Dual-purpose keyboard charging circuit and dual-purpose keyboard

Abstract

The utility model discloses a dual-purpose keyboard charging circuit and a dual-purpose keyboard, and relates to the technical field of dual-purpose keyboards, the dual-purpose keyboard charging circuit is characterized in that a rechargeable battery is arranged in the dual-purpose keyboard, the rechargeable battery is charged with the outside through a USB data line, and the charging circuit comprises a main controller; the dual-purpose keyboard comprises a charging selection circuit, a power supply switching circuit, a wireless communication module and a main controller, so that the main controller can switch an external power supply to supply power to a load of the dual-purpose keyboard by controlling the power supply switching circuit when being connected with controlled equipment for wired transmission, and outputs a charging control signal when the dual-purpose keyboard is in a standby state; the charging selection circuit is controlled to charge the rechargeable battery through the external power supply, so that when the dual-purpose keyboard is connected with the controlled equipment, the power supply provided by the controlled equipment can be reasonably distributed, the service life of the rechargeable battery is prolonged, the burden of the battery is reduced, and the dual-purpose keyboard is prevented from being damaged due to overheating of the battery and too low power supply voltage of the controlled equipment.

Description

Technical Field

[0001] This application relates to the technical field of wireless and wired dual-purpose keyboards, and particularly to a charging circuit for a dual-purpose keyboard and a dual-purpose keyboard. Background Art

[0002] In existing wireless transmission control and wired transmission control dual-purpose keyboards, when performing wired transmission control, the controlled device both charges the rechargeable battery in the dual-purpose keyboard and enables data transmission control. However, since the voltage and current provided by the controlled device are small, in this case, it may cause the rechargeable battery to overheat, shorten its lifespan, and damage the internal circuit and load. Summary of the Utility Model

[0003] The main purpose of this application is to provide a charging circuit for a dual-purpose keyboard, aiming to solve the problem that since the voltage and current provided by the controlled device are small, in the case of connecting the controlled device to both charge the dual-purpose keyboard and perform data transmission, it may cause the rechargeable battery to overheat, shorten its lifespan, and damage the internal circuit.

[0004] To achieve the above object, this application proposes a charging circuit for a dual-purpose keyboard. A rechargeable battery is provided inside the dual-purpose keyboard, and the rechargeable battery is charged through a USB data cable from an external power source. The charging circuit includes:

[0005] A main controller;

[0006] The voltage input terminals of the power supply switching circuit are respectively connected to the voltage output terminal of the USB data cable and the rechargeable battery. The controlled terminal of the charging selection circuit is electrically connected to the main controller, and the voltage output terminal of the charging selection circuit is electrically connected to the rechargeable battery. The charging selection circuit is used to charge the rechargeable battery according to the charging control signal output by the main controller when it detects that the dual-purpose keyboard is connected to an external power source or a controlled device through the USB data cable;

[0007] A power supply switching circuit, the voltage input terminals of the power supply switching circuit are respectively connected to the voltage output terminal of the USB data cable and the rechargeable battery, and the voltage output terminal of the power supply switching circuit is connected to the load access terminal of the dual-purpose keyboard. The power supply switching circuit is used to select the rechargeable battery or the external power source to supply power to the load of the dual-purpose keyboard;

[0008] A wireless communication module, the wireless communication module is electrically connected to the main controller and is used to send the control signal output by the main controller to the controlled device;

[0009] The main controller is used to generate a corresponding control signal according to the key signal triggered by the user and send it to the controlled device through the wireless communication module or the USB data cable; and,

[0010] When the dual-purpose keyboard is in a wired connection state with the controlled device and the controlled device is in the standby working mode, a charging control signal is output to control the charging selection circuit to charge the charging battery.

[0011] In one embodiment, the charging circuit includes:

[0012] A charging prompt circuit, which is electrically connected to the charging selection circuit and is used to prompt the user of the charging state when controlling the charging selection circuit to charge the charging battery.

