Microphone testing device

Abstract

The utility model aims to provide the microphone testing device which is high in testing precision, supports differential input and is high in anti-interference capability. The device comprises a microphone, a noise corrector and a test unit, the noise corrector is connected to a receiving hole of the microphone through a sound guide tube, the test unit comprises a filtering module, a signal amplification module and an analog-to-digital converter, the microphone is connected with the signal amplification module, and the analog-to-digital converter is connected with the signal amplification module. The signal amplification module is connected with the filtering module, and an upper computer is connected to the signal amplification module through the analog-to-digital converter. The microphone testing device is applied to the technical field of microphone testing.

Description

Technical Field

[0001] The utility model is applied to the technical field of microphone testing, and particularly relates to a microphone testing device. Background Art

[0002] Microphone sensitivity refers to the size of the electrical signal output by the microphone when it is subjected to sound of a certain intensity. The higher the sensitivity, the higher the sound-to-electricity conversion efficiency of the microphone, and the more sensitive it is to weak sound signals. Since microphone sensitivity is an important indicator of microphone performance, microphones must be tested for sensitivity before leaving the factory. In the prior art, when testing the sensitivity of a microphone, it is necessary to hold a test pen and stick the positive and negative electrodes onto the positive and negative electrodes of the microphone accordingly. This method is extremely inefficient, requires a high level of operator proficiency, and is prone to fatigue in the continuous production process. Therefore, it is necessary to provide a microphone testing device with high testing accuracy, support for differential input, high anti-interference ability, and the ability to enhance anti-interference ability. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a microphone testing device with high testing accuracy, support for differential input and high anti-interference capability.

[0004] The technical solution adopted by the utility model is: the utility model includes a microphone, a noise corrector and a test unit, the noise corrector is connected to the receiving hole of the microphone through a sound guide tube, the test unit includes a filtering module, a signal amplifying module, and an analog-to-digital converter, the microphone is connected to the signal amplifying module, the signal amplifying module is connected to the filtering module, and the host computer is connected to the signal amplifying module via the analog-to-digital converter.

[0005] It can be seen from the above scheme that the signal amplification module supports differential input, which is conducive to enhancing anti-interference ability; using a center frequency adjustable filter for filtering is conducive to improving anti-interference ability; using a 16-bit ADC for sampling is conducive to improving test accuracy.

[0006] A preferred solution is that the signal amplification module includes a relay, a first operational amplifier and a second operational amplifier, the normally closed contacts of the relay are connected to the MIC+ pin and the MIC- pin of the microphone, the common end of the relay is connected to the input end of the first operational amplifier, the input end of the first operational amplifier is connected to the inverting input end of the second operational amplifier, and the inverting input end of the second operational amplifier is connected to the MIC_FLITER_IN pin of the filtering module.

[0007] A preferred solution is that the RMS_DC_OUT pin of the filtering module is connected to the corresponding pin of the signal amplifying module.

[0008] A preferred solution is that the analog-to-digital converter includes a third operational amplifier and a multiplexer, the non-inverting input end of the third operational amplifier is connected to the ADC_VI pin of the signal amplification module, the output end of the third operational amplifier is connected to the IN0 pin of the multiplexer, and the PE pin of the multiplexer is connected to the host computer via the single-chip microcomputer. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a circuit schematic diagram of the filtering module;

[0010] Figure 2 is a circuit schematic diagram of the first part of the signal amplification module;

[0011] Figure 3 is a circuit schematic diagram of the second part of the signal amplification module;

[0012] Figure 4 is a circuit schematic diagram of the analog-to-digital converter;

[0013] Figure 5 It is a test principle diagram of the utility model. DETAILED DESCRIPTION

