Automatic voltage detection circuit of intelligent battery charger

Abstract

The utility model discloses a voltage automatic detection circuit of an intelligent battery charger, which comprises a power supply input module, a main control chip, a voltage detection module, a charging control module and a battery module, the battery module is connected with a BATT pin of the main control chip, the voltage detection module is used for monitoring the voltage of the battery module, and the charging control module is used for controlling the charging control module. And the charging control module is connected with the battery module and feeds back a voltage signal to the main control chip, and is used for receiving a control signal from the main control chip and adjusting the charging current of the battery module. According to the utility model, the power supply input module provides stable voltage for the master control chip, and the voltage detection module enables the master control chip to sense the voltage change of the battery in real time and dynamically adjust the charging mode, thereby avoiding the over-charging or under-charging of the battery; the charging control module adjusts the charging current according to the signal of the main control chip, realizes quick charging when the voltage is low and enters a trickle mode when the voltage is close to full charge, prevents the battery from being damaged by overlarge current, improves the charging efficiency, and prolongs the service life of the battery.

Description

Technical Field

[0001] This utility model relates to the field of battery chargers, and in particular to an automatic voltage detection circuit for an intelligent battery charger. Background Technology

[0002] A battery charger is a device used to replenish the electrical energy of a battery. It works by converting electrical energy into current and voltage parameters that meet the battery's charging requirements, thereby enabling safe and efficient charging of the battery.

[0003] In existing technologies, battery chargers often lack a precise voltage detection mechanism during the charging process, which makes it impossible to automatically adjust the charging mode when the battery is in different charging states. This can easily lead to overcharging or undercharging, thereby affecting battery performance, shortening battery life, and even causing safety hazards.

[0004] Therefore, existing technologies have shortcomings and need to be improved. Utility Model Content

[0005] The technical problem to be solved by this utility model is: to provide an automatic voltage detection circuit for an intelligent battery charger that can automatically adjust the charging mode according to the voltage to avoid overcharging or undercharging.

[0006] To achieve this objective, the present invention adopts the following technical solution: an automatic voltage detection circuit for an intelligent battery charger, comprising a power input module, a main control chip, a voltage detection module, a charging control module, and a battery module;

[0007] The power input module is connected to the DCIN pin of the main control chip, and the power input module is used to provide input voltage to the main control chip;

[0008] The battery module is connected to the BATT pin of the main control chip;

[0009] The voltage detection module is connected to the CSSP and CSSN pins of the main control chip. The voltage detection module is used to monitor the voltage of the battery module and feed back the voltage signal to the main control chip.

[0010] The charging control module is connected to the DHI, DLO and CSIN pins of the main control chip. The charging control module is used to receive control signals from the main control chip and adjust the charging current of the battery module.

[0011] Using the above technical solution, in the automatic voltage detection circuit of the intelligent battery charger, the power input module includes resistor R6, resistor R7, field-effect transistor P3, diode D4, capacitor C5 and capacitor C22;

[0012] One end of the power input terminal is connected to the first end of the resistor R6, the anode of the diode D4, and the drain of the field-effect transistor P3. The second end of the resistor R6 is connected to the ACIN pin of the main control chip and the first end of the resistor R7. The second end of the resistor R7 is connected to the first end of the capacitor C5.

[0013] The DCIN pin of the main control chip is connected to the second terminal of capacitor C5 and the cathode of diode D4, respectively. The gate of field-effect transistor P3 is connected to the PDS pin of the main control chip. The source of field-effect transistor P3 is connected to the first terminal of capacitor C22 and the SRC pin of the main control chip, respectively. The second terminal of capacitor C22 is grounded.

[0014] Using the above technical solution, in the automatic voltage detection circuit of the intelligent battery charger, the voltage detection module includes a detection resistor RS1, a capacitor C1, and a capacitor C17.

[0015] The first end of the detection resistor RS1 is connected to the CSSP pin of the main control chip and the source of the effect transistor P3, respectively. The second end of the detection resistor RS1 is connected to the CSSN pin of the main control chip and one end of the capacitor C1, respectively. The second end of the capacitor C1 is grounded. The first end of the capacitor C17 is connected to the DHIV pin of the main control chip, and the second end is connected to the SRC pin of the main control chip.

[0016] Using the above technical solution, in the automatic voltage detection circuit of the intelligent battery charger, the charging control module includes a detection resistor RS2, a field-effect transistor P1, a field-effect transistor P2, a field-effect transistor N1, an inductor L1, and a capacitor C4.

