Coal mine noise and vibration detector based on alarm sound

Abstract

The present invention discloses a coal mine noise and vibration detector based on alarm sound, which comprises a pickup circuit, a high-pass filter circuit, a linear amplifier circuit, a comparator circuit, a multivibrator circuit, a speaker circuit, a switch circuit, a vibration signal generating circuit, and a ±4.5V power supply generating circuit. The vibration signal is generated by a sensor 801S, and a weak noise signal generated by the speaker circuit and the pickup circuit is amplified by the linear amplifier, enters the comparator circuit through the switch circuit, and is compared with a safety threshold. If the noise or vibration exceeds the safety value, the comparator circuit outputs a signal to trigger the multivibrator circuit, and the generated oscillation signal is amplified and sounded by the speaker circuit, indicating that a safety plan needs to be immediately started to ensure personal safety.

Description

Technical Field

[0001] The present invention relates to a technology of a coal mine noise and vibration detector based on alarm sound. For the detection of vibration or noise, the detection results can generally only be recorded by a computer or indicated by optical technology (such as light emitting diodes, liquid crystal displays, etc.). This technology can realize the detection and warning of abnormal noise and vibration of the mine production environment or mechanical equipment by using alarm sound. Background Art

[0002] The noise or vibration sources of mines and mining shafts are relatively complex, such as the main fan in the mine ventilation room, the main belt head part of the ground production system, crushers, vibrating screens, cutting machines in production workshops, pneumatic rock drills, etc.

[0003] Industrial workers in the above production environment suffer from the adverse effects of production vibration and noise for a long time, and may develop symptoms such as vascular tension disorders such as autonomic nervous system weakness syndrome and autonomic polyneuropathy, as well as audioanalyzer damage.

[0004] In addition, modern mechanical equipment is developing in the direction of large-scale and high efficiency, and the problem of equipment vibration is attracting more and more attention. The vibration monitoring system can be used to timely detect and identify these abnormal vibration phenomena. By observing and analyzing the vibration development trend, controlling or reducing vibration, major accidents can be avoided.

[0005] Therefore, in order to protect the health of industrial workers and to ensure the normal operation of production equipment, it is very necessary to detect and warn of noise and vibration in mines, mechanical processing and other places.

[0006] In a broad sense, vibration sources are also noise sources, so some vibrations that are inaudible to the human ear are also considered noise. For the detection of noise and vibration, the output of the corresponding industrial sensor can be used as the signal source of the control system. For example, the opening of the noise shielding system can be automatically controlled through the results of noise or vibration detection; or it can be used as a detection of electromechanical or mechanical equipment failure or shutdown to ensure the normal operation of the equipment and implement an alarm at the same time; the detection results can also be uploaded to the remote control system for processing by the console or computer.

[0007] For the detection of noise or vibration, generally a computer-controlled noise recorder is used to save data or serve as a warning, or optical technologies such as light-emitting diodes and liquid crystal displays are used directly to indicate the generation of noise.

[0008] It is usually difficult to alert staff in time through recorders or optical indicators. If the "alarm sound" is used as a noise or vibration warning, it is easier to alert people. However, the "alarm sound" also belongs to the category of noise. The "alarm sound" as noise may activate the detection equipment to alert itself.

[0009] Design a noise and vibration detection instrument based on alarm sound. The instrument can detect and alarm only for external noise and vibration, but will not alarm for the alarm sound emitted by the detector itself. The noise or vibration detector can be designed as a portable device for noise or vibration detection and warning in industrial production environments such as machinery and mines. It can also be embedded as a detection module in some control or test systems. For example, a commonly used noise tester can add a sound alarm function by adding this module.

[0010] Once the noise or vibration of the working surface exceeds the safety threshold, or there is abnormal vibration in the operation of electromechanical equipment, an immediate sound alarm will be implemented and the safety plan will be immediately activated to ensure the safety of people and public property. Summary of the invention

[0011] The technical problem to be solved by the present invention is to provide a device which has a simple structure, low cost, reliable use and can implement abnormal noise and abnormal vibration detection by using alarm sound.

