Production test device with audio power amplifier output function for building intercom mainboard

Abstract

The utility model provides a building talkback mainboard production test device with an audio power amplifier output function, comprising an Audio DAC module and an audio power amplifier output module, the audio power amplifier output module is connected with a low-pass filtering module, the low-pass filtering module is connected with a detection module, and the detection module is connected with the audio power amplifier output module. And the detection module is used for detecting the filtered sine wave signal. Whether the sine wave signal meets the preset value is judged through the detection module, so that the accuracy of the audio power amplifier output test result does not need to be subjectively judged, and the test consistency is high. The test of the output of the audio power amplifier does not need to consider the test environment noise. According to the test result, the red indicating lamp or the green indicating lamp is turned on, the faulty mainboard can be effectively intercepted, the production test efficiency is improved, and the original test time needs 3-8 s, but now only needs 1 s. And the MCU returns the test result to the building intercom mainboard, so that the problem of test omission can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of building intercom testing, in particular to a production testing device of a building intercom mainboard with an audio power amplifier output function. Background Art

[0002] As a supporting equipment of a real estate, building intercom is generally installed in each household. When a visitor comes, the visitor generally calls the building intercom at home through the host placed at the entrance of the floor. Therefore, audio output is the most basic function of building intercom products. In some building intercom products, the mainboard has an audio amplifier output function. At present, during the mainboard debugging stage, a speaker is usually connected to the output end to listen and judge whether the speaker has sound output, whether the volume is too loud or too low, etc.

[0003] Since everyone's subjective judgment is different, there is no testing standard, the production test workshop environment is also relatively complex, and the single test time is determined by human habits. The time may be long or short, with the longest taking 7-8s and the shortest taking 3-4s. The test efficiency is not high, and there are also cases of missed tests. These undoubtedly bring many problems to the consistency of production testing and product quality. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a production test device with an audio power amplifier output function for a building intercom mainboard, which can ensure the accuracy of the audio power amplifier output result without the need for human subjective judgment, with high test consistency. The test of the audio power amplifier output does not need to consider the test environment noise, and can improve the production test efficiency. At the same time, it can also avoid the problem of missed tests.

[0005] The utility model is achieved in this way:

[0006] The utility model provides a production test device with an audio power amplifier output function for a building intercom mainboard, comprising an Audio DAC module and an audio power amplifier output module, wherein the Audio DAC module is used to output a sine wave signal, the audio power amplifier output module is used to modulate and amplify the sine wave signal, the audio power amplifier output module is connected with a low-pass filter module, the low-pass filter module is used to filter the signal output by the audio power amplifier output module, the low-pass filter module is connected with a detection module, and the detection module is used to detect the sine wave signal after filtering.

[0007] Further, the low-pass filter module includes a left channel filter circuit and a right channel filter circuit, the left channel filter circuit includes an inductor L1, one end of the inductor L1 is connected to the left channel signal input end, the other end of the inductor L1 is connected to a resistor R1, the resistor R1 is connected to a capacitor C2, the other end of the capacitor C2 is connected to the left channel signal output end, a capacitor C1 is further connected between the inductor L1 and the resistor R1, one end of the capacitor C1 is connected to the ground end, a resistor R2 is further connected between the resistor R1 and the capacitor C2, and one end of the resistor R2 is connected between the capacitor C1 and the ground end;

[0008] The right channel filter circuit includes an inductor L2, one end of the inductor L2 is connected to the right channel signal input terminal, the other end of the inductor L2 is connected to a resistor R3, the resistor R3 is connected to a capacitor C4, the other end of the capacitor C4 is connected to the right channel signal output terminal, a capacitor C3 is also connected between the inductor L2 and the resistor R3, one end of the capacitor C3 is connected to the ground terminal, a resistor R4 is also connected between the resistor R3 and the capacitor C4, and one end of the resistor R4 is connected between the capacitor C4 and the ground terminal.

[0009] Furthermore, the inductance value of the inductors L1 and L2 is 22 μH, the resistance value of the resistors R1 , R2 , R3 and R4 is 4.7 KΩ, and the capacitance value of the capacitors C1 , C2 , C3 and C4 is 1 μF.

[0010] Furthermore, the withstand voltage of the capacitors C1, C2, C3 and C4 is 25V.

[0011] Furthermore, the detection module includes an MCU, the MCU is connected to the low-pass filter module, the MCU is respectively connected to a red indicator light and a green indicator light, and the MCU is also connected to a main board of the building intercom to transmit the test results back to the building intercom main board.

