Keyboard protection circuit and keyboard

Abstract

The utility model discloses a keyboard protection circuit and a keyboard, and relates to the technical field of computer peripheral equipment. Wherein the keyboard protection circuit comprises a liquid detection circuit, a control circuit and a switching circuit, the control circuit is electrically connected with the liquid detection circuit, the switching circuit is electrically connected with the control circuit, and the switching circuit is arranged between the keyboard power supply input end and the power supply in series. The liquid detection circuit is used for detecting the immersion condition below the key and outputting a corresponding first detection signal to the control circuit when liquid exists below the key, and the control circuit generates a corresponding power-off control signal according to the first detection signal and outputs the power-off control signal to the switching circuit, so that the switching circuit switches the key according to the power-off control signal. And disconnecting a power supply path of the power supply to the keyboard. Therefore, the keyboard protection circuit can quickly cut off a power supply access of the power supply to the keyboard when liquid exists below the keys, so that the keyboard is protected in time, and the keyboard is prevented from being damaged by the liquid.

Description

Technical Field

[0001] The utility model relates to the technical field of computer peripheral devices, and particularly relates to a keyboard protection circuit and a keyboard. Background Art

[0002] In the current technical field of computer peripheral devices, as an important part of human-computer interaction, the keyboard is widely used in computers, laptops, various consoles, and other electronic devices. With the development of technology and the improvement of user requirements, the reliability and durability of the keyboard have become key factors in design. However, the keyboard faces various potential threats during use, and liquid splashing is one of the most common problems. Liquids, such as water, coffee, etc., once seep into the keyboard, will not only cause key failures and circuit short circuits, but may also cause permanent damage, seriously affecting the performance and lifespan of electronic devices. Summary of the Utility Model

[0003] The main purpose of the utility model is to propose a keyboard protection circuit and a keyboard, aiming to protect the keyboard in time when liquid seeps in.

[0004] To achieve the above purpose, the utility model proposes a keyboard protection circuit applied to a keyboard. The keyboard includes keys, and the keyboard protection circuit includes:

[0005] A liquid detection circuit for detecting the liquid immersion condition below the keys and outputting a corresponding first detection signal when there is liquid below the keys;

[0006] A control circuit electrically connected to the liquid detection circuit, which is used to output a corresponding power-off control signal according to the first detection signal;

[0007] A switch circuit electrically connected to the control circuit. The switch circuit is serially arranged between the keyboard power input terminal and the power supply. The switch circuit is used to disconnect the power supply path of the power supply to the keyboard according to the power-off control signal.

[0008] In an embodiment, the liquid detection circuit includes a plurality of capacitive sensors. The plurality of capacitive sensors are arranged below the keys, and the plurality of capacitive sensors are respectively electrically connected to the control circuit.

[0009] In an embodiment, the liquid detection circuit further includes:

[0010] A charge amplifier, the first end of which is respectively electrically connected to the plurality of capacitive sensors;

[0011] An oscillator, the first end of which is connected to the second end of the charge amplifier;

[0012] A comparator, a first end of the comparator is electrically connected to a second end of the oscillator, and a second end of the comparator is electrically connected to the control circuit.

[0013] In an embodiment, the switch circuit includes an isolation relay. The control circuit is connected to a control end of the isolation relay. A first conducting end of the isolation relay is connected to the power supply, and a second conducting end of the isolation relay is connected to the keyboard power input terminal.

[0014] In an embodiment, the keyboard protection circuit further includes a plurality of heating sheets. The plurality of heating sheets are respectively disposed at different positions of the keyboard, and the plurality of heating sheets are respectively electrically connected to the control circuit. The heating sheet is configured to heat and evaporate the liquid when there is liquid under the key.

[0015] In an embodiment, the liquid detection circuit is further configured to output a corresponding second detection signal when there is no liquid under the key;

[0016] The control circuit is further configured to output a corresponding conduction control signal according to the second detection signal;

[0017] The switch circuit is further configured to conduct a power supply path of the power supply to the keyboard according to the conduction control signal.

[0018] In an embodiment, the keyboard protection circuit further includes a warning circuit. The warning circuit is electrically connected to the control circuit. The warning circuit is configured to emit a warning signal when there is liquid under the key.

