A nickel-hydrogen lithium dual-purpose charger

Abstract

The application discloses a nickel-hydrogen lithium battery two-in-one charger, which comprises a power supply circuit, a charging circuit and a main control circuit, the power supply circuit is used for supplying power for the charger, the charging circuit comprises at least one nickel-hydrogen battery charging module and at least one lithium battery charging module, a battery type signal input end of the main control circuit is used for acquiring battery type information of the nickel-hydrogen battery charging module and / or the lithium battery charging module, and a battery type signal output end of the main control circuit is used for adjusting a charging strategy of the nickel-hydrogen battery and / or the lithium battery according to the battery type information, so that the nickel-hydrogen battery and the lithium battery can be mixed charged. The main control circuit automatically identifies whether the nickel-hydrogen battery is charged or the lithium battery is charged by acquiring the battery type information, and then adjusts a suitable charging strategy according to the identification result, so that the charger can support charging of the nickel-hydrogen battery and charging of the lithium battery, the universality of the charger is improved, and a user can meet the charging demand of different types of batteries without purchasing multiple special chargers.

Description

Technical Field

[0001] This utility model relates to the field of charger technology, and in particular to a nickel-metal hydride lithium battery dual-charger. Background Technology

[0002] With the widespread use of electronic devices, nickel-metal hydride (NiMH) and lithium-ion batteries are widely used in various electronic devices due to their different performance characteristics. NiMH battery chargers operate by charging with a constant current until the battery exhibits a negative voltage, at which point it is considered fully charged. Lithium-ion battery chargers, on the other hand, use constant voltage and constant current charging because lithium-ion batteries require extremely high voltage accuracy.

[0003] Existing chargers typically only support one charging method, either nickel-metal hydride (NiMH) or lithium-ion (Li-ion) batteries, and cannot be compatible with both. This forces users to purchase dedicated chargers for each type of battery. Furthermore, incompatibility issues can easily arise during use. For example, using a Li-ion charger to charge a NiMH battery may result in incomplete charging, while using a NiMH charger to charge a Li-ion battery may lead to severe overcharging, posing serious safety hazards. Summary of the Invention

[0004] To address the current issue that chargers cannot be simultaneously compatible with both nickel-metal hydride and lithium batteries, which necessitates users purchasing multiple dedicated chargers and can easily lead to charging safety problems due to incompatible chargers, this invention proposes a nickel-metal hydride and lithium battery dual-use charger.

[0005] A nickel-metal hydride (NiMH) and lithium-ion battery dual-use charger includes a power supply circuit, a charging circuit, and a main control circuit. The power supply circuit supplies power to the charger. The charging circuit includes at least one NiMH battery charging module and at least one lithium-ion battery charging module. The power input terminal of the NiMH battery charging module is connected to the power output terminal of the power supply circuit, and the power output terminal of the NiMH battery charging module is electrically connected to the NiMH battery. The power input terminal of the lithium-ion battery charging module is connected to the power output terminal of the power supply circuit, and the power output terminal of the lithium-ion battery charging module is electrically connected to the lithium-ion battery. The battery type signal input terminal of the main control circuit is connected to the power output terminals of the NiMH battery charging module and the lithium-ion battery charging module, respectively, for acquiring battery type information of the NiMH battery charging module and / or the lithium-ion battery charging module. The battery type signal output terminal of the main control circuit is used to adjust the charging strategy of the NiMH battery and / or the lithium-ion battery according to the battery type information, so that the NiMH battery and the lithium-ion battery can be charged together.

[0006] By adopting the above technical solution, the main control circuit can automatically identify whether it is charging a nickel-metal hydride battery or a lithium battery by acquiring battery type information. Based on the identification result, it can adjust the appropriate charging strategy, enabling the charger to support charging both nickel-metal hydride batteries and lithium batteries simultaneously. This improves the charger's versatility, and users do not need to purchase multiple dedicated chargers to meet the charging needs of different types of batteries, thus avoiding charging safety issues.

[0007] Preferably, the power supply circuit includes a rectifier module and a step-down module. The rectifier module's rectifier input terminal is connected to the mains power, and the rectifier output terminal is used to rectify the mains power to output a first DC voltage. The step-down module's input terminal is connected to the rectifier output terminal of the rectifier module, and the step-down module is used to step down the first DC voltage to a second DC voltage.

[0008] Preferably, the rectifier module includes a transformer LF1, the live wire of the mains power is connected to the positive terminal of the primary input of the transformer LF1, the neutral wire of the mains power is connected to the negative terminal of the primary input of the transformer LF1, the positive terminal of the secondary output of the transformer LF1 outputs a first DC voltage, and the negative terminal of the secondary output of the transformer LF1 is grounded.

[0009] By adopting the above technical solution, transformer LF1 can convert the AC voltage of the mains power into a stable DC voltage, effectively filtering out voltage fluctuations and noise in the AC power. Secondly, transformer LF1 can provide electrical isolation between the AC power grid and the internal circuit of the charger, thereby effectively reducing electromagnetic interference and improving the electromagnetic compatibility of the charger.

[0010] Preferably, the step-down module includes a voltage regulator U2, a switching transistor Q1, resistors R17, R18, and R19. The rectified output terminal of the rectifier module is connected to one end of resistor R17, the other end of resistor R17 is connected to the controlled terminal of the switching transistor Q1, the other end of resistor R17 is also connected to the anode terminal of the voltage regulator U2, the rectifier output terminal of the rectifier module is also connected to the first conducting terminal of the switching transistor Q1, the second conducting terminal of the switching transistor Q1 is connected to one end of resistor R18, the other end of resistor R18 is connected to the feedback terminal of the voltage regulator U2, the cathode terminal of the voltage regulator U2 is grounded, and resistor R19 is also connected between the other end of resistor R18 and ground.

