CN218955915U

CN218955915U - Noise testing device

Info

Publication number: CN218955915U
Application number: CN202223134268.3U
Authority: CN
Inventors: 张芯; 周睿京; 宋国勇
Original assignee: Intelligent Automation Equipment Zhuhai Co Ltd
Current assignee: Intelligent Automation Equipment Zhuhai Co Ltd
Priority date: 2022-11-25
Filing date: 2022-11-25
Publication date: 2023-05-02
Anticipated expiration: 2032-11-25

Abstract

The utility model aims to provide a noise testing device with simple structure and high testing precision. The utility model comprises an amplifying and filtering module, an audio collecting module, a microphone and an upper computer, wherein a communication interface of the audio collecting module is connected with the upper computer, an audio interface of the audio collecting module is connected with an audio output interface of the amplifying and filtering module, an audio input interface of the amplifying and filtering module is connected with an audio interface of the microphone, and the microphone collects external environment sounds. The method is applied to the technical field of noise testing.

Description

Noise testing device

Technical Field

The utility model is applied to the technical field of noise testing, and particularly relates to a noise testing device.

Background

With the development of technology, audio information testing is an important content of environmental monitoring, NVH testing and automobile detection, and because the quality requirements of users on audio information to be listened to are higher and higher, and the quality of the audio information is mainly influenced by noise, in order to meet the listening requirements of users on the audio information, noise detection is often required to be performed on the audio information recorded in a server. The types of noise meters on the market are very many at present, basically, a single chip microcomputer collects voltage signals of an analog microphone through an analog-digital conversion chip, and after data are collected for a period of time, the single chip microcomputer displays results on a screen through calculation. The test accuracy of the existing scheme is lower, and the test requirement for high accuracy of sound size cannot be met. Therefore, it is necessary to provide a noise testing device with a simple structure and high testing accuracy.

Disclosure of Invention

The utility model aims to solve the technical problem of overcoming the defects of the prior art and providing the noise testing device with simple structure and high testing precision.

The technical scheme adopted by the utility model is as follows: the utility model comprises an amplifying and filtering module, an audio collecting module, a microphone and an upper computer, wherein a communication interface of the audio collecting module is connected with the upper computer, an audio interface of the audio collecting module is connected with an audio output interface of the amplifying and filtering module, an audio input interface of the amplifying and filtering module is connected with an audio interface of the microphone, and the microphone collects external environment sounds.

According to the scheme, the signals collected by the microphone sequentially pass through the amplifying and filtering module, the audio collecting module and the upper computer, and the upper computer performs spectrum analysis to calculate the frequency characteristics in the sound signals. The microphone is a constant-current microphone of B & K company, the model of the microphone is 4958A, the test precision of the microphone is high, the microphone can provide corresponding calibration parameters, and calibration is carried out on the calibration parameters to obtain a more accurate test result; the upper computer uses standard instruments in the acoustic field, the model of which is AP555, and the error of the upper computer is not more than 0.2dB in the frequency range of 50Hz-10KHz, so that the testing precision is high, and the measurement is more accurate.

The noise testing device further comprises a constant current power supply, wherein the constant current power supply comprises a first diode, a second diode, a triode and a resistor, the anode of the first diode is connected with 24V voltage, the cathode of the first diode is divided into two paths, one path is connected with the base electrode of the triode through the second diode, the other path is connected with the emitting electrode of the triode through the resistor, and the collecting electrode of the triode is connected with a power port of the microphone.

In one preferred scheme, the noise testing device further comprises a USB interface, the AUDIO acquisition module is connected with the upper computer through the USB interface, a D-port of the AUDIO acquisition module is connected with a USB_AUDIO_N port of the AUDIO acquisition module, and a D+ port of the AUDIO acquisition module is connected with a USB_AUDIO_P port of the AUDIO acquisition module.

In one preferred scheme, the amplifying and filtering module comprises a first operational amplifier and a second operational amplifier, wherein the input end of the first operational amplifier is connected with the left interface of the microphone, the OUTPUT end of the first operational amplifier is connected with the L_MIC_OUTPUT port of the audio acquisition module, the input end of the second operational amplifier is connected with the right interface of the microphone, and the OUTPUT end of the second operational amplifier is connected with the R_MIC_OUTPUT port of the audio acquisition module.

In one preferred scheme, the noise testing device further comprises a touch display screen, and the touch display screen is connected with the upper computer.

Drawings

FIG. 1 is a block diagram of the structure of the present utility model;

FIG. 2 is a schematic circuit diagram of the audio acquisition module;

FIG. 3 is a schematic circuit diagram of the USB interface;

FIG. 4 is a schematic circuit diagram of the amplification filter module;

FIG. 5 is a schematic circuit diagram of the constant current power supply;

fig. 6 is a spectrum characteristic curve of the noise test device.

Detailed Description

As shown in fig. 1 to 6, in this embodiment, the present utility model includes an amplifying and filtering module 1, an audio collecting module 2, a microphone 3 and an upper computer 4, where a communication interface of the audio collecting module 2 is connected with the upper computer 4, an audio interface of the audio collecting module 2 is connected with an audio output interface of the amplifying and filtering module 1, an audio input interface of the amplifying and filtering module 1 is connected with an audio interface of the microphone 3, the microphone 3 collects external environmental sound 5, the microphone 3 converts a sound signal into a high-quality electrical signal, an electrical signal of an analog sound is transmitted to the audio collecting module 2 through the amplifying and filtering module 1, the audio collecting module 2 performs analog-to-digital conversion on the analog electrical signal output by the microphone 3, the upper computer 4 collects a digital signal of the audio collecting module 2, and after collecting for a period of time, the upper computer 4 analyzes the collected digital signal, and calculates a frequency characteristic in the sound signal.

