Vibration detection circuit
By combining a vibration switch, pulse width shaping circuit, clock generation circuit, counting circuit, and timing circuit into a vibration detection circuit for gas filling equipment, the problems of false triggering and sensitivity adjustment are solved, achieving reliable multi-directional vibration detection and improving equipment safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU HUAQI HOUPU ELECTRONICS TECH
- Filing Date
- 2025-07-31
- Publication Date
- 2026-05-19
AI Technical Summary
The vibration detection circuit of existing gas refueling equipment is prone to false triggering, has limited sensitivity adjustment, and its parameters are easily changed in outdoor environments, making it difficult to reliably detect and cut off the gas supply under multi-directional vibration.
The detection circuit, consisting of a vibration switch, pulse width shaping circuit, clock generation circuit, counting circuit, timing circuit, and synchronization circuit, confirms vibration events through pulse sequence signals and clock signals. Combined with a delay circuit, it avoids false triggering and issues an alarm signal after multiple confirmations.
It improves the reliability and flexibility of vibration detection for gas refueling equipment, reduces false triggering, adapts to multi-directional vibration, and maintains stable detection in outdoor environments, ensuring equipment safety.
Smart Images
Figure CN224262629U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of vibration detection technology for gas refueling equipment, and more specifically, to a vibration detection circuit. Background Technology
[0002] Vibration detection is crucial for the safety of gas refueling equipment such as CNG dispensers and LNG dispensers. During operation, these equipment may be subjected to external impacts, vehicle collisions, or other unexpected shocks, causing them to tilt or collapse, potentially leading to gas leaks or even fires and explosions. Therefore, having a reliable vibration detection device that can quickly trigger a shut-off mechanism to cut off the gas supply when abnormal vibrations occur is key to improving the safety of gas refueling equipment.
[0003] Currently, vibration detection is typically achieved using sensing components such as accelerometers, piezoelectric sensors, MEMS sensors, and mechanical vibration switches. These technologies each have their own advantages and disadvantages in different application scenarios; therefore, vibration detection in such devices usually does not employ a single detection method, but rather uses multiple methods simultaneously for comprehensive judgment.
[0004] Mechanical vibration switches, due to their simple structure and sensitivity to multi-directional vibrations, are suitable for detecting strong vibration events (such as impacts and drops), and have certain advantages in the safety monitoring of gas refueling equipment. In practical applications, the output signal of a mechanical vibration switch is usually a switching signal (on or off), but to integrate it into an automatic shut-off system, it still requires appropriate processing circuitry to improve reliability and stability. Its processing circuitry often faces the following problems:
[0005] Mechanical vibration switches may falsely trigger the processing circuit, especially during occasional vibrations that occur during normal equipment operation, which could lead to false alarms. For example, a vibration detection circuit disclosed in Chinese invention patent application number 201010570753.8 uses an MCU for identification, requiring software development for judgment. When the program malfunctions, the detection risks failure. This patent only uses an RC circuit + buffer for debouncing to prevent rapid oscillations when the input signal crosses a threshold; however, if the output signal of the preceding RC circuit falls within the hysteresis window of the buffer, it may not completely suppress all bouncing. Repeated and dense signal bouncing may constitute interference in the judgment process, making it difficult to determine the judgment criteria.
[0006] In addition, the sensitivity adjustment of the relevant detection circuit is limited, and the relevant detection circuit is usually installed outdoors and exposed to temperature changes for a long time. The internal parameters may change, and flexible adjustments or corrections are required according to the actual situation. Utility Model Content
[0007] The present invention aims to solve at least one of the aforementioned technical problems existing in the prior art.
[0008] Therefore, this utility model provides a vibration detection circuit.
[0009] The vibration detection circuit proposed in this utility model includes:
[0010] A vibration switch is installed at a vibration detection point on a gas refueling device to monitor the vibration of the device and generate a vibration detection signal.
