Key circuit enabling touch spring to be equivalent to mechanical switch
By equivalently equating the touch spring into a mechanical switch, using a combination of 5551 transistor and AM01B touch chip, the problem of high cost of multiplexed design is solved, and flexibility and cost-effectiveness is achieved. It is suitable for compact electronic products.
Patent Information
- Application Number
- CN202420685642.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-07
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-04-07
AI Technical Summary
In the prior art, touch springs are independent of each other, resulting in the need to do multiple-channel designs when designing circuits, which is relatively expensive.
By equivalently equating the touch spring into a mechanical switch, using the combination of the main circuit board, power supply module, main microcontroller, touch chip, switch tube and protection resistor, using the 5551 transistor and AM01B touch chip, an IO port detection multi-channel touch spring and Mechanical switch.
Achieve flexibility, programmability and cost-effectiveness, reduce design costs, and implement personalized functions and control strategies through modification of code.
Smart Images
Figure CN222192338U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of key detection circuits, in particular to a key circuit in which a touch spring is equivalent to a mechanical switch. Background Art
[0002] Common touch spring detection methods can be used in the following ways:
[0003] ①Touch chip
[0004] Basic features: High integration: Touch chips usually integrate functions such as touch detection, signal processing and digital interface, which simplifies circuit design and layout; High sensitivity: Touch chips can quickly and accurately detect slight touch operations, providing a good user experience; Space saving: Due to the high integration, touch chips can help save space inside the device and are suitable for various compact electronic product designs.
[0005] ②Touch microcontroller:
[0006] Basic features: Integrated touch detection module: The touch microcontroller has an integrated touch detection module, which can be directly connected to the touch sensor to collect and process touch signals; digital signal processing: The touch microcontroller can convert the analog signal obtained from the touch sensor into a digital signal through the internal ADC, thereby facilitating subsequent data processing and operation; low power design: For battery-powered application scenarios, touch microcontrollers are usually designed with low power consumption to extend battery life.
[0007] ③Sensor:
[0008] Basic features: No need for mechanical buttons: Touch sensors can achieve touch control without physical buttons, providing a simpler and more convenient operation method; High sensitivity: Touch sensors can respond to tiny touch signals and have high sensitivity; Multiple working principles: Touch sensors can adopt different working principles, such as capacitive, resistive, acoustic wave, etc., suitable for different application scenarios; Energy saving and environmental protection: Since no mechanical structure is required, touch sensors have advantages in energy saving and environmental protection.
[0009] The above three detection methods are essentially applications of touch sensors, which convert level signals into digital signals. In theory, their working principles are different from those of mechanical buttons. Each touch spring is independent of each other, and multi-channel design is required during circuit design, which results in high design costs. Utility Model Content
[0010] In order to solve the above technical problems, a key circuit is provided that converts a touch spring into a mechanical switch. This technical solution solves the problem that each touch spring is independent of each other, multiple circuits need to be designed during circuit design, and the design cost is high.
[0011] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0012] A key circuit that converts a touch spring into a mechanical switch includes a main circuit board, the main circuit board is electrically connected to a power supply module, the main circuit board is electrically connected to a main single-chip computer, the main circuit board is electrically connected to a touch chip, the touch chip is electrically connected to a switch tube, the touch chip is electrically connected to a protection resistor, and the touch chip is electrically connected to a spring.
[0013] Preferably, the output end of the power supply module is electrically connected to the input end of the main circuit board.
[0014] Preferably, the peripheral circuit of the touch chip, the switch tube, the protection resistor, and the spring are equivalent to a mechanical switch.
[0015] Preferably, the power supply module adopts a lithium battery pack.
[0016] Preferably, the main single chip microcomputer adopts MC51F7424, and the operating voltage range of the MC51F7424 is 2.0-5.5V.
[0017] Preferably, the switch tube adopts a 5551 transistor, which is used to control the switch of the main circuit board.
[0018] Preferably, the touch chip adopts AM01B.
[0019] Compared with the prior art, the utility model provides a key circuit that converts a touch spring into a mechanical switch, which has the following beneficial effects:
[0020] 1) Flexibility and programmability: By converting the touch spring into a mechanical switch, multiple touch springs and mechanical switches can be detected using only one IO port, making circuit design and program design more convenient.
[0021] 2) Cost-effectiveness: To convert the touch spring into a mechanical switch, only common transistors and single-channel touch chips are needed, which costs less than touch sensors and is more efficient.
[0022] 3) Customizability: After the touch spring is equivalent to a mechanical switch, specific functions and control strategies can be implemented by modifying the code. This means that it can be customized according to the requirements of the application to meet specific needs. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a structural schematic diagram of the key circuit in the utility model.
[0024] Figure 2 It is a structural schematic diagram of the main single-chip microcomputer in the utility model. DETAILED DESCRIPTION
[0025] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.
