Novel rain sensor

Abstract

The utility model discloses a novel rain sensor which comprises a rain sensing panel and a rain sensing circuit. The rain sensing panel comprises a rain sensing substrate, a piezoelectric ceramic piece and a plurality of side-by-side metal strips, the piezoelectric ceramic piece is fixed on the outer surface of the rain sensing substrate, and the plurality of side-by-side metal strips are fixed on the outer surface of the rain sensing substrate and distributed on the two sides of the piezoelectric ceramic piece; the rain sensing circuit is arranged in the rain sensing panel, and the piezoelectric ceramic piece and the multiple side-by-side metal strips are electrically connected with the rain sensing circuit. According to the novel rain sensor, the piezoelectric effect and the resistance change monitoring technology are combined, and the high-precision and reliable rainfall detection capacity is achieved. The complex circuit design ensures that signals can be effectively processed in each link from the sensor to the output end, accurate rain sensing identification signals are finally provided, important meteorological data support is provided for users, and the system is widely applied to the fields of agriculture, urban management, traffic safety and the like.

Description

Technical Field

[0001] The utility model relates to the field of sensors, in particular to a novel rain sensor. Background Art

[0002] The meteorological industry is very important for collecting rainfall, because accurate rainfall data is of great significance for weather forecasting, water resources management, agricultural production, etc. In meteorology, rainfall refers to the depth of precipitation per unit area, usually in millimeters. The methods and technologies for collecting rainfall in the meteorological industry are constantly developing and improving to ensure the accuracy and comprehensiveness of the data.

[0003] First of all, rainfall is usually collected using a rain gauge or rain gauge observer. The traditional rain gauge is an instrument based on the principle of a funnel, which collects rainwater through a funnel and then determines the rainfall by measuring the change in the water level in the water collection container. In recent years, with the development of science and technology, digital rain gauge observers have gradually been applied to the meteorological industry. These new observers can automatically record rainfall data, and can realize remote monitoring and real-time data transmission, greatly improving the efficiency and accuracy of data collection.

[0004] In addition to traditional rainfall observation equipment, the modern meteorological industry has also adopted a series of advanced technologies and methods to assist in the collection and analysis of rainfall. For example, remote sensing technology can obtain a wide range of precipitation information through satellite remote sensing and radar remote sensing, helping the meteorological department to better grasp the temporal and spatial distribution of precipitation. In addition, meteorological radar technology is also widely used in rainfall detection and monitoring, which can provide high-resolution precipitation data, which is of great significance for the early warning and monitoring of extreme weather events such as heavy rain and thunderstorms.

[0005] In the process of collecting rainfall data, the accuracy and comprehensiveness of the data are crucial. Therefore, the meteorological industry not only continuously updates and improves equipment and technology, but also strengthens the management and maintenance of the observation environment. For example, the location and environment of the observation point have an important impact on the accuracy of the observation data. The meteorological department usually strictly regulates the selection and setting of the observation point to ensure the reliability of the observation data.

[0006] The collected rainfall data has a wide range of applications in the meteorological industry. First, rainfall data is an important basis for making weather forecasts and weather warnings, which can help people understand future weather conditions in a timely manner and take corresponding preventive measures. Secondly, rainfall data is also of great significance for water resources management and agricultural production. By analyzing rainfall data, we can better assess the supply and demand of water resources, guide the irrigation and planting of crops, and ensure the smooth progress of agricultural production.

[0007] With the impact of climate change and global warming, the collection and analysis of rainfall data has become particularly important. The meteorological industry needs to continuously improve rainfall observation technology and improve the accuracy and timeliness of data to better respond to the challenges brought by climate change. At the same time, it is also necessary to strengthen the comprehensive analysis and utilization of rainfall data to provide more accurate and reliable meteorological information for all sectors of society to promote sustainable development and respond to climate change.

[0008] The collection of rainfall in the meteorological industry is a systematic project, involving the comprehensive use of multiple equipment, technologies and methods. Accurate and reliable rainfall data is of great significance for weather forecasting, water resources management, agricultural production and other aspects. With the development of science and technology and the impact of climate change, the meteorological industry needs to continuously improve and perfect rainfall collection technology to better meet the needs of society.