[0011] A pulse width shaping circuit, connected to a vibration switch to receive a vibration detection signal, is used to convert the vibration detection signal into a pulse sequence signal.
[0012] The clock generation circuit, connected to the pulse width shaping circuit, receives pulse sequence signals and converts the pulse sequence signals into clock signals containing vibration information.
[0013] A counting circuit, connected to a clock generating circuit to receive a clock signal, is used to count the effective edges of the clock signal and generate a count valid signal when the count reaches a predetermined number.
[0014] A timing circuit, connected to a counting circuit, is used to receive a valid counting signal. If the timing circuit does not receive a valid counting signal within a given time, it outputs a result signal indicating that a valid vibration event has occurred.
[0015] The vibration detection circuit according to the above-described technical solution of this utility model may also have the following additional technical features:
[0016] In the above technical solution, the vibration switch has a first end and a second end. The first end of the vibration switch is connected to the power supply, and the second end of the vibration switch is coupled to ground through an RC circuit.
[0017] Alternatively, the vibration switch has a first end and a second end, the first end of the vibration switch being coupled to a power supply via an RC circuit, and the second end of the vibration switch being coupled to ground.
[0018] In the above technical solution, the pulse width shaping circuit includes:
[0019] An RC circuit has a first terminal and a second terminal, wherein the first terminal of the RC circuit is coupled to the second terminal of a vibration switch, and the second terminal of the RC circuit is coupled to ground.
[0020] The first buffer has an input terminal and an output terminal, and the input terminal of the first buffer is coupled to the first terminal of the RC circuit.
[0021] A monostable circuit has an input terminal and an output terminal. The input terminal of the monostable circuit is connected to the output terminal of a first buffer. It is used to output a single pulse with a fixed pulse width time when the effective edge of the signal output by the first buffer is detected, so as to output a pulse sequence signal at its output terminal.
[0022] In the above technical solution, the clock generating circuit includes:
[0023] The third resistor has a first terminal and a second terminal, with the first terminal of the third resistor connected to the power supply.
[0024] The fourth resistor has a first terminal and a second terminal, and the first terminal of the fourth resistor is connected to the second terminal of the third resistor.
[0025] The fourth capacitor has a first terminal and a second terminal. The first terminal of the fourth capacitor is connected to the second terminal of the fourth resistor, and the second terminal of the fourth capacitor is connected to ground.
[0026] A transistor has an emitter, a collector, and a base. The base of the transistor receives the pulse sequence signal. The emitter of the transistor is connected to the first terminal of a fourth capacitor. The collector of the transistor is connected to ground.
[0027] The first multivibrator has a discharge terminal, a trigger terminal, a threshold terminal, and an output terminal. The discharge terminal of the first multivibrator is connected to the second terminal of the third resistor, the trigger terminal of the first multivibrator is connected to the first terminal of the fourth capacitor, the threshold terminal of the first multivibrator is connected to the first terminal of the fourth capacitor, and the output terminal of the first multivibrator generates a clock signal containing vibration information.
[0028] When no vibration occurs, the clock signal generated by the clock generating circuit is a continuous square wave with a fixed frequency; when vibration occurs, the monostable circuit generates continuous or intermittent trigger pulses, causing part of the square wave of the clock signal generated by the clock generating circuit to be lost.
[0029] In the above technical solution, the counting circuit includes:
[0030] A counter has an input terminal and an output terminal. The input terminal of the counter receives a clock signal, the counter counts the effective edges of the clock signal, and when the count reaches a predetermined number, its output terminal reverses to generate a count valid signal.
[0031] In the above technical solution, the timing circuit includes:
[0032] A timer has a manual reset terminal and an output terminal. The manual reset terminal of the timer receives a valid count signal. If the manual reset terminal receives a valid count signal within the set time of the timer, the timer outputs a result signal indicating that no vibration event has occurred. If the manual reset terminal does not receive a valid count signal within the set time of the timer, the timer outputs a result signal indicating that a valid vibration event has occurred.
