Charging circuit, charging equipment and keyboard

Abstract

The utility model discloses a charging circuit, charging equipment and a keyboard. The charging circuit comprises an input voltage detection circuit, a booster circuit, a bypass circuit and a control circuit. The input voltage detection circuit is used for detecting an input voltage of an external power supply and generating a corresponding detection signal, the booster circuit is used for boosting the input voltage to a preset charging voltage and outputting the preset charging voltage to a charging interface of the keyboard, and the bypass circuit is used for outputting the input voltage to the charging interface of the keyboard; and the control circuit is used for controlling the boosted circuit or the bypass circuit to be switched on according to the detection signal so as to provide corresponding charging voltage for the charging interface. Therefore, when the input voltage of the external power supply is relatively low, the input voltage can be boosted to the preset charging voltage through the boosted circuit, and when the input voltage of the external power supply is relatively high, the input voltage is directly output to the charging interface of the keyboard through the bypass circuit, so that the adaptability of the keyboard to a charging scene is improved.

Description

Technical Field

[0001] The utility model relates to the technical fields of charging and discharging and electronic devices, and particularly relates to a charging circuit, a charging device and a keyboard. Background Art

[0002] In the current era of rapid development of electronic devices, especially with the wide application of mobile devices and wireless peripherals, higher requirements are put forward for battery endurance and charging efficiency. As one of the common computer peripherals, the keyboard has gradually developed towards wireless with technological progress, and built-in battery and charging functions have become standard configurations. However, in actual applications, users may face various charging scenarios, such as using chargers, mobile power supplies, and even solar charging panels with different specifications, and the voltages provided by these power sources are not always stable or meet the optimal charging voltage requirements of the battery.

[0003] Traditional charging schemes are often relatively single and cannot flexibly cope with variable input voltage conditions, which may lead to low charging efficiency and damage to battery health. Especially when the external power supply voltage is lower than the charging voltage of the keyboard battery, conventional charging methods usually cannot be effectively carried out, thus greatly limiting the charging scenarios of the keyboard and making the charging convenience of the keyboard relatively low. Summary of the Utility Model

[0004] The main purpose of the utility model is to propose a charging circuit, a charging device and a keyboard, aiming to improve the adaptability of the keyboard to charging scenarios.

[0005] To achieve the above purpose, the utility model proposes a charging circuit applied to a keyboard. The keyboard includes a charging interface, and the charging circuit includes:

[0006] An input voltage detection circuit for detecting the input voltage of an external power supply and generating a corresponding detection signal;

[0007] A boost circuit electrically connected to the external power supply, for boosting the input voltage to a preset charging voltage and outputting the preset charging voltage to the charging interface of the keyboard;

[0008] A bypass circuit electrically connected to the external power supply, for outputting the input voltage to the charging interface of the keyboard;

[0009] A control circuit electrically connected to the input voltage detection circuit, the boost circuit and the bypass circuit respectively, for controlling any one of the boost circuit or the bypass circuit to conduct according to the detection signal to provide a corresponding charging voltage for the charging interface.

[0010] In one embodiment, the input voltage detection circuit includes:

[0011] A voltage dividing resistor group, which is electrically connected to an external power supply and is used to divide the input voltage into a detection voltage;

[0012] A comparator, the non-inverting input terminal of the comparator is electrically connected to the voltage dividing resistor group, the inverting input terminal of the comparator is connected to a reference voltage, and the output terminal of the comparator is connected to the control circuit; the comparator is used to compare the detection voltage with the reference voltage, generate a corresponding detection signal and output it to the control circuit.

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

[0014] An inductor, the first end of the inductor is electrically connected to an external power supply;

[0015] A first switching transistor, the first end of the first switching transistor is connected to the second end of the inductor, and the controlled end of the first switching transistor is electrically connected to the control circuit;

[0016] A diode, the anode of the diode is electrically connected to the second end of the inductor, and the cathode of the diode is used to output the preset charging voltage;

[0017] A capacitor, one end of the capacitor is electrically connected to the cathode of the diode, and the other end is grounded.

[0018] In one embodiment, the control circuit includes:

[0019] A microcontroller, the microcontroller is electrically connected to the input voltage detection circuit and is used to receive the detection signal; the microcontroller is also used to generate a corresponding PWM signal according to the detection signal;

[0020] A driving circuit, the driving circuit is respectively electrically connected to the microcontroller and the first switching transistor; the driving circuit is used to receive the PWM signal and control the on / off of the first switching transistor according to the PWM signal.

