Wireless keyboard circuit and wireless keyboard

Abstract

The utility model discloses a wireless keyboard circuit and a wireless keyboard, and relates to the technical field of keyboards. Wherein the wireless keyboard circuit comprises a battery, a key matrix circuit, a wireless transmitting circuit, an electric quantity detection circuit, an electric quantity display circuit and a control circuit. The key matrix circuit can detect key triggering and generate a first signal. After receiving the first signal, the control circuit encodes and converts the first signal, converts the first signal into a wireless signal and outputs the wireless signal to the wireless transmitting circuit, and the wireless transmitting circuit further conditions the wireless signal and transmits the wireless signal. Meanwhile, the electric quantity detection circuit can monitor the electric quantity of the battery and generate an electric quantity detection signal. The control circuit can obtain battery electric quantity information according to the electric quantity detection signal so as to control the electric quantity display circuit to display the electric quantity information of the battery. Therefore, a user can know the battery electric quantity information in real time so as to charge the wireless keyboard or replace the battery in time.

Description

Technical Field

[0001] The utility model relates to the technical field of keyboards, and particularly relates to a wireless keyboard circuit and a wireless keyboard. Background Art

[0002] A wireless keyboard is one of the important accessories for mobile office. When used in conjunction with portable devices such as laptops, tablets, and smartphones, users can perform text input and operations anytime and anywhere. Among them, a wireless keyboard generally needs to be equipped with a rechargeable battery. When the battery runs out of power, the rechargeable battery needs to be charged to ensure the normal use of the wireless keyboard.

[0003] However, in the existing wireless keyboards, generally when the battery power is completely used up, the user can only find that the battery power has been exhausted, which affects the continued use of the wireless keyboard. Summary of the Utility Model

[0004] The main purpose of the utility model is to provide a wireless keyboard circuit, aiming to prompt the user of the battery power of the wireless keyboard to ensure the normal use of the wireless keyboard.

[0005] To achieve the above purpose, the wireless keyboard circuit proposed by the utility model is applied to a wireless keyboard. The wireless keyboard circuit includes:

[0006] A battery;

[0007] A key matrix circuit, the key matrix circuit is connected to the battery, and the key matrix circuit is used to input a first signal when triggered by the user;

[0008] A wireless transmission circuit, the wireless transmission circuit is connected to the battery, and the wireless transmission circuit is used to transmit wireless signals;

[0009] A power detection circuit, the power detection circuit is connected to the battery, and the power detection circuit is used to detect the power of the battery and output a power detection signal;

[0010] A power display circuit, the power display circuit is connected to the battery, and the power display circuit is used to display the power of the battery;

[0011] A control circuit, the control circuit is respectively connected to the battery, the key matrix circuit, the wireless transmission circuit, the power detection circuit and the power display circuit; the control circuit is used to control the operation of the wireless transmission circuit according to the first signal, and is used to control the operation of the power display circuit according to the power detection signal.

[0012] In an embodiment, the power detection circuit includes a first resistor, a second resistor and a first capacitor;

[0013] One end of the first resistor is connected to the detection end of the battery. The other end of the first resistor, one end of the first capacitor, and one end of the second resistor are connected to the output end of the power detection circuit. The other end of the first capacitor and the other end of the second resistor are grounded.

[0014] In one embodiment, the control circuit includes a control chip, a second capacitor, a third capacitor, a fourth capacitor, and a crystal oscillator element.

[0015] One end of the second capacitor, the VCC pin of the control chip are connected to the battery, and the other end of the second capacitor is grounded. The XIN pin of the control chip, the third pin of the crystal oscillator element are connected to one end of the fourth capacitor. The XOUT pin of the control chip, one end of the third capacitor are connected to the first pin of the crystal oscillator element. The second pin of the crystal oscillator element, the fourth pin of the crystal oscillator element, the other end of the third capacitor and the other end of the fourth capacitor are grounded.

[0016] In one embodiment, the wireless transmission circuit includes a first inductor, a second inductor, a third inductor, a fourth inductor, a fifth inductor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, and an antenna.