[0019] In an embodiment, the warning circuit includes:

[0020] A buzzer, the buzzer is electrically connected to the control circuit. The buzzer is configured to emit an audible warning signal when there is liquid under the key;

[0021] And / or, the keyboard protection circuit includes an LED. The LED is electrically connected to the control circuit. The LED is configured to emit a visual warning signal when there is liquid under the key.

[0022] In an embodiment, the keyboard protection circuit further includes an independent power source. The independent power source is configured to supply power to the plurality of heating sheets and / or the warning circuit.

[0023] The present invention also provides a keyboard, and the keyboard includes the keyboard protection circuit described above.

[0024] The keyboard protection circuit of the present utility model includes a liquid detection circuit, a control circuit, and a switch circuit. The control circuit is electrically connected to the liquid detection circuit, and the switch circuit is electrically connected to the control circuit. The switch circuit is serially disposed between the keyboard power input terminal and the power supply. The liquid detection circuit detects the liquid immersion condition under the keys, and when there is liquid under the keys, outputs a corresponding first detection signal to the control circuit. The control circuit then generates a corresponding power-off control signal according to the first detection signal and outputs it to the switch circuit, so that the switch circuit disconnects the power supply path of the power supply to the keyboard according to the power-off control signal. Thus, when there is liquid infiltration in the keyboard, the keyboard protection circuit can detect the liquid immersion condition under the keyboard keys, and when there is liquid under the keys, quickly cut off the power supply path of the power supply to the keyboard, timely protect the keyboard, and prevent the liquid from damaging the keyboard. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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 following drawings 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.

[0026] Figure 1 FIG. is a schematic structural diagram of an embodiment of the keyboard protection circuit provided by the present utility model;

[0027] Figure 2 FIG. is a schematic structural diagram of another embodiment of the keyboard protection circuit provided by the present utility model;

[0028] Figure 3 FIG. is a schematic structural diagram of still another embodiment of the keyboard protection circuit provided by the present utility model;

[0029] Figure 4 FIG. is a schematic structural diagram of yet another embodiment of the keyboard protection circuit provided by the present utility model.

[0030] DESCRIPTION OF THE REFERENCE NUMERALS IN THE DRAWINGS:

[0031] 10. Liquid detection circuit; 11. Charge amplifier; 12. Oscillator; 13. Comparator; 20. Control circuit; 30. Switch circuit; H1 to HN, first heating sheet to Nth heating sheet; 40. Warning circuit.

[0032] The realization of the purpose, functional features, and advantages of the present utility model will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0034] 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 invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0035] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, 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 that satisfies both A and B at the same time. In addition, the technical solutions between the 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 invention.

[0036] In the current technical field of computer peripheral devices, as an important part of human-computer interaction, the keyboard is widely used in computers, laptops, various consoles, and other electronic devices. With the development of technology and the improvement of user requirements, the reliability and durability of the keyboard have become key factors in design. However, the keyboard faces various potential threats during use, and liquid splashing is one of the most common problems. Liquids, such as water, coffee, etc., once seep into the keyboard, will not only cause key failures and circuit short circuits, but may also cause permanent damage, seriously affecting the performance and lifespan of electronic devices.

[0037] The present invention proposes a keyboard protection circuit and a keyboard.

[0038] Please refer to Figure 1, in an embodiment of the present utility model, the keyboard protection circuit is applied to a keyboard. The keyboard includes keys. The keyboard protection circuit includes a liquid detection circuit 10, a control circuit 20, and a switch circuit 30. The control circuit 20 is electrically connected to the liquid detection circuit 10, and the switch circuit 30 is electrically connected to the control circuit 20. The switch circuit 30 is serially arranged between the keyboard power input terminal and the power supply. The liquid detection circuit 10 is used to detect the liquid immersion condition under the keys and output a corresponding first detection signal when there is liquid under the keys; the control circuit 20 is used to output a corresponding power-off control signal according to the first detection signal; the switch circuit 30 is used to disconnect the power supply path of the power supply to the keyboard according to the power-off control signal.