[0012] To achieve the above-mentioned purpose, the present invention provides a coal mine noise and vibration detector based on alarm sound, which includes a pickup circuit, a high-pass filter circuit, a linear amplifier circuit, a comparator circuit, a multivibrator circuit, a speaker circuit, a switch circuit, a vibration signal generating circuit, and a ±4.5V power supply generating circuit; the +4.5V power supply passes through the resistor R12, the CE pole of the transistor T1, the speaker speaker, and the working ground in sequence to form the speaker circuit; the speaker speaker itself also constitutes the pickup circuit, and the capacitor C1 is connected to the resistor R1 to form the high-pass The filter circuit, the upper end of the speaker speaker is connected to the right end of the capacitor C1; the operational amplifier A1, resistors R1 and R2 constitute the linear amplifier circuit, the left end of the resistor R1 is connected to the inverting input of the operational amplifier A1, and the resistor R2 is connected between the output and the inverting input of the operational amplifier A1; the operational amplifier A2, resistors R3, R4, R6 and capacitor C3 constitute the comparator circuit, the power supply +4.5V is connected to the working ground through resistors R3 and R4 in sequence, the connection point of resistors R3 and R4 is connected to the in-phase input of the operational amplifier A2, and the inverting input of the operational amplifier A2 is simultaneously connected to the working ground through the parallel resistor R6 and capacitor C3; the field effect transistor T2, resistor R5, capacitors C2, C8, diode D3, and resistor R11 constitute the switching circuit, the output end of the operational amplifier A1 is connected to the drain D of the field effect tube T2 through the diode D1, the source S of T2 is connected to the inverting input end of the operational amplifier A2, the output end of the operational amplifier A2 is connected to the working ground through the resistor R5, capacitors C2, and C8 in sequence, the positive electrode of the capacitor C2 is connected to the gate G of the field effect tube T2 through the reverse diode D3, and the gate G is connected to the working ground through the resistor R11; the operational amplifier A3, potentiometer P1, resistor R7, and capacitor C4 constitute the multivibrator circuit, the output end of the operational amplifier A3 is connected to the working ground through the potentiometer P1 The output of the amplifier A3 is connected to the ground, the sliding end of the potentiometer P1 is connected to the non-inverting input of the amplifier A3, the output of the amplifier A3 is connected to the working ground through the resistor R7 and the capacitor C4, and the connection point of the resistor R7 and the capacitor C4 is connected to the inverting input of the amplifier A3; the output of the amplifier A2 is connected to the inverting input of the amplifier A3 through the forward diode; the output of the amplifier A3 is connected to the base of the transistor T1 through the current limiting resistor R8; the vibration sensor 801S, the resistor R01, the capacitor C01, the resistor R02, the Schmitt trigger A01, the potentiometer P01, the capacitor C02, and the Schmitt trigger A02 constitute the vibration signal generating circuit, and the power supply is +4.5V is connected to the vibration sensor 801S through the pull-up resistor R01, the output end of 801S is connected to the input end of the Schmitt trigger A01 through the differential circuit composed of the capacitor C01 and the resistor R02, the output end of A01 is connected to the input end of the Schmitt trigger A02 through the integration circuit composed of the potentiometer P01 and the capacitor C02, and the output end of A02 is connected to the drain D of the field effect tube T2 of the switch circuit; 9V power supply, operational amplifier A4, resistors R9, R10, Capacitors C5 and C6 constitute the ±4.5V power supply generation circuit, the 9V power supply is connected to the negative electrode of the 9V power supply through resistors R9 and R10 in sequence, the connection point of R9 and R10 is connected to the non-inverting input terminal of the operational amplifier A4, the output terminal of the operational amplifier A4 is connected to the inverting input terminal of A4, the positive electrode of capacitor C5 is connected to the positive electrode of the 9V power supply, the negative electrode of capacitor C5 is connected to the output terminal of the operational amplifier A4, the positive electrode of capacitor C6 is connected to the output terminal of the operational amplifier A4, and the negative electrode of capacitor C6 is connected to the negative electrode of the 9V power supply.

[0013] In the comparator circuit, the positive electrode of the capacitor C3 is connected to the inverting input terminal of the operational amplifier A2, and the negative electrode of the capacitor C3 is connected to the working ground.

[0014] In the switch circuit, the negative electrodes of capacitors C2 and C8 are connected, the positive electrode of C8 is connected to the working ground, and the positive electrode of C2 is connected to the lower end of the resistor R5.

[0015] In the vibration signal generating circuit, pins 1 and 2 of the Schmitt trigger A01 are connected as the input end of A01, and pins 5 and 6 of the Schmitt trigger A02 are connected as the input end of A02.