[0033] The above technical solution also includes:
[0034] The synchronization circuit is connected to the clock generation circuit, the counting circuit, and the timing circuit respectively, and is used to periodically reset and synchronize the clock generation circuit, the counting circuit, and the timing circuit.
[0035] In the above technical solution, the synchronization circuit generates a synchronization signal;
[0036] The synchronization signal is input to the reset terminal of the first multivibrator through the second buffer;
[0037] The synchronization signal is input to the reset terminal of the counter;
[0038] The synchronization signal and the valid count signal are passed through an OR gate and then input to the manual reset terminal of the timer.
[0039] The above technical solution also includes:
[0040] The delay circuit, connected to the output of the timer, is used to ensure that the output of the vibration detection circuit remains in standby mode for a set time, avoiding false triggering or erroneous output caused by transient interference or instability of the circuit.
[0041] In the above technical solution, the delay circuit includes:
[0042] The voltage monitoring circuit is connected to the system power supply and is used to generate a delayed signal at its output when the system is powered on.
[0043] An AND gate has a first terminal, a second terminal, and an output terminal. The first terminal of the AND gate is connected to the output terminal of a timer, the second terminal of the AND gate is connected to the output terminal of a voltage monitoring circuit, and the output terminal of the AND gate generates the final detection signal.
[0044] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of this utility model are:
[0045] The vibration detection circuit provided by this utility model performs multiple confirmations on the vibration event after detection. An alarm signal is only issued when the vibration event reaches a predetermined trigger condition (the frequency or duration of vibration events within a preset detection period accumulates to a certain range), without the need for software intervention. Based on the circuit structure of this application, the circuit can also adjust the trigger condition according to application requirements, exhibiting strong flexibility.
[0046] Additional aspects and advantages of this invention will become apparent in the description that follows, or may be learned by practice of this invention. Attached Figure Description
[0047] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0048] Figure 1 This is a system block diagram of a vibration detection circuit according to an embodiment of the present invention;
[0049] Figure 2 This is a circuit diagram of a vibration detection circuit according to an embodiment of the present invention.
[0050] in, Figures 1 to 2 The correspondence between the reference numerals and component names in the attached drawings is as follows:
[0051] 1. Vibration switch; 2. Pulse width shaping circuit; 3. Clock generation circuit; 4. Counting circuit; 5. Timing circuit; 6. Synchronization circuit; 7. Delay circuit. Detailed Implementation
[0052] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.
[0053] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.
[0054] The following reference Figures 1 to 2 This describes a vibration detection circuit provided according to some embodiments of the present invention.
[0055] Some embodiments of this application provide a vibration detection circuit.
[0056] like Figure 1As shown, the first embodiment of this utility model proposes a vibration detection circuit, including: a vibration switch 1, a pulse width shaping circuit 2, a clock generating circuit 3, a counting circuit 4, a timing circuit 5, a synchronization circuit 6, and a delay circuit 7. It is understood that the delay circuit 7 and the synchronization circuit 6 are not essential components.
[0057] Vibration switch 1 is installed at the vibration detection point on the gas refueling equipment to monitor the vibration of the equipment and generate a vibration detection signal. It can be understood that vibration switch 1 is usually in the form of a sensor. When it is subjected to vibration or tilting, the circuit is closed (conducted); when the vibration stops, the circuit is opened.
[0058] The pulse width shaping circuit 2 is connected to the vibration switch 1 to receive the vibration detection signal. The pulse width shaping circuit 2 is used to convert the vibration detection signal into a pulse sequence signal. The pulse width of the pulse sequence signal can be fixed or not fixed.
[0059] The clock generation circuit 3 is connected to the pulse width shaping circuit 2 to receive pulse sequence signals and convert the pulse sequence signals into clock signals containing vibration information.