[0013] In one embodiment, the charging circuit includes:

[0014] A wake-up circuit, which is electrically connected to the signal input end of the main controller and is used to generate a wake-up signal and send the wake-up signal to the main controller to wake up the main controller.

[0015] In one embodiment, the charging circuit includes:

[0016] A wireless charging receiving circuit, which is electrically connected to the charging battery and is used to receive the external magnetic flux to charge the charging battery.

[0017] In one embodiment, the wireless communication module is one or more of a Bluetooth communication module, a WIFI communication module, an infrared communication module, and a ZIGBEE communication module.

[0018] In one embodiment, the main controller is set as an nRF52840 Bluetooth system chip.

[0019] In one embodiment, the power supply switching circuit includes a first resistor, a second resistor, a first PMOS transistor, a second PMOS transistor, and a first NMOS transistor. The drain of the first PMOS transistor is electrically connected to the external power supply. The gate of the first PMOS transistor is electrically connected to the first end of the first resistor, the drain of the second PMOS transistor, the gate of the first NMOS transistor, and the voltage output end of the charging battery. The second end of the first resistor and the source of the first NMOS transistor are grounded. The drain of the first NMOS transistor is electrically connected to the gate of the second PMOS transistor and the first end of the second resistor. The second end of the second resistor, the source of the second PMOS transistor, and the source of the first PMOS transistor are respectively electrically connected to the voltage input end of the main controller.

[0020] In addition, to achieve the above object, the present application also proposes a dual-purpose keyboard, and the charging circuit of the dual-purpose keyboard includes the charging circuit of the dual-purpose keyboard as described above.

[0021] One or more technical solutions proposed in this application have at least the following technical effects:

[0022] A rechargeable battery is provided inside the dual-purpose keyboard. The rechargeable battery is charged through a USB data cable connected to an external power supply. The charging circuit includes: a main controller; a charging selection circuit, the voltage input end of the charging selection circuit is electrically connected to the voltage output end of the USB data cable, the controlled end of the charging selection circuit is electrically connected to the main controller, and the voltage output end of the charging selection circuit is electrically connected to the rechargeable battery; the charging selection circuit is configured to charge the rechargeable battery according to a charging control signal output by the main controller when it detects that the dual-purpose keyboard is connected to an external power supply or a controlled device through the USB data cable; a power supply switching circuit, the voltage input end of the power supply switching circuit is respectively electrically connected to the voltage output end of the USB data cable and the rechargeable battery, and the voltage output end of the power supply switching circuit is electrically connected to the load access end of the dual-purpose keyboard; the power supply switching circuit is configured to select the rechargeable battery or the external power supply to supply power to the load of the dual-purpose keyboard; a wireless communication module, the wireless communication module is electrically connected to the main controller and is configured to send a control signal output by the main controller to the controlled device; a main controller, configured to generate a corresponding control signal according to a key signal triggered by a user and send the control signal to the controlled device through the wireless communication module or the USB data cable; and, when the dual-purpose keyboard is in a wired connection state with the controlled device and the controlled device is in a standby operating mode, output a charging control signal to control the charging selection circuit to charge the rechargeable battery. With such a setting, the main controller can switch the external power supply to supply power to the load of the dual-purpose keyboard by controlling the power supply switching circuit when connecting to the controlled device for wired transmission, and when the dual-purpose keyboard is in a standby state, the main controller outputs a charging control signal to control the charging selection circuit to charge the rechargeable battery through the external power supply, so as to reasonably allocate the power provided by the controlled device when the dual-purpose keyboard is connected to the controlled device, thereby increasing the service life of the rechargeable battery, reducing the battery burden, and avoiding the harm to the internal load of the dual-purpose keyboard caused by overheating of the battery and too low supply voltage of the controlled device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present application and, together with the specification, are used to explain the principles of the present application.