[0009] At present, the meteorological industry generally uses tipping bucket rain gauges to collect rainfall. This type of sensor has high collection accuracy, but it also has obvious disadvantages. During use, the rainwater inlet is easily blocked, and the core component of the sensor (reed switch) may produce abnormal conditions in the field environment with high temperature and high humidity. In order to detect and identify this risk in a timely manner, it is necessary to install a new type of rain sensor that can accurately identify whether it is raining. In addition, since the power supply system of the automatic weather station generally adopts solar power supply, the power consumption is relatively low. Therefore, the operating power consumption of the new rain sensor is required to be low enough, generally less than 20mW, which basically does not affect the overall endurance of the automatic weather station. In addition, the commonly used rain sensing methods are resistive, piezoelectric and photoelectric. Among them, the disadvantage of the resistive type is that dew causes false triggering, the disadvantage of the piezoelectric type is that shaking (especially when the wind is strong) causes false triggering, and the disadvantage of the photoelectric type is that the power consumption is too large, which seriously affects the overall endurance of the automatic weather station. Summary of the invention

[0010] In order to make up for the above shortcomings, the utility model provides a new type of rain sensor, which realizes highly accurate and reliable rainfall detection capability by combining piezoelectric effect and resistance change monitoring technology. Its complex circuit design ensures that every link from sensor to output end can effectively process signals and finally provide accurate rain sensing identification signals, providing users with important meteorological data support.

[0011] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0012] A novel rain sensor comprises a rain sensing panel and a rain sensing circuit; the rain sensing panel comprises a rain sensing substrate, a piezoelectric ceramic sheet and a plurality of parallel metal strips, the piezoelectric ceramic sheet is fixed on the outer surface of the rain sensing substrate, the plurality of parallel metal strips are fixed on the outer surface of the rain sensing substrate and distributed on both sides of the piezoelectric ceramic sheet; the rain sensing circuit is arranged inside the rain sensing panel, and the piezoelectric ceramic sheet and the plurality of parallel metal strips are electrically connected to the rain sensing circuit respectively.

[0013] The plurality of parallel metal strips are used to measure the resistance of a raindrop falling between two parallel metal strips.

[0014] Furthermore, the piezoelectric ceramic sheet is an electronic ceramic material with piezoelectric effect. Under the action of external mechanical stress, the material will generate electric charge and convert pressure into an electrical signal for measuring and monitoring pressure changes.

[0015] Furthermore, the rain sensing circuit includes a piezoelectric signal filtering circuit, a piezoelectric signal amplifying circuit, a raindrop signal judging circuit and a rain sensing identification signal output circuit; the piezoelectric ceramic sheet and a plurality of parallel metal strips are respectively connected to the input end of the piezoelectric signal filtering circuit, the output end of the piezoelectric signal filtering circuit is connected to the input end of the piezoelectric signal amplifying circuit, the output end of the piezoelectric signal amplifying circuit is connected to the input end of the raindrop signal judging circuit, and the output end of the raindrop signal judging circuit is connected to the input end of the rain sensing identification signal output circuit.

[0016] Furthermore, the piezoelectric signal filtering circuit includes R2, D45, D2, R5 and C4, and the piezoelectric signal amplifying circuit includes a MAX44248 high-precision operational amplifier to form an operational amplifier follower and an operational amplifier with an amplification factor of 5 times. The weak voltage signal converted by the piezoelectric ceramic piece is input into the piezoelectric signal filtering circuit from the U9 or H2 port, and after filtering and amplification, the piezoelectric conversion signal YDOUT is output.

[0017] Furthermore, the raindrop signal judgment circuit is composed of a voltage detection circuit and a monostable circuit. The voltage detection circuit includes MAX16050 to form a 500mV threshold voltage detection circuit. The monostable circuit includes HE4011, C16 and R3. When the piezoelectric conversion signal YDOUT is greater than 500mV, a 1-second piezoelectric high-level pulse signal YUDI is formed.

[0018] Furthermore, the rain sensing identification signal output circuit includes a variable resistance conversion circuit composed of multiple parallel metal strips and HEF4071, which outputs an accurate high-level rain sensing pulse with a pulse width of 1 second; the HEF4071 is an OR gate. When there are no raindrops but the rain sensing panel vibrates, the voltage converted by the variable resistance of the multiple parallel metal strips is a high level due to the absence of raindrops, and the OR gate output is locked to avoid false triggering of the piezoelectric ceramic piece.