[0039] In this embodiment, the liquid detection circuit 10 may include a conductive film or a plurality of capacitive sensors arranged under the keys of the keyboard. When the conductive film comes into contact with the liquid, it will cause a change in the capacitance value of the capacitance structure formed between the conductive film and the adjacent conductive layer (such as the keyboard bottom plate or another layer of film). Then, this capacitance value is converted into an electrical signal, that is, the first detection signal, and output to the control circuit 20 for signal processing, so as to be able to judge whether there is liquid under the keys. The capacitive sensor can judge the presence of liquid by detecting the change in the electric field under the keys. When liquid enters under the keys, the dielectric constant of the liquid will affect the electric field distribution, resulting in a change in the electrical signal output by the capacitive sensor, which is then recognized by the control circuit 20 as a signal indicating the presence of liquid.

[0040] In this embodiment, the control circuit 20 may be a circuit formed by connecting discrete components or an integrated circuit (chip). As long as it can generate a corresponding power-off control signal according to the first detection signal, the circuit and chip are within the protection scope of the present utility model. The control circuit 20 judges by analyzing the received first detection signal. When the change of the first detection signal exceeds a preset voltage threshold or frequency threshold, it is judged that there is liquid under the keys, and a power-off control signal for disconnecting the power supply path of the power supply to the keyboard is generated; when the change of the detection signal is lower than the preset voltage threshold or frequency threshold, it is judged that there is no liquid under the keys.

[0041] In this embodiment, the power supply may be a power supply provided by an external device or a power supply module built into the keyboard, which is used to provide a stable working voltage for the keyboard to ensure the normal operation of the keyboard. The switch circuit 30 may include one or more switching devices, such as relays, transistors, etc., which are used to control the on / off of the power supply path of the power supply to the keyboard according to the power-off control signal output by the control circuit 20. When the switch control signal indicates disconnecting the power supply path, the switch circuit 30 will disconnect the connection between the power supply and the keyboard input terminal, thereby avoiding damage to the keyboard circuit caused by liquid.

[0042] In this embodiment, the keyboard protection circuit includes a liquid detection circuit 10, a control circuit 20, and a switch circuit 30. The control circuit 20 is electrically connected to the liquid detection circuit 10, and the switch circuit 30 is electrically connected to the control circuit 20. The switch circuit 30 is serially arranged between the keyboard power input terminal and the power supply. The liquid detection circuit 10 detects the liquid immersion condition under the key, and outputs a corresponding first detection signal to the control circuit 20 when there is liquid under the key. The control circuit 20 then generates a corresponding power-off control signal according to the first detection signal and outputs it to the switch circuit 30, so that the switch circuit 30 disconnects the power supply path of the power supply to the keyboard according to the power-off control signal. In this way, when there is liquid infiltration into the keyboard, the keyboard protection circuit can detect the liquid immersion condition under the keyboard keys, and when there is liquid under the keys, quickly cut off the power supply path of the power supply to the keyboard, timely protect the keyboard, and prevent the liquid from damaging the keyboard.

[0043] In a feasible implementation manner, the liquid detection circuit 10 includes a plurality of capacitive sensors. The plurality of capacitive sensors are arranged under the keys, and the plurality of capacitive sensors are respectively electrically connected to the control circuit 20.

[0044] In this embodiment, the plurality of capacitive sensors can be respectively arranged at different positions under the keys. Optionally, in another embodiment of the present invention, capacitive sensors with the same number as the number of keys on the keyboard can be arranged, and the plurality of capacitive sensors are arranged in one-to-one correspondence with the plurality of keys. In this way, the liquid condition under the keys can be more comprehensively detected. In this embodiment, the specific quantity and specific positions of the capacitive sensors can be flexibly adjusted according to factors such as the size of the keyboard, the key layout, and the design requirements, and are not limited here. When liquid enters under the keys, the capacitive sensors at different positions will respectively sense the change of the electric field and send the corresponding detection signals to the control circuit 20. The control circuit 20 can make a comprehensive judgment according to the signals received from the plurality of capacitive sensors to more accurately judge whether there is liquid under the keys, thereby improving the accuracy and reliability of the detection and further protecting the keyboard from liquid damage.

