阅读说明：本技术 一种电控发声装置 (Electric control sound generating device ) 是由 牟小龙 周安健 邓承浩 喻成 刘卫国 周富明 于 2021-06-29 设计创作，主要内容包括：本发明是一种电控发声装置,可以作为汽车行业的声学激励,开展传递路径分析测试。该电控发声装置中,在滞回电压解锁电路中的解锁开关和触发电路中的触发开关均断开时,若滞回电压解锁电路中的第二运算放大器输出高电平且触发电路中的第一运算放大器输出低电平,促使布置在交流电源和变压器之间的开关电路形成为超级电容充电的通路；在触发电路中的触发开关被闭合且滞回电压解锁电路中的解锁开关保持断开时,若滞回电压解锁电路中的第二运算放大器输出的信号由低电平跳变为高电平且触发电路中的第一运算放大器输出高电平,促使布置在交流电源和变压器之间的开关电路重新形成为超级电容充电的通路；触发开关被闭合时,触发发声头利用超级电容中存储的能量进行发声。(The invention relates to an electric control sound generating device which can be used as acoustic excitation in the automobile industry to carry out analysis and test of a transmission path. In the electric control sound generating device, when an unlocking switch in the hysteresis voltage unlocking circuit and a trigger switch in the trigger circuit are both switched off, if a second operational amplifier in the hysteresis voltage unlocking circuit outputs a high level and a first operational amplifier in the trigger circuit outputs a low level, a switch circuit arranged between an alternating current power supply and a transformer is prompted to form a super capacitor charging passage; when the trigger switch in the trigger circuit is closed and the unlocking switch in the hysteresis voltage unlocking circuit is kept open, if the signal output by the second operational amplifier in the hysteresis voltage unlocking circuit jumps from a low level to a high level and the first operational amplifier in the trigger circuit outputs a high level, the switch circuit arranged between the alternating current power supply and the transformer is caused to be formed into a charging path of the super capacitor again; when the trigger switch is closed, the trigger sounding head utilizes the energy stored in the super capacitor to sound.)

1. An electrically controlled sound generating device, comprising:

the device comprises an alternating current power supply, a transformer (B2), a switch circuit (3), a super capacitor (5), a sounding head (6), a hysteresis voltage unlocking circuit (8) and a trigger circuit (9);

when an unlocking switch (SB 2) in the hysteresis voltage unlocking circuit (8) and a trigger switch (SB 1) in the trigger circuit (9) are both turned off, if a second operational amplifier (IC 4) in the hysteresis voltage unlocking circuit (8) outputs a high level and a first operational amplifier (IC 3) in the trigger circuit (9) outputs a low level, a switch circuit (3) arranged between an AC power supply and the transformer (B2) is caused to form a path for charging the super capacitor (5);

when an unlocking switch (SB 2) in the hysteresis voltage unlocking circuit (8) and a trigger switch (SB 1) in the trigger circuit (9) are both opened, if a signal output by a second operational amplifier (IC 4) in the hysteresis voltage unlocking circuit (8) jumps from a high level to a low level and a first operational amplifier (IC 3) in the trigger circuit (9) outputs a low level, a switch circuit (3) arranged between an alternating current power supply and the transformer (B2) is caused to form an open circuit for stopping charging the super capacitor (5);

when an unlocking switch (SB 2) in the hysteresis voltage unlocking circuit (8) is closed, a trigger switch (SB 1) in the trigger circuit (9) is driven to be opened through a mechanical linkage device, and if a second operational amplifier (IC 4) in the hysteresis voltage unlocking circuit (8) outputs a low level and a signal output by a first operational amplifier (IC 3) in the trigger circuit (9) jumps from the low level to the high level, a switch circuit (3) arranged between an alternating current power supply and the transformer (B2) is caused to form an open circuit for stopping charging the super capacitor (5);

when a trigger switch (SB 1) in the trigger circuit (9) is closed and an unlocking switch (SB 2) in the hysteresis voltage unlocking circuit (8) is kept open, if a signal output by a second operational amplifier (IC 4) in the hysteresis voltage unlocking circuit (8) jumps from a low level to a high level and a first operational amplifier (IC 3) in the trigger circuit (9) outputs a high level, a switch circuit (3) arranged between an alternating current power supply and the transformer (B2) is caused to be formed again as a path for charging the super capacitor (5); meanwhile, when the trigger switch (SB 1) is closed, the sound-emitting head (6) is triggered to emit sound by using the energy stored in the super capacitor (5).

2. An electrically controlled sound generating device according to claim 1, further comprising:

an AC-DC chip (B1);

the voltage stabilizing circuit (7) is connected with the AC-DC chip (B1), and the voltage stabilizing circuit (7) is used for converting the voltage of the AC-DC chip (B1) into two paths of low voltages;

one end of the trigger circuit (9) is connected with the AC-DC chip (B1);

one path of low-voltage output of the voltage stabilizing circuit (7) is used as the reference voltage of the trigger circuit (9), and the other path of low-voltage output of the voltage stabilizing circuit (7) is used as the reference voltage of the hysteresis voltage unlocking circuit (8).

3. An electronically controlled sound generating device according to claim 2, further comprising:

a rectifier filter circuit (4) connected between the super capacitor (5) and the transformer (B2);

the sampling circuit (2) is connected between the rectifying and filtering circuit (4) and the super capacitor (5), and the sampling circuit (2) is connected with a sampling end of the hysteresis voltage unlocking circuit (8).

4. An electrically controlled sound emitting device according to claim 3, characterized in that the switching circuit (3) comprises:

the current limiting resistor (R16) and the anti-static resistor (R17) are connected, the current limiting resistor (R16) is connected with the output end of the trigger circuit (9), and the other end of the anti-static resistor (R17) is grounded;

the positive electrode of the unidirectional silicon controlled rectifier (SCR 1) is connected with the output end of the hysteresis voltage unlocking circuit (8), the control electrode of the unidirectional silicon controlled rectifier (SCR 1) is connected between the current limiting resistor (R16) and the anti-static resistor (R17), and the cathode of the unidirectional silicon controlled rectifier (SCR 1) is grounded;

the positive electrode of a light emitting diode in the silicon controlled optocoupler (IC 5) is connected with the output end of the hysteresis voltage unlocking circuit (8), and the negative electrode of the light emitting diode is grounded;

a control electrode of the bidirectional thyristor (SCR 2) is connected with one electrode of a bidirectional trigger diode in the thyristor optocoupler (IC 5); a first electrode of the bidirectional thyristor (SCR 2) is connected with the alternating current power supply, and a second electrode of the bidirectional thyristor (SCR 2) is connected with the transformer (B2);

a fifteenth resistor (R15), the fifteenth resistor (R15) being connected between the second anode of the triac (SCR 2) and the other pole of the diac in the thyristor optocoupler (IC 5).