[0012] The advantages of the utility model are:

[0013] 1. The sine wave signal output by the low-pass filter module is input into the detection module, and the detection module determines whether the sine wave signal meets the preset value, so that the accuracy of the audio amplifier output test result does not require human subjective judgment, and the test consistency is high.

[0014] 2. The test of audio amplifier output does not need to consider the test environment noise.

[0015] 3. According to the test results, the red or green indicator light is on, which can effectively intercept the faulty motherboard and improve the production test efficiency. The original test time took 7-8s for the longest and 3-4s for the shortest, but now it only takes 1s.

[0016] 4. MCU returns the test results to the building intercom mainboard to avoid the problem of missed tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the embodiments with reference to the accompanying drawings.

[0018] Figure 1 It is a schematic diagram of a specific implementation method of the production and testing device of the utility model.

[0019] Figure 2 This is a schematic diagram of the circuit structure of the low-pass filter module of the utility model.

[0020] Figure 3 This is a schematic diagram of the detection module of the utility model.

[0021] Figure 4 It is a schematic diagram of the waveform input to the low-pass filter module and the waveform output by the low-pass filter module of the present invention.

[0022] Figure 5 It is a schematic diagram of the waveform expansion of the utility model input to the low-pass filter module. DETAILED DESCRIPTION

[0023] The overall idea of ​​the utility model is: the Audio DAC module outputs a 1KHz 0dB sine wave signal, which is amplified and modulated by the audio power amplifier output module, and then filtered out by the low-pass filter module to become a sine wave signal of a standard voltage value (the signal output by the audio power amplifier output module is usually modulated, and it is not easy for the MCU to process it directly. Therefore, it needs to be filtered and converted into a sine wave signal of a standard voltage value before processing and judgment), and then given to the MCU for processing.

[0024] See also Figures 1 to 5 The utility model provides a production test device with an audio power amplifier output function for a building intercom mainboard, including an Audio DAC module (audio digital-to-analog converter module) and an audio power amplifier output module. The Audio DAC module and the audio power amplifier output module are part of the building intercom mainboard. The Audio DAC module is used to output a sine wave signal. The Audio DAC module outputs a 1KHz 0dB sine wave signal. The audio power amplifier output module is used to modulate and amplify the sine wave signal. The audio power amplifier output module is connected to a low-pass filter module. Figure 4 The red part in the middle is the sine wave signal input to the low-pass filter module. Figure 5 Schematic diagram of the waveform expansion input to the low-pass filter module, the low-pass filter module is used to filter the signal output by the audio amplifier output module. The sine wave signal after the low-pass filter module is as follows Figure 4As shown in the middle blue part, the low-pass filter module is connected to a detection module, and the detection module is used to detect the sine wave signal after filtering. The low-pass filter module and the detection module constitute a test tool for the building intercom motherboard with audio power amplifier function.

[0025] Specifically, the low-pass filter module includes a left channel filter circuit and a right channel filter circuit, the left channel filter circuit includes an inductor L1, one end of the inductor L1 is connected to the left channel signal input end, the other end of the inductor L1 is connected to a resistor R1, the resistor R1 is connected to a capacitor C2, the other end of the capacitor C2 is connected to the left channel signal output end, a capacitor C1 is further connected between the inductor L1 and the resistor R1, one end of the capacitor C1 is connected to the ground end, a resistor R2 is further connected between the resistor R1 and the capacitor C2, and one end of the resistor R2 is connected between the capacitor C1 and the ground end;

[0026] The right channel filter circuit includes an inductor L2, one end of the inductor L2 is connected to the right channel signal input terminal, the other end of the inductor L2 is connected to a resistor R3, the resistor R3 is connected to a capacitor C4, the other end of the capacitor C4 is connected to the right channel signal output terminal, a capacitor C3 is also connected between the inductor L2 and the resistor R3, one end of the capacitor C3 is connected to the ground terminal, a resistor R4 is also connected between the resistor R3 and the capacitor C4, and one end of the resistor R4 is connected between the capacitor C4 and the ground terminal.

[0027] Specifically, the inductance of the inductors L1 and L2 is 22μH, the resistance of the resistors R1, R2, R3 and R4 is 4.7KΩ, the resistance precision of the resistors R1, R2, R3 and R4 is 1%, the capacitance of the capacitors C1, C2, C3 and C4 is 1μF, the capacitance precision of the capacitors C1, C2, C3 and C4 is 10%, and the withstand voltage of the capacitors C1, C2, C3 and C4 is 25V. Of course, the specifications of the inductors L1 and L2, the resistors R1, R2, R3 and R4, and the capacitors C1, C2, C3 and C4 can be adjusted accordingly by those skilled in the art according to the actual circuit application.