[0021] In one embodiment, the charging circuit further includes a temperature detection circuit, and the temperature detection circuit is electrically connected to the control circuit; the temperature detection circuit is used to detect the working temperature of the boost circuit, generate a corresponding temperature detection signal and output it to the control circuit; the control circuit is also used to adjust the duty cycle of the PWM signal according to the temperature detection signal.

[0022] In one embodiment, the bypass circuit includes:

[0023] A second switching transistor, a first end of the second switching transistor is electrically connected to the external power supply, a second end of the second switching transistor is electrically connected to the charging interface, and a controlled end of the second switching transistor is electrically connected to the control circuit.

[0024] In one embodiment, the charging circuit further includes:

[0025] A regulated output circuit, the regulated output circuit is electrically connected to the boost circuit; the regulated output circuit is configured to perform voltage regulation processing on the preset charging voltage and output it to provide a corresponding charging voltage for the charging interface.

[0026] In one embodiment, the regulated output circuit includes:

[0027] A linear voltage regulator, an input end of the linear voltage regulator is electrically connected to the boost circuit, and an output end is configured to output a stable charging voltage;

[0028] A filter capacitor, the filter capacitor is electrically connected to the output end of the linear voltage regulator and is configured to perform filtering processing on the stable charging voltage.

[0029] The present utility model further provides a charging device, which is applied to a keyboard. The keyboard includes a charging interface, and the charging device includes the charging circuit described above.

[0030] The present utility model further provides a keyboard, and the keyboard includes the charging circuit described above.

[0031] The charging circuit of the present utility model includes an input voltage detection circuit, a boost circuit, a bypass circuit and a control circuit. The control circuit is electrically connected to the input voltage detection circuit, the boost circuit and the bypass circuit respectively. The boost circuit and the bypass circuit are electrically connected to the external power supply respectively. The input voltage detection circuit is configured to detect the input voltage of the external power supply and generate a corresponding detection signal. The boost circuit is configured to boost the input voltage to a preset charging voltage and output the preset charging voltage to the charging interface of the keyboard. The bypass circuit is configured to output the input voltage to the charging interface of the keyboard. The control circuit is configured to control any one of the boost circuit or the bypass circuit to conduct according to the detection signal to provide a corresponding charging voltage for the charging interface. In this way, when the input voltage of the external power supply is relatively low, the input voltage can be boosted to the preset charging voltage through the boost circuit, so that the keyboard can be effectively charged even when the input voltage is relatively low. When the input voltage of the external power supply is relatively high, the input voltage is directly output to the charging interface of the keyboard through the bypass circuit, avoiding unnecessary energy loss, thereby improving the adaptability of the keyboard to the charging scenario and further improving the charging convenience of the keyboard. Description of the Drawings

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0033] Figure 1 Schematic diagram of a structure of an embodiment of the charging circuit provided by the present invention;

[0034] Figure 2 Schematic diagram of a structure of another embodiment of the charging circuit provided by the present invention;

[0035] Figure 3 Schematic diagram of a structure of yet another embodiment of the charging circuit provided by the present invention;

[0036] Figure 4 Schematic diagram of a structure of still another embodiment of the charging circuit provided by the present invention;

[0037] Figure 5 Schematic diagram of a structure of another embodiment of the charging circuit provided by the present invention;

[0038] Figure 6 Schematic diagram of a structure of another embodiment of the charging circuit provided by the present invention;

[0039] Figure 7 Schematic diagram of a structure of yet another embodiment of the charging circuit provided by the present invention.

[0040] Explanation of the reference numerals of the attached drawings:

[0041] U1, charging interface; VCC, external power supply; 100, charging circuit; 10, input voltage detection circuit; 20, boost circuit; 30, bypass circuit; 40, control circuit; R1, first resistor; R2, second resistor; U2, comparator; Rf, reference voltage; L1, inductor; Q1, first switching tube; VD, diode; C1, capacitor; U3, microcontroller; 41, drive circuit; 50, temperature detection circuit; Q2, second switching tube; 60, regulated output circuit.

[0042] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0043] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with 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 embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model.