[0017] One end of the fifth capacitor, one end of the first inductor, one end of the second inductor, and one end of the fourth inductor are connected to the ANT1 pin of the control chip, and the other end of the fifth capacitor is connected to the other end of the first inductor. The other end of the second inductor and one end of the sixth capacitor are connected to the ANT2 pin of the control chip. The other end of the fourth inductor, one end of the fifth inductor, one end of the ninth capacitor, and the other end of the sixth capacitor are connected to one end of the seventh capacitor. The other end of the seventh capacitor and one end of the third inductor are connected to the ANT3 pin of the control chip. The other end of the third inductor and one end of the eighth capacitor are connected to the battery. The other end of the fifth inductor and one end of the tenth capacitor are connected to the first end of the antenna. The other end of the eighth capacitor, the other end of the ninth capacitor, and the other end of the tenth capacitor are grounded to the second end of the antenna.

[0018] In one embodiment, the power display circuit includes a digital tube display circuit, a third resistor, and a fourth resistor.

[0019] Wherein, the power supply terminal of the digital tube display circuit is connected to the battery, the grounding terminal of the digital tube display circuit is grounded, the first controlled terminal of the digital tube display circuit is connected to one end of the third resistor, and the other end of the third resistor is connected to the GPIO1 pin of the control chip; the second controlled terminal of the digital tube display circuit is connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the GPIO2 pin of the control chip.

[0020] In one embodiment, the control chip is an SH87F8805 chip.

[0021] In one embodiment, the control circuit further includes a voltage conversion circuit, and the voltage conversion circuit is connected to the control chip; the voltage conversion circuit is used for performing voltage conversion on the external power supply voltage and then outputting.

[0022] In one embodiment, the wireless keyboard circuit further includes a charging circuit, and the charging circuit is connected to the battery; the charging circuit is used for converting the external power supply voltage into a battery charging voltage and then outputting.

[0023] In one embodiment, the charging circuit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, an eleventh capacitor, a twelfth capacitor and a TP4056 chip;

[0024] Wherein, one end of the eleventh capacitor, the fourth pin of the TP4056 chip, one end of the seventh resistor, the fifth pin of the TP4056 chip, and one end of the eighth resistor are connected to the power input terminal of the charging circuit; the other end of the eleventh capacitor, one end of the fifth resistor, one end of the sixth resistor, the grounding pin, the third pin, and the seventh pin of the TP4056 chip, and one end of the twelfth capacitor are grounded; the other end of the fifth resistor and the other end of the seventh resistor are connected to the first pin of the TP4056 chip; the other end of the sixth resistor is connected to the second pin of the TP4056 chip; the eighth pin of the TP4056 chip and the other end of the twelfth capacitor are connected to the positive electrode of the battery.

[0025] The present utility model also proposes a keyboard, and the keyboard includes the wireless keyboard circuit as described above.

[0026] The technical solution of the present utility model adopts a wireless keyboard circuit, which includes a battery, a key matrix circuit, a wireless transmission circuit, a power detection circuit, a power display circuit and a control circuit. Among them, when a user presses a key on the wireless keyboard, the key matrix circuit detects the key trigger and generates a first signal. After receiving the first signal, the control circuit encodes and converts the first signal, converts it into a wireless signal and outputs it to the wireless transmission circuit, and the wireless transmission circuit further conditions and transmits the wireless signal so that a receiving device wirelessly connected to the wireless keyboard can receive the wireless signal. At the same time, the power detection circuit can also monitor the power of the battery and generate a power detection signal. After receiving the power detection signal, the control circuit controls the operation of the power display circuit according to the state of the battery power, and the power display circuit can display the power information of the battery by means of digital tube display or the like. In this way, the user can understand the battery power information in real time, so as to charge the wireless keyboard or replace the battery in time, avoiding the inconvenience caused to the user by the exhaustion of the battery power. Brief Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0028] Figure 1 It is a schematic structural diagram of an embodiment of the wireless keyboard circuit provided by the present utility model;

[0029] Figure 2 It is an electronic circuit diagram of the power detection circuit of an embodiment of the wireless keyboard circuit provided by the present utility model;

[0030] Figure 3 It is an electronic circuit diagram of the control circuit and the wireless transmission circuit of an embodiment of the wireless keyboard circuit provided by the present utility model;

[0031] Figure 4 It is an electronic circuit diagram of the power display circuit of an embodiment of the wireless keyboard circuit provided by the present utility model;

[0032] Figure 5 It is a schematic structural diagram of the wireless charging circuit of an embodiment of the wireless keyboard circuit provided by the present utility model;

[0033] Figure 6 It is an electronic circuit diagram of the charging circuit of another embodiment of the wireless keyboard circuit provided by the present utility model.

