Audio intensity testing device

Abstract

The utility model relates to the field of audio intensity testing, in particular to an audio intensity testing device. The testing device comprises a high-sensitivity microphone used for converting a weak audio signal into an electric signal; the audio amplifying circuit is used for amplifying the electric signal output by the high-sensitivity microphone; and the LED driving circuit is used for converting the signal voltage output by the audio amplifying circuit into a mode that an LED is lightened step by step, and the LED driving circuit outputs the signal voltage from the emitting electrode of the triode. According to the utility model, weak audio signals are converted into electric signals through the high-sensitivity microphone, adjustable gain amplification is carried out on the signals through the audio amplification circuit, and finally, signal voltage is converted into an LED step-by-step lightening mode through the LED driving circuit, so that the visual display of noise intensity is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to audio intensity test field, concretely is an audio intensity testing device. BACKGROUND

[0002] Audio intensity test is to verify whether the noise generated when the equipment is full load running can meet the customer's requirements, especially the noise generated when the high-power POE switch with multiple fans is larger, and the customer generally has requirements for the noise. In the test verification process, the customer will also compare the noise intensity difference between the same series of products. In addition to the standard laboratory sound pressure value test, multiple testers are required to compare the noise difference between the competitive products or the same series of products or the same product with different BOM devices by human ear listening. But the human ear listening comparison is not accurate, and there is a difference in the sense of different experimental listeners. UTILITY MODEL CONTENT

[0003] The utility model provides an audio intensity testing device to solve the problem of how to improve the accuracy of audio intensity test.

[0004] The technical scheme for solving the above technical problem of the utility model is as follows:

[0005] An audio intensity testing device is provided, and the testing device comprises:

[0006] A high-sensitivity microphone is used to convert weak audio signals into electrical signals.

[0007] An audio amplification circuit is used to amplify the electrical signals output by the high-sensitivity microphone.

[0008] An LED driving circuit is used to convert the signal voltage output by the audio amplification circuit into an LED step-by-step lighting mode, and the LED driving circuit outputs the signal voltage from the emitter of the triode.

[0009] The high-sensitivity microphone is placed at a fixed distance and angle from the test sample machine to ensure the consistency of signal collection.

[0010] Further, the output end of the high-sensitivity microphone is connected to the 5-pin of the LM324 operational amplifier IC in the audio amplification circuit through a capacitor C2, and the capacitor C2 is an aluminum electrolytic capacitor with a withstand voltage of 16V.

[0011] Further, the audio amplification circuit is composed of an LM324 operational amplifier IC and a peripheral circuit, and the peripheral circuit comprises resistors R1, R2, R3, R4, R5, a potentiometer Rp, and capacitors C1 and C2; the resistors R1-R5 are 1 / 4W carbon film resistors or metal film resistors, and the potentiometer Rp is a super-small potentiometer or a vertical variable resistor.

[0012] Further, the number of light emitting diodes in the LED driving circuit is adjusted according to actual test requirements, and the test device supports step-by-step lighting of not less than 5 light emitting diodes to cover the audio frequency range from low intensity to high intensity.

[0013] Further, one end of the potentiometer Rp is connected to the input end of the audio amplification circuit, the other end is connected to the 5 pin of the LM324 operational amplifier IC through the resistor R2, the resistor R1 is connected between the 7 pin and the 8 pin of the LM324 operational amplifier IC, and the capacitor C1 is connected in parallel across the resistor R1.

[0014] Further, the LED driving circuit comprises a triode V, a capacitor C3, a voltage stabilizing diode VS, resistors R1-Rn, light emitting diodes VL1-VLn and diodes VD1-VDn; the triode V is a C8050 or 58050 or 3DG8050 type silicon NPN transistor, the capacitor C3 is an aluminum electrolytic capacitor with a withstand voltage of 16V, the voltage stabilizing diode VS is a 1 / 2W, 3.6V silicon voltage stabilizing diode, the resistors R1-Rn are 1 / 4W carbon film resistors or metal film resistors, the light emitting diodes VL1-VLn are 5mm red high-brightness light emitting diodes, and the diodes VD1-VDn are 1N4148 type silicon switching diodes.

[0015] Further, the output end of the audio amplification circuit is connected to the base of the triode V, the signal voltage is output from the emitter of the triode V, and the step-by-step lighting of the light emitting diodes VL1-VLn is controlled by the resistors R1-Rn and the diodes VD1-VDn.