[0044] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0045] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present utility model, the descriptions of "first", "second", etc. 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 such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. 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 scope of protection required by the present utility model.

[0046] In the current era of rapid development of electronic devices, especially the widespread application of mobile devices and wireless peripherals, higher requirements are put forward for battery life and charging efficiency. As one of the common computer peripherals, the keyboard has gradually developed towards wireless with technological progress, and built-in battery and charging functions have become standard configurations. However, in actual applications, users may face various charging scenarios, such as using chargers, mobile power supplies, or even solar charging panels with different specifications, and the voltages provided by these power sources are not always stable or meet the best charging voltage requirements of the battery.

[0047] Traditional charging solutions are often relatively single and cannot flexibly handle changing input voltage conditions, which may lead to low charging efficiency and damage to battery health. Especially when the external power supply VCC voltage is lower than the charging voltage of the keyboard battery, conventional charging methods usually cannot be effectively carried out, thus greatly limiting the charging scenarios of the keyboard and making the charging convenience of the keyboard relatively low.

[0048] To improve the adaptability of the keyboard to the charging scenario, an embodiment of the present application provides a charging circuit 100, which is applied to a keyboard. The keyboard includes a charging interface U1. Refer to Figure 1 , the charging circuit 100 includes an input voltage detection circuit 10, a boost circuit 20, a bypass circuit 30, and a control circuit 40. The boost circuit 20 is electrically connected to the external power supply VCC, and the bypass circuit 30 is also electrically connected to the external power supply VCC. The control circuit 40 is electrically connected to the input voltage detection circuit 10, the boost circuit 20, and the bypass circuit 30 respectively. The input voltage detection circuit 10 is configured to detect the input voltage of the external power supply VCC and generate a corresponding detection signal. The boost circuit 20 is configured to boost the input voltage to a preset charging voltage and output the preset charging voltage to the charging interface U1 of the keyboard. The bypass circuit 30 is configured to output the input voltage to the charging interface U1 of the keyboard. The control circuit 40 is configured to control any one of the boost circuit 20 or the bypass circuit 30 to conduct according to the detection signal, so as to provide a corresponding charging voltage for the charging interface U1.

[0049] In this embodiment, the charging interface U1 of the keyboard can be a USB interface, a Type-C interface, a Lightning interface, or other charging interfaces U1 that conform to common standards, or can be an interface with specific specifications to adapt to the charging requirements of different devices. The input voltage detection circuit 10 can adopt a resistor voltage division, a voltage comparator U2, or other voltage detection circuit structures to detect the input voltage of the external power supply VCC in real time and convert the detected voltage value into an electrical signal (i.e., the detection signal) for subsequent processing by the control circuit 40. The boost circuit 20 can adopt a Boost boost circuit 20, a Flyback boost circuit 20, or other applicable boost topology structures to boost the input voltage to a preset charging voltage to meet the charging requirements of the keyboard battery. For example, boost the 5V USB interface voltage to the charging voltage required by the keyboard battery, such as 7.4V or 9V, etc. The bypass circuit 30 can be a simple conduction path. When the voltage of the external power supply VCC is already close to the charging voltage of the keyboard battery, the output voltage of the external power supply VCC can be directly supplied to the charging interface U1 of the keyboard as the charging voltage through the bypass circuit 30 to reduce unnecessary energy loss and circuit complexity. The control circuit 40 can be implemented by including a microcontroller U3, a logic gate circuit, or other programmable logic devices. According to the detection signal sent by the input voltage detection circuit 10, it judges whether the input voltage of the current external power supply VCC is lower than the charging voltage of the keyboard battery, so as to control the conduction state of the boost circuit 20 or the bypass circuit 30 to ensure that the keyboard can be charged efficiently and safely.

