Charger battery connection misjudgment prevention circuit

Abstract

The utility model relates to the technical field of battery charging, and discloses a charger battery connection misjudgment prevention circuit, which comprises a power supply input module, a negative electrode control switch module, an output current detection module, a master control MCU (Microprogrammed Control Unit) module and a battery voltage detection module, the power input module is in signal connection with a negative electrode control switch module, the negative electrode control switch module is electrically connected with an output current detection module, the output current detection module is in bidirectional connection with a main control MCU module, and the main control MCU module is in signal connection with the negative electrode control switch module. And the main control MCU module is bidirectionally connected with a battery voltage detection module. According to the utility model, all the modules form a closed-loop control system through signal interaction, so that accurate control, state monitoring, fault protection and intelligent management of battery charging and discharging are realized, and stable and reliable operation of a circuit is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of battery charging technology, and in particular to a charger battery connection anti-misjudgment circuit. Background Technology

[0002] After the battery is removed from the charger, the voltage release takes a relatively long time due to the presence of capacitors in the output circuit. In previous technologies, in time-sensitive applications, the MCU often misjudges whether the battery and charger are disconnected, leading to malfunctions in the charging function. Therefore, it is necessary to develop a charger-battery connection misjudgment circuit. Utility Model Content

[0003] To overcome the above shortcomings, this utility model provides a charger battery connection anti-misjudgment circuit, which aims to improve the problem in the prior art where, in some time-sensitive situations, the MCU often misjudges (whether the battery and charger are disconnected), resulting in poor charging function.

[0004] To achieve the above objectives, this utility model adopts the following technical solution: a charger battery connection anti-misjudgment circuit, including a power input module, a negative electrode control switch module, an output current detection module, a main control MCU module, and a battery voltage detection module. The input interface of the power input module obtains +28V and +12.6V power from the outside. The power input module is signal-connected to the negative electrode control switch module. The negative electrode control switch module is electrically connected to the output current detection module. The output current detection module is bidirectionally connected to the main control MCU module. The main control MCU module is signal-connected to the negative electrode control switch module. The main control MCU module is bidirectionally connected to the battery voltage detection module.

[0005] Through the above technical solutions: the power input module ensures stable circuit operation and reduces circuit faults or misjudgments caused by power fluctuations and noise; the negative terminal control switch module, controlled by the main control MCU module, determines the on / off state of the battery negative terminal (Bat-), realizing the opening and closing control of the battery charging and discharging circuit; the output current detection module allows the main control MCU module to judge the battery charging and discharging status and whether there are abnormalities such as overcurrent based on the current, and then take corresponding measures, such as adjusting the charging strategy and cutting off the circuit, to prevent the battery from overcharging or over-discharging, improve battery life and safety, and avoid misjudgments caused by abnormal current; the battery voltage detection module allows the main control MCU module to judge the battery's charge status and whether there are abnormal voltage conditions (such as overvoltage or undervoltage) based on the battery voltage, thereby performing operations such as charging mode switching and fault alarms, preventing battery damage due to abnormal voltage, and avoiding charging abnormalities caused by voltage misjudgments.

[0006] As a further description of the above technical solution:

[0007] The output current detection module includes a sampling resistor R74, a diode D9, a filter capacitor C41, and a voltage divider resistor R77. The sampling resistor R74 is connected in series in the output circuit. The filter capacitor C41 and the voltage divider resistor R77 form an RC filter circuit. The sampling resistor R74, the filter resistor R77, and the voltage divider capacitor C41 together form the output current detection circuit. The output terminal of the output current detection module outputs a current detection signal LOAD and transmits it to the MCU chip in the main control MCU module. The diode D9 clamps and protects the output current detection signal LOAD to prevent reverse voltage from damaging the pins of the MCU chip.

[0008] Through the above technical solution: the RC filter circuit can effectively suppress the high-frequency noise generated by the switching power supply, making the LOAD signal more stable; the sampling resistor R74 converts the output current into a voltage signal, which, together with the RC filter circuit, filters out high-frequency noise and ensures a smooth signal; the diode D9 clamps the voltage within the safe range to prevent reverse voltage from damaging the MCU pins and enhances system reliability; the MCU obtains current data in real time through the LOAD signal, enabling precise control and fault diagnosis of the charging and discharging process.

[0009] As a further description of the above technical solution:

[0010] The power input module includes a filter capacitor C10, an electrolytic capacitor EC6, a relay RY2, a voltage divider resistor R116, a voltage divider resistor R117, an inductor LF7, and a capacitor C17.