5. An electrically controlled sound emitting device according to claim 4, characterized in that the hysteresis voltage unlock circuit (8) comprises:

an unlocking switch (SB 2), one end of the unlocking switch (SB 2) is grounded;

a second operational amplifier (IC 4), the sampling end of the second operational amplifier (IC 4) is connected with the sampling circuit (2); the reference end of the second operational amplifier (IC 4) is connected to the other low-voltage output end of the voltage stabilizing circuit (7) through a twelfth resistor (R12); the output end of the second operational amplifier (IC 4) is respectively connected with the light emitting diode in the unidirectional thyristor (SCR 1), the unlocking switch (SB 2) and the thyristor optocoupler (IC 5) through a thirteenth resistor (R13); the output terminal of the second operational amplifier (IC 4) is further connected to the reference terminal of the second operational amplifier (IC 4) through a seventh diode (D7) and an eleventh resistor (R11);

one low-voltage output end of the voltage stabilizing circuit (7) is sequentially connected with a sixth diode (D6), a tenth resistor (R10), a seventh diode (D7) and an eleventh resistor (R11) and then connected to the reference end of the second operational amplifier (IC 4).

6. An electrically controlled sound emitting device according to claim 5, characterized in that the trigger circuit (9) comprises:

a trigger switch (SB 1);

the first operational amplifier (IC 3), one low voltage output end of the voltage stabilizing circuit (7) is connected with the reference end of the first operational amplifier (IC 3) through the trigger switch (SB 1);

a ninth resistor (R9) having one end connected between the reference terminal of the first operational amplifier (IC 3) and the trigger switch (SB 1) and the other end grounded;

a first RC resistor-capacitor (C7) having one end connected between the reference terminal of the first operational amplifier (IC 3) and the trigger switch (SB 1) and the other end connected to ground;

the other low-voltage output end of the voltage stabilizing circuit (7) is connected with the reference end of the first operational amplifier (IC 3), and the other low-voltage output end of the voltage stabilizing circuit (7) is grounded through an eighth capacitor (C8);

the output end of the first operational amplifier (IC 3) is connected to the current limiting resistor (R16) all the way; the other path is connected with the voltage division branch circuit and then is grounded;

a field effect transistor (T1), wherein the grid electrode of the field effect transistor (T1) is connected with the voltage dividing branch; the source electrode of the field effect transistor (T1) is grounded;

an electromagnet (YA) connected between the AC-DC chip (B1) and the drain of the FET (T1);

a fifth diode (D5) arranged in parallel with the electromagnet (YA) and connected between the AC-DC chip and the drain of the FET (T1);

when the trigger switch (SB 1) is closed, the first RC resistor-capacitor (C7) is charged, and the first operational amplifier (IC 3) is triggered to output a high level; when the trigger switch (SB 1) is turned off, the first RC resistance-capacitance (C7) discharges slowly, and the first operational amplifier (IC 3) is triggered to output a low level in a delayed mode; when the trigger switch (SB 1) is closed, the electromagnet (YA) pushes the negative electrode to move towards the positive electrode, and the sound-generating head (6) is triggered to generate sound by utilizing the energy stored in the super capacitor (5);

when the second operational amplifier (IC 4) outputs high level, the unlocking switch (SB 1) is closed and the first operational amplifier (IC 3) outputs high level, the one-way thyristor (SCR 1) is conducted and the thyristor optical coupler (IC 5) is conducted, so as to drive the two-way thyristor (SCR 2) to be conducted, so that an alternating current power supply and a transformer (B2) form a passage therebetween.

7. An electronically controlled sound generating device according to claim 6, further comprising:

a thyristor protection circuit (10) connected between the ac power source and the transformer (B2); the silicon controlled rectifier protection circuit (10) is connected with the switch circuit (3) in parallel to prevent the super capacitor (5) from inducing potential to break down the silicon controlled rectifier optical coupler (IC 5) in the discharging process;

a first detection lamp (H1) connected after the AC power source, the first detection lamp (H1) being connected before the thyristor protection circuit (10) and the switch circuit (3);

a second check lamp (H2) connected before the transformer (B2), and the second check lamp (H2) is connected after the thyristor protection circuit (10) and the switching circuit (3);

a third inspection lamp (H3) connected between the AC-DC chip (B1) and the drain of the field effect transistor (T1), and the third inspection lamp (H3) is connected in parallel with the fifth diode (D5);

a fourth detection lamp (H4) connected between the positive and negative electrodes of the AC-DC chip (B1).

8. An electronically controlled sound generating device according to claim 4, characterised in that the rectifying and filtering circuit (4) comprises:

a full-wave rectifier bridge, a first input end of the full-wave rectifier bridge is connected with a first secondary end of the transformer (B2), and a second input end of the full-wave rectifier bridge is connected with a second secondary end of the transformer (B2);

a bypass capacitor (C3), the bypass capacitor (C3) being connected between the third and fourth inputs of the full wave rectifier bridge;

a first resistor (R1), the first resistor (R1) is connected between the third access terminal of the full-wave rectifying bridge and one end of the super capacitor (5), and the other end of the super capacitor (5) is connected with the fourth access terminal of the full-wave rectifying bridge and grounded;

one end of the sampling circuit (2) is connected between the first resistor (R1) and the super capacitor (5), and the other end is grounded.

9. An electrically controlled sound emitting device according to claim 6,

the sampling circuit (2) comprises: a second resistor (R2) and a third resistor (R3) which are arranged in series, the other end of the third resistor (R3) is grounded, and the sampling end of the second operational amplifier (IC 4) is connected between the second resistor (R2) and the third resistor (R3);

the voltage dividing branch includes: a seventh resistor (R7) and an eighth resistor (R8) which are arranged in series, wherein one end of the eighth resistor (R8) is grounded, one end of the seventh resistor (R7) is connected with the output end of the first operational amplifier (IC 3), and the grid of the field effect transistor (T1) is connected between the seventh resistor (R7) and the eighth resistor (R8).

10. An electrically controlled sound emitting device according to claim 6, wherein the voltage stabilizing circuit (7) comprises:

the input end of the voltage stabilizing chip (IC 1), the input end of the voltage stabilizing chip (IC 1) is connected with the AC-DC chip (B1), and one path of the output end of the voltage stabilizing chip (IC 1) is connected with the trigger switch (SB 1), the positive electrode of the sixth diode (D6) and the power supply positive electrode of the second operational amplifier (IC 4); the other path of the output end of the voltage-stabilizing chip (IC 1) is grounded after being connected with a fifth capacitor (C5), the other path of the output end of the voltage-stabilizing chip (IC 1) is grounded after being connected with a second RC (C6) to absorb ripples, and the other path of the output end of the voltage-stabilizing chip (IC 1) is connected with a twelfth resistor (R12) and the reverse input end of a first operational amplifier (IC 3) after being connected with a fourth resistor (R4); the other way of output of steady voltage chip (IC 1) still connects ground connection through parallelly connected steady voltage integrated circuit (IC 2) behind fourth resistance (R4), the other way of output of steady voltage chip (IC 1) still is connected ground connection through the fifth resistance (R5) and the sixth resistance (R6) of series arrangement behind fourth resistance (R4).