[0050] In this embodiment, the charging circuit 100 includes an input voltage detection circuit 10, a boost circuit 20, a bypass circuit 30, and a control circuit 40. The control circuit 40 is electrically connected to the input voltage detection circuit 10, the boost circuit 20, and the bypass circuit 30 respectively. The boost circuit 20 and the bypass circuit 30 are electrically connected to an external power supply VCC respectively. The input voltage detection circuit 10 is configured to detect the input voltage of the external power supply VCC and generate a corresponding detection signal. The boost circuit 20 is configured to boost the input voltage to a preset charging voltage and output the preset charging voltage to the charging interface U1 of the keyboard. The bypass circuit 30 is configured to output the input voltage to the charging interface U1 of the keyboard. The control circuit 40 is configured to control any one of the boost circuit 20 or the bypass circuit 30 to conduct according to the detection signal, so as to provide a corresponding charging voltage for the charging interface U1. In this way, when the input voltage of the external power supply VCC is relatively low, the input voltage can be boosted to the preset charging voltage through the boost circuit 20, so that the keyboard can be effectively charged even when the input voltage is relatively low. When the input voltage of the external power supply VCC is relatively high, the input voltage is directly output to the charging interface U1 of the keyboard through the bypass circuit 30, avoiding unnecessary energy loss, thereby improving the adaptability of the keyboard to the charging scenario and further improving the charging convenience of the keyboard.

[0051] In a feasible implementation manner, referring to Figure 2 , the input voltage detection circuit 10 includes a voltage dividing resistor group and a comparator U2. The voltage dividing resistor group is electrically connected to the external power supply VCC and is configured to divide the input voltage into a detection voltage. The non-inverting input terminal of the comparator U2 is electrically connected to the voltage dividing resistor group. The inverting input terminal of the comparator U2 is connected to a reference voltage Rf. The output terminal of the comparator U2 is connected to the control circuit 40. The comparator U2 is configured to compare the detection voltage with the reference voltage Rf, generate a corresponding detection signal and output it to the control circuit 40.

[0052] In this embodiment, the voltage dividing circuit includes a first resistor R1 and a second resistor R2. The external power supply VCC is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the second resistor R2, the common end of the first resistor R1 and the second resistor R2 is connected to the non-inverting input terminal of the comparator U2, the inverting input terminal of the comparator U2 is connected to the reference voltage Rf, and the output terminal of the comparator U2 is connected to the control circuit 40. It can be understood that the number and resistance value of the resistors in the voltage dividing circuit can be adjusted according to actual needs to achieve precise voltage division and detection of the input voltage, which is not limited here. The reference voltage Rf can be provided by a stable voltage source, such as a power supply voltage, a reference voltage source, etc. This reference voltage Rf is related to the charging voltage of the keyboard battery and is used as a reference for the comparator U2 to make a comparison. Its specific voltage value can be set according to the charging voltage requirements of the keyboard battery, which is not limited here. The comparator U2 compares the detected voltage with the reference voltage Rf. When the detected voltage is lower than the reference voltage Rf, it indicates that the input voltage of the external power supply VCC is relatively low and the boost circuit 20 needs to perform a boost process. At this time, the comparator U2 outputs a low-level signal. When the detected voltage is higher than or equal to the reference voltage Rf, it indicates that the input voltage of the external power supply VCC is already high enough and can be directly charged through the bypass circuit 30. At this time, the comparator U2 outputs a high-level signal. This detection signal is sent to the control circuit 40, and the control circuit 40 controls the conduction state of the boost circuit 20 or the bypass circuit 30 according to the detection signal, thereby achieving flexible adjustment of the keyboard charging voltage.

[0053] In a feasible implementation manner, referring to Figure 3 , the boost circuit 20 includes an inductor L1, a first switching transistor Q1, a diode VD, and a capacitor C1. The first end of the inductor L1 is electrically connected to the external power supply VCC, the first end of the first switching transistor Q1 is connected to the second end of the inductor L1, the controlled end of the first switching transistor Q1 is electrically connected to the control circuit 40, the anode of the diode VD is electrically connected to the second end of the inductor L1, and the cathode of the diode VD is used to output the preset charging voltage; one end of the capacitor C1 is electrically connected to the cathode of the diode VD, and the other end is grounded.

[0054] In this embodiment, when the control circuit 40 receives the low-level signal sent by the input voltage detection circuit 10, it indicates that the input voltage of the external power supply VCC is relatively low, and the boost circuit 20 needs to be activated for boost processing. At this time, the control circuit 40 controls the first switching transistor Q1 to conduct, and the input voltage of the external power supply VCC charges the capacitor C1 through the inductor L1. At the same time, the current in the inductor L1 gradually increases and stores energy. When the first switching transistor Q1 is turned off, the energy in the inductor L1 is released through the diode VD, causing the voltage across the capacitor C1 to gradually increase, realizing the boost function. Finally, the voltage across the capacitor C1 is the preset charging voltage, and this preset charging voltage is output to the charging interface U1 of the keyboard through the cathode of the diode VD to charge the keyboard battery. By reasonably designing the parameters of the inductor L1, capacitor C1, and switching transistor, a stable boost effect can be achieved to ensure that the keyboard battery can be charged safely and effectively.