[0045] In a feasible implementation manner, referring to Figure 2 , the liquid detection circuit 10 further includes a charge amplifier 11, an oscillator 12, and a comparator 13. The first end of the charge amplifier 11 is respectively electrically connected to the plurality of capacitive sensors, the first end of the oscillator 12 is connected to the second end of the charge amplifier 11, the first end of the comparator 13 is electrically connected to the second end of the oscillator, and the second end of the comparator 13 is electrically connected to the control circuit 20.

[0046] In this embodiment, the oscillator 12 can be an RC oscillator 12 or an LC oscillator 12. When the capacitive sensor senses a change in the electric field, it outputs a corresponding electrical signal to the charge amplifier 11 for amplification processing. The amplified electrical signal is sent to the oscillator 12. The oscillator 12 generates a corresponding oscillation signal according to the change in the electrical signal and outputs it to the comparator 13. The comparator 13 compares the oscillation signal with a preset reference threshold. When the oscillation signal exceeds the reference threshold, the comparator 13 outputs a high-level signal to the control circuit 20; when the oscillation signal is lower than the reference threshold, the comparator 13 outputs a low-level signal to the control circuit 20. The control circuit 20 determines whether there is liquid under the key according to the signal output by the comparator 13 and generates a corresponding switch control signal, thereby realizing the control of the power supply path of the keyboard.

[0047] In this embodiment, by using the charge amplifier 11, the oscillator 12, and the comparator 13, the electrical signal output by the capacitive sensor is amplified, frequency modulated, and compared, improving the accuracy and reliability of the detection.

[0048] In a feasible implementation manner, the switch circuit 30 includes an isolation relay. The control circuit 20 is connected to the control end of the isolation relay. The first conduction end of the isolation relay is connected to the power supply, and the second conduction end of the isolation relay is connected to the keyboard power input terminal.

[0049] In this embodiment, when the control circuit 20 determines that there is liquid under the key, it outputs a power-off control signal for disconnecting the power supply path of the keyboard to the control end of the isolation relay, causing the isolation relay to disconnect the connection between its first conduction end and the second conduction end, thereby cutting off the power supply to the keyboard from the power supply end and preventing the liquid from damaging the keyboard circuit. In this embodiment, by using the isolation relay as the core component of the switch circuit 30, reliable control of the power supply path between the power supply end and the keyboard is achieved. The isolation relay has excellent electrical isolation performance, can effectively isolate the circuit between the power supply end and the keyboard, and prevent circuit short-circuit or damage caused by liquid intrusion. At the same time, the isolation relay has a fast action speed and a short response time, can cut off or restore the power supply path in a timely manner, and ensure the safety and stability of the keyboard.

[0050] In a feasible implementation manner, referring to Figure 3 , the keyboard protection circuit further includes a plurality of heating elements (H1 to HN, where N is an integer and N is greater than 1). The plurality of heating elements are respectively arranged at different positions of the keyboard, and the plurality of heating elements are respectively electrically connected to the control circuit 20; the heating elements are used to heat and evaporate the liquid when there is liquid under the key.

[0051] In this embodiment, when there is liquid under the keys of the keyboard, in addition to cutting off the power supply path from the power supply terminal to the keyboard, the liquid can also be heated and evaporated by a heating sheet, thereby further accelerating the liquid removal process. Multiple heating sheets are respectively arranged at different positions of the keyboard, which can more comprehensively cover the liquid under the keyboard and improve the efficiency of heating and evaporation. The number of heating sheets can be 2, 3, 4 or other numbers. The specific number and specific position of the capacitive sensors can be flexibly adjusted according to factors such as the size of the keyboard, the key layout, and the design requirements, and are not limited here. When the control circuit 20 determines that there is liquid under the keys, the control circuit 20 controls the corresponding heating sheet to start and heat and evaporate the liquid. The heating temperature of the heating sheet can be flexibly selected according to the production process of the keyboard to ensure that the liquid can be quickly and effectively removed without damaging the internal circuit of the keyboard.

[0052] In a feasible implementation manner, the liquid detection circuit is further configured to output a corresponding second detection signal when there is no liquid under the keys; the control circuit is further configured to output a corresponding conduction control signal according to the second detection signal; the switch circuit is further configured to conduct the power supply path of the power supply to the keyboard according to the conduction control signal.