[0016] In the ±4.5V power supply generating circuit, both ends of the capacitor C5 output a +4.5V power supply, with the upper end being positive and the lower end being negative, and both ends of the capacitor C6 output a -4.5V power supply, with the upper end being positive and the lower end being negative. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 , Attachment Figure 2 , Attachment Figure 3 , Attachment Figure 4 It is used to provide a further understanding of the present invention and constitutes a part of this application. Figure 1 This is the electrical schematic diagram of the noise detector based on the alarm sound. Figure 2 This is the waveform diagram of the multivibrator composed of hysteresis comparator. Figure 3 This is a typical circuit for generating vibration signals based on the vibration sensor 801S. Figure 4 This is the schematic diagram of the ±4.5V symmetrical power supply generation. DETAILED DESCRIPTION

[0018] Principle of noise and vibration detection scheme based on alarm sound

[0019] For common noise detection, such as fan noise, crusher noise, etc., high-sensitivity pickups can be used to obtain noise signals.

[0020] In fact, some vibrations are different from noise, such as vibrations caused by geological disasters and vibrations caused by the operation of the above-mentioned mechanical equipment. The detection of these vibrations must be distinguished from the detection of noise sources.

[0021] For mechanical or geological vibrations, the common vibration sensor 801S can be used to detect the vibration and obtain vibration information.

[0022] Therefore, a noise and vibration detector circuit can be designed from two aspects. No matter whether it detects noise or vibration, this detector can emit a harsh alarm sound, but it only alarms for external noise and vibration detection, and will not alarm for its own alarm sound.

[0023] Electrical principle of noise detector based on alarm sound

[0024] This noise detector consists of six module circuits, including a pickup circuit, a linear amplifier circuit, a comparison circuit, a multivibrator circuit composed of a hysteresis comparator, a speaker circuit, and a switch circuit composed of a field effect tube T2 that can periodically turn on and off the input signal. A high-sensitivity speaker is used to integrate sound pickup and sound generation. The electrical schematic diagram is shown in the figure below. Figure 1 shown.

[0025] The linear amplifier circuit is composed of operational amplifier A1.

[0026] The circuit uses a high-sensitivity speaker with an internal resistance of 8Ω, which is used as a microphone and for picking up sound. The signal picked up from the microphone is very weak, and R1 and C1 form a high-pass filter with a cutoff frequency f T You can ask for this:

[0027]

[0028] where f T The unit is seconds, the unit for resistance is ohms, and the unit for capacitance is volts.

[0029] That is to say, the input signal frequency must be higher than this value f T Therefore, for detection objects with different types of noise, the electrical parameters of the detector can be designed flexibly and specifically to achieve the best circuit effect.

[0030] Operational amplifier A1 (TL084, A2, A3, A4 are the same below) forms a linear inverting proportional operational amplifier with input resistor R1 and feedback resistor R2. Since the signal picked up from the microphone is extremely weak and the load of the operational amplifier only needs a threshold value, the amplification factor of the operational amplifier can be very large. The gain G of the operational amplifier is calculated as follows:

[0031]

[0032] The noise signal is amplified by operational amplifier A1, rectified by diode D1, and filtered by electrolytic capacitor C3. The rectified DC voltage is added to the inverting terminal of comparator A2 and compared with the alarm threshold voltage at the inverting terminal.

[0033] The comparator circuit is composed of op amp A2

[0034] When noise or vibration is detected by the microphone, it is amplified by the operational amplifier A1, unidirectionally rectified by the diode D1, and shaped by the filter capacitor C3 to output a DC voltage, which is added to the inverting input terminal (pin 6) of the operational amplifier A2. The voltage suddenly rises to about 4V, and then slowly drops to 0V. In addition, the front stage of the inverting input terminal of A2 is also connected to a field effect transistor T controlled by the output voltage of A2. 2, After T2 is turned off (the reason for the turn-off is described below), since capacitor C3 discharges through resistor R6, the voltage at the inverting input terminal of A2 drops exponentially from 4V to 0V. The drop time depends on the time constant of the resistor-capacitor network R6 / C3.

[0035] The voltage at the non-inverting input terminal (pin 5) of op amp A2 is divided by the +4.5V power supply through the resistor network R3 and R4 voltage divider to maintain a constant 0.7V. As mentioned above, due to the detection of external noise, the voltage at the inverting input terminal (pin 6) of A2 suddenly rises to 4V, so the voltage at the output terminal (pin 7) of A2 immediately reverses to -4.5V. This -4.5V will cause the switch diode D2 to reverse cutoff, and the multivibrator A3 will immediately self-oscillate and output a square wave oscillation signal; of course, if A2 outputs +4.5V, the diode D2 is forward-conducted, and the capacitor C4 voltage is a stable +4V, A3 will not oscillate.