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0025] Figure 1 System block diagram provided for an embodiment of the charging circuit of the dual-purpose keyboard of the present application;

[0026] Figure 2 Structural block diagram of the charging selection circuit provided for an embodiment of the charging circuit of the dual-purpose keyboard of the present application;

[0027] Figure 3 Structural block diagram of the power supply switching circuit provided for an embodiment of the charging circuit of the dual-purpose keyboard of the present application.

[0028] Explanation of the reference numerals in the drawings:

[0029] 1 - Main controller; 2 - Power supply switching circuit; 3 - Wireless communication module; 4 - Charging selection circuit; 5 - Charging battery; 6 - Wake-up circuit; 7 - Charging prompt circuit; 8 - Wireless charging receiving circuit; R1 - First resistor; R2 - Second resistor; R62 - Third resistor; R63 - Fourth resistor; R64 - Fifth resistor; R65 - Sixth resistor; R66 - Seventh resistor; Q1 - First NMOS transistor; Q2 - First PMOS transistor; Q3 - Second PMOS transistor; LED6 - First LED; LED7 - First LED; C50 - First capacitor; CN3 - Battery interface; U24 - Charging management chip.

[0030] The realization of the purpose, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0031] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0032] In order to better understand the technical solutions of the present application, the following will be described in detail with reference to the drawings in the specification and the specific implementation manners.

[0033] The main solution of the embodiment of the present application is that when the main controller is connected to a controlled device for wired transmission, it can switch the external power supply to supply power to the load of the dual-purpose keyboard by controlling the power supply switching circuit, and when the dual-purpose keyboard is in the standby state, the main controller outputs a charging control signal to control the charging selection circuit to charge the charging battery through the external power supply, so as to reasonably allocate the power provided by the controlled device when the dual-purpose keyboard is connected to the controlled device, thereby increasing the service life of the charging battery, reducing the battery burden, and avoiding the harm to the internal load of the dual-purpose keyboard caused by overheating of the battery and too low supply voltage of the controlled device.

[0034] In existing keyboards that support both wireless and wired transmission control, when performing wired transmission control, the controlled device not only charges the rechargeable battery within the dual-purpose keyboard but also enables data transmission control. However, since the voltage and current provided by the controlled device are relatively small, this may cause the rechargeable battery to overheat and have a shortened lifespan, thereby damaging the internal circuit.

[0035] Based on this, please refer to Figures 1 to 3 , an embodiment of the present application provides a charging circuit for a dual-purpose keyboard, characterized in that a rechargeable battery 5 is provided within the dual-purpose keyboard, and the rechargeable battery 5 is charged from the outside through a USB data cable. The charging circuit includes:

[0036] A main controller 1;

[0037] A charging selection circuit 4, the voltage input terminal of the charging selection circuit 4 is electrically connected to the voltage output terminal of the USB data cable, the controlled terminal of the charging selection circuit 4 is electrically connected to the main controller 1, and the voltage output terminal of the charging selection circuit 4 is electrically connected to the rechargeable battery 5; the charging selection circuit 4 is configured to charge the rechargeable battery 5 according to a charging control signal output by the main controller 1 when it detects that the dual-purpose keyboard is connected to an external power source or a controlled device through the USB data cable;

[0038] A power supply switching circuit 2, the voltage input terminals of the power supply switching circuit 2 are respectively electrically connected to the voltage output terminal of the USB data cable and the rechargeable battery 5, and the voltage output terminal of the power supply switching circuit 2 is electrically connected to the load access terminal of the dual-purpose keyboard; the power supply switching circuit 2 is configured to select the rechargeable battery 5 or the external power source to supply power to the load of the dual-purpose keyboard;

[0039] A wireless communication module 3, the wireless communication module 3 is electrically connected to the main controller 1 and is used to send a control signal output by the main controller 1 to the controlled device;

[0040] The main controller 1 is configured to generate a corresponding control signal according to a key signal triggered by a user and send it to the controlled device through the wireless communication module 3 or the USB data cable; and,

[0041] When the dual-purpose keyboard is in a wired connection state with the controlled device and the controlled device is in a standby operating mode, a charging control signal is output to control the charging selection circuit 4 to charge the rechargeable battery 5.