[0016] The utility model discloses the beneficial effect is:

[0017] The utility model discloses a weak audio signal is converted into electric signal through high sensitivity microphone, and the signal is amplified through audio amplification circuit with adjustable gain, and finally signal voltage is converted into the mode of LED step-by-step lighting through LED driving circuit, thereby the intuitive display of noise intensity is realized. ACCURACY AND INDIVIDUAL SENSORY DIFFERENCES, AND ENSURES THE CONSISTENCY AND RELIABILITY OF TEST RESULTS.

[0018] Figure 1 It is the circuit structure schematic drawing of the utility model;

[0019] Figure 2 It is the LM324 integrated operational amplifier pin diagram of the utility model;

[0020] Figure 3 It is the operation flow schematic diagram of the utility model. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the utility model clearer, the utility model will be further described in detail below in combination with the drawings and examples. The examples of the examples are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The examples described below by reference to the drawings are exemplary and are used only to explain the utility model and cannot be understood as limiting the utility model. In addition, it should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0022] In the description of the utility model, it should be pointed out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0023] In the utility model, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0024] The following disclosure provides many different embodiments or examples for implementing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the utility model. In addition, the utility model can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0025] The utility model provides the following preferred examples:

[0026] Embodiment one

[0027] In order to solve the problem that the comparison result is not accurate and there is a sensory difference between different experimental listeners in the existing audio intensity test, the embodiment provides an audio intensity test device which can convert weak audio signals into electrical signals and amplify them, and finally display the noise intensity through the way of LED step-by-step lighting, thereby improving the accuracy and efficiency of the test.

[0028] In the embodiment, the audio intensity test device mainly includes a high-sensitivity microphone, an audio amplification circuit and an LED driving circuit. The high-sensitivity microphone selects a microphone with a model of Gaojian-2021K145. The microphone has high sensitivity and can capture weak audio signals in a long distance and low noise environment and convert them into electrical signals. Further, the high-sensitivity microphone is placed at a fixed distance and angle of the test sample to ensure the consistency of the collected audio signals. Specifically, according to the test standard requirements, the microphone is placed at a position 1 meter away from the sample at an angle of 90 degrees to collect the noise signal generated by the sample when it is running at full load.

[0029] Further, the audio amplification circuit is composed of an LM324 operational amplifier IC and a peripheral circuit, which is used to amplify the electrical signals output by the high-sensitivity microphone with adjustable gain. The peripheral circuit includes resistors R1, R2, R3, R4, R5 and a potentiometer Rp, and capacitors C1 and C2. Among them, R1-R5 selects 1 / 4W carbon film resistor or metal film resistor, Rp selects super small potentiometer or vertical variable resistor. Capacitors C1 and C2 select aluminum electrolytic capacitors with a voltage resistance value of 16V. The specific connection relationship is as follows: the output end of the high-sensitivity microphone is connected to the 5-pin of the LM324 operational amplifier IC through the capacitor C2, and the capacitor C2 plays a coupling role to transmit the audio signals output by the microphone to the input end of the operational amplifier IC without distortion. One end of the potentiometer Rp is connected to the input end of the audio amplification circuit, and the other end is connected to the 5-pin of the LM324 operational amplifier IC through the resistor R2. This connection mode can adjust the gain of the amplification circuit by adjusting the resistance value of Rp, thereby adapting to different test requirements. Resistor R1 is connected between the 7-pin and 8-pin of the LM324 operational amplifier IC, and capacitor C1 is connected in parallel across the resistor R1, forming a feedback loop to ensure the stability and reliability of the amplified signal.

[0030] Further, the LED driving circuit is used to convert the signal voltage output by the audio amplification circuit into a mode of step-by-step lighting of the LEDs. The circuit includes a triode V, a capacitor C3, a voltage stabilizing diode VS, resistors R1-Rn, light emitting diodes VL1-VLn, and diodes VD1-VDn. Among them, the triode V is selected from a C8050 or 58050 or 3DG8050 type silicon NPN transistor, the capacitor C3 is selected from an aluminum electrolytic capacitor with a voltage resistance value of 16V, the voltage stabilizing diode VS is selected from a 1 / 2W, 3.6V silicon voltage stabilizing diode, the resistors R1-Rn are selected from 1 / 4W carbon film resistors or metal film resistors, the light emitting diodes VL1-VLn are selected from 5mm red high-brightness light emitting diodes, and the diodes VD1-VDn are selected from 1N4148 type silicon switching diodes. The specific connection relationship is as follows: the output end of the audio amplification circuit is connected to the base of the triode V, and the signal voltage is output from the emitter of the triode V. The signal voltage controls the step-by-step lighting of the light emitting diodes VL1-VLn through the resistors R1-Rn and the diodes VD1-VDn. It should be understood that the stronger the audio input signal, the higher the signal voltage, and the more light emitting diodes that are lit, thereby achieving a direct display of the noise intensity.