11. The electronic control sound generating device according to claim 7, wherein a copper wire shielding net is wrapped at a joint where the output end of the electromagnet (YA) is connected with the sound generating head (6), and a copper wire shielding net is wrapped at a joint where the sampling end of the hysteresis voltage unlocking circuit (8) is connected with the sampling circuit (2);

the trigger circuit (9), the hysteresis voltage unlocking circuit (8), the voltage stabilizing circuit (7), the switch circuit (3), the one-way silicon controlled rectifier (SCR 1) and the silicon controlled rectifier protection circuit (10) are all arranged in a metal shell.

Technical Field

The invention belongs to the field of automobile vibration noise testing, and particularly relates to an electric control sound production device.

Background

Vibration noise performance is an important performance index of a vehicle. Vibration, noise and harshness (NVH) have become a specialized area of research, with a multidisciplinary background involving multiple physical fields, and are deeply coupled, highly correlated with other vehicle performance. Transmission Path Analysis (TPA) is to identify the energy transmission from the excitation source to the response in the vehicle, and by using the structure optimization design, the impedance matching of the system is perfected, and the transmission rate of the structure noise and the air noise is directly reduced, so that the response in the vehicle is reduced. The transmission path analysis is to carry out excitation detection, system transfer function identification and response prediction analysis work from the perspective of system dynamics, and establish a dynamic relation between input excitation, system transfer function and output response, and in the three quantities, under the basic assumption of linear time-invariant dynamics, a third quantity can be identified by testing two quantities.

The TPA technology can be used for identifying the contribution of a certain path, analyzing and sequencing the structural sound and air sound contribution of each path, and finding the path with the maximum contribution, thereby providing directional guidance for optimization design. Because a large amount of tool designs, manual grinding tool designs and part replacement are reduced, the optimization design workload based on the traditional control variable method is reduced, more than ten paths can be analyzed at one time, and the optimization design working efficiency is improved.

To accomplish TPA, the stimulus composition of the vibration and noise response in the vehicle must be considered. In the fuel vehicle or the pure electric vehicle, excitation can be divided into three main categories, wherein the first category is the internal excitation force of a power assembly, the second category is the road surface, and the third category is flowing air. The operating principle and the structural design of the drive train determine that a dynamic excitation force is present, the flowing air is always present when the vehicle is driven, and the excitation occurs in the form of force or pressure, respectively. Noise sources inside a vehicle are generally classified into two types, one is airborne sound and the other is structural sound. Regardless of the noise form, the current simplified processing mode closer to engineering application is to consider the transfer function of a structural acoustic system, the transfer function is the non-parametric description of the NVH performance of the system and is a very important 'middle link', and the vibration-sound transfer function test is not enough only by a piezoelectric hammer or a high-power vibration exciter, because the normal direction of the surface of the structure usually has no movement space required by the hammer knocking and no space for installing corresponding vibration excitation equipment, even if the space allows the hammer to be used, the transfer function test in two tangential directions of the surface cannot be completed. The method for completing the test through the boss tooling structure has low efficiency, modifies the dynamic characteristics of the structure, and easily causes test errors under the condition of insufficient structural adhesive rigidity. The method for solving the test problem is to jointly use the three-way acceleration sensor and the volume acceleration sound source, under the assumption of the reciprocity principle, the system transfer function test can be completed in the anechoic room environment, and the system pole and the vibration mode can be identified.

The volume sound source is an indispensable hardware device for transmission path analysis in the automobile industry and is divided into a volume velocity sound source and a volume acceleration sound source. As a sound-producing excitation device, a large-range microphone and a loudspeaker are usually built in, and a large frequency response range, large input power and small volume are required for a volume sound source. The volume sound source patent technology disclosed has various forms, one is to adopt a reference sound cavity volume method to calculate the volume velocity; one is based on the volume velocity test, and carries out analog circuit differentiation to obtain the volume acceleration; research has also reported that similar to the P-P sound intensity test technique, a volume acceleration test is indirectly performed by a differential algorithm using two or more microphones. In the existing volume sound source excitation mode, part of the volume sound source excitation mode is based on a function generator to send out signals, and sound is sent out through filtering and power amplification; one part is to send out a frequency sweep signal by controlling the motion of the actuating mechanism. Since the power amplifier has a bandwidth limitation and a power limitation and easily causes signal distortion at a high frequency, the power amplifying device is mainly applied to a low frequency. Based on the pipeline acoustics, the technology for separating incident sound and reflected sound under the one-dimensional assumption is limited by the cut-off frequency of the pipeline size, the high-frequency part cannot be analyzed, and the high-frequency reciprocity result is poor.

Disclosure of Invention

The invention relates to an electric control sound production device which can be used as acoustic excitation in the automobile industry to carry out analysis and test of a transmission path.

The technical scheme of the invention is as follows:

the embodiment of the invention provides an electronic control sound generating device, which comprises:

the device comprises an alternating current power supply, a transformer (B2), a switch circuit (3), a super capacitor (5), a sounding head (6), a hysteresis voltage unlocking circuit (8) and a trigger circuit (9);

when an unlocking switch (SB 2) in the hysteresis voltage unlocking circuit (8) and a trigger switch (SB 1) in the trigger circuit (9) are both turned off, if a second operational amplifier (IC 4) in the hysteresis voltage unlocking circuit (8) outputs a high level and a first operational amplifier (IC 3) in the trigger circuit (9) outputs a low level, a switch circuit (3) arranged between an AC power supply and the transformer (B2) is caused to form a path for charging the super capacitor (5);

when an unlocking switch (SB 2) in the hysteresis voltage unlocking circuit (8) and a trigger switch (SB 1) in the trigger circuit (9) are both opened, if a signal output by a second operational amplifier (IC 4) in the hysteresis voltage unlocking circuit (8) jumps from a high level to a low level and a first operational amplifier (IC 3) in the trigger circuit (9) outputs a low level, a switch circuit (3) arranged between an alternating current power supply and the transformer (B2) is caused to form an open circuit for stopping charging the super capacitor (5);

when an unlocking switch (SB 2) in the hysteresis voltage unlocking circuit (8) is closed, a trigger switch (SB 1) in the trigger circuit (9) is driven to be opened through a mechanical linkage device, and if a second operational amplifier (IC 4) in the hysteresis voltage unlocking circuit (8) outputs a low level and a signal output by a first operational amplifier (IC 3) in the trigger circuit (9) jumps from the low level to the high level, a switch circuit (3) arranged between an alternating current power supply and the transformer (B2) is caused to form an open circuit for stopping charging the super capacitor (5);

when a trigger switch (SB 1) in the trigger circuit (9) is closed and an unlocking switch (SB 2) in the hysteresis voltage unlocking circuit (8) is kept open, if a signal output by a second operational amplifier (IC 4) in the hysteresis voltage unlocking circuit (8) jumps from a low level to a high level and a first operational amplifier (IC 3) in the trigger circuit (9) outputs a high level, a switch circuit (3) arranged between an alternating current power supply and the transformer (B2) is caused to be formed again as a path for charging the super capacitor (5); meanwhile, when the trigger switch (SB 1) is closed, the sound-emitting head (6) is triggered to emit sound by using the energy stored in the super capacitor (5).