[0017] The source of the field-effect transistor P1 is connected to the CSSN pin of the main control chip, the gate of the field-effect transistor P1 is connected to the DHI pin of the main control chip, and the drain of the field-effect transistor P1 is connected to the first terminal of the inductor L1 and the drain of the field-effect transistor N1, respectively.

[0018] The gate of the field-effect transistor N1 is connected to the DLO pin of the main control chip, the source of the field-effect transistor N1 is grounded, and the second end of the inductor L1 is connected to the CSIP pin of the main control chip and the first end of the sensing resistor RS2, respectively.

[0019] The second end of the detection resistor RS2 is connected to the CSIN pin of the main control chip, the first end of the capacitor C4, and the positive terminal of the battery module, respectively, and the second end of the capacitor C4 is grounded.

[0020] The gate of the field-effect transistor P2 is connected to the PDL pin of the main control chip, the drain of the field-effect transistor P2 is connected to the BATT pin of the main control chip, and the source of the field-effect transistor P2 is connected to the CSSN pin of the main control chip.

[0021] Using the above technical solution, in the automatic voltage detection circuit of the intelligent battery charger, the charging control module further includes a resistor R13, a capacitor C13, and a capacitor C16. The LDO pin of the main control chip is connected to the first end of the capacitor C13 and the first end of the resistor R13, respectively. The second end of the capacitor C13 is grounded. The second end of the resistor R13 is connected to the DLOV pin of the main control chip and the first end of the capacitor C16, respectively. The second end of the capacitor C16 is grounded.

[0022] Using the above technical solution, in the automatic voltage detection circuit of the intelligent battery charger, the voltage detection module further includes a resistor R5, a capacitor C9, a capacitor C10, a capacitor C11, and a capacitor C12.

[0023] The first end of resistor R5 is connected to the CCV pin of the main control chip, and the second end is connected to the first end of capacitor C11. The second end of capacitor C11 is grounded. The first end of capacitor C9 is connected to the CCI pin of the main control chip, and the second end is connected to the first end of capacitor C10 and then grounded. The second end of capacitor C10 is connected to the CCS pin of the main control chip. The REF pin of the main control chip is connected to the first end of capacitor C12, and the second end of capacitor C12 is grounded.

[0024] Using the above technical solution, the main control chip in the automatic voltage detection circuit of the intelligent battery charger is model MAX8725.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The power input module of this invention can provide a stable input voltage to the main control chip. The voltage detection module is connected to the main control chip, enabling the main control chip to sense changes in battery voltage in real time and dynamically adjust the charging method according to the voltage status, thereby avoiding overcharging or undercharging problems caused by abnormal battery voltage. The charging control module can receive control signals from the main control chip and accurately adjust the charging current according to different voltage states, realizing rapid charging of the battery when the voltage is low and entering trickle mode when it is close to full charge to avoid excessive current and damage to the battery. This circuit structure can dynamically adjust the charging current according to the actual state of the battery, effectively improving charging efficiency and extending battery life. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0028] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0029] Figure 1 This is a schematic diagram of the circuit structure of this utility model. Detailed Implementation

[0030] To make the utility model's objectives, features, and advantages more apparent and understandable, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0031] In the description of this utility model, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0032] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1As shown in the figure, this utility model embodiment provides an automatic voltage detection circuit for an intelligent battery charger, including a power input module, a main control chip, a voltage detection module, a charging control module, and a battery module. The power input module is connected to the DCIN pin of the main control chip and is used to provide input voltage to the main control chip. The battery module is connected to the BATT pin of the main control chip. The voltage detection module is connected to the CSSP and CSSN pins of the main control chip and is used to monitor the voltage of the battery module and feed back a voltage signal to the main control chip. The charging control module is connected to the DHI, DLO, and CSIN pins of the main control chip and is used to receive control signals from the main control chip and adjust the charging current of the battery module. The power input module provides a stable input voltage to the main control chip. The main control chip, acting as a controller, receives the voltage signal from the power input module via its DCIN pin and manages the battery charging process. The battery module connects to the BATT pin of the main control chip, allowing the chip to acquire the battery's voltage status and charging status. When the battery voltage changes, the voltage detection module feeds back the voltage signal to the main control chip. Upon receiving the signal, the main control chip, combined with parameters such as the current battery voltage level and charging status, determines whether the battery is in a suitable stage for fast charging, trickle charging, or fully charged, and adjusts the charging current accordingly. The charging control module receives control signals from the main control chip to dynamically adjust the charging current. Specifically, when the battery voltage is low, the main control chip can control the charging control module to output a larger charging current to accelerate battery recovery. Conversely, when the battery voltage is close to full charge, the main control chip can adjust the charging control module to output a smaller current or enter trickle charging mode to prevent overcharging and improve battery life.