[0042] In this embodiment, the dual-purpose keyboard generates corresponding control signals according to the key signals triggered by the user, and transmits them to the controlled device through a USB data cable for wired transmission or through a wireless communication module 3 for wireless transmission. The controlled device is controlled to perform operations corresponding to the received control signals. When the dual-purpose keyboard detects data transmission from the controlled device, the main controller 1 preferentially controls the power supply switching circuit 2 to directly use the external power supply provided by the controlled device to supply power to the load of the dual-purpose keyboard. Or when the controlled device is in the standby working mode, the main controller 1 issues a charging control signal to control the charging selection circuit 4 to use the external power supply provided by the controlled device to charge the charging battery 5. It is worth mentioning that when the controlled device enters the standby working mode, two methods can be adopted to control the main controller 1. First, the controlled device sends a standby signal to the main controller 1, thereby prompting the main controller 1 to generate a charging control signal. Second, the main controller 1 with a built-in timer sets a specific time threshold. Once the user does not trigger the key signal of the dual-purpose keyboard within this time threshold, the main controller 1 will automatically issue a charging control signal. The time threshold in this setting is consistent with the time threshold when the controlled device enters the standby working state when it is not triggered within a certain time threshold. Such a setting can reasonably allocate the power supply provided by the controlled device when the dual-purpose keyboard is connected to the controlled device, thereby increasing the lifespan of the charging battery 5, reducing the battery burden, and avoiding the harm to the internal load of the dual-purpose keyboard caused by overheating of the battery and too low supply voltage of the controlled device.

[0043] Specifically, the wireless communication module 3 is one or more of a Bluetooth communication module, a WIFI communication module, an infrared communication module, and a ZIGBEE communication module.

[0044] Specifically, the main controller 1 is set as an nRF52840 Bluetooth system chip, and the Bluetooth system chip is provided with a timer function and a Bluetooth transmission function.

[0045] Specifically, the power supply switching circuit 2 includes a first resistor R1, a second resistor R2, a first PMOS transistor Q2, a second PMOS transistor Q3, and a first NMOS transistor Q1. The drain of the first PMOS transistor Q2 is electrically connected to the external power supply. The gate of the first PMOS transistor Q2 is electrically connected to the first end of the first resistor R1, the drain of the second PMOS transistor Q3, the gate of the first NMOS transistor Q1, and the voltage output terminal of the rechargeable battery 5. The second end of the first resistor R1 and the source of the first NMOS transistor Q1 are grounded. The drain of the first NMOS transistor Q1 is electrically connected to the gate of the second PMOS transistor Q3 and the first end of the second resistor. The second end of the second resistor R2, the source of the second PMOS transistor Q3, and the source of the first PMOS transistor Q2 are respectively electrically connected to the voltage input terminal of the main controller 1;

[0046] When the external power supply directly supplies power to the load of the dual-purpose keyboard, at this time, the first PMOS transistor Q2 is turned on, the second PMOS transistor Q3 and the first NMOS transistor Q1 are turned off, and the voltage of the external power supply flows through the first PMOS transistor Q2 to supply power to the load. When the rechargeable battery 5 supplies power to the load of the dual-purpose keyboard, the rechargeable battery outputs a voltage, a voltage is applied to the gate of the first NMOS transistor Q1, the first NMOS transistor Q1 is turned on, and since a voltage is applied to the gate of the first PMOS transistor Q2, the first PMOS transistor Q2 is turned off. At this time, the conduction voltage between the gate and the source of the first PMOS transistor Q2 is equal to the conduction voltage drop of the second PMOS transistor Q3, the second PMOS transistor Q3 is turned on, and the voltage of the rechargeable battery 5 flows through the second PMOS transistor Q3 and then directly supplies power to the load of the dual-purpose keyboard.