[0034] Explanation of the reference numerals in the drawings:

[0035]

[0036]

[0037] The realization, functional features and advantages of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0038] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0039] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0040] In addition, the descriptions involving "first", "second", etc. in the present utility model are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0041] In the existing wireless keyboard, generally, when the battery 01 runs out of power, the user can only find out that the battery 01 has run out of power, which affects the continued use of the wireless keyboard.

[0042] The present utility model provides a wireless keyboard circuit.

[0043] Please refer to Figure 1 , in an embodiment of the present utility model, the wireless keyboard circuit includes:

[0044] Battery 01;

[0045] A key matrix circuit 02, the key matrix circuit 02 is connected to the battery 01, and the key matrix circuit 02 is used to input a first signal when triggered by the user;

[0046] A wireless transmission circuit 03, the wireless transmission circuit 03 is connected to the battery 01, and the wireless transmission circuit 03 is used for transmitting wireless signals;

[0047] A power detection circuit 04, the power detection circuit 04 is connected to the battery 01, and the power detection circuit 04 is used for detecting the power of the battery 01 and outputting a power detection signal;

[0048] A power display circuit 05, the power display circuit 05 is connected to the battery 01, and the power display circuit 05 is used for displaying the power of the battery 01;

[0049] A control circuit 06, the control circuit 06 is respectively connected to the battery 01, the key matrix circuit 02, the wireless transmission circuit 03, the power detection circuit 04 and the power display circuit 05; the control circuit 06 is used for controlling the operation of the wireless transmission circuit 03 according to the first signal, and for controlling the operation of the power display circuit 05 according to the power detection signal.

[0050] It should be noted that the key matrix circuit 02 may include a keyboard array module and a keyboard array scanning module. The keyboard array can be set in the style of a keyboard array of a desktop computer, or in the style of a keyboard array of an ordinary tablet or mobile phone. The keyboard array scanning module is respectively connected to the keyboard array and the control circuit 06, and is used for receiving the key operation information sent by the keyboard array, scanning and generating a corresponding first signal according to the key operation information, and sending the generated first signal to the control circuit 06. The keyboard array scanning module can continuously scan the keyboard array to obtain the current key operation information of the user in real time, and generate a corresponding key signal according to the key operation information of the user. For example, if the operation information of the user pressing the "S" key is obtained, a key signal corresponding to "S" is generated. In an embodiment, when the user presses any key on the keyboard array, the keyboard array scanning module identifies the pressed key signal, and then inputs the corresponding first signal to the control circuit 06. For example, when the first signal is at a low level, the switching tube inside the control circuit 06 is cut off, and at this time, the oscillating element inside the control circuit 06 does not work and does not generate wireless signals. When the first signal is at a high level, the switching tube inside the control circuit 06 is turned on, and at this time, the oscillating element inside the control circuit 06 works and generates wireless signals, which are transmitted through the wireless transmission circuit 03.