[0011] By adopting the above technical solution, the voltage regulator U2 is an adjustable parallel voltage regulator. The voltage regulator U2 can stabilize the 12V DC voltage output by the rectifier module within the range of 5V DC voltage. Even if the input voltage or load changes, it can still stably output 5V DC voltage, providing a reliable power supply for circuits that require 5V.

[0012] Preferably, the nickel-metal hydride battery charging module includes switching transistors Q101, Q102, and Q103, diodes D101, D102, and D103, inductor L101, and resistors R101, R102, R103, R104, R107, and R108. The rectifier output terminal of the rectifier module is connected to the first conducting terminal of switching transistor Q101, the first conducting terminal of switching transistor Q102, and one end of resistor R101. The other end of resistor R101 is connected to the controlled terminal of switching transistor Q102. The second conducting terminal of switching transistor Q102 is connected to the controlled terminal of switching transistor Q101. The second conducting terminal of switching transistor Q101 is connected to one end of inductor L101. The other end of inductor L101 is also connected to the positive terminal of diode D103. The negative terminal of diode D103 is electrically connected to the nickel-metal hydride battery.

[0013] The positive terminal of the nickel-metal hydride battery is connected to one end of the resistor R107, and the other end of the resistor R107 is connected to the first voltage detection terminal of the main control circuit. The negative terminal of the nickel-metal hydride battery is connected to one end of the resistor R104, and the other end of the resistor R104 is connected to one end of the resistor R108. The other end of the resistor R108 is connected to the first current detection terminal of the main control circuit. The first control signal terminal of the main control circuit is connected to one end of the resistor R103, and the other end of the resistor R103 is connected to the controlled terminal of the switch Q103. The first conducting terminal of the switch Q103 is connected to one end of the resistor R102, and the second conducting terminal of the switch Q103 is grounded. The other end of the resistor R102 is connected to the controlled terminal of the switch Q102 and the negative terminal of the diode D102, respectively. The controlled terminal of the switch Q101 is connected to the positive terminal of the diode D102.

[0014] By adopting the above technical solution, a constant current charging mode is achieved through a switching transistor. By dynamically adjusting the working state of the switching transistor, the charging current and voltage can be controlled more precisely to optimize the charging process and extend battery life.

[0015] Preferably, the lithium battery charging module includes switching transistors Q301, Q302, and Q303, diodes D301, D302, and D303, inductor L301, and resistors R301, R302, R303, R304, R307, and R308. The rectifier output terminal of the rectifier module is connected to the first conducting terminal of switching transistor Q301, the first conducting terminal of switching transistor Q302, and one end of resistor R301. The other end of resistor R301 is connected to the controlled terminal of switching transistor Q302. The second conducting terminal of switching transistor Q302 is connected to the controlled terminal of switching transistor Q301. The second conducting terminal of switching transistor Q301 is connected to one end of inductor L301. The other end of inductor L301 is also connected to the positive terminal of diode D303. The negative terminal of diode D303 is electrically connected to the lithium battery.

[0016] The positive terminal of the lithium battery is connected to one end of the resistor R307, and the other end of the resistor R307 is connected to the second voltage detection terminal of the main control circuit. The negative terminal of the lithium battery is connected to one end of the resistor R304, and the other end of the resistor R304 is connected to one end of the resistor R308. The other end of the resistor R308 is connected to the second current detection terminal of the main control circuit. The second control signal terminal of the main control circuit is connected to one end of the resistor R303, and the other end of the resistor R303 is connected to the controlled terminal of the switch Q303. The first conducting terminal of the switch Q303 is connected to one end of the resistor R302, and the second conducting terminal of the switch Q303 is grounded. The other end of the resistor R302 is connected to the controlled terminal of the switch Q302 and the negative terminal of the diode D302, respectively. The controlled terminal of the switch Q301 is connected to the positive terminal of the diode D302.

[0017] By adopting the above technical solution, a constant current and constant voltage charging mode can be achieved through a switching transistor. By dynamically adjusting the working state of the switching transistor, the charging current and voltage can be controlled more precisely to optimize the charging process and extend battery life.

[0018] Preferably, the device further includes a USB charging circuit, which comprises a charging module and a load detection module. The power input terminal of the charging module is connected to the power output terminal of the power circuit, and the power output terminal of the charging module is electrically connected to the USB device. The enable control terminal of the charging module is connected to the enable control terminal of the main control circuit. The detection input terminal of the load detection module is connected to the power output terminal of the charging module, and the detection output terminal of the load detection module is connected to the load detection terminal of the main control circuit. The load detection module is used to detect whether the USB device is connected for charging, and when it is not connected, the enable control terminal of the main control circuit outputs an enable control signal to cut off the output of the charging module.

[0019] Preferably, the charging module includes a buck converter U3, a power port USB, and an inductor L1. The rectifier output terminal of the rectifier module is connected to the power input terminal of the buck converter U3. The enable control terminal of the main control circuit is connected to the enable control terminal of the buck converter U3. The power output terminal of the buck converter is connected to one end of the inductor L1, and the other end of the inductor L1 is electrically connected to the power port USB.

[0020] By adopting the above technical solution, the buck converter U3 can convert the 12V DC voltage output by the power supply circuit into a 5V DC voltage suitable for charging USB devices. The buck converter U3 has an output current limiting function and an output current protection function to ensure the safety of the charging process and prevent damage to the circuit and battery.

[0021] Preferably, the load detection module includes an operational amplifier U4B, resistors R13, R15, and R16. The power output terminal of the charging module is connected to one end of resistor R13, the other end of resistor R13 is connected to the non-inverting input terminal of the operational amplifier U4B, resistor R15 is connected between the inverting input terminal of the operational amplifier U4B and ground, the output terminal of the operational amplifier U4B is connected to one end of resistor R16, and the other end of resistor R16 is connected to the load detection terminal of the main control circuit.