[0019] The MAX44248 is a high-precision, low-power operational amplifier produced by Maxim Integrated. It is primarily designed for applications that require high-precision amplification and signal processing, and is particularly suitable for sensor signal amplification, precision measurement, data acquisition systems, and industrial automation.

[0020] Key features and benefits include:

[0021] Low power consumption: The MAX44248 has low power consumption, making it suitable for portable devices and wireless sensor networks that require high battery life.

[0022] High precision: It has the characteristics of low input bias current, low input bias voltage and low noise, ensuring high precision and accuracy in the signal amplification process.

[0023] Wide bandwidth: With wide bandwidth, it can support high-frequency signal processing and is suitable for applications that require fast response and large dynamic range.

[0024] Accurate supply voltage range: Ability to operate over a wide supply voltage range, providing design flexibility and compatibility.

[0025] Small Packages: Small package options are often available, which helps achieve compact designs in space-constrained applications.

[0026] Application flexibility: Suitable for a variety of applications, including industrial measurement, medical equipment, communication equipment, etc., providing designers with flexibility and choices in different fields.

[0027] Typical application scenarios:

[0028] Sensor signal amplification: Accurately amplify and process the sensor output signal.

[0029] Precision measurement: used in environments that require high-precision measurement, such as temperature measurement, pressure measurement, etc.

[0030] Data acquisition system: used to obtain data from the sensor and accurately amplify it to a range suitable for ADC (analog-to-digital converter) input.

[0031] Industrial Automation: Used for signal processing and amplification in industrial control systems.

[0032] In general, as a high-performance operational amplifier, MAX44248 can meet the requirements of the circuit design of this application through its high precision, low power consumption and wide application flexibility.

[0033] The MAX16050 is a power monitoring circuit produced by Maxim Integrated that monitors the status of voltage rails and provides corresponding fault indications. It is widely used in systems that require reliable power monitoring, such as servers, communication equipment, industrial control, and consumer electronics.

[0034] Key features and benefits:

[0035] Multi-channel voltage monitoring:

[0036] The MAX16050 can monitor up to four voltage rails, ensuring that all critical voltage rails in the system are operating within safe limits.

[0037] Programmable Voltage Thresholds:

[0038] The user can set the undervoltage and overvoltage thresholds for each channel via an external resistor network. This flexibility allows adaptation to the specific needs of different systems.

[0039] Fault indication output:

[0040] The MAX16050 triggers fault-indication outputs when any of the voltage rails is detected to exceed a set threshold. These outputs can be used to drive LEDs, buzzers, or for further processing by a microcontroller.

[0041] Power-on reset (POR) function:

[0042] The device can provide a reliable reset signal during the power-on process to ensure that the system will not malfunction before the power supply is stable.

[0043] Wide operating voltage range:

[0044] Features a wide supply voltage range, typically 2.7V to 16V, making it suitable for a variety of power supply environments.

[0045] Low Power Consumption:

[0046] Designed with very low quiescent current consumption, it is very suitable for applications that require energy saving.

[0047] Small package:

[0048] Small package options such as TQFN are available for space-constrained designs.

[0049] Typical application scenarios:

[0050] Servers and Data Centers: Monitor multiple power rails to ensure reliable server operation.

[0051] Communication equipment: Ensure the power supply stability of communication base stations and equipment.

[0052] Industrial control systems: Monitor and protect the power supply of industrial equipment.

[0053] Consumer Electronics: Monitor power in complex electronic devices to improve reliability and user experience.

[0054] Recommended use:

[0055] Set Voltage Thresholds: Precisely set undervoltage and overvoltage thresholds for each channel via external resistors based on system requirements.

[0056] Fault Handling: Connect fault indication outputs to an alarm device or microcontroller for prompt response to power failure conditions.

[0057] Modular design: When designing a power-monitoring solution, the MAX16050 can be used as a modular component for easy integration into different systems.