In this embodiment, the noise testing device further includes a constant current power supply 6, where the constant current power supply 6 includes a first diode D1002, a second diode D1004, a triode Q1002, and a resistor R1004, where an anode of the first diode D1002 is connected to a 24V voltage, a cathode of the first diode D1002 is divided into two paths, one path is connected to a base of the triode Q1002 through the second diode D1004, and the other path is connected to an emitter of the triode Q1002 through the resistor R1004, and a collector of the triode Q1002 is connected to a power port of the microphone 3. The constant current power supply 6 provides cross current power for the microphone 3 with high precision, the constant current power supply 6 is connected with external 24V voltage, and the working voltage of the second diode D1004 is 2V, the resistance value of the resistor R1004 is 220R, and the working voltage of the second diode D1004 is divided by the resistance value of the resistor R1004, so that a constant cross current of 9mA is output.

In this embodiment, the noise testing device further includes a USB interface J801, the AUDIO collection module 2 is connected to the host computer 4 through the USB interface J801, a D-port of the AUDIO collection module 2 is connected to a usb_audio_n port of the AUDIO collection module 2, and a d+ port of the AUDIO collection module 2 is connected to a usb_audio_p port of the AUDIO collection module 2. The chip model of the AUDIO acquisition module 2 is CM118B, the USB_AUDIO_P port of the AUDIO acquisition module 2 and the USB_AUDIO_N port of the AUDIO acquisition module 2 are both communication ports, and the AUDIO acquisition module 2 exchanges with the upper computer 4.

In this embodiment, the amplifying and filtering module 1 includes a first operational amplifier U1002 and a second operational amplifier U1001, where an input end of the first operational amplifier U1002 is connected to a left interface of the microphone 3, an OUTPUT end of the first operational amplifier U1002 is connected to an l_mic_output port of the audio collecting module 2, an input end of the second operational amplifier U1001 is connected to a right interface of the microphone 3, and an OUTPUT end of the second operational amplifier U1001 is connected to an r_mic_output port of the audio collecting module 2. The chip types of the first operational amplifier U1002 and the second operational amplifier U1001 are OPA1611AID, and the first operational amplifier U1002 and the second operational amplifier U1001 transmit the electric signals of the analog sound to the audio acquisition module 2 for analog-to-digital conversion.

In this embodiment, the noise testing device further includes a touch display screen 7, and the touch display screen 7 is connected to the upper computer 4. The upper computer 4 displays the calculated frequency characteristic on the touch display screen 7 and displays a noise decibel value.

The working principle of the utility model is as follows: the constant current power supply provides cross current power for the microphone, the microphone gathers external environment sound, high accuracy the microphone converts sound signal into high-quality electrical signal, and the electrical signal of analog sound passes through amplification filter module gives the audio acquisition module, audio acquisition module will the analog electrical signal of microphone output is analog-to-digital conversion, and conversion is digital signal, the host computer gathers audio acquisition module's digital signal, gathers and preserve after a period of time, the host computer is spectral analysis with the digital signal who gathers, the host computer will calculate frequency characteristic demonstration and be in on the touch-control display screen to display noise decibel value.

Claims

1. Noise testing arrangement, including amplifying filter module (1), its characterized in that: the noise testing device further comprises an audio acquisition module (2), a microphone (3) and an upper computer (4), wherein a communication interface of the audio acquisition module (2) is connected with the upper computer (4), an audio interface of the audio acquisition module (2) is connected with an audio output interface of the amplification filtering module (1), an audio input interface of the amplification filtering module (1) is connected with an audio interface of the microphone (3), and the microphone (3) acquires external environment sound (5).

2. A noise testing device according to claim 1, characterized in that: the noise testing device further comprises a constant current power supply (6), the constant current power supply (6) comprises a first diode (D1002), a second diode (D1004), a triode (Q1002) and a resistor (R1004), the anode of the first diode (D1002) is connected with 24V voltage, the cathode of the first diode (D1002) is divided into two paths, one path is connected with the base electrode of the triode (Q1002) through the second diode (D1004), the other path is connected with the emitter electrode of the triode (Q1002) through the resistor (R1004), and the collector electrode of the triode (Q1002) is connected with the power port of the microphone (3).

3. A noise testing device according to claim 1, characterized in that: the noise testing device further comprises a USB interface (J801), the AUDIO acquisition module (2) is connected with the upper computer (4) through the USB interface (J801), the D-port of the AUDIO acquisition module (2) is connected with the USB_AUDIO_N port of the AUDIO acquisition module (2), and the D+ port of the AUDIO acquisition module (2) is connected with the USB_AUDIO_P port of the AUDIO acquisition module (2).

4. A noise testing device according to claim 1, characterized in that: the amplifying and filtering module (1) comprises a first operational amplifier (U1002) and a second operational amplifier (U1001), wherein the input end of the first operational amplifier (U1002) is connected with the left interface of the microphone (3), the OUTPUT end of the first operational amplifier (U1002) is connected with the L_MIC_OUTPUT port of the audio acquisition module (2), the input end of the second operational amplifier (U1001) is connected with the right interface of the microphone (3), and the OUTPUT end of the second operational amplifier (U1001) is connected with the R_MIC_OUTPUT port of the audio acquisition module (2).

5. A noise testing device according to claim 1, characterized in that: the noise testing device further comprises a touch display screen (7), and the touch display screen (7) is connected with the upper computer (4).