[0060] The counting circuit 4 is connected to the clock generating circuit 3 to receive the clock signal, and is used to count the effective edges of the clock signal, and generate a count valid signal when the count reaches a predetermined number.
[0061] The timing circuit 5 is connected to the counting circuit 4 and is used to receive the valid counting signal. When the timing circuit 5 does not receive the valid counting signal within a given time, the timing circuit 5 outputs a result signal indicating that a valid vibration event has occurred.
[0062] Synchronization circuit 6 is connected to clock generation circuit 3, counting circuit 4 and timing circuit 5 respectively, and is used to periodically reset and synchronize clock generation circuit 3, counting circuit 4 and timing circuit 5.
[0063] The delay circuit 7 is connected to the output of the timer to ensure that the output of the vibration detection circuit remains in standby mode for a set time, thus avoiding false triggering or erroneous output caused by transient interference or instability of the circuit.
[0064] In some embodiments, the vibration switch 1 has a first end and a second end. The first end of the vibration switch 1 is connected to the power supply Vcc1, and the second end of the vibration switch 1 is coupled to ground through an RC circuit.
[0065] In other embodiments, the vibration switch 1 has a first end and a second end. The first end of the vibration switch 1 is coupled to the power supply Vcc1 via an RC circuit, and the second end of the vibration switch 1 is coupled to ground.
[0066] Specifically, in Figure 2In the illustrated embodiment, the connection method of the first vibration switch 1 is taken as an example for explanation. The vibration switch 1 is schematically represented as K1. The vibration switch 1 typically consists of a conductive ball or spring and two electrodes. It can be considered equivalent to a normally open or normally closed switch. When subjected to vibration or tilting, the ball or spring moves due to inertia and contacts the electrodes, closing the circuit (conducting). After the vibration stops, the ball or spring returns to its original position, opening the circuit (closing). Due to inertia, elasticity, and other factors, the contacts of the vibration switch 1 will repeatedly and briefly open and close, exhibiting the characteristic of non-one-time stable contact.
[0067] Furthermore, in this disclosure, all active devices can be powered by power supply Vcc1.
[0068] In some embodiments, the pulse width shaping circuit 2 includes an RC circuit, a first buffer, and a monostable circuit, and the aforementioned RC circuit connected to the vibration switch 1 is part of the pulse width shaping circuit 2.
[0069] The RC circuit has a first terminal and a second terminal. The first terminal of the RC circuit is coupled to the second terminal of the vibration switch 1, and the second terminal of the RC circuit is coupled to ground. Specifically, Figure 2 In the illustrated embodiment, the RC circuit includes a second resistor R2 and a second capacitor C2. One end of the second resistor R2 and the second capacitor C2 are grounded, and the other ends are connected in parallel to the second terminal of the vibration switch 1. It can be understood that the grounded terminal of the second resistor R2 and the second capacitor C2 is the second terminal of the RC circuit, and their common terminal is the first terminal of the RC circuit. The RC circuit is used to filter out narrow pulses generated when the vibration switch 1 makes unstable contact.
[0070] The first buffer U2A has an input terminal and an output terminal. The input terminal of the first buffer U2A is coupled to the first terminal of the RC circuit. Specifically, the first buffer U2A can be a non-inverting or inverting buffer. The first buffer U2A can use its hysteresis characteristic to convert the slow signal output by the RC circuit into a stable digital signal, avoiding oscillation of the input signal near the logic level or edge critical voltage.
[0071] The monostable circuit U1 has an input terminal and an output terminal. The input terminal of the monostable circuit U1 is connected to the output terminal of the first buffer U2A. It outputs a single pulse with a fixed pulse width when a valid edge (either a rising or falling edge) of the signal output by the first buffer U2A is detected, thus outputting a pulse sequence signal at its output terminal. Specifically, when a falling or rising edge of the signal output by the first buffer U2A is detected, the monostable circuit U1 outputs a single pulse with a fixed pulse width. The monostable circuit U1 can be configured in a non-repeatable triggering mode (frequency detection method) to ensure that other edge triggering is blocked during the output transition, allowing subsequent detection only after a fixed delay. The monostable circuit U1 can also be configured in a repeatable triggering mode (duration detection method), where any valid triggering edge occurring within the transient time can extend the output transition time.