[0022] By adopting the above technical solution, the main control circuit can accurately detect whether the USB device is connected for charging through the voltage comparison function of the operational amplifier U4B. When it is detected that the USB device is not connected for charging, the charging circuit can be cut off in time, the charging can be stopped, the power loss can be reduced, and the energy utilization efficiency can be improved.

[0023] Preferably, the device further includes an LCD display circuit and a charger status indicator circuit. The display input terminal of the LCD display circuit is connected to the battery display output terminal of the main control circuit, and the display output terminal of the LCD display circuit is electrically connected to the LCD screen for displaying the battery information of the charger. The indicator input terminal of the charger status indicator circuit is connected to the status indicator output terminal of the main control circuit for indicating the current status of the charger.

[0024] By adopting the above technical solution, information such as battery type, power level, and battery status can be clearly displayed, allowing users to intuitively understand the specific information of the battery and the working status of the charger, thus improving the user experience.

[0025] Compared with the prior art, the nickel-metal hydride lithium battery dual-charger proposed in this utility model has the following beneficial effects:

[0026] 1. The charger proposed in this utility model obtains battery type information through the main control circuit and can automatically identify whether it is charging a nickel-metal hydride battery or a lithium battery. Based on the identification result, it adjusts the appropriate charging strategy, enabling the charger to support charging both nickel-metal hydride batteries and lithium batteries simultaneously. This improves the charger's versatility, and users do not need to purchase multiple dedicated chargers to meet the charging needs of different types of batteries, thus avoiding charging safety issues.

[0027] 2. The USB charging circuit proposed in this utility model can accurately detect whether a USB device is connected for charging. When it is detected that the USB device is not connected for charging, the charging circuit can be cut off in time to stop charging, reduce power loss, and improve energy utilization efficiency. Attached Figure Description

[0028] Figure 1 This is a circuit structure block diagram of the present invention;

[0029] Figure 2 This is a partial circuit schematic diagram of the rectifier module of this utility model;

[0030] Figure 3 This is a partial circuit diagram of the step-down module of this utility model;

[0031] Figure 4 This is a partial circuit diagram of the nickel-metal hydride battery charging module of this utility model;

[0032] Figure 5 This is a partial circuit diagram of the lithium battery charging module of this utility model;

[0033] Figure 6 This is a partial circuit diagram of the main control circuit of this utility model;

[0034] Figure 7This is a partial circuit diagram of the USB charging circuit of this utility model;

[0035] Figure 8 This is a partial circuit diagram of the LCD display circuit of this utility model;

[0036] Figure 9 This is a partial circuit diagram of the charger status display circuit of this utility model. Detailed Implementation

[0037] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0038] In one embodiment, such as Figures 1 to 9 As shown, this utility model discloses a nickel-metal hydride and lithium battery two-in-one charger, including a power supply circuit 100, a charging circuit 200, and a main control circuit 300. The power supply circuit 100 is used to supply power to the charger. The charging circuit 200 includes at least one nickel-metal hydride battery charging module 210 and at least one lithium battery charging module 220. The power input terminal of the nickel-metal hydride battery charging module 210 is connected to the power output terminal of the power supply circuit 100, and the power output terminal of the nickel-metal hydride battery charging module 210 is electrically connected to the nickel-metal hydride battery. The power input terminal of the lithium battery charging module 220 is connected to the power supply circuit 100. The power output terminal of the main control circuit 300 is connected to the power output terminal of the nickel-metal hydride battery charging module 210 and the power output terminal of the lithium battery charging module 220, respectively. This is used to obtain the battery type information of the nickel-metal hydride battery charging module 210 and / or the lithium battery charging module 220. The battery type signal output terminal of the main control circuit 300 is used to adjust the charging strategy of the nickel-metal hydride battery and / or the lithium battery according to the battery type information, so that the nickel-metal hydride battery and the lithium battery can be charged in a mixed manner.

[0039] The charging strategy is a constant current charging mode for nickel-metal hydride batteries and a constant current and constant voltage charging mode for lithium batteries.

[0040] In this embodiment, the main control circuit can automatically identify whether it is charging a nickel-metal hydride battery or a lithium battery by acquiring battery type information. Based on the identification result, it adjusts the appropriate charging strategy, enabling the charger to support charging both nickel-metal hydride batteries and lithium batteries simultaneously. This improves the charger's versatility, and users do not need to purchase multiple dedicated chargers to meet the charging needs of different types of batteries, thus avoiding charging safety issues.

[0041] Furthermore, as a preferred embodiment of this solution and not a limitation, the battery type signal input terminal of the main control circuit 300 determines the battery type through the open-circuit voltage of the power output terminal of the nickel-metal hydride battery charging module 210 or the power output terminal of the lithium battery charging module 220.

[0042] Specifically, when the battery is plugged into the charger, the main control circuit 300 first detects the open circuit voltage of the battery. If the detected open circuit voltage is greater than or equal to a preset voltage threshold, it is determined to be a lithium battery and outputs a first battery type signal. The main control circuit 300 adopts a lithium battery charging strategy according to the first battery type signal, that is, it adopts the constant current and constant voltage charging mode of the lithium battery.

[0043] If the detected open-circuit voltage is less than the preset voltage threshold, it is determined to be a nickel-metal hydride battery, and a second battery type signal is output. The main control circuit 300 adopts the charging strategy of nickel-metal hydride battery according to the second battery type signal, that is, it adopts the constant current charging mode of nickel-metal hydride battery.

[0044] In this embodiment, the preset voltage threshold is set to 1.2V.