[0036] The hysteresis comparator circuit and multivibrator circuit are composed of operational amplifier A3.

[0037] The output terminal (pin 8) of operational amplifier A3 is connected to the in-phase input terminal (pin 10) of A3 through potentiometer P1 to introduce a positive feedback network to form a hysteresis comparator. The output voltage U A3-8 ≈±4.5V (where U A3-8 The voltage at the 8th pin of the operational amplifier A3 is U N =U C4 , where UC4 It represents the voltage of capacitor C4, the voltage of the inverting input terminal of hysteresis comparator A3, and the voltage of the non-inverting input terminal of op amp A3.

[0038]

[0039] Where P1" is the upper half of the potentiometer P1, P1' is the lower half of P1, and the resistance unit is ohm.

[0040] Let U N =U P , the obtained U C4 It is the threshold voltage U of the hysteresis comparator. T , so it is concluded that

[0041] Where +U T is the rising edge threshold voltage of the hysteresis comparator, -U T is the falling edge threshold voltage of the hysteresis comparator.

[0042] The negative feedback resistor R7 is led back from the output end of A3 to the inverting input end, and an integration circuit is formed with the oscillation capacitor C4. The integration circuit and the hysteresis comparator A3 form a multi-harmonic self-excited oscillation circuit. The oscillation process is briefly described as follows:

[0043] When the power is turned on, because the initial voltage of capacitor C4 is zero, the hysteresis comparator A3 outputs a high level of +4.5V and starts to charge capacitor C4 through resistor R7. When the capacitor C4 is charged to the input voltage U C4 =+U T , when an infinitesimal amount is added, the output of A3 jumps to a low level of -4.5V, and the capacitor C4 discharges to the output of A3 through the resistor R7.

[0044] When discharged to U C4 =-U T , and then decreases by an infinitesimal amount, the output potential of A3 jumps to a high level +4.5V, and the capacitor C4 starts to charge again. This cycle repeats endlessly, and the circuit oscillates continuously. C4 and U A3-8 The voltage waveform is as follows Figure 2 shown.

[0045] The oscillation period of the square wave output by op amp A3 is related to the time constants of R7 and C4, and also to the ratio of P1” and P1’. The oscillation period can be calculated as follows:

[0046]

[0047] Where P1" is the upper half of the potentiometer P1, P1' is the lower half of P1, the resistance unit is ohm, the capacitance unit is farad, and the period unit is second.

[0048] Therefore, the frequency (i.e., tone) of the oscillator can be preset by the potentiometer P1. The square wave signal output from the 8-pin of the oscillator A3 passes through the resistor R8 to the base of the transistor T1. The resistor R8 is the current-limiting resistor of the base of T1. Since the base-emitter impedance of T1 is low, if the comparator A3 is directly connected to the transistor T1, the large base drive current may damage the comparator A3.

[0049] T1 works as a common collector amplifier circuit (emitter follower), which drives the speaker to produce sound.

[0050] If the external noise or vibration continues, capacitor C3 will continue to charge, and the output end (pin 7) of comparator A2 will maintain a negative output voltage, so that oscillator A3 will continue to work and the alarm will continue.

[0051] Vibration detection solution based on vibration sensor 801S

[0052] The vibrations caused by geological disasters or mechanical vibrations caused by the operation of mechanical equipment mentioned above are actually different from the traditional noise vibrations. If the vibration signals are still obtained by using a pickup, it is impossible to achieve good results. Now we try to use the common vibration sensor 801S to detect the above vibrations. The principle is as follows Figure 3 As shown, A 01 , A 02 All are part of IC2 (CD4093) quad 2-input Schmitt trigger.

[0053] The working principle of the vibration sensor 801S is easy to understand. Simply put, the internal structure of the vibration sensor is equivalent to a metal ball fixed on a special spring as one pole, and the metal ball is surrounded by another pole. When the vibration reaches a certain amplitude, the two poles are connected and a discontinuous pulse signal is output. The function of the subsequent conditioning circuit is nothing more than eliminating interference signals and shaping the output.