[0072] In one specific embodiment, the transient time of the monostable circuit U1 is determined by the first resistor R1 and the first capacitor C1 and can be flexibly adjusted. The trigger source is set to fall-edge triggering, and the output is selected as the inverted output terminal. It is understood that the above example is only illustrative, and the trigger edge is not limited to the fall-edge, but depends on the type of vibration switch 1.
[0073] In some embodiments, the clock generating circuit 3 includes a third resistor R3, a fourth resistor R4, a fourth capacitor C4, a transistor Q1, and a first multivibrator U3.
[0074] The third resistor R3 has a first terminal and a second terminal, and the first terminal of the third resistor R3 is connected to the power supply Vcc1; the fourth resistor R4 has a first terminal and a second terminal, and the first terminal of the fourth resistor R4 is connected to the second terminal of the third resistor R3; the fourth capacitor C4 has a first terminal and a second terminal, and the first terminal of the fourth capacitor C4 is connected to the second terminal of the fourth resistor R4, and the second terminal of the fourth capacitor C4 is connected to ground; the transistor Q1 has an emitter, a collector, and a base, the base of the transistor Q1 receives the pulse sequence signal, the emitter of the transistor Q1 is connected to the first terminal of the fourth capacitor C4, and the collector of the transistor Q1 is connected to ground.
[0075] The first multivibrator U3 has a discharge terminal DISCH, a trigger terminal TRIG, a threshold terminal THRES, and an output terminal OUT. The discharge terminal DISCH of the first multivibrator U3 is connected to the second terminal of the third resistor R3. The trigger terminal TRIG of the first multivibrator U3 is connected to the first terminal of the fourth capacitor C4. The threshold terminal THRES of the first multivibrator U3 is connected to the first terminal of the fourth capacitor C4. The output terminal OUT of the first multivibrator U3 generates a clock signal containing vibration information.
[0076] When no vibration occurs, the clock signal generated by the clock generating circuit 3 is a continuous square wave with a fixed frequency; when vibration occurs, the monostable circuit generates continuous or intermittent trigger pulses, causing part of the square wave of the clock signal generated by the clock generating circuit 3 to be lost.
[0077] In some embodiments, the counting circuit 4 includes a counter U4.
[0078] Counter U4 has input and output terminals. The input terminal receives a clock signal, counts the effective edges of the clock signal, and inverts its output to generate a count valid signal when the count reaches a predetermined value. Figure 2 In the illustrated embodiment, when the number of square wave levels or edges received by counter U4 reaches a predetermined number, the output of counting circuit 4 generates a reversal. In this embodiment, counter U4 implements a counting function, and the count reversal value can be adjusted according to the actual situation, that is, the output can be output from different frequency division pins of U4, and is not fixed.
[0079] In some embodiments, the timing circuit 5 includes a timer U6.
[0080] Timer U6 has a manual reset terminal M_R and an output terminal OUTPUT. The manual reset terminal of timer U6 receives a valid count signal. If the manual reset terminal M_R of timer U6 receives a valid count signal within the set time of timer U6, timer U6 outputs a result signal indicating that no vibration event has occurred. If the manual reset terminal M_R of timer U6 does not receive a valid count signal within the set time of timer U6, timer U6 outputs a result signal indicating that a valid vibration event has occurred.