[0058] Core parameters:

[0059] Number of monitoring channels: 4;

[0060] Operating voltage range: 2.7V to 16V;

[0061] Quiescent current: as low as tens of microamperes;

[0062] Package type: such as TQFN, etc.

[0063] The MAX16050 provides designers with an efficient and reliable power monitoring solution through its flexible settings, reliable monitoring capabilities, and low power consumption, ensuring system stability and safety under various operating conditions.

[0064] HE4011 is a classic CMOS integrated circuit, specifically CD4011 or HEF4011. These chips belong to the 4000 series CMOS logic gate family and are commonly used in various digital circuit applications. Both CD4011 and HEF4011 are four two-input NAND gates.

[0065] Key features and benefits:

[0066] Low Power Consumption: A significant advantage of CMOS technology is its low power consumption, making it ideal for battery-powered devices and other applications that require energy conservation.

[0067] Wide operating voltage range: Typical operating voltage ranges from 3V to 15V, which makes them suitable for a variety of different power supply configurations.

[0068] High noise tolerance: CMOS logic gates have a high noise tolerance, ensuring that they can still work reliably in complex environments.

[0069] TTL compatible input: The input is compatible with TTL levels, so it can be seamlessly integrated with traditional TTL circuits.

[0070] Inverting Output: Due to the characteristics of the NAND gate, it inverts the logic state of the input and outputs it, which is very useful in logic design.

[0071] Core parameters: Number of gate circuits: 4 two-input NAND gates;

[0072] Each gate delay time: a few nanoseconds to tens of nanoseconds, depending on the operating voltage and load conditions;

[0073] Static power consumption: extremely low (typically microwatts);

[0074] Operating temperature range: -55℃ to +125℃;

[0075] Package Type:

[0076] Common package types include DIP (dual in-line package), SOIC (small outline integrated circuit), and TSSOP (thin outline compact package).

[0077] HE4011 or CD4011 based CMOS integrated circuits are widely used due to their reliability and ease of use.

[0078] Principles of this application:

[0079] When raindrops fall and impact the piezoelectric ceramics, the piezoelectric effect is generated, that is, the voltage increases significantly, and the resistance between the metal strips changes significantly when raindrops fall on two adjacent metal strips. The rain sensing panel transmits the voltage and resistance change signals to the rain sensing circuit. The rain sensing circuit filters, amplifies, and sorts the voltage and resistance change signals, and then outputs an accurate rainfall identification signal through a monostable circuit.

[0080] Specifically, the piezoelectric signal filtering circuit and the piezoelectric signal amplifying circuit filter and sort out the raindrop piezoelectric voltage signal generated by the piezoelectric ceramic sheet, and then enter the operational amplifier follower and the operational amplifier. The raindrop signal judgment circuit judges the validity of the piezoelectric signal according to the change in the resistance of the raindrops attached to the multiple parallel metal strips. The rain sensing identification signal output circuit outputs a high-level pulse rain sensing identification signal according to the output signal of the raindrop signal judgment circuit through a monostable circuit, and the signal is input into the rain sensing identification signal output circuit.

[0081] The utility model has the following beneficial effects:

[0082] 1. Accurate raindrop detection capability: Piezoelectric ceramics use the piezoelectric effect to convert the mechanical pressure of raindrops into electrical signals. This ensures that a significant voltage change occurs when raindrops hit the panel, thereby achieving highly sensitive raindrop detection. The combination of resistive and piezoelectric technology effectively avoids false triggering of rain caused by dew or shaking, thereby improving the accuracy of rain sensing.

[0083] 2. Real-time monitoring of resistance changes: Multiple metal strips are placed side by side on the rain sensing substrate, and the location and intensity of raindrops are identified by monitoring the resistance changes between the metal strips. This design can accurately sense the size and density of raindrops, and thus provide detailed rainfall data;

[0084] 3. Complex rain sensing circuit design: The piezoelectric signal filtering circuit and the piezoelectric signal amplifying circuit ensure that the weak signal obtained from the piezoelectric ceramic piece can be effectively processed and analyzed in the subsequent circuit after stable filtering and amplification;

[0085] 4. Efficient signal processing flow: The raindrop signal judgment circuit combines voltage detection and monostable circuit to accurately judge the validity of the piezoelectric signal and the actual existence of raindrops. This design ensures that the correct rain sensing recognition signal can be stably output under various environmental conditions;