[0054] Figure 3 As vibration occurs, the vibration sensor 801S outputs a weak and irregular pulse signal, and the capacitor C 01 , resistor R 02 、Schmitt trigger A 01 It constitutes a differential circuit. The function of the differential circuit is to highlight the sudden change in the signal. The differential circuit can be used to convert the rectangular signal into a sharp pulse signal. The output waveform of the differential circuit only reflects the sudden change part of the input waveform, that is, there is output only when the input rectangular waveform suddenly changes, and there is no output for the constant part.

[0055] Potentiometer P 01 , capacitor C 02 、Schmitt trigger A02 Constitute an integrator circuit, a differential circuit A 01 The irregular rectangular wave output passes through the potentiometer P 01 For capacitor C 02 Charging, based on the characteristic that the voltage at the capacitor terminal cannot change suddenly, 02 The charging and discharging process of the device passes through the Schmitt trigger A 02 The rising edge threshold voltage and falling edge threshold voltage, so A 02 The output of Figure 3 Point A in the middle shows a very regular rectangular wave pulse signal, with a maximum pulse amplitude of 4.5V and a minimum of 0V.

[0056] By adjusting the potentiometer P 01 The capacitance C can be changed 02 The charge and discharge time actually changes A 02 The duty cycle of the output rectangular wave. The larger the duty cycle, the higher the sensitivity of the vibration sensor 801S.

[0057] The principle that the noise and vibration detection circuit will not respond to the alarm sound

[0058] However, the purpose of this circuit is not to make the detector sound all the time, but when the noise source or vibration source is eliminated, a certain link in the circuit must be able to block the signal, otherwise the detector may continue to sound its own "alarm sound". For this reason, a field effect tube T2 is added to the circuit to act as a switch.

[0059] If T2 remains on all the time, through the above analysis, the monitoring system may sound an alarm for its own alarm continuously. If the on and off of the switch tube T2 can be controlled so that it can be turned off immediately when needed, a wonderful phenomenon will occur in the noise or vibration monitoring system: it will not monitor its own alarm sound, and will not sound an alarm for its own alarm sound. The working principle is analyzed as follows.

[0060] When the output of comparator A2 is -4.5V, A3 self-oscillates, and the switching diode D3 is turned on. The gate potential of the switching field effect tube T2 is reversed to a low level, T2 is cut off, and the input signal (including normal noise and its own alarm sound) is blocked. When the charge on the electrolytic capacitor C3 is released to 0.7V and then reduced by an infinitesimal amount, the output of comparator A2 (pin 7) becomes +4.5V, the oscillator A3 stops oscillating, the switching diode D3 is turned off, the gate potential of the switching field effect tube T2 becomes positive, and T2 is turned on.

[0061] The process of "T2 cuts off → A2 output becomes positive → D3 cuts off → T2 turns on" cannot be carried out too quickly, otherwise it is easy to mistake its own alarm sound for noise and cause a false alarm. Once this state is entered, the alarm sound will continue (although the real noise source or vibration source may have been eliminated).

[0062] Therefore, the gate (driving input end) of the switching field effect transistor T2 must be connected to the ground line through two capacitors C2 and C8. When T2 is turned off, the +4.5V output of A2 charges the two capacitors forward; when T2 is turned on, the -4.5V output of A2 charges the two capacitors reversely.

[0063] The result of this connection is that the re-conduction of the switching field effect transistor T2 can be delayed to ensure that the detector will not respond within half a second after the speaker stops sounding. This is the innovation of the detector circuit and also the most important part. Improper time design will result in the phenomenon of the alarm sounding but not stopping.

[0064] The capacity of non-polar capacitors is generally small, while the capacity of electrolytic capacitors can be very large. When two electrolytic capacitors of the same capacity are connected in series, the overall performance is double the withstand voltage and half the capacity. Figure 1 It can be seen that C2 is connected to the negative pole of C8. The essence of connecting the negative poles of C2 and C8 is to obtain a larger capacity non-polar capacitor through this connection method. Figure 1 The data can be used to obtain a non-polar capacitor with a capacity of 11uF and a withstand voltage of 32V. This capacitor is sufficient to eliminate the "false alarm" mentioned above.