[0053] In this embodiment, when there is no liquid under the keys, the liquid detection circuit outputs a corresponding second detection signal to the control circuit. The control circuit determines that there is no liquid under the keys according to the received second detection signal, and thus outputs a conduction control signal to the switch circuit. After receiving the conduction control signal, the switch circuit restores the connection between the first conduction end and the second conduction end of the isolation relay, and the keyboard resumes normal operation. In this way, the keyboard protection circuit can realize the intelligent control of the power supply path of the keyboard. It can not only cut off the power supply in time when liquid invades to prevent short circuit or damage of the circuit, but also automatically restore the power supply after the liquid is removed to ensure the normal use of the keyboard. This design not only improves the safety and reliability of the keyboard, but also provides a more convenient and intelligent user experience for users.

[0054] In a feasible implementation manner, referring to Figure 4 , the keyboard protection circuit further includes a warning circuit 40, and the warning circuit 40 is electrically connected to the control circuit 20; the warning circuit 40 is configured to issue a warning signal when liquid is detected under the keys.

[0055] In this embodiment, when liquid is detected under the keyboard, in addition to cutting off the power supply path to the keyboard and using a heating sheet to remove the liquid, the warning circuit 40 will also emit a warning signal to alert the user of the liquid entry and prompt timely handling. The warning circuit 40 can adopt methods such as sound alarm, light alarm or vibration alarm to alert the user. For example, when the control circuit 20 determines that there is liquid under a key, the control circuit 20 can control the buzzer in the warning circuit 40 to emit a beeping sound to attract the user's attention; or control the LED in the warning circuit 40 to blink to alert the user of the liquid entry. Through the setting of the warning circuit 40, the user's perception and response speed to the keyboard protection circuit can be further improved, ensuring the safety and stability of the keyboard.

[0056] In a feasible implementation manner, the warning circuit 40 further includes a buzzer, and the buzzer is electrically connected to the control circuit 20; the buzzer is used to emit a sound warning signal when liquid is detected under the key.

[0057] In this embodiment, the warning circuit 40 is further refined into a specific implementation manner including a buzzer. When liquid is detected under the keyboard, the control circuit 20 will send an instruction to the buzzer, and the buzzer will immediately emit a sound warning signal. This sound warning signal can be directly conveyed to the user through hearing, alerting the user of the liquid entry and prompting corresponding handling measures. Parameters such as the sound frequency, volume and duration of the buzzer can be adjusted according to actual needs to ensure that the sound warning signal can effectively attract the user's attention. Through the setting of the buzzer, the keyboard protection circuit can provide a more direct and clear warning when detecting liquid, further enhancing the user's safety awareness and emergency response ability.

[0058] In a feasible implementation manner, the keyboard protection circuit includes an LED, and the LED is electrically connected to the control circuit 20. The LED is used to emit a light warning signal when liquid is detected under the key.

[0059] In this embodiment, the warning circuit 40 is further refined into a specific implementation manner including an LED. When liquid is detected under the keyboard, the control circuit 20 will send an instruction to the LED, and the LED will immediately light up and emit a light warning signal. This light warning signal can be directly conveyed to the user visually to remind the user to pay attention to the situation of liquid entry. Parameters such as the color, brightness, and flashing frequency of the LED can be adjusted according to actual needs to ensure that the light warning signal can clearly and obviously attract the user's attention. At the same time, the LED can also be used in combination with other warning methods (such as sound warning) to provide a more comprehensive and effective warning. Through the setting of the LED, the keyboard protection circuit can provide a more intuitive and obvious visual prompt for the user when detecting liquid, enhancing the user's perception and judgment of the safety status of the keyboard.

[0060] In a feasible implementation manner, the keyboard protection circuit further includes an independent power supply; the independent power supply is used to supply power to the plurality of heating sheets and / or the warning circuit 40. In this embodiment, an independent power supply is provided specifically to supply power to the plurality of heating sheets and / or the warning circuit 40 to ensure that the keyboard protection circuit can operate normally at critical moments, ensuring that when liquid is detected under the keyboard, the heating sheets and / or the warning circuit 40 can operate stably without being interfered by other circuits. Through the introduction of the independent power supply, the keyboard protection circuit can more reliably and effectively protect the safety and stability of the keyboard when dealing with emergencies such as liquid intrusion.