[0055] In a feasible implementation manner, referring to Figure 4 , the control circuit 40 includes a microcontroller U3 and a drive circuit 41. The microcontroller U3 is electrically connected to the input voltage detection circuit 10 and is used to receive the detection signal. The microcontroller U3 is also used to generate a corresponding PWM signal according to the detection signal. The drive circuit 41 is respectively electrically connected to the microcontroller U3 and the first switching transistor Q1. The drive circuit 41 is used to receive the PWM signal and control the on / off of the first switching transistor Q1 according to the PWM signal.

[0056] In this embodiment, the microcontroller U3 can be a low-power single-chip microcomputer with ADC (analog-to-digital converter) and PWM (pulse width modulation) functions, such as STC89C52, ATmega328P, etc., or it can also be an FPGA (field programmable gate array) or ASIC (application-specific integrated circuit) with similar functions. When the input voltage detection circuit 10 sends a detection signal to the microcontroller U3, the microcontroller U3 will judge whether the current input voltage of the external power supply VCC is lower than the charging voltage of the keyboard battery according to this detection signal. If the detection signal is a low-level signal, it indicates that the input voltage is relatively low and the boost circuit 20 needs to be activated for boost processing. At this time, the microcontroller U3 will generate a corresponding PWM signal, and this PWM signal has a specific duty cycle and frequency and is used to control the on / off of the first switching transistor Q1. After receiving the PWM signal, the drive circuit 41 will control the on / off state of the first switching transistor Q1 according to this signal, thereby realizing the precise control of the boost circuit 20. By adjusting the duty cycle and frequency of the PWM signal, the output voltage can be precisely adjusted to meet the charging requirements of the keyboard battery. In this way, both high-efficiency charging effects can be achieved, and the safety and stability of the keyboard battery can be ensured.

[0057] In a feasible embodiment, refer to Figure 5 , the charging circuit 100 further includes a temperature detection circuit 50, and the temperature detection circuit 50 is electrically connected to the control circuit 40; the temperature detection circuit 50 is configured to detect the operating temperature of the boost circuit 20, generate a corresponding temperature detection signal and output it to the control circuit 40; the control circuit 40 is further configured to adjust the duty cycle of the PWM signal according to the temperature detection signal.

[0058] In this embodiment, the temperature detection circuit 50 includes a thermistor, a resistor voltage division circuit and a voltage conversion circuit. The thermistor is disposed on the boost circuit 20 and is configured to detect the operating temperature of the boost circuit 20 and convert the operating temperature into a change in resistance value; one end of the resistor voltage division circuit is electrically connected to the thermistor and the other end is grounded; the resistor voltage division circuit is configured to convert the change in resistance value of the thermistor into a voltage signal, and the voltage conversion circuit is electrically connected to the resistor voltage division circuit; the voltage conversion circuit is configured to convert the voltage signal into a digital signal and output it to the microcontroller U3.

[0059] In this embodiment, the thermistor, as a temperature sensor, is closely integrated into the boost circuit 20 to sense the change in its operating temperature in real time. As the temperature rises or falls, the resistance value of the thermistor changes accordingly, and this change is converted into a voltage signal through the resistor voltage division circuit. The voltage conversion circuit further converts this analog voltage signal into a digital signal that can be processed by the microcontroller U3, that is, the temperature detection signal. After receiving the temperature detection signal, the microcontroller U3 performs analysis and processing. If the detected operating temperature is too high, it means that there may be a risk of overheating in the boost circuit 20, which may damage the components in the circuit and even cause potential safety hazards. At this time, the microcontroller U3 will respond quickly and reduce the conduction time of the first switching transistor Q1 by adjusting the duty cycle of the PWM signal, thereby reducing the operating current of the boost circuit 20 and achieving the purpose of reducing the temperature.