[0011] Through the above technical solution, relay RY2 can realize the on / off control of the main power supply, provide electrical isolation protection for the system, and convert high voltage into a low voltage signal that can be collected by the main control MCU module through voltage divider resistors R116 and R117 for power supply voltage monitoring and fault diagnosis.

[0012] As a further description of the above technical solution:

[0013] The filter capacitor C10 and the electrolytic capacitor EC6 are connected in parallel to form a π-type filter circuit, and the inductor LF7 and the capacitor C17 form an LC filter circuit.

[0014] Through the above technical solutions: the power input module can filter out various ripples and noises in the power input through the π-type filter circuit, making the output voltage more stable and avoiding ripple interference from affecting the normal operation of the subsequent circuits. The LC filter circuit can provide clean power to the subsequent modules and reduce ripple interference to the precision detection circuit.

[0015] As a further description of the above technical solution:

[0016] The negative control switch module includes a MOSFET (Q13), a transistor Q8, a resistor R69, a resistor R104, a transistor Q8, and a protection diode D6.

[0017] Through the above technical solution, the negative electrode control switch module can accurately control the battery charging and discharging process, avoid the battery from charging and discharging at inappropriate times, protect the battery and circuit safety, and also prevent abnormal current from occurring when the battery is connected incorrectly due to misoperation.

[0018] As a further description of the above technical solution:

[0019] The MOSFET (Q13) is a negative control switch. The gate of the MOSFET (Q13) is driven by a circuit consisting of resistor R69, resistor R104 and transistor Q8, and is controlled by the MCU control signal.

[0020] The above technical solution uses a MOSFET (Q13) as a negative control switch to control the on / off state of the battery's negative terminal, thereby achieving precise control of the charging and discharging circuit with fast response speed (μs level) and low loss.

[0021] As a further description of the above technical solution:

[0022] The protection diode D6 is used to clamp and protect the gate drive signal of the MOSFET (Q13) to prevent the voltage spike generated at the gate when the transistor Q8 is turned off from damaging the MOSFET.

[0023] The above technical solution effectively protects the MOSFET (Q13) from voltage spikes by using diode clamping and transistor driving, and ensures that it switches normally according to the MCU signal.

[0024] As a further description of the above technical solution:

[0025] The battery voltage detection module includes filter capacitor C59 and filter capacitor C61, which together form a dual-capacitor filter circuit.

[0026] Through the above technical solution: the battery voltage detection module performs voltage division and filtering on the battery positive voltage BAT+, and transmits the battery voltage signal to the main control MCU module for real-time monitoring of the battery voltage status. The dual-capacitor filter circuit composed of filter capacitor C59 and filter capacitor C61 can filter out high-frequency noise, thereby ensuring that the battery voltage signal collected by the main control MCU module is stable and free of glitches.

[0027] This utility model has the following beneficial effects:

[0028] 1. In this utility model, each module forms a closed-loop control system through signal interaction, realizing precise control of battery charging and discharging, status monitoring, fault protection and intelligent management, and ensuring stable and reliable operation of the circuit.

[0029] 2. In this utility model, by combining dynamic voltage pulse testing with current response detection, it is possible to effectively distinguish between actual battery disconnection and instantaneous voltage fluctuations, thereby achieving highly reliable battery connection status judgment and improving the reliability, safety and intelligence of the entire charger system. Attached Figure Description

[0030] Figure 1 This is a schematic block diagram of the system module for the charger battery connection anti-false judgment circuit proposed in this utility model;

[0031] Figure 2 This is a schematic diagram of the circuit connection for the charger battery connection anti-misjudgment circuit proposed in this utility model. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments 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 of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] Reference Figure 1 This utility model provides an embodiment of a charger battery connection anti-misjudgment circuit, including a power input module, a negative electrode control switch module, an output current detection module, a main control MCU module, and a battery voltage detection module. The input interface of the power input module obtains +28V and +12.6V power from the outside. The power input module is signal-connected to the negative electrode control switch module. The negative electrode control switch module is electrically connected to the output current detection module. The output current detection module is bidirectionally connected to the main control MCU module. The main control MCU module is signal-connected to the negative electrode control switch module. The main control MCU module is bidirectionally connected to the battery voltage detection module.