Preferably, the electronic control sound generating device further comprises:

an AC-DC chip (B1);

the voltage stabilizing circuit (7) is connected with the AC-DC chip (B1), and the voltage stabilizing circuit (7) is used for converting the voltage of the AC-DC chip (B1) into two paths of low voltages;

one end of the trigger circuit (9) is connected with the AC-DC chip (B1);

one path of low-voltage output of the voltage stabilizing circuit (7) is used as the reference voltage of the trigger circuit (9), and the other path of low-voltage output of the voltage stabilizing circuit (7) is used as the reference voltage of the hysteresis voltage unlocking circuit (8).

Preferably, the apparatus further comprises:

a rectifier filter circuit (4) connected between the super capacitor (5) and the transformer (B2);

and the sampling circuit is connected between the rectifying and filtering circuit (4) and the super capacitor (5), and is connected with the sampling end of the hysteresis voltage unlocking circuit (8).

Preferably, the switching circuit (3) comprises:

the current limiting resistor (R16) and the anti-static resistor (R17) are connected, the current limiting resistor (R16) is connected with the output end of the trigger circuit (9), and the other end of the anti-static resistor (R17) is grounded;

the positive electrode of the unidirectional silicon controlled rectifier (SCR 1) is connected with the output end of the hysteresis voltage unlocking circuit (8), the control electrode of the unidirectional silicon controlled rectifier (SCR 1) is connected between the current limiting resistor (R16) and the anti-static resistor (R17), and the cathode of the unidirectional silicon controlled rectifier (SCR 1) is grounded;

the positive electrode of a light emitting diode in the silicon controlled optocoupler (IC 5) is connected with the output end of the hysteresis voltage unlocking circuit (8), and the negative electrode of the light emitting diode is grounded;

a control electrode of the bidirectional thyristor (SCR 2) is connected with one electrode of a bidirectional trigger diode in the thyristor optocoupler (IC 5); a first electrode of the bidirectional thyristor (SCR 2) is connected with the alternating current power supply, and a second electrode of the bidirectional thyristor (SCR 2) is connected with the transformer (B2);

a fifteenth resistor (R15), the fifteenth resistor (R15) being connected between the second anode of the triac (SCR 2) and the other pole of the diac in the thyristor optocoupler (IC 5).

Preferably, the hysteresis voltage unlocking circuit (8) includes:

an unlocking switch (SB 2), one end of the unlocking switch (SB 2) is grounded;

a second operational amplifier (IC 4), a sampling end of the second operational amplifier (IC 4) is connected with the sampling circuit; the reference end of the second operational amplifier (IC 4) is connected to the other low-voltage output end of the voltage stabilizing circuit (7) through a twelfth resistor (R12); the output end of the second operational amplifier (IC 4) is respectively connected with the light emitting diode in the unidirectional thyristor (SCR 1), the unlocking switch (SB 2) and the thyristor optocoupler (IC 5) through a thirteenth resistor (R13); the output terminal of the second operational amplifier (IC 4) is further connected to the reference terminal of the second operational amplifier (IC 4) through the seventh diode (D7) and an eleventh resistor (R11);

one low-voltage output end of the voltage stabilizing circuit (7) is sequentially connected with a sixth diode (D6), a tenth resistor (R10), a seventh diode (D7) and an eleventh resistor (R11) and then connected to the reference end of the second operational amplifier (IC 4).

Preferably, the trigger circuit (9) comprises:

a trigger switch (SB 1);

the first operational amplifier (IC 3), one low voltage output end of the voltage stabilizing circuit (7) is connected with the reference end of the first operational amplifier (IC 3) through the trigger switch (SB 1);

a ninth resistor (R9) having one end connected between the reference terminal of the first operational amplifier (IC 3) and the trigger switch (SB 1) and the other end grounded;

a first RC resistor-capacitor (C7) having one end connected between the reference terminal of the first operational amplifier (IC 3) and the trigger switch (SB 1) and the other end connected to ground;

the other low-voltage output end of the voltage stabilizing circuit (7) is connected with the reference end of the first operational amplifier (IC 3), and the other low-voltage output end of the voltage stabilizing circuit (7) is grounded through an eighth capacitor (C8);

the output end of the first operational amplifier (IC 3) is connected to the current limiting resistor (R16) all the way; the other path is connected with the voltage division branch circuit and then is grounded;

a field effect transistor (T1), wherein the grid electrode of the field effect transistor (T1) is connected with the voltage dividing branch; the source electrode of the field effect transistor (T1) is grounded;

an electromagnet (YA) connected between the AC-DC chip (B1) and the drain of the FET (T1);

a fifth diode (D5) arranged in parallel with the electromagnet (YA) and connected between the AC-DC chip and the drain of the FET (T1);

when the trigger switch (SB 1) is closed, the first RC resistor-capacitor (C7) is charged, and the first operational amplifier (IC 3) is triggered to output a high level; when the trigger switch (SB 1) is turned off, the first RC resistance-capacitance (R7) discharges slowly, and the first operational amplifier (IC 3) is triggered to output a low level in a delayed mode; when the trigger switch (SB 1) is closed, the electromagnet (YA) pushes the negative electrode to move towards the positive electrode, and the sound-generating head (6) is triggered to generate sound by utilizing the energy stored in the super capacitor (5);

when the second operational amplifier (IC 4) outputs high level, the unlocking switch (SB 1) is closed and the first operational amplifier (IC 3) outputs high level, the one-way thyristor (SCR 1) is conducted and the thyristor optical coupler (IC 5) is conducted, so as to drive the two-way thyristor (SCR 2) to be conducted, so that an alternating current power supply and a transformer (B2) form a passage therebetween.

Preferably, the apparatus further comprises:

a thyristor protection circuit (10) connected between the ac power source and the transformer (B2); the silicon controlled rectifier protection circuit (10) is connected with the switch circuit (3) in parallel to prevent the super capacitor (5) from inducing potential to break down the silicon controlled rectifier optical coupler (IC 5) in the discharging process;

a first detection lamp (H1) connected after the AC power source, the first detection lamp (H1) being connected before the thyristor protection circuit (10) and the switch circuit (3);

a second check lamp (H2) connected before the transformer (B2), and the second check lamp (H2) is connected after the thyristor protection circuit (10) and the switching circuit (3);

a third inspection lamp (H3) connected between the AC-DC chip (B1) and the drain of the field effect transistor (T1), and the third inspection lamp (H3) is connected in parallel with the fifth diode (D5);

a fourth detection lamp (H4) connected between the positive and negative electrodes of the AC-DC chip (B1).