[0031] Further, in order to ensure the accuracy and reliability of the test results, the embodiment also designs a test process. First, a high-sensitivity microphone is placed at a fixed distance and angle from the test sample to receive sound, and then the audio signal received by the microphone is coupled to the 5-pin of the LM324 operational amplifier IC through C2, the gain is adjusted by adjusting the resistance value of Rp according to the test requirements, and the amplified signal is output from the 7-pin of the operational amplifier IC. Next, the audio signal after gain is input from the base of the triode, and the signal voltage is output from the emitter, and VL1-VLn is step-by-step lit. During this process, the experimenter can directly judge the noise intensity of the test sample by observing the number of LEDs lit, and record the corresponding data to complete the comparative test.

[0032] The benefit of the embodiment is that, through the combination of the high-sensitivity microphone and the audio amplification circuit, weak audio signals can be accurately captured and amplified, thereby ensuring the reliability of the test results. The design of the LED driving circuit makes the display of noise intensity more intuitive, facilitating the experimenter to quickly judge and record data, and improving the test efficiency. In addition, by fixing the placement position and angle of the microphone, the consistency of signal collection during the test is ensured, and the accuracy of the test is improved.

[0033] Embodiment Two

[0034] In order to solve the consistency and repeatability of the audio intensity test results under different environmental conditions, the audio intensity test device is further optimized in this embodiment. In the selection of high-sensitivity microphones, although the Gaojian-2021K145 model is used, in order to adapt to different environmental conditions, this embodiment also adds an environmental noise filter. The environmental noise filter is used to filter out background noise, making the noise signal generated by the test prototype more pure, thereby improving the accuracy of the test results.

[0035] Specifically, the environmental noise filter is composed of a low-pass filter and a band-pass filter. The low-pass filter is used to filter out high-frequency noise, and the band-pass filter is used to select the appropriate audio frequency range. The low-pass filter is composed of capacitor C4 and resistor R6, and the band-pass filter is composed of capacitors C5, C6 and resistors R7, R8. The selection of these components is as follows: capacitors C4, C5, C6 are selected as aluminum electrolytic capacitors with a voltage resistance of 16V, and resistors R6, R7, R8 are selected as 1 / 4W carbon film resistors or metal film resistors. The output end of the filter is connected to the input end of the audio amplification circuit, and through the double filtering of the low-pass filter and the band-pass filter, the audio signal input to the audio amplification circuit is more pure, avoiding the interference of background noise.

[0036] Further, an automatic gain control (AGC) function is added to the audio amplification circuit to adapt to different audio intensity test requirements. The automatic gain control circuit is composed of a field effect transistor Q1 and several resistors and capacitors. The field effect transistor Q1 is selected as N-channel MOSFET with model number 2N7000, and the selection of resistors R9, R10, R11 and capacitors C7, C8 is as follows: resistors R9, R10, R11 are selected as 1 / 4W carbon film resistors or metal film resistors, and capacitors C7, C8 are selected as aluminum electrolytic capacitors with a voltage resistance of 16V. The input end of the automatic gain control circuit is connected to the output end of the filter, and the output end is connected to pin 5 of the LM324 operational amplifier IC. Through the automatic gain control circuit, the signal intensity input to the operational amplifier IC is kept within a suitable range, preventing inaccurate test results caused by excessively strong or weak signals.

[0037] Further, the design and embodiment of the LED driving circuit are similar to those of the first embodiment, but in order to improve the lighting efficiency and stability of the LED, the LED driving circuit is further optimized in this embodiment. The base of the triode V is increased with a bias resistor R12 for stabilizing the working state of the triode and avoiding the flickering of the LED caused by signal voltage fluctuation. The resistor R12 is selected from a 1 / 4W carbon film resistor or a metal film resistor, and its resistance value is selected according to actual test requirements. In addition, the reverse parallel diodes of the diodes VD1-VDn increase the filtering effect, making the signal voltage more stable, and further improving the stability and reliability of the LED lighting. The reverse parallel diodes are selected from silicon switching diodes of type 1N4148.