[0060] In this embodiment, if the temperature detection signal indicates that the operating temperature is too low, this may also indicate that the operating state of the boost circuit 20 is abnormal, which may be caused by insufficient power supply of the external power supply VCC or other reasons. The microcontroller U3 will also make corresponding adjustments according to this situation, such as increasing the duty cycle of the PWM signal to try to increase the output voltage of the boost circuit 20, or sending a warning signal to prompt the user to check the connection of the external power supply VCC or the charging interface U1. Through temperature detection and the above feedback adjustment mechanism, the keyboard charging circuit 100 can effectively prevent circuit damage or potential safety hazards caused by overheating or insufficient power supply while ensuring the charging efficiency, improve the stability and reliability of the keyboard charging circuit 100, and provide a safer and more efficient charging experience for users.

[0061] In a feasible embodiment, referring to Figure 6 , the bypass circuit 30 includes a second switching transistor Q2. The first end of the second switching transistor Q2 is electrically connected to the external power supply VCC. The second end of the second switching transistor Q2 is electrically connected to the charging interface U1. The controlled end of the second switching transistor Q2 is electrically connected to the control circuit 40.

[0062] In this embodiment, when the input voltage of the external power supply VCC is high enough to meet the charging requirements of the keyboard battery, the control circuit 40 controls the second switching transistor Q2 to conduct, so that the input voltage of the external power supply VCC is directly transmitted to the charging interface U1 through the bypass circuit 30 to charge the keyboard battery. In this case, the boost circuit 20 is in the off state and does not participate in the charging process, thereby reducing the circuit power consumption and improving the charging efficiency. Through the precise control of the second switching transistor Q2 by the control circuit 40, flexible switching under different input voltage conditions can be achieved to ensure that the keyboard battery can always be charged in an optimal manner.

[0063] In a feasible embodiment, referring to Figure 7 , the charging circuit 100 further includes a regulated output circuit 60. The regulated output circuit 60 is electrically connected to the boost circuit 20. The regulated output circuit 60 is used to perform voltage regulation processing on the preset charging voltage and output it to provide a corresponding charging voltage for the charging interface U1.

[0064] In this embodiment, the regulated output circuit 60 includes a linear voltage regulator and a filter capacitor C1. The input end of the linear voltage regulator is electrically connected to the boost circuit 20, and the output end is used to output a stable charging voltage. The filter capacitor C1 is electrically connected to the output end of the linear voltage regulator and is used to perform filtering processing on the stable charging voltage.

[0065] In this embodiment, when the voltage output by the boost circuit 20 passes through the regulated output circuit 60, the linear voltage regulator stabilizes it to the preset charging voltage value. The filter capacitor C1 plays a role in smoothing the output voltage waveform, eliminating voltage instability caused by noise or fluctuations in the circuit, and ensuring the stability and reliability of the charging voltage. In this way, through the processing of the regulated output circuit 60, the keyboard battery can obtain a stable and required charging voltage, ensuring the safety and effectiveness of the charging process.

[0066] In this embodiment, the charging circuit 100 includes an input voltage detection circuit 10, a boost circuit 20, a bypass circuit 30, and a control circuit 40. The control circuit 40 is electrically connected to the input voltage detection circuit 10, the boost circuit 20, and the bypass circuit 30 respectively. The boost circuit 20 and the bypass circuit 30 are electrically connected to an external power supply VCC respectively. The input voltage detection circuit 10 is configured to detect the input voltage of the external power supply VCC and generate a corresponding detection signal. The boost circuit 20 is configured to boost the input voltage to a preset charging voltage and output the preset charging voltage to the charging interface U1 of the keyboard. The bypass circuit 30 is configured to output the input voltage to the charging interface U1 of the keyboard. The control circuit 40 is configured to control any one of the boost circuit 20 or the bypass circuit 30 to conduct according to the detection signal, so as to provide a corresponding charging voltage for the charging interface U1. Thus, when the input voltage of the external power supply VCC is relatively low, the input voltage can be boosted to the preset charging voltage through the boost circuit 20, so that the keyboard can be effectively charged even when the input voltage is low. When the input voltage of the external power supply VCC is relatively high, the input voltage is directly output to the charging interface U1 of the keyboard through the bypass circuit 30, avoiding unnecessary energy loss, thereby improving the adaptability of the keyboard to the charging scenario and further improving the charging convenience of the keyboard.

[0067] The present utility model further provides a charging device applied to a keyboard. The keyboard includes a charging interface U1. The charging device includes the charging circuit 100. The specific structure of the charging circuit 100 refers to the above embodiment. Since the charging device 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 here one by one.