[0081] Specifically, if timer U6 does not detect the output of counting circuit 4 within a given time period, meaning no predetermined counting pulses are received within the predetermined time (equivalent to a certain number of counting pulses being lost), then a valid vibration event is confirmed to have occurred. The output of timing circuit 5 immediately flips and remains in the reverse state until the start of the next detection cycle (synchronized by synchronization circuit 6). If a preset number of counting pulses are detected within a given time period, the output of counting circuit 4 flips to reset the timer (the timer is reset before overflow), resulting in no change in the timer output (i.e., no valid vibration event is detected) until the start of the next detection cycle.
[0082] exist Figure 2 In the embodiment shown, the minimum time unit set by the seventh resistor R7, the seventh capacitor C7, and the eighth resistor R8 is determined, and the timing duration can be flexibly adjusted and is not limited to the example shown.
[0083] In some embodiments, the synchronization circuit 6 generates a synchronization signal. Specifically, the synchronization circuit 6 may consist of a multivibrator (such as...) Figure 2 The circuit consists of U5 (shown) or other devices and some logic circuits capable of generating an adjustable duty cycle. The synchronization signal output by the synchronization circuit 6 is coupled to the counting circuit 4, the timing circuit 5, and the clock generation circuit 3 for periodic reset, thus achieving synchronization of the counting circuit 4, the timing circuit 5, and the clock generation circuit 3. The multivibrator U5 periodically resets and synchronizes U3, U4, and U6, achieving periodic cyclic detection. The duty cycle of the synchronization circuit 6 can be adjusted according to actual conditions.
[0084] In one specific implementation, the synchronization signal is input to the reset terminal of the first multivibrator U3 via the second buffer U2B. The synchronization signal is also input to the reset terminal of the counter. The synchronization signal and the count valid signal are ORed by an OR gate U7A and then input to the manual reset terminal of the timer.
[0085] In some embodiments, the delay circuit 7 includes a voltage monitoring circuit U9 and a logic circuit (such as...). Figure 2 The AND gate U8A (shown) has its reset terminal RESET of the voltage monitoring circuit U9 connected to the system power supply Vcc1, used to generate a delayed signal at its output when the system is powered on. AND gate U8A has a first terminal, a second terminal, and an output terminal. The first terminal of the AND gate is connected to the output of the timer, the second terminal is connected to the output of the voltage monitoring circuit, and the output of the AND gate generates the final detection signal. This final detection signal can be further connected to other triggers, latches, or actuators to implement further countermeasures to ensure system safety.
[0086] By setting the delay circuit 7, the output of the detection circuit is ensured to be in a reliable standby state, and the specific delay duration is adjustable.
[0087] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0088] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model shall be included within the protection scope of this utility model.
Claims
1. A vibration detection circuit, characterized in that, include: A vibration switch is installed at a vibration detection point on a gas refueling device to monitor the vibration of the device and generate a vibration detection signal. A pulse width shaping circuit, connected to a vibration switch to receive a vibration detection signal, is used to convert the vibration detection signal into a pulse sequence signal. The clock generation circuit, connected to the pulse width shaping circuit, receives pulse sequence signals and converts the pulse sequence signals into clock signals containing vibration information. A counting circuit, connected to a clock generating circuit to receive a clock signal, is used to count the effective edges of the clock signal and generate a count valid signal when the count reaches a predetermined number. A timing circuit, connected to a counting circuit, is used to receive a valid counting signal. If the timing circuit does not receive a valid counting signal within a given time, it outputs a result signal indicating that a valid vibration event has occurred.
2. The vibration detection circuit according to claim 1, characterized in that, The vibration switch has a first end and a second end. The first end of the vibration switch is connected to a power supply, and the second end of the vibration switch is coupled to ground through an RC circuit. Alternatively, the vibration switch has a first end and a second end, the first end of the vibration switch being coupled to a power supply via an RC circuit, and the second end of the vibration switch being coupled to ground.