[0045] In this embodiment, the main control circuit can adopt appropriate charging strategies based on the charging characteristics of nickel-metal hydride batteries and lithium batteries, making the charging process more precise and efficient. A constant current charging mode is used for nickel-metal hydride batteries to ensure charging efficiency and battery performance, while a constant current / constant voltage charging mode is used for lithium batteries to achieve fast charging while avoiding overcharging that could damage the battery.

[0046] Furthermore, as a preferred embodiment of this solution and not a limitation thereof, the power supply circuit 100 includes a rectifier module 110 and a step-down module 120. The rectifier input terminal of the rectifier module 110 is connected to the mains power, and the rectifier output terminal of the rectifier module 110 is used to rectify the mains power and output a first DC voltage. The input terminal of the step-down module 120 is connected to the rectifier output terminal of the rectifier module 110, and the step-down module 120 is used to step down the first DC voltage to a second DC voltage.

[0047] In this embodiment, the first DC voltage is 12V and the second DC voltage is 5V. That is, the power supply circuit 100 of the charger can rectify the mains power to a 12V DC voltage to power the charger, and at the same time, the output terminal of the charger can step down the 12V DC voltage to a 5V DC voltage.

[0048] In a preferred embodiment, the rectifier module 110 includes a transformer LF1, the live wire of the mains power is connected to the positive terminal of the primary input of the transformer LF1, the neutral wire of the mains power is connected to the negative terminal of the primary input of the transformer LF1, the positive terminal of the secondary output of the transformer LF1 outputs a first DC voltage, and the negative terminal of the secondary output of the transformer LF1 is grounded.

[0049] In this embodiment, transformer LF1 can convert the AC voltage of the mains power into a stable DC voltage, effectively filtering out voltage fluctuations and noise in the AC power. Secondly, transformer LF1 can provide electrical isolation between the AC power grid and the internal circuit of the charger, thereby effectively reducing electromagnetic interference and improving the electromagnetic compatibility of the charger.

[0050] In a preferred embodiment, the step-down module 120 includes a voltage regulator U2, a switching transistor Q1, resistors R17, R18, and R19. The rectified output terminal of the rectifier module 110 is connected to one end of the resistor R17, and the other end of the resistor R17 is connected to the controlled terminal (i.e., base) of the switching transistor Q1. The other end of the resistor R17 is also connected to the anode of the voltage regulator U2. The rectified output terminal of the rectifier module 110 is also connected to the first conducting terminal (i.e., collector) of the switching transistor Q1. The second conducting terminal (i.e., emitter) of the switching transistor Q1 is connected to one end of the resistor R18, and the other end of the resistor R18 is connected to the feedback terminal of the voltage regulator U2. The cathode of the voltage regulator U2 is grounded, and the other end of the resistor R18 is connected to ground via a resistor R19.

[0051] Preferably, the voltage regulator U2 is model TL431. In specific implementations, other models with the same function can also be used instead of the voltage regulator U2.

[0052] In this embodiment, the voltage regulator TL431 is an adjustable parallel voltage regulator. The voltage regulator TL431 can stabilize the 12V DC voltage output by the rectifier module within the range of 5V DC voltage. Even if the input voltage or load changes, it can still stably output 5V DC voltage, providing a reliable power supply for circuits that require 5V.

[0053] As a preferred embodiment, the charging circuit 200 described in this specification can support four independent charging circuits, that is, the charging circuit 200 can support the simultaneous charging of two nickel-metal hydride battery charging modules 210 and two lithium battery charging modules 220. In the following embodiments, only one nickel-metal hydride battery charging module 210 and one lithium battery charging module 220 are used as examples for illustrative description. In addition, this specification does not specifically limit the number of independent charging circuits.

[0054] Furthermore, as a preferred embodiment of this solution and not a limitation, the nickel-metal hydride battery can be a size 5 nickel-metal hydride battery or a size 7 nickel-metal hydride battery, that is, the nickel-metal hydride battery charging module 210 supports charging a size 5 nickel-metal hydride battery or a size 7 nickel-metal hydride battery.

[0055] In a preferred embodiment, the nickel-metal hydride battery charging module 210 includes switching transistors Q101, Q102, and Q103, diodes D101, D102, and D103, an inductor L101, and resistors R101, R102, R103, R104, R107, and R108. The rectified output terminal of the rectifier module 110 is connected to the first conducting terminal (drain) of switching transistor Q101 and the first conducting terminal (collector) of switching transistor Q102, respectively. One end of the resistor R101 is connected to the control terminal (i.e., base) of the switch Q102. The second conducting terminal (i.e., emitter) of the switch Q102 is connected to the control terminal (i.e., gate) of the switch Q101. The second conducting terminal (i.e., source) of the switch Q101 is connected to one end of the inductor L101. The other end of the inductor L101 is also connected to the anode of the diode D103. The cathode of the diode D103 is electrically connected to a No. 5 or No. 7 nickel-metal hydride battery.

[0056] The positive terminal of the AA or AAA NiMH battery is connected to one end of resistor R107, and the other end of resistor R107 is connected to the first voltage detection terminal (CV1 terminal in this embodiment) of the main control circuit 300. The negative terminal of the AA or AAA NiMH battery is connected to one end of resistor R104, and the other end of resistor R104 is connected to one end of resistor R108. The other end of resistor R108 is connected to the first current detection terminal (CC1 terminal in this embodiment) of the main control circuit 300. The first control terminal of the main control circuit 300... The signal terminal (i.e., the PWM1 terminal in this embodiment) is connected to one end of the resistor R103, the other end of the resistor R103 is connected to the controlled terminal (i.e., the base) of the switch Q103, the first conducting terminal (i.e., the collector) of the switch Q103 is connected to one end of the resistor R102, the second conducting terminal (i.e., the emitter) of the switch Q103 is grounded, the other end of the resistor R102 is connected to the controlled terminal of the switch Q102 and the negative terminal of the diode D102, and the controlled terminal of the switch Q101 is connected to the positive terminal of the diode D102.