[0051] It should be noted that the control circuit 06 may include a controller and a wireless signal processor. Among them, the controller can convert the first signal into a digital first signal, and the wireless signal processor can achieve wireless connection, which can be implemented by wireless technologies such as Bluetooth, infrared, and radio frequency. The wireless signal processor may include a wireless baseband core, a carrier generation unit, and a switch unit. The wireless baseband core is respectively connected to the controller and the wireless transmission circuit 03, can receive the digital first signal converted by the controller, convert the digital first signal into a wireless baseband signal, and then send it to the wireless transmission circuit 03. The wireless baseband core can be a Bluetooth baseband core, an infrared baseband core, or a radio frequency baseband core. The carrier generation unit is connected to the wireless transmission circuit 03, can generate a wireless carrier signal, and send the wireless carrier signal to the wireless transmission circuit 03. Among them, the carrier generation unit can be implemented by circuit modules such as a crystal oscillator and a frequency synthesis module. The switch unit can open the transmission channel of the wireless transmission circuit 03 when the wireless keyboard is in the transmission state. The wireless transmission circuit 03 is respectively connected to the wireless baseband core, the carrier generation unit, and the switch unit, can receive the wireless baseband signal generated by the wireless baseband core and the wireless carrier signal generated by the carrier generation unit and synthesize a wireless signal, and after the switch unit opens the transmission channel, transmit it through the antenna ANT of the wireless transmission circuit 03.

[0052] It should be noted that the wireless transmission circuit 03 may include a high-frequency amplifier, a low-pass filter, and an antenna ANT. Among them, the high-frequency amplifier is connected to the control circuit 06 and can amplify the wireless signal output by the control circuit 06. The low-pass filter is connected to the high-frequency amplifier and can filter out unnecessary low-frequency components output by the high-frequency amplifier. The antenna ANT is connected to the low-pass filter and can transmit the processed wireless signal. The wireless transmission circuit 03 may further include a tuning circuit, which is arranged between the low-pass filter and the antenna ANT and can be used to tune the wireless signal to adjust the phase, amplitude, or frequency of the wireless signal so that the receiving device can receive it effectively.

[0053] In this embodiment, when the user presses a key on the wireless keyboard, the key matrix circuit 02 detects the key trigger and generates a first signal. After receiving the first signal, the control circuit 06 encodes and converts the first signal, converts it into a wireless signal and outputs it to the wireless transmission circuit 03. The wireless transmission circuit 03 further conditions and transmits the wireless signal, so that the receiving device wirelessly connected to the wireless keyboard can correctly receive the wireless signal. At the same time, the power detection circuit 04 can also monitor the power of the battery 01 and generate a power detection signal. After receiving the power detection signal, the control circuit 06 controls the operation of the power display circuit 05 according to the state of the battery 01 power, so as to display the power information of the battery 01 by means of digital tube display or the like. In this way, the user can understand the power information of the battery 01 in real time, so as to charge the wireless keyboard or replace the battery 01 in time.

[0054] In the present utility model, when the user presses a key on the wireless keyboard, the key matrix circuit 02 detects the key trigger and generates a first signal. After receiving the first signal, the control circuit 06 encodes and converts the first signal, converts it into a wireless signal and outputs it to the wireless transmission circuit 03. The wireless transmission circuit 03 further conditions and transmits the wireless signal, so that the receiving device wirelessly connected to the wireless keyboard can correctly receive the wireless signal. At the same time, the power detection circuit 04 can also monitor the power of the battery 01 and generate a power detection signal. After receiving the power detection signal, the control circuit 06 controls the operation of the power display circuit 05 according to the state of the battery 01 power, so as to display the power information of the battery 01 by means of digital tube display or the like. In this way, the user can understand the power information of the battery 01 in real time, so as to charge the wireless keyboard or replace the battery 01 in time.

[0055] Please refer to Figure 2 , in an embodiment of the present utility model, please refer to Figure 2 , in an embodiment of the present utility model, the power detection circuit 04 includes a first resistor R1, a second resistor R2 and a first capacitor C1;

[0056] Wherein, one end of the first resistor R1 is connected to the detection end of the battery 01, the other end of the first resistor R1, one end of the first capacitor C1 and one end of the second resistor R2 are connected to the output end of the power detection circuit 04, and the other end of the first capacitor C1 and the other end of the second resistor R2 are grounded.

[0057] In this embodiment, the circuit composed of the first resistor R1, the second resistor R2, and the first capacitor C1 can sample and detect the voltage of the battery 01, detect the battery power of the battery 01 based on the battery 01 voltage, and output a power detection signal. The control circuit 06 can control the power display circuit 05 to display the remaining power of the battery 01 according to the power detection signal. In one embodiment, the wireless keyboard circuit may further include a battery protection circuit. The battery protection circuit is connected to the battery 01 and is used to control the battery 01 to stop discharging when it detects that the voltage of the battery 01 is lower than a preset voltage, so as to protect the battery 01 from over-discharge damage.