[0034] Specifically, the power input module obtains +28V and +12.6V power from external sources. After filtering and other processing, it provides a stable and clean power input for the entire charger's battery connection anti-misjudgment circuit, ensuring that each module can operate under a suitable power environment. The power input module also provides operating power to the negative terminal control switch module, ensuring its normal operation under appropriate power conditions. The negative terminal control switch module enables the output current module to detect corresponding current changes. Simultaneously, the negative terminal control switch module is controlled by the main control MCU module, using MOSFET switching elements to control the on / off state of the battery's negative terminal. Furthermore, during charging and discharging, the negative terminal control... The switching module can promptly open or close the battery negative terminal circuit according to the control commands issued by the main control MCU module. The output current detection module can detect the output current during the battery charging and discharging process in real time, then convert the current signal into a LOAD current detection signal and transmit it to the main control MCU module so that the MCU can analyze and judge based on the current situation. At the same time, the main control MCU module will set or calibrate the detection parameters of the output current module. The battery voltage detection module transmits the detected battery voltage signal BAT+ to the main control MCU module for the main control MCU module to judge the battery status. Then, the main control MCU module performs parameter configuration and calibration operations on the battery voltage detection module.

[0035] Reference Figure 1 and Figure 2 The output current detection module includes a sampling resistor R74, a diode D9, a filter capacitor C41, and a voltage divider resistor R77. The sampling resistor R74 is connected in series in the output circuit. The filter capacitor C41 and the voltage divider resistor R77 form an RC filter circuit. The sampling resistor R74, the filter resistor R77, and the voltage divider capacitor C41 together form the output current detection circuit. The output terminal of the output current detection module outputs a current detection signal LOAD and transmits it to the MCU chip in the main control MCU module. The diode D9 clamps and protects the output current detection signal LOAD to prevent reverse voltage from damaging the pins of the MCU chip.

[0036] Specifically, the sampling resistor R74 converts the output current into a voltage signal, and the voltage drop across it reflects the current magnitude. An RC filter circuit consisting of filter capacitor C41 and voltage divider resistor R77 filters out high-frequency noise and interference, making the voltage signal smoother and more stable, facilitating subsequent measurement and processing. The output current detection signal LOAD allows the main control MCU module to determine the battery's charging / discharging status and whether there are abnormal conditions such as overcurrent based on the current. This allows for appropriate measures, such as adjusting the charging strategy or cutting off the circuit, to prevent overcharging and over-discharging, improving battery life and safety, and avoiding misjudgments caused by abnormal current. Diode D9 ensures the LOAD signal remains within a safe range, enhancing system reliability.

[0037] Reference Figure 1 and Figure 2 The power input module includes a filter capacitor C10, an electrolytic capacitor EC6, a relay RY2, a voltage divider resistor R116, a voltage divider resistor R117, an inductor LF7, and a capacitor C17; the filter capacitor C10 and the electrolytic capacitor EC6 are connected in parallel to form a π-type filter circuit, and the inductor LF7 and the capacitor C17 form an LC filter circuit.

[0038] Specifically, in the power input module, the π-type filter circuit composed of filter capacitor C10 and electrolytic capacitor EC6 can filter out AC noise in the input power supply to ground, making the output voltage more stable and providing a clean DC power supply for subsequent circuits. In the charger circuit, it can make the power supply to the battery more stable, avoiding the impact of power fluctuations on charging effect and battery life. Through voltage divider resistors R116 and R117, the high positive voltage BAT+ of the battery can be divided according to a certain ratio and converted into a voltage range suitable for detection by the main control MCU module. Through the LC filter circuit composed of inductor LF7 and capacitor C17, high-frequency ripple and switching noise in the power supply can be filtered out, improving the stability of the output voltage. Relay RY2 is used to realize power on / off control, redundancy switching or safety protection.

[0039] Reference Figure 1 and Figure 2 The negative control switch module includes a MOSFET (Q13), a transistor Q8, a resistor R69, a resistor R104, a transistor Q8, and a protection diode D6. The MOSFET (Q13) is the negative control switch. The gate of the MOSFET (Q13) forms a drive circuit through the resistor R69, the resistor R104, and the transistor Q8, and is controlled by the MCU control signal. The protection diode D6 is used to clamp and protect the gate drive signal of the MOSFET (Q13) to prevent the voltage spike generated at the gate of the transistor Q8 from damaging the MOSFET when it is turned off.

[0040] Specifically, MOSFET (Q13) is used as the negative control switch, driven by the MCU control signal, to realize the conduction and cutoff of the battery negative terminal Bat- circuit. Transistor Q8, resistor R69 and R104 are used to drive the gate of MOSFET (Q13), so that MOSFET (Q13) can work normally according to the signal sent by the main control MCU module. The protection diode D6 can effectively prevent the gate-source voltage from exceeding the maximum rated value of MOSFET, avoid gate oxide layer breakdown, and thus extend the life of MOSFET (Q13).

[0041] Reference Figure 1 and Figure 2The battery voltage detection module includes filter capacitor C59 and filter capacitor C61, which together form a dual-capacitor filter circuit.