[0057] Specifically, when the nickel-metal hydride battery is being charged, the main control circuit 300 adopts a constant current charging mode. During the charging process, the first current detection terminal of the main control circuit 300 monitors the charging current of the nickel-metal hydride battery charging module 210 in real time. When the charging current exceeds the preset charging current threshold, the first control signal terminal (PWM1 terminal) of the main control circuit outputs a first PWM signal. By controlling the conduction of the switching transistor Q103, the conduction time of the switching transistors Q101 and Q102 is reduced, thereby lowering the charging current. When the charging current is lower than the preset charging current threshold, the first control signal terminal (PWM1 terminal) of the main control circuit outputs a second PWM signal. By controlling the conduction of the switching transistor Q103, the conduction time of the switching transistors Q101 and Q102 is increased, thereby increasing the charging current and thus realizing the constant current charging mode of the nickel-metal hydride battery.

[0058] In this embodiment, the nickel-metal hydride battery charging module can support charging of AA or AAA nickel-metal hydride batteries, meeting the charging needs of devices with different nickel-metal hydride battery types. Users do not need to worry about battery model incompatibility issues, demonstrating strong versatility. Secondly, a constant current charging mode is achieved through a switching transistor. By dynamically adjusting the operating state of the switching transistor, the charging current and voltage can be controlled more precisely to optimize the charging process and extend battery life.

[0059] Furthermore, as a preferred embodiment of this solution and not a limitation, the lithium battery can be a size 5 lithium battery or a size 7 lithium battery, that is, the lithium battery charging module 220 supports charging size 5 lithium batteries or size 7 lithium batteries.

[0060] In a preferred embodiment, the lithium battery charging module 220 includes switching transistors Q301, Q302, and Q303, diodes D301, D302, and D303, an inductor L301, and resistors R301, R302, R303, R304, R307, and R308. The rectified output terminal of the rectifier module 110 is connected to the first conducting terminal (drain) of switching transistor Q301 and the first conducting terminal (collector) of switching transistor Q302, respectively. One end of the resistor R301 is connected to the control terminal (i.e., base) of the switch Q302. The second conducting terminal (i.e., emitter) of the switch Q302 is connected to the control terminal (i.e., gate) of the switch Q301. The second conducting terminal (i.e., source) of the switch Q301 is connected to one end of the inductor L301. The other end of the inductor L301 is also connected to the anode of the diode D303. The cathode of the diode D303 is electrically connected to a No. 5 or No. 7 lithium battery.

[0061] The positive terminal of the AA or AAA lithium battery is connected to one end of resistor R307, and the other end of resistor R307 is connected to the second voltage detection terminal (i.e., CV3 terminal in this embodiment) of the main control circuit 300. The negative terminal of the AA or AAA lithium battery is connected to one end of resistor R304, and the other end of resistor R304 is connected to one end of resistor R308. The other end of resistor R308 is connected to the second current detection terminal (i.e., CC3 terminal in this embodiment) of the main control circuit 300. The second control signal of the main control circuit 300... The terminal (i.e., the PWM3 terminal in this embodiment) is connected to one end of the resistor R303, the other end of the resistor R303 is connected to the controlled terminal (i.e., the base) of the switch Q303, the first conducting terminal (i.e., the collector) of the switch Q303 is connected to one end of the resistor R302, the second conducting terminal (i.e., the emitter) of the switch Q303 is grounded, the other end of the resistor R302 is connected to the controlled terminal of the switch Q302 and the negative terminal of the diode D302, and the controlled terminal of the switch Q301 is connected to the positive terminal of the diode D302.

[0062] Specifically, when the lithium battery is being charged, the main control circuit 300 adopts a constant current and constant voltage charging mode. During the charging process, the second current detection terminal of the main control circuit 300 will monitor the charging current of the lithium battery charging module 220 in real time. When the charging current exceeds the preset charging current threshold, the second control signal terminal (PWM3 terminal) of the main control circuit will output a third PWM signal. By controlling the conduction of the switching transistor Q303, the conduction time of the switching transistors Q301 and Q302 will be reduced, thereby reducing the charging current. When the charging current is lower than the preset charging current threshold, the second control signal terminal (PWM3 terminal) of the main control circuit will output a fourth PWM signal. By controlling the conduction of the switching transistor Q303, the conduction time of the switching transistors Q301 and Q302 will be increased, thereby increasing the charging current.

[0063] During continuous charging, the battery voltage gradually increases. When the battery voltage reaches the preset voltage threshold, the charger switches to constant voltage charging mode. The second voltage detection terminal of the main control circuit 300 monitors the charging voltage of the lithium battery charging module 220 in real time. At the same time, by controlling the conduction of the switching transistor Q303, the on-time of the switching transistors Q301 and Q302 is affected to ensure the stability of the charging voltage until the battery is fully charged.

[0064] In this embodiment, the lithium battery charging module can support charging of AA or AAA lithium batteries, which can meet the charging needs of devices with different types of lithium batteries. Users do not need to worry about battery model incompatibility when using it, and it has strong versatility. Secondly, the constant current and constant voltage charging mode is realized by the switching transistor. By dynamically adjusting the working state of the switching transistor, the charging current and voltage can be controlled more precisely to optimize the charging process and extend the battery life.

[0065] Furthermore, as a preferred embodiment of this solution and not a limitation, the main control circuit 300 includes a main control chip U1. Preferably, the main control chip U1 is model HT66F40. In specific implementations, other models with the same function can also be used instead of the main control chip U1.