[0047] Specifically, the charging selection circuit 4 includes a third resistor R62, a fourth resistor R63, a fifth resistor R64, a sixth resistor R65, a seventh resistor R66, a first LED lamp LED6, a first LED lamp LED7, a first capacitor C50, a battery interface CN3, and a charging management chip U24. The first end of the third resistor R62 is electrically connected to the first end, the second end, and the third end of the charging management chip U24. The second end of the third resistor R62 is grounded. The fourth end of the charging management chip U24 is electrically connected to an external power supply through the USB data cable. The fifth end of the charging management chip U24 is electrically connected to the first end of the first capacitor C50, the first end of the battery interface CN3, and the first end of the sixth resistor R65. The second end of the sixth resistor R65 is electrically connected to the power supply switching circuit 2 and the first end of the seventh resistor R66. The second end of the seventh resistor R66, the second end of the battery interface CN3, and the second end of the first capacitor C50 are grounded. The cathode of the second LED lamp LED7 is electrically connected to the sixth end of the charging management chip U24, and the anode of the second LED lamp LED7 is electrically connected to the first end of the fifth resistor R64. The cathode of the first LED lamp LED6 is electrically connected to the seventh end of the charging management chip U24, and the anode of the first LED lamp LED6 is electrically connected to the first end of the fourth resistor R63. The eighth end of the charging management chip U24, the second end of the fourth resistor R63, and the second end of the fifth resistor R64 are respectively electrically connected to the signal output end of the main controller 1. The ninth end of the charging management chip U24 is electrically connected to the timing signal output end of the main controller 1;

[0048] Here, the third resistor R62 is a second-port resistor for adjusting the charging current of the charging management chip U24. The sixth resistor R65 and the seventh resistor R66 are battery voltage dividing resistors for dividing the voltage output by the battery. The first LED lamp LED6 is used to indicate the charging status, and the first LED lamp LED7 is used to indicate the charging completion status. The eighth end of the charging management chip U24 is used to receive the charging control signal sent by the main controller 1. When the charging control signal is received, the charging management chip U24 charges the charging battery 5. The ninth end of the charging management chip U24 is used to receive the timing signal sent by the main controller 1 to facilitate setting multiple charging modes.

[0049] In this embodiment, the charging prompt circuit 7 can adopt diversified means such as LED lights, voice, buzzers, etc. to meet the personalized needs and preferences of different users. Specifically, as an intuitive visual prompt method, the LED light indicates different charging states through the flashing or constant-on states of different colors. For example, a red light represents that charging is in progress, and a green light indicates that charging has been completed. In this way, users can quickly and clearly understand the real-time state of the charging battery 5. Voice prompts, as another practical method, broadcast key information such as charging progress and estimated full charge time to users in real time through preset voice messages, which greatly facilitates users to master the charging situation. In addition, the buzzer prompts users of changes in the charging state through different sound frequencies and rhythms, such as emitting a short beep when charging starts and a continuous beep when charging is completed. For example, the main controller 1 is specifically integrated with a buzzer as an important part of the charging prompt circuit 7. By setting up a power management chip and using its precise detection function, this circuit can obtain the charging state information of the battery in real time and convert it into corresponding sound prompts. This design not only significantly improves the intelligence level of the product, but also brings a more convenient and user-friendly charging experience to users.

[0050] In one embodiment, the charging circuit further includes:

[0051] A wake-up circuit 6, which is electrically connected to the signal input terminal of the main controller 1 and is used to generate a wake-up signal and send the wake-up signal to the main controller 1 to wake up the main controller 1.