[0065] At this point, the circuit has this feature: although T2 is in the on state, if the noise source or vibration source has been eliminated at this time, the detector should remain silent; if the noise source still exists, as can be seen from the above, the detector will alarm intermittently, with T2 periodically turning on and off, and the alarm sound will be periodically intermittent, rather than continuously alarming, the purpose of which is to eliminate the interference of its own alarm sound on the detector. The alarm cycle is related to the electrolytic capacitors C2 and C8 connected to the two negative poles, and also to the time constant of the charging and discharging circuit of the resistor R6 and the capacitor C3. The charging and discharging time of the capacitor determines the alarm cycle.

[0066] powered by

[0067] For ease of use, this noise or vibration detector can be designed as a portable device or integrated into a control system. If used as a portable device, the circuit can only be powered by a battery, such as Figure 4 , the ground potential (0 point) in the figure is obtained by the voltage divider R9 / R 10 and impedance transformer A4.

[0068] Since the output terminal of op amp A4 is directly connected to the inverting terminal, it forms a signal follower. The output 4.5V level of A4 is used as Figure 1 The detector works at the "0" level, and the "0" point divides the voltage of the 9V stacked battery into a symmetrical power supply of ±4.5V.

[0069] When T1 is turned on, the supply voltage will drop a little, because the internal resistance of the battery power supply is larger than that of the mains power supply. Therefore, an output oscillation signal of A3 will be superimposed on the power supply. In order to prevent unnecessary feedback, decoupling capacitors C5 and C6 need to be connected here.

[0070] In this design, IC1 op amp TL084 is powered by ±4.5V symmetrical power supply, and IC2 Schmitt trigger CD4093 is powered by +4.5V power supply.

[0071] debug

[0072] When actually making and debugging the circuit, if we encounter a fault caused by the capacitor, we can try to increase the values ​​of R2 (using A1 to increase the gain of the weak noise signal picked up by the speaker), C2 and C8 (increasing the delay of the field effect tube T2 turning on again to avoid falling into the state of false alarm). If there is no improvement, the capacity of C5 and C6 should be increased to increase the degree of decoupling.

[0073] For the design of noise monitoring and vibration detection, except for the difference in the sensor circuit part, the post-stage circuit of the detector is basically the same. This article can integrate the noise detection realized by the pickup and the vibration detection realized by the vibration sensor into one circuit, thereby realizing the unified design of noise and vibration detection solutions based on alarm sound.

[0074] This noise and vibration detector uses a switching field effect transistor T2 to block the DC voltage input to the inverting terminal of the comparison circuit A2, and then uses a large-capacity non-polar capacitor to delay the completion time of the process of "T2 cutoff → A2 output becomes positive → D3 cutoff → T2 turn on" as much as possible, cleverly solving the problem that the detector will not sound its own "alarm".

[0075] The detector is used to monitor the production environment in mines or underground. Once the noise or vibration signal of the working surface exceeds the safety threshold, an audible alarm will be immediately implemented and a safety plan will be immediately activated to ensure personal safety.

[0076] The detector may not share a loudspeaker to pick up sound, but may use a special high-sensitivity pickup device to pick up noise signals. The circuit change is not big. This detector can be used for noise and vibration detection alarm in mines and underground, and can also be used as an alarm for some sounds or vibration signals that are inaudible to the human ear. If R3 or R4 is replaced with an adjustable resistor, this detector can change the threshold or sensitivity of the detector, so it can be used as a detection device for a variety of environmental noise or vibrations.