[0066] Furthermore, as a preferred embodiment of this solution and not a limitation, it also includes a USB charging circuit 400. The USB charging circuit 400 includes a charging module 410 and a load detection module 420. The power input terminal of the charging module 410 is connected to the power output terminal of the power circuit 100, and the power output terminal of the charging module 410 is electrically connected to the USB device. The enable control terminal of the charging module 410 is connected to the enable control terminal of the main control circuit 300. The detection input terminal of the load detection module 420 is connected to the power output terminal of the charging module 410, and the detection output terminal of the load detection module 420 is connected to the load detection terminal of the main control circuit 300. The load detection module 420 is used to detect whether the USB device is connected for charging, and when it is not connected, the enable control terminal of the main control circuit 300 outputs an enable control signal to cut off the output of the charging module 410.

[0067] The situation where the USB device is not connected to a charger includes the USB device being fully charged or the USB device being unplugged midway. The USB device includes, but is not limited to, devices that use USB charging ports such as mobile phones, smart bracelets, and headphones.

[0068] In a preferred embodiment, the charging module 410 includes a buck converter U3, a power port USB, and an inductor L1. The rectifier output terminal of the rectifier module 110 is connected to the power input terminal (i.e., the VIN terminal in this embodiment) of the buck converter U3. The enable control terminal (i.e., the EN terminal in this embodiment) of the main control circuit 300 is connected to the enable control terminal (i.e., the EN terminal in this embodiment) of the buck converter U3. The power output terminal (i.e., the LX terminal in this embodiment) of the buck converter is connected to one end of the inductor L1, and the other end of the inductor L1 is electrically connected to the power port USB.

[0069] Preferably, the buck converter U3 is model AOZ1051. In specific implementations, other models with the same function can also be used instead of buck converter U3.

[0070] In this embodiment, the buck converter U3 can convert the 12V DC voltage output by the power supply circuit into a 5V DC voltage suitable for charging USB devices. The buck converter AOZ1051 selected in this embodiment has output current limiting function and output current protection function to ensure the safety of the charging process and prevent damage to the circuit and battery.

[0071] In a preferred embodiment, the load detection module 420 includes an operational amplifier U4B, resistors R13, R15, and R16. The power output terminal of the charging module 410 is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to the non-inverting input terminal of the operational amplifier U4B. The inverting input terminal of the operational amplifier U4B is connected to ground via the resistor R15. The output terminal of the operational amplifier U4B is connected to one end of the resistor R16, and the other end of the resistor R16 is connected to the load detection terminal (i.e., the Device_sense terminal in this embodiment) of the main control circuit 300.

[0072] Specifically, when a USB device is plugged into the USB power port for charging, the buck converter U3 converts the 12V DC voltage output by the rectifier module 110 into a 5V DC voltage. The converted 5V DC voltage is smoothed by the inductor L1 and then output to the USB power port to charge the USB device.

[0073] During charging, the non-inverting input of operational amplifier U4B is connected to the output of the USB power port to monitor in real time whether the USB device is fully charged or unplugged. The inverting input of the operational amplifier is grounded through resistor R15 to form a reference voltage. If the USB device is fully charged or unplugged, the output voltage of the non-inverting input of operational amplifier U4B will be higher than the voltage of the inverting input, resulting in a high-level output. After the load detection terminal of the main control circuit 300 receives the high-level signal output by operational amplifier U4B, the enable control terminal of the main control circuit 300 outputs an enable control signal. After receiving the enable control signal, the enable control terminal of buck converter U3 stops outputting 5V DC voltage, thereby cutting off the charging circuit of charging module 410.

[0074] In this embodiment, the main control circuit can accurately detect whether the USB device is connected to charging through the voltage comparison function of the operational amplifier U4B. When it is detected that the USB device is not connected to charging, the charging circuit can be cut off in time to stop charging, reduce power loss, and improve energy utilization efficiency.

[0075] Furthermore, as a preferred embodiment of this solution and not a limitation, it also includes an LCD display circuit 500 and a charger status indicator circuit 600. The display input terminal of the LCD display circuit 500 is connected to the battery display output terminal of the main control circuit 300, and the display output terminal of the LCD display circuit 500 is electrically connected to the LCD screen for displaying the battery information of the charger. The indicator input terminal of the charger status indicator circuit 600 is connected to the status indicator output terminal of the main control circuit 300 for indicating the current status of the charger.

[0076] The battery information includes, but is not limited to, battery type, battery level, and battery status.

[0077] In a preferred embodiment, the LCD display circuit 500 includes an LCD display screen, which includes a common signal terminal group and a pixel signal terminal group. The common signal terminal group of the LCD display screen is connected to the common signal terminal group of the main control circuit 300, and the pixel signal terminal group of the LCD display screen is connected to the pixel signal terminal group of the main control circuit 300.

[0078] The common signal terminal group includes a first common signal terminal, a second common signal terminal, a third common signal terminal and a fourth common signal terminal (i.e., COM0-COM3 terminals in this embodiment), and the pixel signal terminal group includes a first pixel signal terminal to a twenty-second pixel signal terminal (i.e., SEG0-SEG21 terminals in this embodiment).

[0079] Specifically, the display principle of the LCD display circuit 500 is as follows: According to the driving principle of the LCD screen, the contrast ratio of the LCD screen is determined by the voltage value at the common signal terminal minus the voltage value at the pixel signal terminal. When the voltage difference is greater than the saturation voltage of the LCD screen, the pixel can be turned on; otherwise, the pixel is turned off. Therefore, the corresponding LCD segment, i.e., the pixel, can be lit up according to the voltage difference between the common signal terminal and the pixel signal terminal, thereby displaying the battery information of the charger.