[0052] In this embodiment, the wake-up circuit 6 can be set as a specific key, toggle switch, a circuit that generates a trigger signal, etc. to realize the function of waking up the keyboard. When the user needs to use the dual-purpose keyboard, they can press a specific key, toggle switch or trigger the wake-up circuit 6 in other ways. After receiving the trigger signal, the wake-up circuit 6 generates a wake-up signal and sends it to the main controller 1. After receiving the wake-up signal, the main controller 1 wakes up from the sleep state and activates the various functions of the keyboard.

[0053] In this way, the charging circuit in this embodiment not only realizes the sleep wake-up function of the dual-purpose keyboard, but also realizes the flexible switching of the power supply mode, making the dual-purpose keyboard more convenient to use, and at the same time improving its stability and durability.

[0054] In one embodiment, the charging circuit includes:

[0055] A wireless charging receiving circuit 8, which is electrically connected to the charging battery 5 and is used to receive the magnetic flux from the outside to charge the charging battery 5.

[0056] In this embodiment, the wireless charging receiving circuit 8 can be configured to receive the magnetic flux from an external wireless charger and convert the received magnetic flux into electrical energy, thereby realizing wireless charging of the charging battery 5. This wireless charging receiving circuit 8 adopts advanced wireless charging technology, which can efficiently and safely complete the charging process, avoiding many inconveniences brought by traditional wired charging methods, such as the bondage of cables and the wear of interfaces, etc.

[0057] In the specific implementation of the wireless charging receiving circuit 8, the principle of electromagnetic induction can be adopted. By means of the built-in receiving coil, the magnetic field emitted by the external wireless charger is induced, and then a current is generated to transmit the electrical energy to the charging battery 5. In addition, the wireless charging receiving circuit 8 can also integrate some protection circuits, such as overvoltage protection, overcurrent protection, etc., to ensure the safety and reliability of the charging process.

[0058] Through the design of the wireless charging receiving circuit 8, users can conveniently realize wireless charging of the charging battery 5 without worrying about the bondage of cables and the wear of interfaces, improving the convenience and comfort of use. At the same time, wireless charging technology also conforms to the current concept of green environmental protection, low-carbon energy conservation, and helps to promote sustainable development.

[0059] This application also provides an automatic switching controller, and the automatic switching controller includes the automatic switching circuit as described above.

[0060] The automatic switching circuit provided by this application includes: A rechargeable battery is provided inside the dual-purpose keyboard, and the rechargeable battery is charged through a USB data cable from an external power source. The charging circuit includes: A main controller; A charging selection circuit, the voltage input terminal of the charging selection circuit is electrically connected to the external power source, the controlled terminal of the charging selection circuit is electrically connected to the main controller, and the voltage output terminal of the charging selection circuit is electrically connected to the rechargeable battery; The charging selection circuit is used to charge the rechargeable battery according to the charging control signal output by the main controller when it detects that the dual-purpose keyboard is connected to an external power source or a controlled device through a USB data cable; A power supply switching circuit, the voltage input terminal of the power supply switching circuit is respectively electrically connected to the external power source and the rechargeable battery, and the voltage output terminal of the power supply switching circuit is electrically connected to the load access terminal of the dual-purpose keyboard; The power supply switching circuit is used to select the rechargeable battery or the external power source to supply power to the load of the dual-purpose keyboard; A wireless communication module, the wireless communication module is electrically connected to the main controller and is used to send the control signal output by the main controller to the controlled device; A main controller, which is used to generate a corresponding control signal according to the key signal triggered by the user and send it to the controlled device through the wireless communication module or the USB data cable; And, when the dual-purpose keyboard and the controlled device are in a wired connection state and the controlled device is in a standby working mode, a charging control signal is output to control the charging selection circuit to charge the rechargeable battery. With such a setting, the main controller can switch the external power source to supply power to the load of the dual-purpose keyboard by controlling the power supply switching circuit when connecting to the controlled device for wired transmission, and when the dual-purpose keyboard is in the standby state, the main controller outputs a charging control signal to control the charging selection circuit to charge the rechargeable battery through the external power source, so as to reasonably distribute the power provided by the controlled device when the dual-purpose keyboard is connected to the controlled device, thereby increasing the service life of the rechargeable battery, reducing the battery burden, and avoiding the harm to the internal load of the dual-purpose keyboard caused by overheating of the battery and too low power supply voltage of the controlled device.