[0061] The technical solution of the present utility model adopts a keyboard protection circuit, which includes a liquid detection circuit 10, a control circuit 20, and a switch circuit 30. The control circuit 20 is electrically connected to the liquid detection circuit 10, and the switch circuit 30 is electrically connected to the control circuit 20. The switch circuit 30 is serially arranged between the keyboard power input terminal and the power supply. The liquid detection circuit 10 detects the liquid immersion situation under the key and outputs a corresponding first detection signal to the control circuit 20 when there is liquid under the key. The control circuit 20 then generates a corresponding power-off control signal according to the first detection signal and outputs it to the switch circuit 30, so that the switch circuit 30 disconnects the power supply path of the power supply to the keyboard according to the power-off control signal. In this way, when there is liquid seeping into the keyboard, the keyboard protection circuit can detect the liquid immersion situation under the keyboard keys and quickly cut off the power supply path of the power supply to the keyboard when there is liquid under the keys, timely protecting the keyboard and preventing the liquid from damaging the keyboard.

[0062] The present utility model also proposes a keyboard, which includes this keyboard protection circuit. The specific structure of the keyboard protection circuit refers to the above embodiment. Since this 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.

[0063] The above are only exemplary embodiments of the present utility model, and do not thereby 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 keyboard protection circuit, applied to a keyboard, characterized in that, The keyboard includes keys, and the keyboard protection circuit includes: A liquid detection circuit for detecting the liquid immersion condition below the keys and outputting a corresponding first detection signal when there is liquid below the keys; A control circuit electrically connected to the liquid detection circuit, which is configured to output a corresponding power-off control signal according to the first detection signal; A switch circuit electrically connected to the control circuit, with the switch circuit serially arranged between the keyboard power input terminal and the power supply. The switch circuit is configured to disconnect the power supply path of the power supply to the keyboard according to the power-off control signal.

2. The keyboard protection circuit according to claim 1, characterized in that The liquid detection circuit includes a plurality of capacitive sensors, and the plurality of capacitive sensors are arranged below the keys and are respectively electrically connected to the control circuit.

3. The keyboard protection circuit according to claim 2, wherein The liquid detection circuit further includes: A charge amplifier, with the first end of the charge amplifier electrically connected to the plurality of capacitive sensors respectively; An oscillator, with the first end of the oscillator connected to the second end of the charge amplifier; A comparator, with the first end of the comparator electrically connected to the second end of the oscillator, and the second end of the comparator electrically connected to the control circuit.

4. The keyboard protection circuit according to claim 1, wherein The switch circuit includes an isolation relay. The control circuit is connected to the control end of the isolation relay. The first conducting end of the isolation relay is connected to the power supply, and the second conducting end of the isolation relay is connected to the keyboard power input terminal.

5. The keyboard protection circuit according to claim 1, characterized in that, The keyboard protection circuit further includes a plurality of heating elements, and the plurality of heating elements are respectively arranged at different positions of the keyboard and are respectively electrically connected to the control circuit. The heating elements are configured to heat and evaporate the liquid when there is liquid below the keys.

6. The keyboard protection circuit according to claim 5, wherein, The liquid detection circuit is further configured to output a corresponding second detection signal when there is no liquid below the keys; The control circuit is further configured to output a corresponding conduction control signal according to the second detection signal; The switch circuit is further configured to conduct the power supply path of the power supply to the keyboard according to the conduction control signal.

7. The keyboard protection circuit according to claim 5, characterized in that, The keyboard protection circuit further includes a warning circuit electrically connected to the control circuit. The warning circuit is configured to emit a warning signal when there is liquid below the keys.

8. The keyboard protection circuit according to claim 7, characterized in that, The warning circuit includes: A buzzer electrically connected to the control circuit. The buzzer is configured to emit an audible warning signal when there is liquid below the keys; And / or, the keyboard protection circuit includes an LED electrically connected to the control circuit. The LED is configured to emit a visual warning signal when there is liquid below the keys.

9. The keyboard protection circuit according to claim 7 or 8, characterized in that, The keyboard protection circuit further includes an independent power supply, which is configured to supply power to the plurality of heating elements and / or the warning circuit.

10. A keyboard, characterized in that, The keyboard includes the keyboard protection circuit according to any one of claims 1 to 9.

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