Device for realizing ultra-large dynamic range measurement of sound level meter

Abstract

The utility model discloses a device for realizing ultra-large dynamic range measurement of a sound level meter. The device comprises a microphone acquisition unit for acquiring sound signals and converting the sound signals into electric signals; the operational amplifier circuit unit and the operational amplifier attenuation circuit unit are used for receiving the sound signals acquired by the microphone acquisition unit and outputting electric signals; the relay switch unit is arranged on a circuit between the microphone acquisition unit and the operational amplification circuit unit and is used for receiving an opening and closing control signal of the processor CPU unit; and the audio ADC unit is used for receiving the electric signals of the operational amplifier circuit unit and the operational amplifier attenuation circuit unit, and outputting digital signals to the processor CPU unit to obtain and display sound level information. According to the utility model, preprocessing of full-scale sound signals of the sound level meter can be realized, and high precision and high dynamic range of measurement are ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to sound level meter, professional audio measurement field, especially relate to a kind of device for realizing the measurement of sound level meter super large dynamic range. BACKGROUND

[0002] The existing sound level meter technology generally directly collects microphone audio signals, or the microphone audio signals are filtered after simple peripheral conditioning circuit, and then input to audio ADC.The input signal is processed using a filter, but the filtering effect is often very unsatisfactory, especially small signals still have noise after filtering, which greatly affects the measurement accuracy and dynamic range error. UTILITY MODEL CONTENTS

[0003] The utility model aims at the deficiency of prior art, and provides a kind of device for realizing the measurement of sound level meter super large dynamic range.The device provided by the utility model divides the collected audio signals into large signals and small signals after collecting microphone audio signals, and the large signals are sent to the first path channel of audio ADC after being reduced by operational amplifier attenuation circuit;The small signals are sent to the second path channel of audio ADC after being amplified by operational amplifier amplification circuit.Further, to prevent the mutual crosstalk influence between the two input channels in audio ADC device, a relay switch circuit is added before operational amplifier amplification circuit to control the on-off of large signals entering operational amplifier amplification circuit.

[0004] The utility model aims to realize the following technical scheme: a kind of device for realizing the measurement of sound level meter super large dynamic range, the device includes:

[0005] Microphone acquisition unit, for collecting sound signals and converting into electrical signals;

[0006] Operational amplifier amplification circuit unit and operational amplifier attenuation circuit unit, for receiving the electrical signals output by microphone acquisition unit and carrying out amplification and attenuation processing;

[0007] Relay switch unit is arranged on the circuit between microphone acquisition unit and operational amplifier amplification circuit unit, and receives the on-off control signal of processor CPU unit;

[0008] Audio ADC unit receives the electrical signals of operational amplifier amplification circuit unit and operational amplifier attenuation circuit unit, and outputs digital signal to processor CPU unit to obtain sound level information and display.

[0009] Further, the audio ADC unit has two channels, one receives the sound signals attenuated by operational amplifier attenuation circuit unit, and the other receives the sound signals amplified by operational amplifier amplification circuit unit.

[0010] Further, the op-amp amplification circuit unit amplification multiple is 1 and the attenuation multiple of the op-amp attenuation circuit unit is adjusted according to actual requirements.

[0011] Further, the audio ADC unit has a single-end 5.0Vrms maximum range input, a dynamic range of 110dB, a minimum resolution of 16uVrms, and a maximum voltage of a single-end output of a microphone of 6.0Vrms.

[0012] Further, the super large dynamic range is 20dBA-130dBA, i.e. 10.0uVrms-3.162Vrms.

[0013] The sound level meter full-range sound signal preprocessing is realized, and high precision and high dynamic range of measurement are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 A structure diagram of the device for realizing the sound level meter super large dynamic range measurement is provided.

[0015] Figure 2 A device structure diagram with adjustable amplification multiple and attenuation multiple is provided. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the single embodiment in the utility model, all other embodiments obtained by the person skilled in the art without creative labor are within the protection scope of the utility model.

[0017] As shown in the drawings, Figure 1 The utility model provides a device for realizing the sound level meter super large dynamic range measurement, including microphone acquisition unit, relay switch unit, op-amp amplification circuit unit, op-amp attenuation circuit unit, audio ADC unit, processor CPU unit and display unit.

[0018] After environmental noise is converted into electric signal by microphone acquisition unit, is sent to audio ADC unit through op-amp amplification circuit unit or op-amp attenuation circuit unit, is sent to processor CPU unit by converting analog voltage signal into digital signal through analog-digital A / D conversion in audio ADC unit. The processor CPU unit processes digital signal and obtains sound level information. After processing, the result is saved, communicated and sent to display unit for display.

