An ultrasonic smart gas meter vibration detection circuit

Abstract

This utility model relates to an ultrasonic smart gas meter vibration detection circuit. Its features include a vibration detection circuit employing an electromagnetically inductive omnidirectional vibration sensor to convert vibration amplitude into an electrical signal; an operational amplifier processing circuit including a filter circuit, a decoupling circuit, and an operational amplifier to amplify and filter the weak signal output by the omnidirectional vibration sensor; an output signal control circuit that raises the bias voltage of the operational amplifier through a resistor voltage divider to ensure that the weak signal can activate the transistor in the output signal determination circuit; and an output signal determination circuit that converts the analog signal into a digital level signal using the switching characteristics of the transistor to determine whether vibration has occurred. This utility model, using an electromagnetically inductive vibration sensor and signal processing circuit, combined with filtering, decoupling, and operational amplifiers, can accurately capture weak vibration signals from the gas meter and its surrounding environment, ensuring the detection of minute vibration changes, exhibiting high sensitivity, and enabling timely response to vibration signals.

Description

Technical Field

[0001] This utility model relates to a vibration detection circuit for an ultrasonic smart gas meter. Background Technology

[0002] With the development of electronic technology, ultrasonic measurement technology has been widely used in the field of gas metering due to its advantages such as no mechanical parts, no pressure loss, and wide measurement range. Ultrasonic smart gas meters are characterized by high accuracy, long lifespan, and low maintenance, and are suitable for residential and industrial / commercial gas metering.

[0003] However, in practical applications, environmental vibrations (such as earthquakes, mechanical shocks, or equipment vibrations) pose a significant challenge to the metering performance of ultrasonic smart gas meters. Meter vibration has multiple impacts on ultrasonic smart gas meter measurement: In terms of measurement accuracy, vibration causes micro-displacement of the transducer, resulting in changes in sound path, leading to calculation errors, and exacerbating waveform distortion. Regarding measurement stability, vibration may cause the transducer to generate false signals. Long-term vibration can also reduce the durability of the equipment. In terms of measurement range, noise from vibration reduces the resolution of ultrasonic signals passing through low-velocity fluids, thus affecting the measurement performance of ultrasonic smart gas meters.

[0004] Currently, to reduce the impact of meter vibration on ultrasonic smart gas meter measurement, physical vibration reduction measures are generally adopted to optimize the installation environment and improve the equipment's vibration resistance. However, these measures still have limitations. To ensure the measurement accuracy and safety of ultrasonic smart gas meters, vibration detection of the ultrasonic smart gas meter needs to be considered. Ensuring the safety and reliability of the circuit is a prerequisite for assisting the entire ultrasonic gas metering system in making reasonable judgments in the next step. Utility Model Content

[0005] To address the problems existing in the prior art, the purpose of this utility model is to provide a technical solution for an ultrasonic intelligent gas meter vibration detection circuit.

[0006] The ultrasonic smart gas meter vibration detection circuit is characterized by comprising:

[0007] Vibration detection circuit: It adopts an electromagnetic induction omnidirectional vibration sensor to convert the vibration amplitude into an electrical signal;

[0008] Operational amplifier processing circuit: including filter circuit, decoupling circuit and operational amplifier, used to amplify and filter the weak signal output by the omnidirectional vibration sensor;

[0009] Output signal control circuit: The bias voltage of the operational amplifier is raised by resistor voltage division to ensure that weak signals can turn on the transistor of the output signal determination circuit;

[0010] Output signal determination circuit: Converts analog signals into digital level signals using the switching characteristics of transistors to determine whether vibration has occurred.

[0011] The ultrasonic smart gas meter vibration detection circuit is characterized in that the vibration detection circuit adopts an omnidirectional vibration sensor L1. The output signal of the omnidirectional vibration sensor L1 is filtered by capacitor C2 and decoupled by capacitor C4, and then input to the inverting input terminal of operational amplifier U1A through resistor R3.

[0012] The ultrasonic smart gas meter vibration detection circuit is characterized in that the operational amplifier processing circuit: the inverting input terminal of the operational amplifier U1A receives the signal through resistor R3, and the feedback resistor R1 and capacitor C1 are connected in parallel to form a low-pass filter network to suppress high-frequency noise; the output signal is further filtered by the RC low-pass filter composed of resistor R4 and capacitor C5 and then input to the base of transistor Q1.

[0013] The ultrasonic smart gas meter vibration detection circuit is characterized in that the output signal control circuit raises the bias voltage of the operational amplifier U1A to the transistor's turn-on voltage point through voltage division by resistors R5 and R6, thus avoiding the loss of weak signals.