[0058] Please refer to Figure 3 , in an embodiment of the present utility model, the control circuit 06 includes a control chip U1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a crystal oscillator element Y;

[0059] Among them, one end of the second capacitor C2, the VCC pin of the control chip U1 are connected to the battery 01, and the other end of the second capacitor C2 is grounded; the XIN pin of the control chip U1, the third pin of the crystal oscillator element Y are connected to one end of the fourth capacitor C4; the XOUT pin of the control chip U1, one end of the third capacitor C3 are connected to the first pin of the crystal oscillator element Y; the second pin of the crystal oscillator element Y, the fourth pin of the crystal oscillator element Y, the other end of the third capacitor C3 and the other end of the fourth capacitor C4 are grounded.

[0060] In this embodiment, the VCC pin of the control chip U1 inputs power through the circuit connected by the second capacitor C2. The crystal oscillator element Y is connected to the XIN pin of the control chip U1 through its third pin and to the XOUT pin of the control chip U1 through its first pin, which can provide a clock signal to the control chip U1. Among them, the third capacitor C3 and the fourth capacitor C4 can stabilize the voltage signal transmitted in the circuit. In this embodiment, the wireless transmission circuit 03 can transmit wireless signals according to the clock signal to ensure the correctness and reliability of data transmission. The clock signal can also be used to control the timing operations of various components inside the keyboard, such as scanning the keyboard matrix, processing key events, etc., to ensure the normal operation of the keyboard function.

[0061] It should be noted that, in one embodiment, the wireless keyboard circuit further includes a plurality of LED backlights, and the control circuit 06 may further include a backlight power control circuit 06. The backlight power control circuit 06 may include a driving chip and a switching tube. Among them, a plurality of power output terminals of the driving chip are respectively connected to the plurality of LED backlights one by one. The input terminal of the driving chip is connected to the first end of the switching tube. The second end of the switching tube is connected to the battery 01. The controlled terminal of the switching tube is connected to the control chip U1, and the lighting / extinguishing of the plurality of LED backlights can be controlled by controlling the on / off of the switching tube.

[0062] It should be noted that the control circuit 06 may further include a second oscillation circuit, which is connected to the control chip U1 and is used to provide a second clock signal to the control chip U1, and can be used to synchronize the control of the LED backlight. In this way, the control chip U1 can control the on / off time and brightness of the LED backlight based on the second clock signal to achieve different backlight effects, such as adjusting the brightness, achieving a blinking effect, a breathing light effect, a gradient light effect, etc., enhancing the user experience.

[0063] Please refer to Figure 3 , in an embodiment of the present invention, the wireless transmission circuit 03 includes a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, a fifth inductor L5, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10 and an antenna ANT;

[0064] Among them, one end of the fifth capacitor C5, one end of the first inductor L1, one end of the second inductor L2, and one end of the fourth inductor L4 are connected to the ANT1 pin of the control chip U1, and the other end of the fifth capacitor C5 is connected to the other end of the first inductor L1; the other end of the second inductor L2 and one end of the sixth capacitor C6 are connected to the ANT2 pin of the control chip U1; the other end of the fourth inductor L4, one end of the fifth inductor L5, one end of the ninth capacitor C9, and the other end of the sixth capacitor C6 are connected to one end of the seventh capacitor C7; the other end of the seventh capacitor C7 and one end of the third inductor L3 are connected to the ANT3 pin of the control chip U1; the other end of the third inductor L3 and one end of the eighth capacitor C8 are connected to the battery 01; the other end of the fifth inductor L5 and one end of the tenth capacitor C10 are connected to the first end of the antenna ANT; the other end of the eighth capacitor C8, the other end of the ninth capacitor C9, and the other end of the tenth capacitor C10 are grounded to the second end of the antenna ANT.