[0019] The operational amplifier amplification circuit unit amplifies weak signals that cannot be recognized by the audio ADC unit. Figure 2 As shown in the figure, the operational amplifier amplification circuit unit and the operational amplifier attenuation circuit unit receive control signals of the processor CPU unit to adjust the amplification multiple of the operational amplifier amplification circuit unit and the attenuation multiple of the operational amplifier attenuation circuit unit according to actual requirements.

[0020] The sound signals collected by the microphone collection unit are sent to two channels of the audio ADC unit through the operational amplifier amplification circuit unit and the operational amplifier attenuation circuit unit.

[0021] Specifically, the measurement dynamic range of the sound level meter is 20dBA (10.0uVrms) to 130dBA (3.162Vrms).

[0022] The model of the audio ADC used in the utility model is PCM6480-Q1, and the maximum range input of single-end 5.0Vrms is used; the dynamic range is 110dB, and the minimum resolution is 16uVrms in theory.

[0023] The attenuation multiple of the operational amplifier attenuation circuit is 0.5, that is, the maximum voltage of the single-end output of the microphone is 6.0Vrms, and the amplitude of the signal sent to the audio ADC through the operational amplifier attenuation circuit is 6.0Vrms*0.5=3.0Vrms, which does not exceed the maximum amplitude 5Vrms requirement of the audio ADC.

[0024] When the signal input to the audio ADC is greater than 0.7 times the maximum input amplitude of the ADC (0.7*5.0=3.5Vrms), that is, the audio amplitude input by the microphone is 3.5Vrms / 10=0.35Vrms, the processor CPU controls the relay to disconnect the operational amplifier amplification circuit, and switches to the operational amplifier attenuation circuit.

[0025] When the input signal is less than 0.7 times the maximum input amplitude of the ADC, that is, the amplitude of the input signal sent to the audio ADC through the operational amplifier attenuation circuit is less than 0.175Vrms, the processor CPU controls the relay switch to open the operational amplifier amplification circuit, switches to the operational amplifier amplification circuit, and the operational amplifier attenuation circuit is always in the on state.

[0026] The above process ensures that the sound level meter realizes a measurement dynamic range of 20dBA (10.0uVrms) to 130dBA (3.162Vrms).

[0027] In addition, the above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, wherein the switching switch relay, the audio ADC model PCM6480-Q1, the operational amplifier amplification circuit, the operational amplifier attenuation circuit parameters, etc. can be adjusted, changed and replaced. Therefore, the claimed rights should be covered within the protection scope of the application.

[0028] The above embodiments are used to explain and illustrate the present application, but not to limit the present application, and any modification and change made to the present application within the spirit and protection scope of the claims falls within the protection scope of the present application.

Claims

1. An apparatus for implementing sound level meter super-dynamic range measurements, characterized by, The device comprises: a microphone acquisition unit for acquiring sound signals and converting them into electric signals; an operational amplifier amplification circuit unit and an operational amplifier attenuation circuit unit for receiving the electric signals output by the microphone acquisition unit and performing amplification and attenuation processing; a relay switch unit arranged on the circuit between the microphone acquisition unit and the operational amplifier amplification circuit unit and receiving the opening and closing control signals of the processor CPU unit; an audio ADC unit receiving the electric signals of the operational amplifier amplification circuit unit and the operational amplifier attenuation circuit unit and outputting digital signals to the processor CPU unit to obtain sound level information and display it.

2. The device for implementing the sound level meter ultra-wide dynamic range measurement according to claim 1, characterized in that, The audio ADC unit has two channels, one receiving the sound signals attenuated by the operational amplifier attenuation circuit unit and the other receiving the sound signals amplified by the operational amplifier amplification circuit unit.

3. The device for implementing the sound level meter ultra-wide dynamic range measurement of claim 1, wherein, The amplification multiple of the operational amplifier amplification circuit unit is and the attenuation multiple of the operational amplifier attenuation circuit unit is adjusted according to actual requirements.

4. The device for implementing the sound level meter ultra-wide dynamic range measurement of claim 1, wherein, The audio ADC unit has a single-end 5.0Vrms maximum range input, a dynamic range of 110dB, a minimum resolution of 16uVrms, and a single-end output maximum voltage of the microphone of 6.0Vrms.

5. The device for implementing the sound level meter ultra-wide dynamic range measurement of claim 1, wherein, The super large dynamic range is 20dBA-130dBA, i.e. 10.0uVrms-3.162Vrms.

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