Preferably, the rectifying-filtering circuit (4) comprises:

a full-wave rectifier bridge, a first input end of the full-wave rectifier bridge is connected with a first secondary end of the transformer (B2), and a second input end of the full-wave rectifier bridge is connected with a second secondary end of the transformer (B2);

a bypass capacitor (C3), the bypass capacitor (C3) being connected between the third and fourth inputs of the full wave rectifier bridge;

a first resistor (R1), the first resistor (R1) is connected between the third access terminal of the full-wave rectifying bridge and one end of the super capacitor (5), and the other end of the super capacitor (5) is connected with the fourth access terminal of the full-wave rectifying bridge and grounded;

one end of the sampling circuit is connected between the first resistor (R1) and the super capacitor (5), and the other end of the sampling circuit is grounded.

Preferably, the sampling circuit (2) comprises: a second resistor (R2) and a third resistor (R3) which are arranged in series, the other end of the third resistor (R3) is grounded, and the sampling end of the second operational amplifier (IC 4) is connected between the second resistor (R2) and the third resistor (R3);

the voltage dividing branch includes: a seventh resistor (R7) and an eighth resistor (R8) which are arranged in series, wherein one end of the eighth resistor (R8) is grounded, one end of the seventh resistor (R7) is connected with the output end of the first operational amplifier (IC 3), and the grid of the field effect transistor (T1) is connected between the seventh resistor (R7) and the eighth resistor (R8).

Preferably, the voltage stabilizing circuit (7) comprises:

the input end of the voltage stabilizing chip (IC 1), the input end of the voltage stabilizing chip (IC 1) is connected with the AC-DC chip (B1), and one path of the output end of the voltage stabilizing chip (IC 1) is connected with the trigger switch (SB 1), the positive electrode of the sixth diode (D6) and the power supply positive electrode of the second operational amplifier (IC 4); the other path of the output end of the voltage-stabilizing chip (IC 1) is grounded after being connected with a fifth capacitor (C5), the other path of the output end of the voltage-stabilizing chip (IC 1) is grounded after being connected with a second RC (C6) to absorb ripples, and the other path of the output end of the voltage-stabilizing chip (IC 1) is connected with a twelfth resistor (R12) and the reverse input end of a first operational amplifier (IC 3) after being connected with a fourth resistor (R4); the other way of output of steady voltage chip (IC 1) still connects ground connection through parallelly connected steady voltage integrated circuit (IC 2) behind fourth resistance (R4), the other way of output of steady voltage chip (IC 1) still is connected ground connection through the fifth resistance (R5) and the sixth resistance (R6) of series arrangement behind fourth resistance (R4).

Preferably, a copper wire shielding net wraps a joint of the output end of the electromagnet (YA) and the sounding head (6), and a copper wire shielding net wraps a joint of the sampling end of the hysteresis voltage unlocking circuit (8) and the sampling circuit (2);

the trigger circuit (9), the hysteresis voltage unlocking circuit (8), the voltage stabilizing circuit (7), the switch circuit (3), the one-way silicon controlled rectifier (SCR 1) and the silicon controlled rectifier protection circuit (10) are all arranged in a metal shell.

The invention is different from the existing sounding excitation modes, and does not need to use a power amplifier, thus avoiding the problems of low-pass filtering action and high-frequency distortion of the power amplifier; in addition, the invention is different from the signal type sent out by the prior patent technology, the prior excitation signal type is mainly white noise, step sine, sweep frequency sine, pink noise, burst random noise and the like generated by a function sounder, and the prior excitation signal type is not a pulse noise source, but the invention directly provides and only provides a pulse sound source; the sound production mechanism is different, and the sound is produced not through a loudspeaker but through ionized air, which is the biggest difference between the technical scheme of the invention and the prior art. In order to enable the vibration response signal to meet the signal-to-noise ratio requirement, a higher instantaneous pulse amplitude needs to be obtained, and a higher sound pressure pulse is directly provided through reasonably matching components, which is an important characteristic of the invention.

The device has the advantages that the instantaneous sound pressure of the near field at a distance of 1 meter is about 140dB, the device can meet the test requirement of higher signal-to-noise ratio when being applied to the field of automobiles, and the acceleration signal-to-noise ratio also meets 10dB even under the common indoor environment; the instantaneous sound pressure duration is short, the spike pulse excitation width is very small, the sound pressure duration is about 1 haystack, the frequency response range is wide, and the method is very suitable for the test requirement of the field of pure electric vehicles in the high-frequency range; the test device has the advantages of small volume, light weight, portability and installation, no echo interference in a short time, great significance for reducing the requirements of test environment, reducing the difficulty of test operation and improving the precision of test results, capability of realizing the dynamic characteristic test of the system by further combining a wide-range and wide-frequency-response microphone test technology, and wide application background.

The basic principle of the invention is that a low-voltage power supply is used for charging a discharging device after boosting, and generates larger sound pressure in the discharging process, so that a sharp pulse sound pressure signal is directly radiated to an open space. In order to store sufficient power, a high voltage resistant super capacitor is used. The basic components of the circuit comprise a boosting charging circuit, a rectifying circuit, a sounding head, an unlocking switch, a trigger switch, a self-locking circuit, a hysteresis voltage unlocking loop and a radiator, and other accessories comprise an electric quantity indicator lamp consisting of voltage feedback, an electromagnetic shielding net, a high-voltage shielding cable and the like.

The invention is mainly characterized in that the instantaneous sound pressure sounding device is used, so that the test precision in a high-frequency range can be improved; meanwhile, the device can be used in a common indoor environment, still can ensure a higher signal-to-noise ratio, and reduces the requirement on the environment of a anechoic room; the sound generating device is small in size, the size of the sound generating head is about 200mm multiplied by 60mm, and the sound generating head can be placed in narrow spaces such as a vehicle.

Drawings

FIG. 1 is a schematic diagram of the structural components of an apparatus in an embodiment of the present invention;

FIG. 2 is a schematic diagram of the main detailed circuit design of the apparatus in an embodiment of the present invention;

fig. 3 is a graph of the sound pressure test results generated by the device of the present invention.