[0038] Further, the embodiment also designs an intelligent test process. During the test process, the environmental noise filter first filters the background noise to ensure that the signal input to the audio amplification circuit is pure. Then, the automatic gain control circuit adjusts the signal strength to keep it within a suitable range. Next, the audio signal after gain is input from the base of the triode and the signal voltage is output from the emitter, which gradually lights up VL1-VLn. It should be understood that through the double optimization of filtering and automatic gain control, the test result is more accurate and reliable, avoiding test errors caused by environmental noise and inconsistent signal strength.

[0039] Through the design of this embodiment, not only the problem of environmental noise interference with the test result is solved, but also the adaptability and accuracy of the test are improved through automatic gain control. The combination of the environmental noise filter and the automatic gain control circuit enables the audio intensity test device to maintain high test performance in various environmental conditions, thus meeting the test needs of different customers.

[0040] Embodiment three

[0041] In order to solve the problem that the dynamic range of the audio signal is large in a complex test environment, resulting in large fluctuations in the test result, the audio intensity test device is further optimized in this embodiment. In the selection of the high-sensitivity microphone, although the Gaojian-2021K145 type is still used, in order to adapt to a wider audio dynamic range, a dynamic range compression circuit is added in this embodiment. The dynamic range compression circuit is used to compress the dynamic range of the audio signal, making the test result more stable.

[0042] Specifically, the dynamic range compression circuit is composed of a compressor IC and several resistors and capacitors. The compressor IC is a dual N-channel symmetric gain control operational amplifier with model number LM13700. The resistors R13, R14, R15 are 1 / 4W carbon film resistors or metal film resistors, and the capacitors C9, C10 are aluminum electrolytic capacitors with a voltage resistance of 16V. The input end of the dynamic range compression circuit is connected to the output end of the audio amplification circuit, and the output end is connected to the input end of the LED driving circuit. Through the dynamic range compression circuit, the signal voltage input to the LED driving circuit is more stable, avoiding the problem of LED flickering caused by the fluctuation of audio signal intensity.

[0043] Further, a differential input function is added to the audio amplification circuit to improve the signal's anti-interference ability. The differential input function is composed of the differential input pins of two LM324 operational amplifier ICs, which are connected to the positive and negative output ends of the high-sensitivity microphone. This design enables the audio amplification circuit to effectively suppress common-mode noise and improve the signal-to-noise ratio. It should be understood that through the differential input design, the anti-interference ability of the audio signal is significantly improved, thereby improving the stability of the test results.

[0044] Further, the design of the LED driving circuit is similar to that of Embodiment One, but to further improve the lighting efficiency and stability of the LED, the LED driving circuit is further optimized in this embodiment. The base of the transistor V is increased with a bias resistor R12 to stabilize the working state of the transistor and avoid LED flickering caused by signal voltage fluctuations. The resistor R12 is a 1 / 4W carbon film resistor or a metal film resistor, and its resistance value is selected according to actual test requirements. In addition, a buffer resistor R16 is added between the anode and cathode of the light-emitting diodes VL1-VLn to further stabilize the working state of the LED and avoid LED damage caused by transient signals. The buffer resistor R16 is a 1 / 4W carbon film resistor or a metal film resistor, and its resistance value is selected according to actual test requirements.

[0045] Further, this embodiment also designs an adaptive test process. During the test process, the dynamic range compression circuit first compresses the dynamic range of the audio signal to make the signal voltage more stable. Then, the audio amplification circuit with differential input function further amplifies and anti-interference processes the audio signal to ensure the purity and intensity of the signal. Next, the gain-adjusted audio signal is input from the base of the transistor and output from the emitter to gradually light up VL1-VLn. It should be understood that through the optimization of dynamic range compression and differential input, the audio intensity test device can still maintain high test performance in complex test environments, thereby meeting the customer's requirements for the stability of test results.

[0046] Through the design of the embodiment, not only the problem of test result fluctuation caused by the large dynamic range of the audio signal is solved, but also the anti-interference ability of the signal is improved through the differential input design. The combination of the dynamic range compression circuit and the differential input circuit makes the audio intensity test device maintain high stability and reliability under various test conditions, thereby meeting the test requirements of customers.

[0047] Embodiment Four

[0048] In order to solve the stability problem of the audio intensity test device during a long test process, the audio intensity test device is further optimized in the embodiment. In the selection of the high-sensitivity microphone, although the Gaojian-2021K145 model is still used, in order to improve the durability and stability of the microphone, the dustproof and waterproof function of the microphone is added. The dustproof and waterproof function is realized by installing a waterproof dustproof cover outside the microphone, and the material of the waterproof dustproof cover is silicone, which has good elasticity and durability, and can effectively protect the microphone from dust and moisture.