[0080] Alternatively, the scanning process of the LCD display screen in this embodiment is as follows: First, the timer of the main control circuit 300 is set to interrupt once every 2ms. During the first interruption, the first common signal terminal (COM0) is set to output a high level. Due to the voltage division effect of the external resistor, the input pin voltage of other common signal terminals outputs VDD / 2. Then, the output voltage of the pixel signal terminal group is set according to the data to be displayed. During the second interruption, the first common signal terminal (COM0) is set to output a low level. Due to the voltage division effect of the external resistor, the input pin voltage of other common signal terminals outputs VDD / 2. Then, the output voltage of the pixel signal terminal group is set according to the data to be displayed. During the third interruption, the second common signal terminal (COM1) is set to output a high level. Due to the voltage division effect of the external resistor, the input pin voltage of other common signal terminals outputs VDD / 2. Then, the output voltage of the pixel signal terminal group is set according to the data to be displayed. During the fourth interruption, the second common signal terminal (COM1) is set to output a low level. Due to the voltage division effect of the external resistor, the input pin voltage of other common signal terminals outputs VDD / 2. Next, set the output voltage of the pixel signal terminal group according to the data to be displayed; during the fifth interrupt, set the third common signal terminal (COM2) to output a high level, and the input pin voltages of other common signal terminals, due to the voltage division effect of the external resistor, output VDD / 2, and then set the output voltage of the pixel signal terminal group according to the data to be displayed; during the sixth interrupt, set the third common signal terminal (COM2) to output a low level, and the input pin voltages of other common signal terminals, due to the voltage division effect of the external resistor, output VDD / 2, and then set the output voltage of the pixel signal terminal group according to the data to be displayed; during the seventh interrupt, set the fourth common signal terminal (COM3) to output a high level, and the input pin voltages of other common signal terminals, due to the voltage division effect of the external resistor, output VDD / 2, and then set the output voltage of the pixel signal terminal group according to the data to be displayed; during the eighth interrupt, set the third common signal terminal (COM3) to output a high level, and the input pin voltages of other common signal terminals, due to the voltage division effect of the external resistor, output VDD / 2, and then set the output voltage of the pixel signal terminal group according to the data to be displayed.

[0081] In this embodiment, the LCD display circuit can clearly display information such as battery type, battery level, and battery status, allowing users to intuitively understand the specific information of the battery. Especially during the charging process, users can view the changes in battery level and charging progress in real time, improving the user experience.

[0082] In a preferred embodiment, the charger status indicator circuit 600 includes a light-emitting diode (LED) and a resistor R11. The status indicator output terminal of the main control circuit 300 (i.e., the LED terminal in this embodiment) is connected to one end of the resistor R11, the other end of the resistor R11 is connected to the positive terminal of the LED, and the negative terminal of the LED is connected to ground.

[0083] In this embodiment, when the charger is working normally, the light-emitting diode (LED) is always on. If the LED flashes or goes out, it indicates that the charger is in an abnormal state or has stopped working. This allows users to intuitively observe the working status of the charger and enhances the user experience.

[0084] Those skilled in the art should understand that the above description is one embodiment provided in conjunction with specific content, and does not imply that the specific implementation of this utility model is limited to these descriptions. Furthermore, due to differences in industry naming conventions, it is not limited to the above names or English names. Any methods or structures similar to or identical to those of this utility model, or any technical deductions or substitutions made based on the concept of this utility model, should be considered within the scope of protection of this utility model.

Claims

1. A dual charger for nickel-hydrogen and lithium batteries, characterized in that, include: ​ A power supply circuit for supplying power to the charger; A charging circuit includes at least one nickel-metal hydride battery charging module and at least one lithium battery charging module. The power input terminal of the nickel-metal hydride battery charging module is connected to the power output terminal of the power circuit, and the power output terminal of the nickel-metal hydride battery charging module is electrically connected to the nickel-metal hydride battery. The power input terminal of the lithium battery charging module is connected to the power output terminal of the power circuit, and the power output terminal of the lithium battery charging module is electrically connected to the lithium battery. The main control circuit has its battery type signal input terminal connected to the power output terminal of the nickel-metal hydride battery charging module and the power output terminal of the lithium battery charging module, respectively. It is used to obtain the battery type information of the nickel-metal hydride battery charging module and / or the lithium battery charging module. The battery type signal output terminal of the main control circuit is used to adjust the charging strategy of the nickel-metal hydride battery and / or the lithium battery according to the battery type information, so that the nickel-metal hydride battery and the lithium battery can be charged in a mixed manner.

2. The charger of claim 1, wherein the charger is a dual charger for charging both a nickel-hydrogen battery and a lithium battery. The power supply circuit includes: A rectifier module, wherein the rectifier input terminal of the rectifier module is connected to the mains power, and the rectifier output terminal of the rectifier module is used to rectify the mains power and output a first DC voltage; A step-down module is provided, the input terminal of which is connected to the rectifier output terminal of the rectifier module. The step-down module is used to step down the first DC voltage to a second DC voltage.

3. The charger of claim 2, wherein the first and second charging terminals are arranged in a row. The rectifier module includes a transformer LF1. The live wire of the mains power is connected to the positive terminal of the primary input of the transformer LF1, the neutral wire of the mains power is connected to the negative terminal of the primary input of the transformer LF1, the positive terminal of the secondary output of the transformer LF1 outputs a first DC voltage, and the negative terminal of the secondary output of the transformer LF1 is grounded.

4. The charger of claim 2, wherein the first and second charging terminals are arranged in a row. The step-down module includes a voltage regulator U2, a switching transistor Q1, resistors R17, R18, and R19. The rectified output terminal of the rectifier module is connected to one end of resistor R17, and the other end of resistor R17 is connected to the controlled terminal of the switching transistor Q1. The other end of resistor R17 is also connected to the anode terminal of the voltage regulator U2. The rectifier output terminal of the rectifier module is also connected to the first conducting terminal of the switching transistor Q1. The second conducting terminal of the switching transistor Q1 is connected to one end of resistor R18, and the other end of resistor R18 is connected to the feedback terminal of the voltage regulator U2. The cathode terminal of the voltage regulator U2 is grounded, and resistor R19 is connected between the other end of resistor R18 and ground.