Detailed Description

Referring to fig. 1 and 2, an embodiment of the present invention provides an electronic control sound generating device, including:

the device comprises an alternating current power supply, a transformer B2, a switch circuit 3, a super capacitor 5, a sounding head 6, a hysteresis voltage unlocking circuit 8 and a trigger circuit 9;

when the unlocking switch SB2 in the hysteresis voltage unlocking circuit 8 and the trigger switch SB1 in the trigger circuit 9 are both turned off, if the second operational amplifier IC4 in the hysteresis voltage unlocking circuit 8 outputs a high level and the first operational amplifier IC3 in the trigger circuit 9 outputs a low level, the switch circuit 3 disposed between the alternating current power supply and the transformer B2 is caused to form a path for charging the super capacitor 5;

when the unlocking switch SB2 in the hysteresis voltage unlocking circuit 8 and the trigger switch SB1 in the trigger circuit 9 are both turned off, if the signal output from the second operational amplifier IC4 in the hysteresis voltage unlocking circuit 8 jumps from high level to low level and the first operational amplifier IC3 in the trigger circuit 9 outputs low level, the switch circuit 3 arranged between the AC power supply and the transformer B2 is caused to form an open circuit which stops charging the super capacitor 5;

when the unlocking switch SB2 in the hysteresis voltage unlocking circuit 8 is closed, the trigger switch SB1 in the trigger circuit 9 is driven to be opened through a mechanical linkage, and if the second operational amplifier IC4 in the hysteresis voltage unlocking circuit 8 outputs a low level and the signal output by the first operational amplifier IC3 in the trigger circuit 9 jumps from the low level to the high level, the switch circuit 3 arranged between an alternating current power supply and the transformer B2 is caused to form an open circuit which stops charging the super capacitor 5;

when the trigger switch SB1 in the trigger circuit 9 is closed and the unlock switch SB2 in the hysteresis voltage unlock circuit 8 remains open, if the signal output from the operational amplifier IC4 in the hysteresis voltage unlock circuit 8 jumps from low level to high level and the operational amplifier IC3 in the trigger circuit 9 outputs high level, the switch circuit 3 disposed between the ac power supply 1 and the transformer B2 is caused to be reformed into a path for charging the supercapacitor 5; meanwhile, when the trigger switch SB1 is closed, the sound head 6 is triggered to sound by the energy stored in the super capacitor 5.

In the embodiment of the invention, the electric control sound head 6 can sound by directly radiating the sharp pulse sound pressure signal to the open space in the discharging process of the super capacitor 5 and instantly sounding when the super capacitor 5 is discharged.

In this embodiment, in order to generate a sufficiently high sound pressure by breaking down air, a very high energy needs to be released, and a super capacitor resistant to more than 3000 volts (V) is actually used.

Wherein, automatically controlled sound generating mechanism still includes:

an AC-DC chip B1;

the voltage stabilizing circuit 7 is connected with the AC-DC chip B1, and the voltage stabilizing circuit 7 is used for converting the voltage of the AC-DC chip B1 into two paths of low voltages;

one end of the trigger circuit 9 is connected with the AC-DC chip B1;

one path of low-voltage output of the voltage stabilizing circuit 7 is used as a reference voltage of the trigger circuit 9, and the other path of low-voltage output of the voltage stabilizing circuit 7 is used as a reference voltage of the hysteresis voltage unlocking circuit 8.

The device further comprises:

a rectifying and filtering circuit 4 connected between the super capacitor 5 and the transformer B2;

and the sampling circuit is connected between the rectifying and filtering circuit 4 and the super capacitor 5 and is connected with the sampling end of the hysteresis voltage unlocking circuit 8.

Wherein the switching circuit 3 includes:

the switching circuit 3 includes:

the current limiting resistor R16 and the anti-static resistor R17 are connected, the current limiting resistor R16 is connected with the output end of the trigger circuit 9, and the other end of the anti-static resistor R17 is grounded;

the anode of the unidirectional silicon controlled rectifier SCR1 is connected with the output end of the hysteresis voltage unlocking circuit 8, the control electrode of the unidirectional silicon controlled rectifier SCR1 is connected between the current limiting resistor R16 and the anti-static resistor R17, and the cathode of the unidirectional silicon controlled rectifier SCR1 is grounded;

the positive electrode of a light-emitting diode in the silicon controlled optocoupler IC5 is connected with the output end of the hysteresis voltage unlocking circuit 8, and the negative electrode of the light-emitting diode is grounded;

a control electrode of the bidirectional thyristor SCR2 is connected with one electrode of a bidirectional trigger diode in the thyristor optocoupler IC 5; a first electrode of the bidirectional thyristor SCR2 is connected with the alternating current power supply, and a second electrode of the bidirectional thyristor SCR2 is connected with the transformer B2;

a fifteenth resistor R15, the fifteenth resistor R15 being connected between the second anode of the triac SCR2 and the other pole of the diac in the triac optocoupler IC 5.

The hysteresis voltage unlocking circuit 8 includes:

an unlocking switch SB2, one end of the unlocking switch SB2 is grounded;

a second operational amplifier IC4, wherein the sampling end of the second operational amplifier IC4 is connected with the sampling circuit; the reference end of the second operational amplifier IC4 is connected to the other low-voltage output end of the voltage stabilizing circuit 7 through a twelfth resistor R12; the output end of the second operational amplifier IC4 is respectively connected to the light emitting diodes in the one-way thyristor SCR1, the unlock switch SB2 and the thyristor optocoupler IC5 through a thirteenth resistor R13; the output terminal of the second operational amplifier IC4 is further connected to the reference terminal of the second operational amplifier IC4 through the seventh diode D7 and an eleventh resistor R11;

one low-voltage output end of the voltage stabilizing circuit 7 is connected with a sixth diode D6, a tenth resistor R10, a seventh diode D7 and an eleventh resistor R11 in sequence and then connected with the reference end of the second operational amplifier IC 4.

The trigger circuit 9 includes:

trigger switch SB 1;

a first operational amplifier IC3, wherein a low voltage output terminal of the voltage regulator circuit 7 is connected to a reference terminal of the first operational amplifier IC3 through the trigger switch SB 1;

a ninth resistor R9, one end of which is connected between the reference terminal of the first operational amplifier IC3 and the trigger switch SB1, and the other end of which is grounded;

a first RC resistor-capacitor C7, one end of which is connected between the reference terminal of the first operational amplifier IC3 and the trigger switch SB1, and the other end of which is grounded;

the other low-voltage output end of the voltage stabilizing circuit 7 is connected to the reference end of the first operational amplifier IC3, and the other low-voltage output end of the voltage stabilizing circuit 7 is further grounded through an eighth capacitor C8;

the output end of the first operational amplifier IC3 is connected to a current limiting resistor R16; the other path is connected with the voltage division branch circuit and then is grounded;

a field effect transistor T1, wherein the grid electrode of the field effect transistor T1 is connected with the voltage dividing branch; the source electrode of the field effect transistor T1 is grounded;

an electromagnet YA connected between the AC-DC chip and the drain of the FET T1;

a fifth diode D5 connected between the AC-DC chip and the drain of the fet T1, and arranged in parallel with the electromagnet YA;

when the trigger switch SB1 is closed, the first RC resistor-capacitor C7 is charged to trigger the first operational amplifier IC3 to output a high level; when the trigger switch SB1 is turned off, the first RC resistor-capacitor R7 discharges slowly, and the first operational amplifier IC3 is triggered to output low level in a delayed mode; when the trigger switch SB1 is closed, the electromagnet YA pushes the negative electrode to move towards the positive electrode, and triggers the sound-emitting head 6 to emit sound by using the energy stored in the super capacitor 5;

when the second operational amplifier IC4 outputs high level, the unlock switch SB1 is closed and the first operational amplifier IC3 outputs high level, the one-way thyristor SCR1 is turned on and the thyristor optocoupler IC5 is turned on, and then the triac BCR is driven to be turned on, so that the ac power supply and the transformer B2 form a passage therebetween.