[0049] Further, a temperature compensation circuit is added in the audio amplification circuit to improve the stability of the circuit under different temperature conditions. The temperature compensation circuit is composed of a thermistor and a plurality of resistors and capacitors. The thermistor is a negative temperature coefficient thermistor with a model number of NTC10K, and the selection of resistors R17, R18, R19 and capacitors C11, C12 is as follows: resistors R17, R18, R19 are 1 / 4W carbon film resistors or metal film resistors, and capacitors C11, C12 are aluminum electrolytic capacitors with a voltage resistance value of 16V. The input end of the temperature compensation circuit is connected to the output end of the audio amplification circuit, and the output end is connected to the input end of the LED driving circuit. Through the temperature compensation circuit, the gain of the audio amplification circuit remains stable under different temperature conditions, thereby improving the reliability of the test results.

[0050] Further, the design of the LED driving circuit is similar to that of Embodiment One, but in order to further improve the lighting efficiency and stability of the LED, the LED driving circuit is further optimized in the embodiment. The base of the triode V is added with a bias resistor R12 for stabilizing the working state of the triode and avoiding the flickering of the LED caused by signal voltage fluctuation. The resistor R12 is a 1 / 4W carbon film resistor or a metal film resistor, and its resistance value is selected according to the actual test requirements. In addition, a buffer resistor R16 is added between the anode and cathode of the light-emitting diodes VL1-VLn for further stabilizing the working state of the LED and avoiding damage to the LED caused by transient signals. The buffer resistor R16 is a 1 / 4W carbon film resistor or a metal film resistor, and its resistance value is selected according to the actual test requirements.

[0051] Further, the embodiment also designs a long-time stable test process. During the test process, the microphone with dustproof and waterproof function first collects the noise generated by the test sample, ensuring the stability and reliability of the microphone under different environmental conditions. Then, the temperature compensation circuit adjusts the gain of the audio amplification circuit, so that the gain remains stable under different temperature conditions. Next, the audio signal after gain is input from the base of the triode and the signal voltage is output from the emitter, which gradually lights up VL1-VLn. It should be understood that through the dustproof and waterproof function and the temperature compensation circuit, the audio intensity test device can still maintain high stability and reliability during long-time testing, thereby meeting the customer's requirement for the continuity of test results.

[0052] Through the design of the embodiment, not only the stability problem of the microphone during long-time testing is solved, but also the stability of the audio amplification circuit under different temperature conditions is improved through the temperature compensation circuit. The combination of the dustproof and waterproof function and the temperature compensation circuit enables the audio intensity test device to maintain high stability and reliability under various test conditions, thereby meeting the test requirements of customers.

[0053] Embodiment five

[0054] In order to solve the consistency problem of audio signal collection in multi-point testing, the audio intensity test device is further optimized in this embodiment. In the selection of high-sensitivity microphones, although Gaojian-2021K145 type is still used, in order to meet the demand of multi-point testing, this embodiment increases the parallel use of multiple high-sensitivity microphones. Specifically, four Gaojian-2021K145 type microphones are used in this embodiment, which are placed at four different positions of the test sample to collect noise signals generated by different parts of the sample. It should be understood that through the parallel use of multi-point microphones, the noise signals of the sample can be more comprehensively collected, thereby improving the comprehensiveness and accuracy of the test results.

[0055] Further, a multi-channel input function is added to the audio amplification circuit to adapt to the input signal of the multi-point microphone. The multi-channel input function is realized through a multi-channel selector, and the model of the multi-channel selector is CD4051 8-channel analog switch. The input end of CD4051 multi-channel selector is connected to the output end of four microphones, and the output end is connected to the input end of the audio amplification circuit. Through the multi-channel selector, the microphone signals at different positions can be flexibly selected to input into the audio amplification circuit, realizing the automatic control of multi-point testing. It should be understood that through the design of the multi-channel selector, the audio intensity test device can adapt to the demand of multi-point testing, improving the automation degree and efficiency of the test.