[0034] Furthermore, the power input module includes resistors R6 and R7, a field-effect transistor P3, a diode D4, a capacitor C5, and a capacitor C22. One end of the power input terminal is connected to the first end of resistor R6, the anode of diode D4, and the drain of field-effect transistor P3. The second end of resistor R6 is connected to the ACIN pin of the main control chip and the first end of resistor R7. The second end of resistor R7 is connected to the first end of capacitor C5. The DCIN pin of the main control chip is connected to the second end of capacitor C5 and the cathode of diode D4. The gate of field-effect transistor P3 is connected to the PDS pin of the main control chip. The source of field-effect transistor P3 is connected to the first end of capacitor C22 and the SRC pin of the main control chip. The second end of capacitor C22 is grounded. Resistor R6 limits the current of the power supply voltage and transmits the divided voltage signal to the ACIN pin of the main control chip, allowing the chip to detect the input voltage status. Resistor R7 is connected to capacitor C5, which filters and smooths the voltage, suppressing ripple and spike interference in the power supply and ensuring a stable voltage signal at the DCIN pin of the main control chip. Diode D4's cathode is connected to the DCIN pin, and its anode is connected to the power input terminal. Diode D4 provides reverse connection protection, preventing damage to the main control chip and other circuit components from incorrect external power supply polarity. Field-effect transistor P3 regulates the current. In addition to its overcurrent protection function, the gate of the field-effect transistor P3 is controlled by the PDS pin of the main control chip. When the main control chip outputs a control signal through the PDS pin, the gate voltage of the field-effect transistor P3 rises, turning it on and allowing current to flow from the drain to the source and into the SRC pin of the main control chip. When the field-effect transistor P3 is on, the capacitor C22 can smooth and filter the current signal to suppress high-frequency noise or current ripple, so that the current signal is stably transmitted to the SRC pin. The SRC pin, as the port for internal current monitoring and regulation of the main control chip, combined with the conduction state of the field-effect transistor P3, can realize stable control of the input current.

[0035] Furthermore, the voltage detection module includes a detection resistor RS1, a capacitor C1, and a capacitor C17. The first end of the detection resistor RS1 is connected to the CSSP pin of the main control chip and the source of the effect transistor P3, respectively. The second end of the detection resistor RS1 is connected to the CSSN pin of the main control chip and one end of the capacitor C1, respectively. The second end of the capacitor C1 is grounded. The first end of the capacitor C17 is connected to the DHIV pin of the main control chip, and the second end is connected to the SRC pin of the main control chip. The detection resistor RS1 forms a voltage drop when current flows through it. The main control chip can receive this voltage signal in real time and use it as a basis for judging the current voltage level of the battery. The CSSN pin serves as a reference point for voltage detection, forming a differential signal input with the CSSP pin, thereby improving the accuracy and anti-interference capability of voltage detection. Capacitor C1 enhances the signal stability of the voltage detection circuit. Connecting capacitor C1 to ground forms a filter circuit, which can suppress high-frequency noise and voltage fluctuations in the power supply, ensuring that the main control chip obtains smooth and stable voltage data when reading the voltage signal. The DHIV pin serves as a high-voltage detection reference signal input within the main control chip, connected to the SRC pin of the main control chip. The RC pin, when used in conjunction with the main control chip, can stabilize and compensate the voltage reference circuit inside the main control chip. When the power input voltage fluctuates or the battery voltage rises abnormally, capacitor C17 smooths and stabilizes the voltage signal, ensuring that the DHIV pin always maintains a relatively stable voltage signal, avoiding false detection problems caused by voltage fluctuations. The entire voltage detection module, through the voltage signal acquisition of detection resistor RS1, the filtering and noise reduction of capacitor C1, and the voltage compensation of capacitor C17, forms a stable voltage detection circuit, enabling the main control chip to determine the battery voltage status in complex power environments, thereby providing voltage data support for the safe and stable charging of the charger.