The device further comprises:

a thyristor protection circuit (10) connected between the ac power source and the transformer B2; the thyristor protection circuit 10 is arranged in parallel with the switch circuit 3 to prevent the super capacitor 5 from inducing a potential to break down the thyristor optocoupler IC5 in a discharging process;

a first detection lamp H1 connected after the ac power source, the first detection lamp H1 being connected before the thyristor protection circuit 10 and the switch circuit 3;

a second check lamp H2 connected before the transformer B2, and the second check lamp H2 connected after the thyristor protection circuit 10 and the switching circuit 3;

a third inspection lamp H3 connected between the AC-DC chip B1 and the drain of the fet T1, and the third inspection lamp H3 connected in parallel with the fifth diode D5;

and a fourth detection lamp H4 connected between the positive and negative electrodes of the AC-DC chip B1.

The rectifying and filtering circuit 4 includes:

a full-wave rectifier bridge, wherein a first access end of the full-wave rectifier bridge is connected with a first secondary end of the transformer B2, and a second access end of the full-wave rectifier bridge is connected with a second secondary end of the transformer B2;

a bypass capacitor C3, the bypass capacitor C3 being connected between the third and fourth input terminals of the full wave rectifier bridge;

a first resistor R1, wherein the first resistor R1 is connected between the third access terminal of the full-wave rectifying bridge and one end of the super capacitor 5, and the other end of the super capacitor 5 is connected with the fourth access terminal of the full-wave rectifying bridge and grounded;

one end of the sampling circuit is connected between the first resistor R1 and the super capacitor 5, and the other end is grounded.

The sampling circuit 2 includes: a second resistor R2 and a third resistor R3 which are arranged in series, wherein the other end of the third resistor R3 is grounded, and a sampling end of the second operational amplifier IC4 is connected between the second resistor R2 and the third resistor R3;

the voltage dividing branch includes: a seventh resistor R7 and an eighth resistor R8 which are arranged in series, wherein one end of the eighth resistor R8 is grounded, one end of the seventh resistor R7 is connected with the output end of the first operational amplifier IC3, and the gate of the field effect transistor T1 is connected between the seventh resistor R7 and the eighth resistor R8.

The voltage stabilizing circuit 7 includes:

the input end of the voltage stabilizing chip IC1, the input end of the voltage stabilizing chip IC1 is connected with the AC-DC chip B1, and one path of the output end of the voltage stabilizing chip IC1 is connected with the trigger switch SB1, the anode of the sixth diode D6 and the power supply anode of the second operational amplifier IC 4; the other path of the output end of the voltage-stabilizing chip IC1 is grounded after being connected with a fifth capacitor C5, the other path of the output end of the voltage-stabilizing chip IC1 is grounded after being connected with a second RC resistor C6 to absorb ripples, and the other path of the output end of the voltage-stabilizing chip IC1 is connected with a twelfth resistor R12 and the reverse input end of the first operational amplifier IC3 after being connected with a fourth resistor R4; the other way of the output end of the voltage-stabilizing chip IC1 is also connected with a fourth resistor R4 and then is grounded through a parallel voltage-stabilizing integrated circuit IC2, and the other way of the output end of the voltage-stabilizing chip IC1 is also connected with a fourth resistor R4 and then is grounded through a fifth resistor R5 and a sixth resistor R6 which are arranged in series.

Preferably, a copper wire shielding net wraps a joint of the output end of the electromagnet YA and the sound head 6, and a copper wire shielding net wraps a joint of the sampling end of the hysteresis voltage unlocking circuit 8 and the sampling circuit 2;

the trigger circuit 9, the hysteresis voltage unlocking circuit 8, the voltage stabilizing circuit 7, the switch circuit 3, the unidirectional silicon controlled rectifier SCR1 and the silicon controlled rectifier protection circuit 10 are all arranged in a metal shell.

The device in the embodiment uses an electrostatic sound production principle, controlled discharge is carried out through capacitors (C1 and C2), an air layer between two adjacent electrodes of the sound head 6 is broken through, air molecules move violently after high-temperature ionization, the volume expands, the air molecules cool and contract, elastic wave energy is released, sound is radiated to the periphery, the time of an instantaneous discharge process is short, and the instantaneous sound pressure is close to an ideal sharp pulse signal. The stiffness of the electrodes must be high enough to avoid the electrode resonant frequency creating an adverse disturbance of the signal by additional sound sources, and the sound emitted by the electrode vibrations is almost negligible overall. The discharge electrode can pass through very big electric current in the short time, brings electromagnetic radiation, needs design shielding layer, avoids causing the influence to test equipment. Meanwhile, thermal shock is brought in the process of releasing energy, and the electrode needs to be rapidly cooled through heat conduction and convection effects so that the electrode cannot be melted at high temperature in the process of repeated use. Discharge generates an oscillating current, which needs R1 to suppress and absorb.

In order to raise the voltage, a transformer B2 is used and rectified by the rectifying and filtering circuit 4. A super capacitor with high voltage resistance and large current needs to be selected. After the power switch BX is closed and the circuit is unlocked by charging through the transformer B2, when the unlock switch SB2 is opened and the trigger switch SB1 is closed, the super capacitor 5 discharges current to make the sound emitting head 6 discharge and emit sound.

The main functional modules and technical design of the device in this embodiment are described as follows:

the boosting energy storage module comprises a transformer B2 and a super capacitor 5

The trigger switch SB1 is turned off, the external power supply is switched on, the transformer B2 is used for outputting high voltage, and the high voltage is rectified (D1-D4) and then charges the super capacitors (C1 and C2) to store the charges. The charging process is unidirectional and does not require reverse charging. Meanwhile, in the discharging process, the external power supply needs to be automatically disconnected so as to prevent the external power supply from short circuit, and the self-locking function is realized. The charging of the super capacitor 5 is a controlled short circuit, and a high-power resistor is selected for current limiting.