Claims

1. A dual-purpose keyboard charging circuit, characterized in that: The dual-purpose keyboard is provided with a rechargeable battery, and the rechargeable battery is charged with an external power supply via a USB data line. The charging circuit includes: Main controller; A charging selection circuit, wherein a controlled end of the charging selection circuit is electrically connected to the main controller, and a voltage output end of the charging selection circuit is electrically connected to a rechargeable battery; the charging selection circuit is used to charge the rechargeable battery according to a charging control signal output by the main controller when detecting that the dual-purpose keyboard is connected to an external power source or a controlled device via a USB data cable; A power supply switching circuit, wherein the voltage input end of the power supply switching circuit is electrically connected to the voltage output end of the USB data line and the rechargeable battery respectively, and the voltage output end of the power supply switching circuit is electrically connected to the load access end of the dual-purpose keyboard; the power supply switching circuit is used to select the rechargeable battery or the external power supply to power the load of the dual-purpose keyboard; A wireless communication module, the wireless communication module is electrically connected to the main controller and is used to send the control signal output by the main controller to the controlled device; A main controller, used to generate a corresponding control signal according to a key signal triggered by a user, and send the control signal to the controlled device through the wireless communication module or the USB data cable; and When the dual-purpose keyboard and the controlled device are in a wired connection state and the controlled device is in a standby working mode, a charging control signal is output to control the charging selection circuit to charge the rechargeable battery.

2. The dual-purpose keyboard charging circuit as claimed in claim 1, characterized in that: The charging circuit further comprises: A charging prompt circuit is electrically connected to the charging selection circuit and is used to prompt a user of a charging status when the charging selection circuit is controlled to charge the rechargeable battery.

3. The dual-purpose keyboard charging circuit as claimed in claim 2, characterized in that: The charging circuit further comprises: A wake-up circuit is electrically connected to a signal input terminal of the main controller and is used to generate a wake-up signal and send the wake-up signal to the main controller to wake up the main controller.

4. The dual-purpose keyboard charging circuit as claimed in claim 1, characterized in that: The charging circuit comprises: A wireless charging receiving circuit is electrically connected to the rechargeable battery and is used to receive external magnetic flux to charge the rechargeable battery.

5. The dual-purpose keyboard charging circuit as claimed in claim 1, characterized in that: The wireless communication module is one or more of a Bluetooth communication module, a WIFI communication module, an infrared communication module and a ZIGBEE communication module.

6. The dual-purpose keyboard charging circuit as claimed in claim 1, characterized in that: The main controller is configured as an nRF52840 Bluetooth system chip.

7. The dual-purpose keyboard charging circuit as claimed in claim 1, characterized in that: The power supply switching circuit includes a first resistor, a second resistor, a first PMOS tube, a second PMOS tube, and a first NMOS tube. The drain of the first PMOS tube is electrically connected to the external power supply, the gate of the first PMOS tube is electrically connected to the first end of the first resistor, the drain of the second PMOS tube, the gate of the first NMOS tube, and the voltage output end of the rechargeable battery, the second end of the first resistor and the source of the first NMOS tube are grounded, the drain of the first NMOS tube is electrically connected to the gate of the second PMOS tube and the first end of the second resistor, and the second end of the second resistor, the source of the second PMOS tube, and the source of the first PMOS tube are electrically connected to the voltage input end of the main controller respectively.

8. A dual-purpose keyboard, characterized in that: The dual-purpose keyboard charging circuit comprises the dual-purpose keyboard charging circuit as claimed in any one of claims 1 to 7.

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