[0056] Further, the design and embodiment of the LED driving circuit are similar to the first embodiment, but in order to further improve the lighting efficiency and stability of the LED, the LED driving circuit is further optimized in this embodiment. The base of the triode V is increased with a bias resistor R12 for stabilizing the working state of the triode and avoiding the flickering of the LED caused by the fluctuation of the signal voltage. The resistor R12 is selected from a 1 / 4W carbon film resistor or a metal film resistor, and the resistance value is selected according to the actual test requirements. In addition, the buffer resistor R16 is added between the anode and the cathode of the light-emitting diode VL1-VLn for further stabilizing the working state of the LED and avoiding the damage of the LED caused by the transient signal. The buffer resistor R16 is selected from a 1 / 4W carbon film resistor or a metal film resistor, and the resistance value is selected according to the actual test requirements.

[0057] Further, the embodiment also designs a multi-point test process. During the test, four high-sensitivity microphones are placed at four different positions of the test sample machine to collect the noise signals generated by different parts of the sample machine. Then, the microphone signals at different positions are selected by the CD4051 multiplexer and input into the audio amplification circuit to realize the automatic control of the multi-point test. Next, the gain audio signal is input from the base of the triode and the signal voltage is output from the emitter, and VL1-VLn is sequentially lit. It should be understood that through the design of multi-point test, the audio intensity test device can more comprehensively collect and display the noise signals of the sample machine, thereby improving the comprehensiveness and accuracy of the test results.

[0058] Through the design of the embodiment, not only the consistency of the audio signal collection in the multi-point test is solved, but also the automatic control of the multi-point test is realized through the multiplexer.

[0059] The beneficial effects of the utility model are embodied in the above-mentioned preferred embodiments of the utility model, and do not limit the utility model, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. An audio intensity testing device, characterized in that, The testing apparatus includes: A high-sensitivity microphone is used to convert weak audio signals into electrical signals; An audio amplifier circuit is used to amplify the electrical signal output by the high-sensitivity microphone; An LED driver circuit is used to convert the signal voltage output by the audio amplifier circuit into a mode in which LEDs light up one after another. The LED driver circuit outputs a signal voltage from the emitter of a transistor. The high-sensitivity microphone is placed at a fixed distance and angle on the test prototype to ensure consistent signal collection.

2. The audio intensity testing device according to claim 1, characterized in that, The output of the high-sensitivity microphone is connected to pin 5 of the LM324 operational amplifier IC in the audio amplifier circuit via capacitor C2. The capacitor C2 is an aluminum electrolytic capacitor with a withstand voltage of 16V.

3. The audio intensity testing device according to claim 1, characterized in that, The audio amplifier circuit consists of an LM324 operational amplifier IC and peripheral circuitry. The peripheral circuitry includes resistors R1, R2, R3, R4, and R5, a potentiometer Rp, and capacitors C1 and C2. Resistors R1-R5 are 1 / 4W carbon film resistors or metal film resistors, and potentiometer Rp is an ultra-miniature potentiometer or a vertical variable resistor.

4. The audio intensity testing device according to claim 1, characterized in that, The number of light-emitting diodes in the LED driving circuit is adjusted according to actual testing requirements. The testing device supports the sequential lighting of no less than 5 light-emitting diodes to cover the audio range from low intensity to high intensity.

5. The audio intensity testing device according to claim 3, characterized in that, One end of the potentiometer Rp is connected to the input terminal of the audio amplifier circuit, and the other end is connected to pin 5 of the LM324 op-amp IC through resistor R2. Resistor R1 is connected between pins 7 and 8 of the LM324 op-amp IC, and capacitor C1 is connected in parallel across resistor R1.

6. The audio intensity testing device according to claim 1, characterized in that, The LED driving circuit includes a transistor V, a capacitor C3, a Zener diode VS, resistors R1-Rn, light-emitting diodes VL1-VLn, and diodes VD1-VDn. The transistor V is a C8050, 58050, or 3DG8050 type silicon NPN transistor. The capacitor C3 is a 16V aluminum electrolytic capacitor. The Zener diode VS is a 1 / 2W, 3.6V silicon Zener diode. The resistors R1-Rn are 1 / 4W carbon film resistors or metal film resistors. The light-emitting diodes VL1-VLn are 5mm red high-brightness light-emitting diodes. The diodes VD1-VDn are 1N4148 type silicon switching diodes.

7. The audio intensity testing device according to claim 6, characterized in that, The output terminal of the audio amplifier circuit is connected to the base of transistor V. The emitter of transistor V outputs a signal voltage, which controls the sequential lighting of LEDs VL1-VLn through resistors R1-Rn and diodes VD1-VDn.

Images