(2) Discharging sound production module

The positive electrode and the negative electrode of the super capacitor 5 are connected, and the air layer between the electrodes can be punctured by passing current through the electrodes of the sound generating head 6 to generate sound. Sufficient sound pressure can be generated only when certain conditions are met, the shortening of the electrode distance and the voltage boosting are beneficial to triggering discharge, but the air layer is too thin, the electrode distance is too short, and the sound generated by air breakdown is not loud enough; too large an electrode distance may not provide a sufficiently high breakdown voltage, may not achieve a tip discharge, or may be limited by an upper limit of capacitance withstand voltage. The high-voltage discharge sound is generated in a mode of breaking down an air layer, the discharge breakdown voltage or working voltage is far larger than 3000V, a large amount of charges need to be released instantaneously, the shorter the time is, the shorter the generated sound is, the wider the frequency response range is, and the higher the high-frequency excitation is provided. The loop resistance does not need to be high, but is subjected to a large current surge in a short time, and needs to have sufficiently high received power. In order to reduce the volume of the sounding head, a high-voltage cable is adopted to separate the sounding head 6 from the super capacitor 5 serving as charging and discharging equipment.

Referring to fig. 3, a high-frequency transformer 2 boosts ac 220V commercial power (the device is provided with an inverter, and can be powered by a 12V storage battery) into high voltage, and the high voltage ac is converted into high voltage dc through a full-wave rectifier bridge composed of D1, D2, D3 and D4 high-voltage silicon columns (a high-voltage rectifier circuit board is arranged in a dashed line frame, C3 is a bypass capacitor, R1 is a current-limiting resistor, and R2 and R3 are sampling resistors). The energy storage capacitors C1, C2 are charged via a current limiting resistor R1. In a discharge loop formed from the positive electrode to the negative electrode of the super capacitor, the smaller the distributed inductance is, the shorter the discharge duration is, and the closer the emitted sound is to an ideal sharp pulse signal. The electrodes are connected to the capacitor through a low inductance coaxial cable to control or shorten the discharge time to the maximum extent. The capacitor is easily burnt by excessive current, so the electrode distance needs to be controlled, and reasonable loop resistance is selected. The stored charge is calculated as Q = U × C, and the operating voltage U can be raised or the withstand voltage level of the capacitor can be lowered by using a series capacitor, but the total capacitance C is lowered after the series capacitor is connected.

(3) Unlock switch and trigger switch design

Because of high voltage and high current, the safety switch is designed, the unlocking switch SB2 is in a closed state under the condition that the shell is not opened, the unlocking switch SB2 is opened after the shell is opened, and the switch circuit 3 is in an open state after the unlocking switch SB2 is opened, so that direct contact with high-voltage components can be avoided, and the discharge process is protected from being damaged; the trigger switch SB1 formed by a common button controls the discharge, and the spark gap conduction time control is designed to be in the nanosecond level. The electrode distance of the sound-emitting head 6 should be controlled to be about 1mm to ensure the working stability. Referring to fig. 2, the output of the third operational amplifier IC3 (pin 7) is split into two paths, one path controlling the discharge using fet T1. Wherein, R9 and C7 form a delay loop, so that the third operational amplifier IC3 has a stable working time after the trigger switch SB1 is released. D5 is a freewheeling diode of the electromagnet coil YA to prevent the induced electromotive force from breaking down the fet T1 when the electromagnet coil YA is powered off. The other path of the first cloud scattered amplifier IC3 triggers a one-way thyristor SCR1 to be switched on, so that (1 pin and 2 pins) of a thyristor optocoupler IC5 are short-circuited, the optocoupler is prevented from normally working, and the equipment is self-locked. To resume the charging function, the unlock switch SB2 needs to be pressed.

(4) Positive feedback false trigger prevention design

When the voltage of the sampling resistor R3 exceeds the reference voltage 5V, the output of the fourth operational amplifier IC4 immediately flips to low level, the above-mentioned operation state is completely reversed, the transformer B2 stops operating, and the voltage on the capacitors C1 and C2 stops rising. Since the output terminal of the fourth operational amplifier IC4 goes low, a current flows through the diode D7, and R11, R12, and D7 act in combination, and the reference voltage of the reference terminal of the fourth operational amplifier IC4 is no longer 5V, but is lower by 0.125V. The calculation formula is as follows: the design makes the output end voltage of the IC4 overturn smoothly (the reference voltage is no longer 5V but 4.875V), and can effectively prevent multiple false triggering.

(5) Heat and pressure resistant design

The electrode of the sound-emitting head 6 is made of heat-resistant tungsten alloy, so that high-current impact is resisted, and the metal electrode is prevented from being melted at high temperature; the electrode is designed into a point discharge shape, which is beneficial to the discharge process; the electrode tip is welded on the copper column base by silver alloy, the good heat-conducting property of copper is utilized, the heat generated in the discharging process is led out, and the electrode is rapidly cooled so as to be repeatedly charged and discharged. The oscillation energy of the discharge circuit is easy to break down components, a high-voltage bypass capacitor C3 is designed to provide a circuit for the oscillation energy, a rectifier tube is protected, and the current-limiting resistor R1 plays a role in consuming the oscillation energy.

(6) Electromagnetic shielding design

The transient discharge process can generate strong electromagnetic radiation, damage electrical measurement equipment and interfere normal work of the sensor. Therefore, the sounding head 6 and the super capacitor 5 adopt an integral metal shell, and meanwhile, a copper wire shielding net is designed near the surface of the sounding head 6, so that the electromagnetic shielding effect is enhanced, and the interference to other electric equipment is reduced.

The basic steps for using the apparatus are as follows:

step 1, turning on a power switch BX, and enabling a first detection lamp H1 serving as a power supply indicator to light green. The third detection lamp H3 as a control power indicator lamp is turned on green, and the second detection lamp H2 as a charging indicator lamp is turned on yellow, and the super capacitor 5 is being charged.

And 2, connecting the device with an external power supply to charge the super capacitor. The charging time is about 10 seconds, and the second detection lamp H2 enters a slightly lit state, at which time the trigger operation by the trigger switch SB1 can be performed. If the voltage drops, the instrument will automatically recharge if it is not triggered for 30 seconds, and the second detection lamp H2 will light up again.

And 3, pressing down a trigger switch SB1, allowing the current to pass through the spark gap, breaking down the air layer to discharge, releasing energy, and generating narrow pulse sound waves. The trigger switch SB1 is released, and the discharge electrode of the sounding head 6 is reset after 0.5 seconds.

And 4, during discharging, the switch circuit 3 serving as a circuit charging loop is closed and self-locked, and if the discharging operation is to be continued, the unlocking switch SB2 needs to be pressed to unlock the circuit.

And 5, completing vibration noise test and system nonparametric identification. After discharge, part of the charge remains, the circuit needs to be disconnected, and the device is kept still for more than one hour to completely release the charge, so that the device is not allowed to be opened during the working process or immediately after the discharge is finished.

The method and engineering scheme is only for the implementation of the invention, not any limitation, all within the spirit and principle of the invention made by any modification, equivalent replacement, and improvement included in the invention, by the protection of patent law.