Claims

1. A coal mine noise and vibration detector based on alarm sound, characterized in that: The detector includes a pickup circuit, a high-pass filter circuit, a linear amplifier circuit, a comparator circuit, a multivibrator circuit, a speaker circuit, a switch circuit, a vibration signal generating circuit, and a ±4.5V power supply generating circuit; the +4.5V power supply passes through the resistor R12, the CE pole of the transistor T1, the speaker speaker, and the working ground in sequence to form the speaker circuit; the speaker speaker itself also constitutes the pickup circuit, the capacitor C1 is connected to the resistor R1 to form the high-pass filter circuit, and the upper end of the speaker speaker is connected to the right end of the capacitor C1; the operational amplifier A1, the resistors R1, R2 The linear amplifier circuit is constituted, the left end of the resistor R1 is connected to the inverting input terminal of the operational amplifier A1, and the resistor R2 is connected between the output terminal and the inverting input terminal of the operational amplifier A1; the operational amplifier A2, the resistors R3, R4, R6, and the capacitor C3 constitute the comparator circuit, the positive electrode of the capacitor C3 is connected to the inverting input terminal of the operational amplifier A2, the negative electrode of the capacitor C3 is connected to the working ground, the power supply +4.5V is connected to the working ground through the resistors R3 and R4 in sequence, the connection point of the resistors R3 and R4 is connected to the non-inverting input terminal of the operational amplifier A2, and the inverting input terminal of the operational amplifier A2 is simultaneously connected to the working ground through the parallel resistor R6 and the capacitor C3; the field effect transistor T2, the resistor R5, the capacitors C2, C8, the diode The switch circuit is formed by a tube D3 and a resistor R11, the negative electrodes of capacitors C2 and C8 are connected, the positive electrode of C8 is connected to the working ground, the positive electrode of C2 is connected to the lower end of the resistor R5, the output end of the operational amplifier A1 is connected to the drain D of the field effect tube T2 through a diode D1, the source S of T2 is connected to the inverting input end of the operational amplifier A2, the output end of the operational amplifier A2 is connected to the working ground through resistors R5, capacitors C2 and C8 in sequence, the positive electrode of capacitor C2 is connected to the gate G of the field effect tube T2 through a reverse diode D3, and the gate G is connected to the working ground through resistor R11; the operational amplifier A3, the potentiometer P1, the resistor R7, and the capacitor C4 form the multivibrator circuit, the output end of the operational amplifier A3 is connected to the drain D of the field effect tube T2 through a diode D1, the source S of T2 is connected to the inverting input end of the operational amplifier A2, the output end of the operational amplifier A2 is connected to the working ground through resistors R5, capacitors C2 and C8 in sequence, the positive electrode of the capacitor C2 is connected to the gate G of the field effect tube T2 through a reverse diode D3, and the gate G is connected to the working ground through resistor R11; the multivibrator circuit is formed by the operational amplifier A3, the potentiometer P1, the resistor R7, and the capacitor C4, The potentiometer P1 is connected to the working ground, the sliding end of the potentiometer P1 is connected to the non-inverting input end of the operational amplifier A3, the output end of the operational amplifier A3 is connected to the working ground through the resistor R7 and the capacitor C4 in turn, and the connection point of the resistor R7 and the capacitor C4 is connected to the inverting input end of the operational amplifier A3; the output end of the operational amplifier A2 is connected to the inverting input end of the operational amplifier A3 through a forward diode; the output end of the operational amplifier A3 is connected to the base of the transistor T1 through a current limiting resistor R8; the vibration sensor 801S, the resistor R01, the capacitor C01, the resistor R02, the Schmitt trigger A01, the potentiometer P01, the capacitor C02, and the Schmitt trigger A02 constitute the vibration signal generating circuit, and the power supply is +4.5V is connected to the vibration sensor 801S through the pull-up resistor R01, the output end of 801S is connected to the input end of the Schmitt trigger A01 through the differential circuit composed of the capacitor C01 and the resistor R02, the output end of A01 is connected to the input end of the Schmitt trigger A02 through the integration circuit composed of the potentiometer P01 and the capacitor C02, and the output end of A02 is connected to the drain D of the field effect tube T2 of the switch circuit; 9V power supply, operational amplifier A4, resistors R9, R10, Capacitors C5 and C6 form the ±4.5V power supply generation circuit, the 9V power supply is connected to the negative electrode of the 9V power supply through resistors R9 and R10 in sequence, the connection point of R9 and R10 is connected to the non-inverting input terminal of the operational amplifier A4, the output terminal of the operational amplifier A4 is connected to the inverting input terminal of A4, the positive electrode of capacitor C5 is connected to the positive electrode of the 9V power supply, the negative electrode of capacitor C5 is connected to the output terminal of the operational amplifier A4, the positive electrode of capacitor C6 is connected to the output terminal of the operational amplifier A4, and the negative electrode of capacitor C6 is connected to the negative electrode of the 9V power supply.

2. The coal mine noise and vibration detector based on alarm sound according to claim 1, characterized in that: In the vibration signal generating circuit, pins 1 and 2 of the Schmitt trigger A01 are connected as the input end of A01, and pins 5 and 6 of the Schmitt trigger A02 are connected as the input end of A02.

3. The coal mine noise and vibration detector based on alarm sound according to claim 1, characterized in that: In the ±4.5V power supply generating circuit, both ends of the capacitor C5 output a +4.5V power supply, with the upper end being positive and the lower end being negative, and both ends of the capacitor C6 output a -4.5V power supply, with the upper end being positive and the lower end being negative.

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