[0065] In this embodiment, the first inductor L1, the second inductor L2, the fourth inductor L4, the fifth capacitor C5 and the sixth capacitor C6 form a first sub-tuning circuit, and the third inductor L3, the seventh capacitor C7 and the eighth capacitor C8 form a second sub-tuning circuit. The wireless signal generated by the control chip U1 is tuned and matched through the first sub-tuning circuit, the second sub-tuning circuit, the fifth inductor L5, the ninth capacitor C9 and the tenth capacitor C10 to achieve the matching of the performance parameters of the transmitted wireless signal and the antenna ANT, thereby ensuring that the transmitted wireless signal is received by the receiving device. In this way, this embodiment can enhance the reliability of wireless signal transmission.

[0066] Please refer to Figure 4 , in an embodiment of the present invention, the power display circuit 05 includes a digital tube display circuit DISPLAY, a third resistor R3 and a fourth resistor R4;

[0067] Among them, the power supply terminal of the digital tube display circuit DISPLAY is connected to the battery 01, the grounding terminal of the digital tube display circuit DISPLAY is grounded, the first controlled terminal of the digital tube display circuit DISPLAY is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the GPIO1 pin of the control chip U1; the second controlled terminal of the digital tube display circuit DISPLAY is connected to one end of the fourth resistor R4, and the other end of the fourth resistor R4 is connected to the GPIO2 pin of the control chip U1.

[0068] In this embodiment, the digital tube display circuit DISPLAY may include two electronic digital tubes, which respectively display the units digit and the tens digit of the digital percentage of the battery power. Compared with the simple high, medium, and low battery level indicators for battery power display, this embodiment can provide more accurate battery power information, and the power consumption of the electronic digital tubes when emitting light is extremely low. Thus, in this embodiment, the user can accurately understand the battery power information of the battery 01 to facilitate the management of the use of the wireless keyboard.

[0069] In an embodiment of the present utility model, the control chip U1 is an SH87F8805 chip.

[0070] In this embodiment, the SH87F8805 chip has good stability and reliability. As a low-power Bluetooth series chip, the SH87F8805 chip is particularly suitable for the control of wireless keyboards. This chip can effectively process the conversion of wireless signals to ensure the stable transmission of signals.

[0071] In an embodiment of the present utility model, the control circuit 06 further includes a voltage conversion circuit, and the voltage conversion circuit is connected to the control chip U1; the voltage conversion circuit is used for converting the external power supply voltage and then outputting it.

[0072] In this embodiment, the voltage conversion circuit may include a voltage conversion chip, and the voltage conversion chip may be an XC6206 chip, which can output a voltage of 3.3V to provide a stable power supply for the operation of the control chip U1.

[0073] In an embodiment of the present utility model, the wireless keyboard circuit further includes a charging circuit, and the charging circuit is connected to the battery 01; the charging circuit is used for converting the external power supply voltage into a battery charging voltage and then outputting it.

[0074] In this embodiment, through the charging circuit, the user can input an external power supply voltage to charge the battery 01 without the need to replace the battery 01, improving the convenience and flexibility of the use of the wireless keyboard. The charging circuit can also be used to provide a charging management function for the battery 01. For example, it can be used for equal charging or floating charging of the battery 01, and can also be used for overcharge and overcurrent protection of the battery 01.

[0075] It should be noted that, please refer to Figure 5 , in an embodiment of the present utility model, the charging circuit may be a wireless charging circuit, that is, the wireless keyboard can be wirelessly charged. Among them, the wireless charging circuit includes a transmitting part and a receiving part. The transmitting part includes a wireless receiving circuit, a switching circuit, a charging control circuit and a transmitting coil, and the receiving part includes a receiving coil. Among them, the receiving coil is connected to the battery 01 and is used to output electric energy for the battery 01 to be charged. Among them, the wireless transmitting circuit 03 is communicatively connected to the wireless receiving circuit, the charging control circuit is connected to the wireless receiving circuit, and the switching circuit is respectively connected to the charging control circuit, the transmitting coil and the external power supply voltage input terminal. The transmitting coil can convert electric energy into electromagnetic energy and transmit the electromagnetic energy. The receiving coil can inductively receive the electromagnetic energy transmitted by the transmitting coil, convert it into electric energy, and supply it to the battery 01 for charging. When the wireless keyboard is wirelessly charged, the wireless keyboard can send the power information and the current keyboard ID information to the wireless receiving circuit of the transmitting part through the wireless transmitting circuit 03, and the charging control circuit can receive the power information and the current keyboard ID information. When the ID information of the keyboard is successfully recognized, the charging control circuit can output PWM signals with different duty cycles according to the received power information, and the switching circuit can control the output power of the transmitting coil according to the PWM signals with different duty cycles. Until the charging control circuit determines that the battery 01 is fully charged according to the power information of the battery 01, it controls the switching circuit to disconnect and stop charging.