[0014] The ultrasonic smart gas meter vibration detection circuit is characterized in that the output signal determination circuit has the collector of transistor Q1 connected to power supply VDD and the emitter of transistor Q1 grounded; when no vibration is detected, transistor Q1 is cut off and outputs a high level; when vibration is detected, transistor Q1 is turned on and outputs a low level.

[0015] This invention utilizes an electromagnetically inductive omnidirectional vibration sensor for vibration detection. The sensor generates a current upon the occurrence of a minute vibration. After filtering and decoupling, the current is input to an operational amplifier circuit, which outputs an amplified voltage. The amplitude of the output voltage is controlled by an output signal control circuit, and then a signal is determined by an output signal determination circuit, resulting in a high or low level output signal. The ultrasonic intelligent gas meter controller can detect vibration in real time by monitoring high and low levels, ensuring the detection of even minute vibration changes. It exhibits high sensitivity and timely response to vibration signals.

[0016] This utility model has the following advantages:

[0017] 1. Employing an electromagnetic induction vibration sensor and signal processing circuitry, combined with filtering, decoupling, and operational amplifier amplification technologies, it can accurately capture weak vibration signals from the gas meter and its surrounding environment (such as illegal prying or disassembly). This ensures the detection of minute vibration changes, exhibits high sensitivity, and can respond promptly to vibration signals. Subsequently, data can be recorded using an ultrasonic smart gas meter controller for subsequent accident investigation and analysis. For example, an audible and visual alarm module can alert users to take appropriate measures, and the data can be transmitted in real-time to the gas company's back-end system. The gas company can then monitor the gas meter's operating status remotely through a platform, promptly detect and handle abnormalities, and provide users with more convenient and efficient services.

[0018] 2. The circuit structure is simple, reliable, and has a long lifespan, enabling it to work stably for extended periods in harsh environments, such as those with smoke, oil, or water vapor. The sensor has no mechanical contacts and operates based on the principle of electromagnetic induction, avoiding the lifespan issues caused by mechanical wear in traditional sensors. The electromagnetic induction principle design makes it unaffected by environmental media, and the overall structure is robust and durable, meeting the long-term outdoor deployment requirements of gas meters.

[0019] 3. The ultrasonic smart gas meter, through the vibration detection circuit of this utility model, can monitor vibration in real time. When abnormal vibration is detected, the metering parameters can be adjusted or metering can be paused in time, and metering can resume after normal operation is restored, thereby effectively avoiding inaccurate metering caused by vibration. The vibration detection circuit can detect vibration in real time. When the ultrasonic smart gas meter detects abnormal vibration, the gas company can take timely measures to deal with it, such as adjusting the installation position and reinforcing the pipeline, thereby reducing the damage of vibration to the equipment and extending the service life of the gas meter. Attached Figure Description

[0020] Figure 1 Block diagram of the vibration detection circuit module for an ultrasonic smart gas meter;

[0021] Figure 2 For the vibration detection circuit of ultrasonic smart gas meter;

[0022] Figure 3 This is the output signal control circuit. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] The purpose of this application is to provide a vibration detection circuit for an ultrasonic smart gas meter. To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general description, nor is it intended to identify key / important components or to describe the scope of protection of these embodiments. Its sole purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0025] This invention includes a vibration detection circuit, an operational amplifier processing circuit, an output signal control circuit, and an output signal determination circuit. External vibrations generate current through the vibration detection circuit. The current passes through the operational amplifier processing circuit to generate an amplified electrical signal, which then flows to the output signal determination circuit. The output signal determination circuit can output high and low levels. The high and low level signals received by the ultrasonic gas meter controller are used to determine whether the meter has vibrated. The output signal control circuit raises the bias voltage of the inverting operational amplifier to the turn-on voltage point of the transistor to avoid the problem of signal loss due to insufficient signal from vibration to turn on the transistor.

[0026] Vibration detection circuit: It adopts an electromagnetic induction omnidirectional vibration sensor to convert the vibration amplitude into an electrical signal;

[0027] Operational amplifier processing circuit: including filter circuit, decoupling circuit and operational amplifier, used to amplify and filter the weak signal output by the omnidirectional vibration sensor;

[0028] Output signal control circuit: The bias voltage of the operational amplifier is raised by resistor voltage division to ensure that weak signals can turn on the transistor of the output signal determination circuit;

[0029] Output signal determination circuit: Converts analog signals into digital level signals using the switching characteristics of transistors to determine whether vibration has occurred.