[0026] Reference Figure 1-2 As shown, a key circuit that uses a touch spring as an equivalent mechanical switch includes a main circuit board, the main circuit board is electrically connected to a power supply module, the power supply module uses a lithium battery pack, the output end of the power supply module is electrically connected to the input end of the main circuit board, the main circuit board is electrically connected to a main single-chip microcomputer, the main circuit board is electrically connected to a touch chip, the touch chip is electrically connected to a switch tube, the touch chip is electrically connected to a protection resistor, and the touch chip is electrically connected to a spring;
[0027] The main single-chip computer and the touch chip share the 5V power supply from the main circuit board; the main single-chip computer U1 can be MC51F7424 in the Shengsiwei series of general-purpose MCUs, whose operating voltage range is 2.0~5.5V. It is a fully static 8-bit 1T 8051 core CMOS microcontroller, and the instruction set is fully compatible with MCS-51, with 2-level priority interrupt configuration; the switch tube uses a 5551 transistor, which is usually used as a component in amplifiers, switches and other circuits, and is particularly suitable for low-power amplifier circuits;
[0028] In the key circuit that uses the touch spring as a mechanical switch, the 5551 transistor acts as a switch in this circuit because the turn-on voltage is lower and only high and low level signals exist after it is turned on.
[0029] The touch chip is AM01B, which is a single-button capacitive sensing control switch chip. The chip has built-in high-precision LDO, low-voltage reset, environmental capacitance self-calibration, de-jitter and other measures to ensure the anti-interference and stability of the touch chip. It should be noted that the peripheral circuit can adjust the size of the C5 capacitor to achieve fine-tuning of the sensitivity. At the same time, due to the shared main circuit board power supply, it can achieve ultra-low power consumption.
[0030] Working principle of 5551 transistor: In the circuit, 5551 transistor can be used as a switch. When the control terminal (base) receives a sufficient voltage signal, the 5551 transistor will turn on, allowing current to flow, realizing a function similar to a mechanical switch;
[0031] Touch chip connection: Connect the output signal of the touch chip to the base of the 5551 transistor as a control signal. When the touch chip detects a touch, it outputs a corresponding signal to the 5551 transistor.
[0032] Based on the above principles, the working process of converting the touch chip into a mechanical switch is as follows:
[0033] The signal output by the touch chip controls the conduction and cutoff of the 5551 transistor to control the load. This design can achieve a contactless, low-power switch control method.
[0034] Furthermore, different voltage division methods can be realized by changing the resistor connecting the 5551 transistor and the IO port of the microcontroller, so that one IO port can detect a key matrix formed by multiple touch springs and mechanical switches through AD values.
[0035] It is worth noting that the single-chip microcomputer model and component selection in this embodiment are only used to implement this embodiment, and they are not used as limitations on the utility model. The circuit design of the single-chip microcomputer analog boost proposed in the utility model can be implemented through the ordinary IO port of any single-chip microcomputer, and is suitable for boosting multi-cell lithium battery packs. The above shows and describes the basic principles, main features and advantages of the utility model. Technicians in this industry should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions only describe the principles of the utility model. The utility model will have various changes and improvements without departing from the spirit and scope of the utility model. These changes and improvements all fall within the scope of the utility model to be protected. The scope of protection required by the present utility model is defined by the attached claims and their equivalents.
Claims
1. A key circuit that converts a touch spring into a mechanical switch, characterized in that: It includes a main circuit board, the main circuit board is electrically connected to a power supply module, the main circuit board is electrically connected to a main single-chip computer, the main circuit board is electrically connected to a touch chip, the touch chip is electrically connected to a switch tube, the touch chip is electrically connected to a protection resistor, and the touch chip is electrically connected to a spring.
2. The key circuit that converts a touch spring into a mechanical switch according to claim 1, characterized in that: The output end of the power supply module is electrically connected to the input end of the main circuit board.
3. The key circuit that converts a touch spring into a mechanical switch according to claim 1, characterized in that: The peripheral circuit of the touch chip, the switch tube, the protection resistor and the spring are equivalent to a mechanical switch.
4. The key circuit that converts a touch spring into a mechanical switch according to claim 1, characterized in that: The power supply module adopts a lithium battery pack.
5. The key circuit that converts a touch spring into a mechanical switch according to claim 1, characterized in that: The main single chip microcomputer adopts MC51F7424, and the operating voltage range of the MC51F7424 is 2.0-5.5V.
6. The key circuit that converts a touch spring into a mechanical switch according to claim 1, characterized in that: The switch tube adopts a 5551 triode, which is used to control the switch of the main circuit board.
7. The key circuit that converts a touch spring into a mechanical switch according to claim 1, characterized in that: The touch chip adopts AM01B.