[0042] Specifically, the dual-capacitor filter circuit composed of filter capacitors C59 and C61 in the battery voltage detection module can effectively filter out high-frequency interference components in the battery voltage signal, ensuring that the main control MCU module acquires a stable and accurate battery voltage signal.

[0043] Working principle: The battery voltage detection module monitors the battery's positive terminal "BAT+" in real time. When properly connected, the voltage is stable. The output current detection module monitors the "LOAD" signal; a corresponding current is present during charging or discharging. Through the main control MCU module, when "BAT+" is detected as normal and "LOAD" shows current, the battery connection is determined to be normal, and normal charging and discharging control is maintained. If the detected voltage drops, the MCU sends a higher output voltage pulse. If the MCU detects the "LOAD" current signal, the battery is not actually disconnected and remains connected. If no "LOAD" current signal is detected at this time, the battery is truly disconnected, preventing false alarms.

[0044] The dual protection of diode clamping and voltage divider design prevents overvoltage damage to the MCU, improving system reliability. Detecting the battery voltage "BAT+" is the core function of the charger control circuit. By monitoring the positive terminal voltage of the battery in real time and combining it with current detection, the MCU can achieve intelligent charging management. The core control unit of the entire system, the main control MCU module, receives the LOAD signal from the output current detection module and the BAT+ voltage signal from the battery voltage detection module. Based on the set logic algorithm, it judges and controls the charging and discharging state of the battery, and sends control signals to the negative terminal control switch module to adjust the circuit's operating state. The output current detection circuit, composed of sampling resistor R74, filter resistor R77, and voltage divider capacitor C41, converts the output current signal into a voltage signal LOAD and transmits it to the main control MCU module for real-time monitoring of the output current. By using diode D9 and protection diode D6 to clamp and protect the LOAD signal and the MOSFET (Q13) drive signal, reverse voltage breakdown of the circuit can be prevented, enhancing system reliability.

[0045] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A charger battery connection anti-false alarm circuit, comprising a power input module, a negative terminal control switch module, an output current detection module, a main control MCU module, and a battery voltage detection module, characterized in that: The power input module's input interface obtains +28V and +12.6V power from the outside. The power input module is signal-connected to a negative control switch module, which is electrically connected to an output current detection module. The output current detection module is bidirectionally connected to a main control MCU module, which is signal-connected to the negative control switch module and bidirectionally connected to a battery voltage detection module.

2. The charger battery connection anti-false judgment circuit according to claim 1, characterized in that: The output current detection module includes a sampling resistor R74, a diode D9, a filter capacitor C41, and a voltage divider resistor R77. The sampling resistor R74 is connected in series in the output circuit. The filter capacitor C41 and the voltage divider resistor R77 form an RC filter circuit. The sampling resistor R74, the filter resistor R77, and the voltage divider capacitor C41 together form the output current detection circuit. The output terminal of the output current detection module outputs a current detection signal LOAD and transmits it to the MCU chip in the main control MCU module. The diode D9 clamps and protects the output current detection signal LOAD to prevent reverse voltage from damaging the pins of the MCU chip.

3. The charger battery connection anti-false judgment circuit according to claim 1, characterized in that: The power input module includes a filter capacitor C10, an electrolytic capacitor EC6, a relay RY2, a voltage divider resistor R116, a voltage divider resistor R117, an inductor LF7, and a capacitor C17.

4. The charger battery connection anti-false judgment circuit according to claim 3, characterized in that: The filter capacitor C10 and the electrolytic capacitor EC6 are connected in parallel to form a π-type filter circuit, and the inductor LF7 and the capacitor C17 form an LC filter circuit.

5. The charger battery connection anti-false judgment circuit according to claim 1, characterized in that: The negative control switch module includes a MOSFET (Q13), a transistor Q8, a resistor R69, a resistor R104, a transistor Q8, and a protection diode D6.

6. The charger battery connection anti-false judgment circuit according to claim 5, characterized in that: The MOSFET (Q13) is a negative control switch. The gate of the MOSFET (Q13) is driven by a circuit consisting of resistor R69, resistor R104 and transistor Q8, and is controlled by the MCU control signal.

7. The charger battery connection anti-false judgment circuit according to claim 5, characterized in that: The protection diode D6 is used to clamp and protect the gate drive signal of the MOSFET (Q13) to prevent the voltage spike generated at the gate when the transistor Q8 is turned off from damaging the MOSFET.

8. The charger battery connection anti-false judgment circuit according to claim 1, characterized in that: The battery voltage detection module includes filter capacitor C59 and filter capacitor C61, which together form a dual-capacitor filter circuit.

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