[0068] The present utility model further provides a keyboard. The keyboard includes the charging circuit 100. The specific structure of the charging circuit 100 refers to the above embodiment. Since the 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 here one by one.

[0069] The above are only exemplary embodiments of the present utility model, and do 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 charging circuit, applied to a keyboard, the keyboard comprising a charging interface, characterized in that: The charging circuit comprises: An input voltage detection circuit, the input voltage detection circuit is used to detect the input voltage of the external power supply and generate a corresponding detection signal; A boost circuit, the boost circuit being electrically connected to the external power supply; the boost circuit being used to boost the input voltage to a preset charging voltage, and output the preset charging voltage to a charging interface of the keyboard; A bypass circuit, the bypass circuit being electrically connected to the external power supply; the bypass circuit being used to output the input voltage to a charging interface of the keyboard; A control circuit, wherein the control circuit is electrically connected to the input voltage detection circuit, the boost circuit and the bypass circuit respectively; the control circuit is used to control the conduction of either the boost circuit or the bypass circuit according to the detection signal to provide a corresponding charging voltage for the charging interface.

2. The charging circuit according to claim 1, characterized in that: The input voltage detection circuit comprises: A voltage-dividing resistor group, the voltage-dividing resistor group is electrically connected to an external power supply and is used to divide the input voltage into a detection voltage; A comparator, wherein the non-inverting input terminal of the comparator is electrically connected to the voltage-dividing resistor group, the inverting input terminal of the comparator is connected to the reference voltage, and the output terminal of the comparator is connected to the control circuit; the comparator is used to compare the detection voltage with the reference voltage, generate a corresponding detection signal and output it to the control circuit.

3. The charging circuit according to claim 1, characterized in that: The boost circuit comprises: an inductor, a first end of the inductor being electrically connected to an external power source; a first switch tube, wherein a first end of the first switch tube is connected to the second end of the inductor, and a controlled end of the first switch tube is electrically connected to the control circuit; a diode, wherein an anode of the diode is electrically connected to the second end of the inductor, and a cathode of the diode is used to output the preset charging voltage; A capacitor, one end of which is electrically connected to the cathode of the diode, and the other end of which is grounded.

4. The charging circuit according to claim 3, characterized in that: The control circuit comprises: A microcontroller, the microcontroller is electrically connected to the input voltage detection circuit and is used to receive the detection signal; the microcontroller is also used to generate a corresponding PWM signal according to the detection signal; A drive circuit, wherein the drive circuit is electrically connected to the microcontroller and the first switch tube respectively; the drive circuit is used to receive the PWM signal and control the on and off of the first switch tube according to the PWM signal.

5. The charging circuit according to claim 4, characterized in that: The charging circuit also includes a temperature detection circuit, which is electrically connected to the control circuit; the temperature detection circuit is used to detect the operating temperature of the boost circuit, generate a corresponding temperature detection signal and output it to the control circuit; the control circuit is also used to adjust the duty cycle of the PWM signal according to the temperature detection signal.

6. The charging circuit according to claim 1, characterized in that: The bypass circuit comprises: A second switch tube, wherein a first end of the second switch tube is electrically connected to the external power supply, a second end of the second switch tube is electrically connected to the charging interface, and a controlled end of the second switch tube is electrically connected to the control circuit.

7. The charging circuit according to claim 1, characterized in that: The charging circuit further comprises: A voltage-stabilizing output circuit, the voltage-stabilizing output circuit is electrically connected to the voltage-boosting circuit; the voltage-stabilizing output circuit is used to stabilize and output the preset charging voltage to provide a corresponding charging voltage for the charging interface.

8. The charging circuit according to claim 7, characterized in that: The voltage stabilizing output circuit comprises: A linear voltage regulator, wherein the input end of the linear voltage regulator is electrically connected to the boost circuit, and the output end of the linear voltage regulator is used to output a stable charging voltage; A filter capacitor is electrically connected to the output end of the linear regulator and is used for filtering the stable charging voltage.

9. A charging device, characterized in that: Applied to a keyboard, the keyboard comprises a charging interface, and the charging device comprises the charging circuit according to any one of claims 1 to 8.

10. A keyboard, characterized in that: The keyboard comprises the charging circuit according to any one of claims 1 to 8.

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