[0086] 5. Stable and reliable output signal: The rain sensing recognition signal output circuit ensures the output of a stable high-level pulse signal through appropriate logic circuits (such as OR gates and monostable circuits). Such a design can be easily recognized and received by other devices or systems, such as activating automatic rain gear or automatically starting equipment protection measures;

[0087] 6. Applicability and reliability: The overall design takes into account the long-term stability and environmental adaptability of the equipment. It can operate reliably under various climatic conditions and provide a long-lasting rainfall monitoring solution. It adopts an ultra-low power design circuit, and the power consumption of the whole machine is less than 10mW. When powered by the automatic weather station power supply, its endurance is hardly affected;

[0088] 7. The novel rain sensor of the present application realizes highly accurate and reliable rainfall detection capability by combining piezoelectric effect and resistance change monitoring technology. Its complex circuit design ensures that every link from sensor to output end can effectively process signals and finally provide accurate rain sensing identification signals, providing users with important meteorological data support and widely used in agriculture, urban management and traffic safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 Schematic diagram of rain sensing panel;

[0090] Figure 2 Piezoelectric signal filtering and amplification circuit diagram;

[0091] Figure 3 Raindrop signal judgment circuit diagram;

[0092] Figure 4 Rain sensing recognition signal output circuit diagram;

[0093] Legend:

[0094] 1. Round piezoelectric ceramic piece; 2. Multiple parallel metal strips; 3. Rain-sensing substrate. DETAILED DESCRIPTION

[0095] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0096] like Figure 1 As shown, a new type of rain sensor includes a rain sensing panel and a rain sensing circuit; the rain sensing panel includes a rain sensing substrate 3, a piezoelectric ceramic sheet 1 and a plurality of side-by-side metal strips 2, the piezoelectric ceramic sheet 1 is fixed on the outer surface of the rain sensing substrate 3, and the plurality of side-by-side metal strips 2 are fixed on the outer surface of the rain sensing substrate 3 and distributed on both sides of the piezoelectric ceramic sheet 1; the rain sensing circuit is arranged inside the rain sensing panel, and the piezoelectric ceramic sheet 1 and the plurality of side-by-side metal strips 2 are electrically connected to the rain sensing circuit respectively.

[0097] The plurality of parallel metal strips 2 are used to measure the resistance of a raindrop landing between two parallel metal strips.

[0098] The piezoelectric ceramic sheet 1 is an electronic ceramic material with piezoelectric effect. Under the action of external mechanical stress, the material will generate electric charge and convert pressure into an electrical signal for measuring and monitoring pressure changes. In this embodiment, the shape of the piezoelectric ceramic sheet 1 is circular.

[0099] The rain sensing panel is tilted at an angle of 20-30 degrees when in use, so that raindrops falling on the panel can be drained off as quickly as possible. When there are raindrops, the rain sensing panel generates a weak voltage signal of piezoelectric conversion and a variable resistance signal generated by multiple parallel metal strips.

[0100] The rain sensing circuit includes a piezoelectric signal filtering circuit, a piezoelectric signal amplifying circuit, a raindrop signal judging circuit and a rain sensing identification signal output circuit; the piezoelectric ceramic sheet and a plurality of parallel metal strips are respectively connected to the input end of the piezoelectric signal filtering circuit, the output end of the piezoelectric signal filtering circuit is connected to the input end of the piezoelectric signal amplifying circuit, the output end of the piezoelectric signal amplifying circuit is connected to the input end of the raindrop signal judging circuit, and the output end of the raindrop signal judging circuit is connected to the input end of the rain sensing identification signal output circuit.

[0101] like Figure 2 As shown, the weak voltage signal of the piezoelectric conversion is input into the piezoelectric signal filtering and amplifying circuit from the U9 or H2 port. The piezoelectric signal filtering circuit is composed of R2, D45, D2, R5 and C4. The amplifying circuit mainly consists of the MAX44248 high-precision operational amplifier, an operational amplifier follower and an operational amplifier with an amplification factor of 5. After filtering and amplification, the piezoelectric conversion signal YDOUT is output.