[0030] like Figure 2 The vibration detection circuit of the ultrasonic smart gas meter is shown below: In this solution, the vibration detection stage preferentially uses an electromagnetic induction omnidirectional vibration sensor as the core detection component. In a specific implementation, such as the BL-8001 omnidirectional vibration sensor L1, the BL-8001 employs non-contact electromagnetic induction technology. Utilizing Faraday's law of electromagnetic induction, the vibration amplitude is directly converted into an electrical signal, eliminating the need for mechanical contacts and avoiding wear.

[0031] The weak current generated by the omnidirectional vibration sensor L1 after being vibrated is filtered by capacitor C2 and decoupled by C4, and then input to the operational amplifier U1A through resistor R3. The filtering by capacitor C2 can filter out high-frequency noise, and the decoupling by capacitor C4 helps to eliminate self-excited oscillation and reduce coupling interference between components.

[0032] U1A is an inverting operational amplifier. The input signal is applied to the inverting input terminal VIN- of the operational amplifier through resistor R3; the voltage VIN+ at the non-inverting input terminal of the inverting operational amplifier is grounded (here, ground is the 0.5V bias point of the operational amplifier, which is obtained by the subsequent output signal control circuit to ensure that the output signal determination circuit can accurately output a high level).

[0033] The input signal path is determined by resistor R3 and feedback resistor R1. The input current flows through R3 to the inverting input terminal VIN- of operational amplifier U1A, and then through feedback resistor R1 to the output terminal of operational amplifier U1A. The closed-loop gain of operational amplifier U1A is directly determined by the ratio of the resistance values ​​of resistors R1 and R3. Meanwhile, resistor R1 and capacitor C1 are connected in parallel to form part of the feedback network. This design is not only used to set the gain, but also to achieve frequency response control through RC combinations. The function of capacitor C1 is to form a low-pass filter, which can effectively suppress high-frequency noise such as electromagnetic interference.

[0034] The output signal of operational amplifier U1A passes through a first-order RC low-pass filter formed by resistor R4 and capacitor C5, ensuring that the base of transistor Q1 receives a stable, low-noise drive signal. This design not only improves the circuit's anti-interference capability but also achieves this through proper setting of the bias point and frequency response.

[0035] The collector of transistor Q1 is connected to the power supply VDD, the emitter is grounded, and the base is connected to one end of resistor R4 and capacitor C5. When no valid vibration is detected, the voltage at the output of operational amplifier U1A is lower than the reference voltage of transistor Q1, insufficient to turn on Q1, so Q1 is in the off state, and a high impedance exists between the collector and emitter of Q1. The output signal volt_CHECK is connected to the power supply VDD through pull-up resistor R2, thus remaining at a high level (close to VDD). When vibration occurs, after amplification and filtering, the output voltage of operational amplifier U1A is higher than the reference voltage of transistor Q1, causing Q1 to turn on. Transistor Q1 is saturated and turned on, presenting a low impedance between the collector and emitter. The output signal volt_CHECK is pulled down to ground (GND) through the turned-on transistor Q1, thus becoming a low level. When no vibration is detected, transistor Q1 is cut off and outputs a high level; when vibration is detected, transistor Q1 is turned on and outputs a low level.

[0036] like Figure 3The output signal control circuit is shown below: Because the conduction of transistor Q1 requires a voltage drop, in order to avoid the problem of signal loss caused by insufficient weak signal generated by vibration to conduct transistor Q1, this solution raises the bias voltage of the inverting operational amplifier to the conduction voltage point of transistor Q1, that is, by using the voltage division method of resistors R5 and R6 to raise the bias voltage, i.e., 0.5V ground.

[0037] In the circuit, resistors R5 and R6 perform their key function through a simple voltage divider principle. These two resistors are connected in series between the power supply VDD and ground (GND), forming a voltage divider network. In the specific design, the voltage divider network formed by resistors R5 and R6 extracts a specific proportion of the voltage from the power supply voltage and directly applies it to the inverting input of the operational amplifier.

[0038] Based on the above description, this invention can determine whether the circuit is vibrating by checking whether transistor Q1 is at a low level. Through the switching characteristics of transistor Q1, the circuit converts the analog vibration signal into a digital level signal (volt_CHECK), thereby detecting the presence or absence of vibration. Its core advantages lie in its simple structure, low cost, and fast response, making it suitable for scenarios requiring real-time vibration monitoring. A well-designed filter network can significantly improve the circuit's reliability and anti-interference capabilities.