[0076] Please refer to Figure 6 , in an embodiment of the present utility model, the charging circuit includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, an eleventh capacitor C11, a twelfth capacitor C12 and a TP4056 chip U2;

[0077] Among them, one end of the eleventh capacitor C11, the fourth pin of the TP4056 chip U2, one end of the seventh resistor R7, the fifth pin of the TP4056 chip U2, one end of the eighth resistor R8 are connected to the power input terminal of the charging circuit; the other end of the eleventh capacitor C11, one end of the fifth resistor R5, one end of the sixth resistor R6, the ground pin, the third pin, the seventh pin of the TP4056 chip U2 and one end of the twelfth capacitor C12 are grounded; the other end of the fifth resistor R5, the other end of the seventh resistor are connected to the first pin of the TP4056 chip U2; the other end of the sixth resistor R6 is connected to the second pin of the TP4056 chip U2; the other end of the eighth resistor R8 is connected to the sixth pin of the TP4056 chip U2; the eighth pin of the TP4056 chip U2, the other end of the twelfth capacitor C12 are connected to the positive electrode of the battery 01.

[0078] In this embodiment, the TP4056 chip U2 integrates many circuits required for charging, such as a constant current charging circuit, a constant voltage charging circuit, and an overcharge protection circuit. It does not require an external detection resistor and an isolation diode, which simplifies the circuit design. The TP4056 chip U2 also integrates a thermal feedback circuit inside. When the external environmental temperature is too high or the charging power is too large, it can adjust the charging current to reduce the chip temperature, which helps to improve the stability and reliability of the charging chip. When the battery 01 is fully charged, the TP4056 chip U2 can detect that the charging current drops below the preset value and can automatically stop charging to prevent overcharging of the battery 01. When the external power supply is disconnected, the TP4056 chip U2 will enter the sleep state, and the leakage current drops below 1 μA, thus saving energy and extending the battery life of the battery 01.

[0079] The present utility model also proposes a wireless keyboard, which includes a wireless keyboard circuit. The specific structure of the wireless keyboard circuit refers to the above embodiment. Since this wireless keyboard adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated one by one here.

[0080] The above description is only an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present utility model.

Claims

1. A wireless keyboard circuit, characterized in that: The wireless keyboard circuit is applied to a wireless keyboard, and the wireless keyboard circuit comprises: Battery; A key matrix circuit, the key matrix circuit is connected to the battery, and the key matrix circuit is used to input a first signal when triggered by a user; A wireless transmitting circuit, the wireless transmitting circuit is connected to the battery, and the wireless transmitting circuit is used to transmit a wireless signal; A power detection circuit, the power detection circuit is connected to a battery, and the power detection circuit is used to detect the power of the battery and output a power detection signal; A power display circuit, the power display circuit is connected to a battery, and the power display circuit is used to display the power level of the battery; A control circuit, wherein the control circuit is respectively connected to the battery, the key matrix circuit, the wireless transmission circuit, the power detection circuit and the power display circuit; the control circuit is used to control the operation of the wireless transmission circuit according to the first signal, and is used to control the operation of the power display circuit according to the power detection signal.

2. The wireless keyboard circuit as claimed in claim 1, characterized in that: The power detection circuit includes a first resistor, a second resistor and a first capacitor; Among them, one end of the first resistor is connected to the detection end of the battery, the other end of the first resistor, one end of the first capacitor, and one end of the second resistor are connected to the output end of the power detection circuit, and the other end of the first capacitor and the other end of the second resistor are grounded.