[0102] like Figure 3 As shown, the raindrop signal judgment circuit is composed of a voltage detection circuit and a monostable circuit. The voltage detection circuit is mainly composed of MAX16050 to form a 500mV threshold voltage detection circuit. The monostable circuit is mainly composed of HE4011, C16 and R3. When the piezoelectric conversion signal YDOUT is greater than 500mV, a 1-second piezoelectric high-level pulse signal YUDI is formed.

[0103] like Figure 4 As shown, the rain sensing identification signal output circuit is composed of a variable resistance conversion circuit of multiple parallel metal strips and HEF4071, and outputs an accurate high-level rain sensing pulse with a pulse width of 1 second. The variable resistance conversion circuit mainly determines whether there are raindrops falling, and eliminates the situation where the vibration of the rain sensing panel causes the piezoelectric ceramic piece to be falsely triggered. The HEF4071 is an OR gate. When there are no raindrops but the rain sensing panel vibrates, the voltage converted by the variable resistance of multiple parallel metal strips is a high level due to the absence of raindrops, which locks the OR gate output and avoids false triggering of the piezoelectric ceramic piece.

[0104] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A novel rain sensor, characterized in that: It includes a rain sensing panel and a rain sensing circuit; the rain sensing panel includes a rain sensing substrate, a piezoelectric ceramic sheet and a plurality of side-by-side metal strips, the piezoelectric ceramic sheet is fixed on the outer surface of the rain sensing substrate, and the plurality of side-by-side metal strips are fixed on the outer surface of the rain sensing substrate and distributed on both sides of the piezoelectric ceramic sheet; the rain sensing circuit is arranged inside the rain sensing panel, and the piezoelectric ceramic sheet and the plurality of side-by-side metal strips are electrically connected to the rain sensing circuit respectively.

2. The novel rain sensor according to claim 1 is characterized in that: The piezoelectric ceramic sheet is an electronic ceramic material with piezoelectric effect. Under the action of external mechanical stress, the material will generate electric charge and convert pressure into electrical signals for measuring and monitoring pressure changes.

3. The novel rain sensor according to claim 1 is characterized in that: The rain sensing circuit comprises a piezoelectric signal filtering circuit, a piezoelectric signal amplifying circuit, a raindrop signal judging circuit and a rain sensing identification signal output circuit; the piezoelectric ceramic sheet and a plurality of parallel metal strips are respectively connected to the input end of the piezoelectric signal filtering circuit, the output end of the piezoelectric signal filtering circuit is connected to the input end of the piezoelectric signal amplifying circuit, the output end of the piezoelectric signal amplifying circuit is connected to the input end of the raindrop signal judging circuit, and the output end of the raindrop signal judging circuit is connected to the input end of the rain sensing identification signal output circuit.

4. The novel rain sensor according to claim 3 is characterized in that: The piezoelectric signal filtering circuit includes R2, D45, D2, R5 and C4. The piezoelectric signal amplifying circuit includes a MAX44248 high-precision operational amplifier to form an operational amplifier follower and an operational amplifier with an amplification factor of 5. The weak voltage signal converted by the piezoelectric ceramic piece is input into the piezoelectric signal filtering circuit from the U9 or H2 port. After filtering and amplification, the piezoelectric conversion signal YDOUT is output.

5. The novel rain sensor according to claim 3 is characterized in that: The raindrop signal judgment circuit is composed of a voltage detection circuit and a monostable circuit. The voltage detection circuit includes MAX16050 to form a 500mV threshold voltage detection circuit. The monostable circuit includes HE4011, C16 and R3. When the piezoelectric conversion signal YDOUT is greater than 500mV, a 1-second piezoelectric high-level pulse signal YUDI is formed.

6. The novel rain sensor according to claim 3 is characterized in that: The rain sensing identification signal output circuit includes a variable resistance conversion circuit composed of multiple parallel metal strips and HEF4071, which outputs an accurate high-level rain sensing pulse with a pulse width of 1 second; the HEF4071 is an OR gate. When there are no raindrops but the rain sensing panel vibrates, the voltage converted by the variable resistance of the multiple parallel metal strips is a high level due to the absence of raindrops, and the OR gate output is locked to avoid false triggering of the piezoelectric ceramic piece.

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