3. The vibration detection circuit according to claim 2, characterized in that, The pulse width shaping circuit includes: An RC circuit has a first terminal and a second terminal, wherein the first terminal of the RC circuit is coupled to the second terminal of a vibration switch, and the second terminal of the RC circuit is coupled to ground. The first buffer has an input terminal and an output terminal, and the input terminal of the first buffer is coupled to the first terminal of the RC circuit. A monostable circuit has an input terminal and an output terminal. The input terminal of the monostable circuit is connected to the output terminal of a first buffer. It is used to output a single pulse with a fixed pulse width time when the effective edge of the signal output by the first buffer is detected, so as to output a pulse sequence signal at its output terminal.
4. The vibration detection circuit according to claim 3, characterized in that, The clock generating circuit includes: The third resistor has a first terminal and a second terminal, with the first terminal of the third resistor connected to the power supply. The fourth resistor has a first terminal and a second terminal, and the first terminal of the fourth resistor is connected to the second terminal of the third resistor. The fourth capacitor has a first terminal and a second terminal. The first terminal of the fourth capacitor is connected to the second terminal of the fourth resistor, and the second terminal of the fourth capacitor is connected to ground. A transistor has an emitter, a collector, and a base. The base of the transistor receives the pulse sequence signal. The emitter of the transistor is connected to the first terminal of a fourth capacitor. The collector of the transistor is connected to ground. The first multivibrator has a discharge terminal, a trigger terminal, a threshold terminal, and an output terminal. The discharge terminal of the first multivibrator is connected to the second terminal of the third resistor, the trigger terminal of the first multivibrator is connected to the first terminal of the fourth capacitor, the threshold terminal of the first multivibrator is connected to the first terminal of the fourth capacitor, and the output terminal of the first multivibrator generates a clock signal containing vibration information. When no vibration occurs, the clock signal generated by the clock generating circuit is a continuous square wave with a fixed frequency; when vibration occurs, the monostable circuit generates continuous or intermittent trigger pulses, causing part of the square wave of the clock signal generated by the clock generating circuit to be lost.
5. The vibration detection circuit according to claim 4, characterized in that, The counting circuit includes: A counter has an input terminal and an output terminal. The input terminal of the counter receives a clock signal, the counter counts the effective edges of the clock signal, and when the count reaches a predetermined number, its output terminal reverses to generate a count valid signal.
6. The vibration detection circuit according to claim 5, characterized in that, The timing circuit includes: A timer has a manual reset terminal and an output terminal. The manual reset terminal of the timer receives a valid count signal. If the manual reset terminal receives a valid count signal within the set time of the timer, the timer outputs a result signal indicating that no vibration event has occurred. If the manual reset terminal does not receive a valid count signal within the set time of the timer, the timer outputs a result signal indicating that a valid vibration event has occurred.
7. The vibration detection circuit according to claim 6, characterized in that, Also includes: The synchronization circuit is connected to the clock generation circuit, the counting circuit, and the timing circuit respectively, and is used to periodically reset and synchronize the clock generation circuit, the counting circuit, and the timing circuit.
8. The vibration detection circuit according to claim 7, characterized in that, The synchronization circuit generates a synchronization signal; The synchronization signal is input to the reset terminal of the first multivibrator through the second buffer; The synchronization signal is input to the reset terminal of the counter; The synchronization signal and the valid count signal are passed through an OR gate and then input to the manual reset terminal of the timer.
9. The vibration detection circuit according to claim 8, characterized in that, Also includes: The delay circuit, connected to the output of the timer, is used to ensure that the output of the vibration detection circuit remains in standby mode for a set time, avoiding false triggering or erroneous output caused by transient interference or instability of the circuit.
10. The vibration detection circuit according to claim 9, characterized in that, The delay circuit includes: The voltage monitoring circuit is connected to the system power supply and is used to generate a delayed signal at its output when the system is powered on. An AND gate has a first terminal, a second terminal, and an output terminal. The first terminal of the AND gate is connected to the output terminal of a timer, the second terminal of the AND gate is connected to the output terminal of a voltage monitoring circuit, and the output terminal of the AND gate generates the final detection signal.