[0039] The specific circuit connection relationship of this utility model is as follows:

[0040] One end of the omnidirectional vibration sensor L1 is connected to 0.5V ground. The other end of L1 is connected to one end of capacitor C2 and one end of capacitor C4. The other end of capacitor C4 is connected to 0.5V ground. The other end of capacitor C2 is connected to one end of resistor R3. The other end of resistor R3 is connected to pin 4 (inverting input VIN-) of operational amplifier U1A. One end of resistor R1 and one end of capacitor C1 are connected to pin 1 (output VOUT) of operational amplifier U1A. Pin 3 (non-inverting input VI) of operational amplifier U1A is connected to the other end of the sensor. The N+ pin of operational amplifier U1A is connected to pin 2 (V-) and ground at 0.5V. The V+ pin of operational amplifier U1A is connected to power supply VDD and one end of capacitor C3. The other end of capacitor C3 is connected to ground at 0.5V. The output VOUT pin of operational amplifier U1A is connected to one end of capacitor C5 and the base of transistor Q1 through resistor R4. The other end of capacitor C5 is connected to ground through the emitter of transistor Q1. The collector of transistor Q1 is connected to power supply VDD through resistor R2. The collector of transistor Q1 is the output signal volt_CHECK of this circuit.

[0041] The power supply VDD is grounded through resistors R5 and R6. The voltage at the connection point of resistors R5 and R6 is 0.5V ground. The two resistors are connected in series between the power supply VDD and ground (GND) to form a voltage divider network.

[0042] The circuit of this invention can be used to detect vibrations in the gas meter and its surrounding environment in real time, and to trigger the gas meter to perform safety protection actions. In the event of earthquakes or strong vibrations, the ultrasonic smart gas meter controller, by acquiring the level signal output by this invention, controls the gas meter to automatically close the gas valve, preventing gas leaks and reducing the risk of gas accidents. It can also simultaneously trigger an audible and visual alarm to warn the user. Furthermore, the ultrasonic smart gas meter can record the time and related parameters of vibration occurrence, and store the vibration time, frequency, and intensity parameters in non-volatile memory to provide data support for accident tracing.

[0043] This invention significantly improves the active safety protection performance of gas circuits by optimizing electromagnetic sensing and multi-level circuits in a coordinated manner, taking into account detection reliability, omnidirectional response capability and intrinsic safety characteristics.

Claims

1. An ultrasonic intelligent gas meter vibration detection circuit, characterized in that include: Vibration detection circuit: It adopts an electromagnetic induction omnidirectional vibration sensor to convert the vibration amplitude into an electrical signal; Operational amplifier processing circuit: including filter circuit, decoupling circuit and operational amplifier, used to amplify and filter the weak signal output by the omnidirectional vibration sensor; Output signal control circuit: The bias voltage of the operational amplifier is raised by resistor voltage division to ensure that weak signals can turn on the transistor of the output signal determination circuit; Output signal determination circuit: Converts analog signals into digital level signals using the switching characteristics of transistors to determine whether vibration has occurred.

2. The ultrasonic intelligent gas meter vibration detection circuit according to claim 1, characterized in that The vibration detection circuit uses an omnidirectional vibration sensor L1. The output signal of the omnidirectional vibration sensor L1 is filtered by capacitor C2 and decoupled by capacitor C4, and then input to the inverting input terminal of operational amplifier U1A through resistor R3.

3. The ultrasonic intelligent gas meter vibration detection circuit according to claim 1, characterized in that The operational amplifier processing circuit: the inverting input terminal of operational amplifier U1A receives the signal through resistor R3, and the feedback resistor R1 and capacitor C1 are connected in parallel to form a low-pass filter network to suppress high-frequency noise; the output signal is further filtered by the RC low-pass filter composed of resistor R4 and capacitor C5 and then input to the base of transistor Q1.

4. The ultrasonic intelligent gas meter vibration detection circuit according to claim 1, characterized in that The output signal control circuit uses resistors R5 and R6 to divide the voltage, raising the bias voltage of operational amplifier U1A to the transistor's on-state voltage to prevent the loss of weak signals.

5. The ultrasonic intelligent gas meter vibration detection circuit according to claim 1, characterized in that The output signal determination circuit is as follows: the collector of transistor Q1 is connected to the power supply VDD, and the emitter of transistor Q1 is grounded; when no vibration is detected, transistor Q1 is cut off and outputs a high level; when vibration is detected, transistor Q1 is turned on and outputs a low level.

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