a linear regulator circuit; The input end of the power chip, the positive electrode of the first electrolytic capacitor, one end of the second capacitor and the power input protection circuit are connected; The negative electrode of the first electrolytic capacitor and the other end of the second capacitor are grounded; The feedback end of the power chip is connected to one end of the fifth resistor and one end of the sixth resistor, and the other end of the fifth resistor is grounded; The other end of the sixth resistor is connected to one end of the first inductor and the positive electrode of the second electrolytic capacitor, and the negative electrode of the second electrolytic capacitor is grounded; The other end of the first inductor is connected to the output end of the power chip and the anode of the second diode, and the cathode of the second diode is grounded; One end of the first inductor is connected to the charger output circuit, and the power chip outputs a first step-down voltage to the single-chip microcomputer and the charger output circuit; The input end of the linear voltage regulator circuit is connected to one end of the first inductor, and the output end of the linear voltage regulator circuit is connected to the single chip microcomputer to output a second step-down voltage to the single chip microcomputer.

6. The one-to-many charger circuit as claimed in claim 1, characterized in that: It also includes: a display circuit, which is connected to the single-chip computer and the step-down circuit, and displays the charging status.

Images