3. The wireless keyboard circuit as claimed in claim 1, characterized in that: The control circuit includes a control chip, a second capacitor, a third capacitor, a fourth capacitor and a crystal oscillator element; Among them, one end of the second capacitor and the VCC pin of the control chip are connected to the battery, and the other end of the second capacitor is grounded; the XIN pin of the control chip and the third pin of the crystal oscillator element are connected to one end of the fourth capacitor; the XOUT pin of the control chip and one end of the third capacitor are connected to the first pin of the crystal oscillator element; the second pin of the crystal oscillator element, the fourth pin of the crystal oscillator element, the other end of the third capacitor and the other end of the fourth capacitor are grounded.

4. The wireless keyboard circuit as claimed in claim 3, characterized in that: The wireless transmitting circuit includes a first inductor, a second inductor, a third inductor, a fourth inductor, a fifth inductor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor and an antenna; Among them, one end of the fifth capacitor, one end of the first inductor, one end of the second inductor, and one end of the fourth inductor are connected to the ANT1 pin of the control chip, and the other end of the fifth capacitor is connected to the other end of the first inductor; the other end of the second inductor and one end of the sixth capacitor are connected to the ANT2 pin of the control chip; the other end of the fourth inductor, one end of the fifth inductor, one end of the ninth capacitor, and the other end of the sixth capacitor are connected to one end of the seventh capacitor; the other end of the seventh capacitor and one end of the third inductor are connected to the ANT3 pin of the control chip; the other end of the third inductor and one end of the eighth capacitor are connected to the battery; the other end of the fifth inductor and one end of the tenth capacitor are connected to the first end of the antenna; the other end of the eighth capacitor, the other end of the ninth capacitor, the other end of the tenth capacitor and the second end of the antenna are grounded.

5. The wireless keyboard circuit as claimed in claim 3, characterized in that: The power display circuit includes a digital tube display circuit, a third resistor and a fourth resistor; Among them, the power supply end of the digital tube display circuit is connected to the battery, the ground end of the digital tube display circuit is grounded, the first controlled end of the digital tube display circuit is connected to one end of the third resistor, and the other end of the third resistor is connected to the GPIO1 pin of the control chip; the second controlled end of the digital tube display circuit is connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the GPIO2 pin of the control chip.

6. The wireless keyboard circuit as claimed in claim 3, characterized in that: The control chip is a SH87F8805 chip.

7. The wireless keyboard circuit as claimed in claim 3, characterized in that: The control circuit also includes a voltage conversion circuit, which is connected to the control chip; the voltage conversion circuit is used to convert the external power supply voltage and then output it.

8. The wireless keyboard circuit as claimed in claim 1, characterized in that: The wireless keyboard circuit also includes a charging circuit, which is connected to the battery; the charging circuit is used to convert the external power supply voltage into a battery charging voltage and then output it.

9. The wireless keyboard circuit as claimed in claim 8, characterized in that: The charging circuit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, an eleventh capacitor, a twelfth capacitor and a TP4056 chip; Among them, one end of the eleventh capacitor, the fourth pin of the TP4056 chip, one end of the seventh resistor, the fifth pin of the TP4056 chip, and one end of the eighth resistor are connected to the power input end of the charging circuit; the other end of the eleventh capacitor, one end of the fifth resistor, one end of the sixth resistor, the ground pin, the third pin, the seventh pin of the TP4056 chip and one end of the twelfth capacitor are grounded; the other end of the fifth resistor and the other end of the seventh resistor are connected to the first pin of the TP4056 chip; the other end of the sixth resistor is connected to the second pin of the TP4056 chip; the other end of the eighth resistor is connected to the sixth pin of the TP4056 chip; the eighth pin of the TP4056 chip and the other end of the twelfth capacitor are connected to the positive electrode of the battery.

10. A wireless keyboard, characterized in that: The wireless keyboard comprises the wireless keyboard circuit as claimed in any one of claims 1 to 9.

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