[0036] Furthermore, the charging control module includes a detection resistor RS2, field-effect transistors P1, P2, and N1, an inductor L1, and a capacitor C4. The source of field-effect transistor P1 is connected to the CSSN pin of the main control chip, the gate of field-effect transistor P1 is connected to the DHI pin of the main control chip, the drain of field-effect transistor P1 is connected to the first terminal of inductor L1 and the drain of field-effect transistor N1, and the gate of field-effect transistor N1 is connected to the DLO pin of the main control chip. The source of the inductor L1 is grounded. The second end of the inductor L1 is connected to the CSIP pin of the main control chip and the first end of the sensing resistor RS2. The second end of the sensing resistor RS2 is connected to the CSIN pin of the main control chip, the first end of the capacitor C4, and the positive terminal of the battery module. The second end of the capacitor C4 is grounded. The gate of the field-effect transistor P2 is connected to the PDL pin of the main control chip. The drain of the field-effect transistor P2 is connected to the BATT pin of the main control chip. The source of the field-effect transistor P2 is connected to the CSSN pin of the main control chip. The sensing resistor RS2 creates a small voltage drop across its terminals when charging current flows through it, and feeds this voltage signal back to the CSIN pin. The main control chip can then determine the battery's charging status based on this signal and dynamically adjust the output current. Specifically, when the battery voltage is low, the main control chip controls the field-effect transistor P1 to conduct through the DHI pin, thereby outputting a larger current to quickly charge the battery. As the battery voltage gradually approaches saturation, the main control chip lowers the DHI signal level, gradually reducing the output current to ensure a stable current input to the battery module. Simultaneously, capacitor C4 is connected in parallel across the sensing resistor RS2, which filters the current and smooths the voltage signal, thereby enhancing the stability of the current detection signal. The drain of the field-effect transistor P2 is connected to the BATT pin of the main control chip, and its source is connected to the CSSN pin, allowing the battery current to flow safely in different charging modes and providing power-off protection.

[0037] Furthermore, the charging control module also includes a resistor R13, a capacitor C13, and a capacitor C16. The LDO pin of the main control chip is connected to the first terminal of capacitor C13 and the first terminal of resistor R13, respectively. The second terminal of capacitor C13 is grounded. The second terminal of resistor R13 is connected to the DLOV pin of the main control chip and the first terminal of capacitor C16, respectively. The second terminal of capacitor C16 is grounded. Capacitor C13, as a bypass capacitor, can filter and smooth the signal, thereby suppressing high-frequency noise and transient voltage fluctuations in the LDO pin voltage output. Resistor R13 can limit current and attenuate the signal to dampen the voltage signal received by the DLOV pin, preventing interference signals from falsely triggering the DLOV pin. Capacitor C16, as a filter capacitor, can improve the anti-interference capability of the DLOV pin signal.

[0038] Furthermore, the voltage detection module also includes a resistor R5, a capacitor C9, a capacitor C10, a capacitor C11, and a capacitor C12. The first end of the resistor R5 is connected to the CCV pin of the main control chip, and the second end is connected to the first end of the capacitor C11. The second end of the capacitor C11 is grounded. The first end of the capacitor C9 is connected to the CCI pin of the main control chip, and the second end is connected to the first end of the capacitor C10 and then grounded. The second end of the capacitor C10 is connected to the CCS pin of the main control chip. The REF pin of the main control chip is connected to the first end of the capacitor C12, and the second end of the capacitor C12 is grounded. Resistor R5 limits the current of the voltage signal entering the CCV pin of the main control chip to prevent excessive transient voltage from interfering with the main control chip; capacitor C11 filters and smooths the voltage signal after resistor R5 to suppress noise and ensure that the CCV pin receives a stable voltage signal; capacitor C9 filters the current control signal of the CCI pin of the main control chip to reduce high-frequency interference and improve signal stability; capacitor C10 filters and smooths the current detection signal of the CCS pin of the main control chip, thereby improving the accuracy of current regulation; capacitor C12 stabilizes and filters the reference voltage signal of the REF pin of the main control chip, thereby improving the stability and anti-interference capability of the voltage reference.

[0039] Furthermore, the main control chip is model MAX8725.