[0014] like Figure 5 As shown, in this embodiment, the utility model includes a microphone 1, a noise corrector 2 and a test unit 3, wherein the noise corrector 2 is connected to the receiving hole of the microphone 1 through a sound guide tube, and the test unit 3 includes a filtering module, a signal amplification module, and an analog-to-digital converter. The microphone 1 is connected to the signal amplification module, and the signal amplification module is connected to the filtering module. The host computer is connected to the signal amplification module through the analog-to-digital converter. The noise corrector 2 adopts a standard noise corrector CENTER 326, outputs a sound with a sound pressure of 94dB and a frequency of 1000Hz, and directly leads to the receiving hole of the microphone 1 through the sound guide tube. The test unit 3 provides a driving power supply to the microphone 1, collects the AC signal output by the microphone 1, and performs corresponding amplification, filtering, true effective value conversion, voltage collection, and calculates the sensitivity value. The present application can realize the sensitivity test of the FPC patch microphone.

[0015] like Figure 1 and Figure 2As shown, in this embodiment, the signal amplification module includes a relay K428A, a first operational amplifier U901 and a second operational amplifier U902, the normally closed contact of the relay K428A is connected to the MIC+ pin and the MIC- pin of the microphone 1, the common end of the relay K428A is connected to the input end of the first operational amplifier U901, the input end of the first operational amplifier U901 is connected to the reverse input end of the second operational amplifier U902, and the reverse input end of the second operational amplifier U902 is connected to the MIC_FLITER_IN pin of the filtering module.

[0016] like Figure 1 As shown, in this embodiment, the RMS_DC_OUT pin of the filtering module is connected to the corresponding pin of the signal amplifying module.

[0017] like Figure 3 and Figure 4 As shown, in this embodiment, the analog-to-digital converter includes a third operational amplifier U602A and a multiplexer U605, the non-inverting input end of the third operational amplifier U602A is connected to the ADC_VI pin of the signal amplification module, the output end of the third operational amplifier U602A is connected to the IN0 pin of the multiplexer U605, and the PE pin of the multiplexer U605 is connected to the host computer via the single-chip microcomputer.

[0018] In this embodiment, if the sensitivity value of the test microphone is too small, check whether the calibration has been performed by checking whether the sound tube is aligned with the microphone pickup hole; if the power-on is abnormal, check whether the power supply voltage is normal and whether the power input port is short-circuited through a multi-transformer; if the test result is unstable, check whether there is interference caused by high-power equipment nearby; if there is communication abnormality, check whether the serial port line connection is loose.

Claims

1. A microphone testing device, characterized in that: It comprises a microphone (1), a noise corrector (2) and a test unit (3); the noise corrector (2) is connected to the receiving hole of the microphone (1) via a sound guide tube; the test unit (3) comprises a filtering module, a signal amplifying module and an analog-to-digital converter; the microphone (1) is connected to the signal amplifying module, the signal amplifying module is connected to the filtering module, and a host computer is connected to the signal amplifying module via the analog-to-digital converter.

2. A microphone testing device according to claim 1, characterized in that: The signal amplification module comprises a relay (K428A), a first operational amplifier (U901) and a second operational amplifier (U902); the normally closed contact of the relay (K428A) is connected to the MIC+ pin and the MIC- pin of the microphone (1); the common end of the relay (K428A) is connected to the input end of the first operational amplifier (U901); the input end of the first operational amplifier (U901) is connected to the inverting input end of the second operational amplifier (U902); and the inverting input end of the second operational amplifier (U902) is connected to the MIC_FLITER_IN pin of the filtering module.

3. A microphone testing device according to claim 1, characterized in that: The analog-to-digital converter comprises a third operational amplifier (U602A) and a multiplexer (U605), wherein the non-inverting input end of the third operational amplifier (U602A) is connected to the ADC_VI pin of the signal amplification module, the output end of the third operational amplifier (U602A) is connected to the IN0 pin of the multiplexer (U605), and the PE pin of the multiplexer (U605) is connected to the host computer via the single-chip microcomputer.

4. A microphone testing device according to claim 1, characterized in that: The RMS_DC_OUT pin of the filtering module is connected to the corresponding pin of the signal amplifying module.

Images