5. The charger of claim 2, wherein the first and second charging terminals are arranged in a row. The nickel-metal hydride battery charging module includes switching transistors Q101, Q102, and Q103, diodes D101, D102, and D103, inductor L101, and resistors R101, R102, R103, R104, R107, and R108. The rectifier output terminal of the rectifier module is connected to the first conducting terminal of switching transistor Q101, the first conducting terminal of switching transistor Q102, and one end of resistor R101. The other end of resistor R101 is connected to the controlled terminal of switching transistor Q102. The second conducting terminal of switching transistor Q102 is connected to the controlled terminal of switching transistor Q101. The second conducting terminal of switching transistor Q101 is connected to one end of inductor L101. The other end of inductor L101 is also connected to the positive terminal of diode D103. The negative terminal of diode D103 is electrically connected to the nickel-metal hydride battery. The positive terminal of the nickel-metal hydride battery is connected to one end of the resistor R107, and the other end of the resistor R107 is connected to the first voltage detection terminal of the main control circuit. The negative terminal of the nickel-metal hydride battery is connected to one end of the resistor R104, and the other end of the resistor R104 is connected to one end of the resistor R108. The other end of the resistor R108 is connected to the first current detection terminal of the main control circuit. The first control signal terminal of the main control circuit is connected to one end of the resistor R103, and the other end of the resistor R103 is connected to the controlled terminal of the switch Q103. The first conducting terminal of the switch Q103 is connected to one end of the resistor R102, and the second conducting terminal of the switch Q103 is grounded. The other end of the resistor R102 is connected to the controlled terminal of the switch Q102 and the negative terminal of the diode D102, respectively. The controlled terminal of the switch Q101 is connected to the positive terminal of the diode D102.

6. The charger of claim 2, wherein the charger is a dual charger for both nickel-hydrogen and lithium batteries. The lithium battery charging module includes switching transistors Q301, Q302, and Q303, diodes D301, D302, and D303, inductor L301, and resistors R301, R302, R303, R304, R307, and R308. The rectifier output terminal of the rectifier module is connected to the first conducting terminal of switching transistor Q301, the first conducting terminal of switching transistor Q302, and one end of resistor R301. The other end of resistor R301 is connected to the controlled terminal of switching transistor Q302. The second conducting terminal of switching transistor Q302 is connected to the controlled terminal of switching transistor Q301. The second conducting terminal of switching transistor Q301 is connected to one end of inductor L301. The other end of inductor L301 is also connected to the positive terminal of diode D303. The negative terminal of diode D303 is electrically connected to the lithium battery. The positive terminal of the lithium battery is connected to one end of the resistor R307, and the other end of the resistor R307 is connected to the second voltage detection terminal of the main control circuit. The negative terminal of the lithium battery is connected to one end of the resistor R304, and the other end of the resistor R304 is connected to one end of the resistor R308. The other end of the resistor R308 is connected to the second current detection terminal of the main control circuit. The second control signal terminal of the main control circuit is connected to one end of the resistor R303, and the other end of the resistor R303 is connected to the controlled terminal of the switch Q303. The first conducting terminal of the switch Q303 is connected to one end of the resistor R302, and the second conducting terminal of the switch Q303 is grounded. The other end of the resistor R302 is connected to the controlled terminal of the switch Q302 and the negative terminal of the diode D302, respectively. The controlled terminal of the switch Q301 is connected to the positive terminal of the diode D302.

7. The charger of claim 6, wherein the first and second charging terminals are arranged in a row. It also includes a USB charging circuit, which comprises: A charging module, wherein the power input terminal of the charging module is connected to the power output terminal of the power circuit, the power output terminal of the charging module is electrically connected to the USB device, and the enable control terminal of the charging module is connected to the enable control terminal of the main control circuit. The load detection module has its detection input terminal connected to the power output terminal of the charging module and its detection output terminal connected to the load detection terminal of the main control circuit. The load detection module is used to detect whether the USB device is connected for charging, and when it is not connected, the enable control terminal of the main control circuit outputs an enable control signal to cut off the output of the charging module.

8. A nickel-metal hydride lithium battery dual-use charger according to claim 7, characterized in that, The charging module includes a buck converter U3, a power port USB, and an inductor L1. The rectifier output terminal of the rectifier module is connected to the power input terminal of the buck converter U3. The enable control terminal of the main control circuit is connected to the enable control terminal of the buck converter U3. The power output terminal of the buck converter is connected to one end of the inductor L1, and the other end of the inductor L1 is electrically connected to the power port USB.

9. A nickel-metal hydride lithium battery dual-charger according to claim 7, characterized in that, The load detection module includes an operational amplifier U4B, resistors R13, R15, and R16. The power output terminal of the charging module is connected to one end of resistor R13, and the other end of resistor R13 is connected to the non-inverting input terminal of the operational amplifier U4B. Resistor R15 is connected between the inverting input terminal of the operational amplifier U4B and ground. The output terminal of the operational amplifier U4B is connected to one end of resistor R16, and the other end of resistor R16 is connected to the load detection terminal of the main control circuit.

10. A nickel-metal hydride lithium battery dual-use charger according to claim 1, characterized in that, Also includes: The LCD display circuit has its display input terminal connected to the battery display output terminal of the main control circuit, and its display output terminal electrically connected to the LCD screen for displaying the charger's battery information. A charger status indicator circuit, wherein the indicator input terminal of the charger status indicator circuit is connected to the status indicator output terminal of the main control circuit, and is used to indicate the current status of the charger.

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