[0040] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. An automatic voltage detection circuit for an intelligent battery charger, characterized in that, It includes a power input module, a main control chip, a voltage detection module, a charging control module, and a battery module; The power input module is connected to the DCIN pin of the main control chip, and the power input module is used to provide input voltage to the main control chip; The battery module is connected to the BATT pin of the main control chip; The voltage detection module is connected to the CSSP and CSSN pins of the main control chip. The voltage detection module is used to monitor the voltage of the battery module and feed back the voltage signal to the main control chip. The charging control module is connected to the DHI, DLO and CSIN pins of the main control chip. The charging control module is used to receive control signals from the main control chip and adjust the charging current of the battery module.

2. The automatic voltage detection circuit of the intelligent battery charger according to claim 1, characterized in that, The power input module includes resistor R6, resistor R7, field-effect transistor P3, diode D4, capacitor C5 and capacitor C22; One end of the power input terminal is connected to the first end of the resistor R6, the anode of the diode D4, and the drain of the field-effect transistor P3. The second end of the resistor R6 is connected to the ACIN pin of the main control chip and the first end of the resistor R7. The second end of the resistor R7 is connected to the first end of the capacitor C5. The DCIN pin of the main control chip is connected to the second terminal of capacitor C5 and the cathode of diode D4, respectively. The gate of field-effect transistor P3 is connected to the PDS pin of the main control chip. The source of field-effect transistor P3 is connected to the first terminal of capacitor C22 and the SRC pin of the main control chip, respectively. The second terminal of capacitor C22 is grounded.

3. The automatic voltage detection circuit of the intelligent battery charger according to claim 2, characterized in that, The voltage detection module includes a detection resistor RS1, a capacitor C1, and a capacitor C17; The first end of the detection resistor RS1 is connected to the CSSP pin of the main control chip and the source of the effect transistor P3, respectively. The second end of the detection resistor RS1 is connected to the CSSN pin of the main control chip and one end of the capacitor C1, respectively. The second end of the capacitor C1 is grounded. The first end of the capacitor C17 is connected to the DHIV pin of the main control chip, and the second end is connected to the SRC pin of the main control chip.

4. The automatic voltage detection circuit of the intelligent battery charger according to claim 3, characterized in that, The charging control module includes a detection resistor RS2, a field-effect transistor P1, a field-effect transistor P2, a field-effect transistor N1, an inductor L1, and a capacitor C4. The source of the field-effect transistor P1 is connected to the CSSN pin of the main control chip, the gate of the field-effect transistor P1 is connected to the DHI pin of the main control chip, and the drain of the field-effect transistor P1 is connected to the first terminal of the inductor L1 and the drain of the field-effect transistor N1, respectively. The gate of the field-effect transistor N1 is connected to the DLO pin of the main control chip, the source of the field-effect transistor N1 is grounded, and the second end of the inductor L1 is connected to the CSIP pin of the main control chip and the first end of the sensing resistor RS2, respectively. The second end of the detection resistor RS2 is connected to the CSIN pin of the main control chip, the first end of the capacitor C4, and the positive terminal of the battery module, respectively, and the second end of the capacitor C4 is grounded. The gate of the field-effect transistor P2 is connected to the PDL pin of the main control chip, the drain of the field-effect transistor P2 is connected to the BATT pin of the main control chip, and the source of the field-effect transistor P2 is connected to the CSSN pin of the main control chip.

5. The automatic voltage detection circuit of the intelligent battery charger according to claim 4, characterized in that, The charging control module also includes a resistor R13, a capacitor C13, and a capacitor C16. The LDO pin of the main control chip is connected to the first end of the capacitor C13 and the first end of the resistor R13, respectively. The second end of the capacitor C13 is grounded. The second end of the resistor R13 is connected to the DLOV pin of the main control chip and the first end of the capacitor C16, respectively. The second end of the capacitor C16 is grounded.

6. The automatic voltage detection circuit of the intelligent battery charger according to claim 3, characterized in that, The voltage detection module also includes a resistor R5, a capacitor C9, a capacitor C10, a capacitor C11, and a capacitor C12. The first end of resistor R5 is connected to the CCV pin of the main control chip, and the second end is connected to the first end of capacitor C11. The second end of capacitor C11 is grounded. The first end of capacitor C9 is connected to the CCI pin of the main control chip, and the second end is connected to the first end of capacitor C10 and then grounded. The second end of capacitor C10 is connected to the CCS pin of the main control chip. The REF pin of the main control chip is connected to the first end of capacitor C12, and the second end of capacitor C12 is grounded.

7. The automatic voltage detection circuit of the intelligent battery charger according to any one of claims 1-6, characterized in that, The main control chip is model MAX8725.

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