[0028] Specifically, the detection module includes an MCU (single-chip microcomputer) with interfaces such as AD, GPIO and serial port. The MCU is connected to a low-pass filter module. The MCU is respectively connected to a red indicator light and a green indicator light. The MCU is also connected to the main board of the building intercom to transmit the test results back to the main board of the building intercom.

[0029] When performing audio testing,

[0030] The Audio DAC module outputs a 1KHz 0dB sine wave signal, which is sent to the audio power amplifier output module for modulation and amplification. The modulated and amplified signal is connected to the low-pass filter module (in the prior art, the audio power amplifier output module is connected to an external speaker, and subjective judgment and testing are performed manually).

[0031] The modulated signal output by the audio amplifier output module is filtered out by low-pass filtering (inductor L1, capacitor C1, inductor L2 and capacitor C3) and converted into a sine wave. The sine wave is given to the microcontroller for processing and judgment after the voltage division of resistors R1, R2, R3 and R4 and the DC isolation of capacitors C2 and C4.

[0032] The MCU judgment result will be displayed on the detection module. The red indicator light indicates that the test fails, and the green indicator light indicates that the test passes. At the same time, regardless of whether the test result passes or not, the MCU will send the test result back to the main board through the serial port, and the main board will display the test result on the display screen of the building intercom.

[0033] The specific working mode of the detection module is as follows:

[0034] The sine wave signal output by the low-pass filter module is input to the AD port on the MCU. The MCU determines whether the sine wave signal meets the preset conditions. The preset conditions are:

[0035] Frequency: 1K±3%

[0036] Voltage: 5V±15%.

[0037] The preset conditions can be adjusted accordingly based on the output frequency, the selection of filter parameters and the supply voltage of the microcontroller.

[0038] If the sine wave signal input to the MCU does not meet the preset conditions, the test fails and the red indicator light on the MCU control detection module turns on;

[0039] If the sine wave signal input to the MCU meets the preset conditions, the test passes and the green indicator light on the MCU control detection module turns on.

[0040] Regardless of whether the test results are passed or not, the microcontroller will send the test results back to the mainboard through the serial port to back up and upload the test data. The mainboard will display the test results on the display screen of the building intercom, so that the operator can intuitively check whether the product has passed the test or missed the test based on the display results on the display screen.

[0041] In this application, a low-pass filter module is connected to the output end of the audio power amplifier output module, and the sine wave signal output by the low-pass filter module is input into the detection module. The detection module determines whether the sine wave signal meets the preset value, so that the accuracy of the audio power amplifier output test result does not require human subjective judgment, and the test consistency is high. Since this test device does not require manual judgment, the test of the audio power amplifier output does not need to consider the test environment noise. According to the test results, the red indicator light or the green indicator light is on, which can effectively intercept the faulty motherboard and improve the production test efficiency. The original test time was long and short, the long one required 7-8s, the short one required 3-4s, and now it only takes 1s. The MCU returns the test results to the building intercom, which can avoid the problem of missed tests.

[0042] Although the specific implementation methods of the present invention are described above, those skilled in the art should understand that the specific embodiments described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A production test device for a building intercom mainboard with an audio power amplifier output function, comprising an Audio DAC module and an audio power amplifier output module, wherein the Audio DAC module is used to output a sine wave signal, and the audio power amplifier output module is used to modulate and amplify the sine wave signal, characterized in that: The audio power amplifier output module is connected to a low-pass filter module, which is used to filter the signal output by the audio power amplifier output module. The low-pass filter module is connected to a detection module, which is used to detect the sine wave signal after filtering.

2. A production test device for a building intercom motherboard with an audio amplifier output function as claimed in claim 1, characterized in that: The low-pass filter module includes a left channel filter circuit and a right channel filter circuit, the left channel filter circuit includes an inductor L1, one end of the inductor L1 is connected to the left channel signal input end, the other end of the inductor L1 is connected to a resistor R1, the resistor R1 is connected to a capacitor C2, the other end of the capacitor C2 is connected to the left channel signal output end, a capacitor C1 is further connected between the inductor L1 and the resistor R1, one end of the capacitor C1 is connected to the ground end, a resistor R2 is further connected between the resistor R1 and the capacitor C2, and one end of the resistor R2 is connected between the capacitor C1 and the ground end; The right channel filter circuit includes an inductor L2, one end of the inductor L2 is connected to the right channel signal input terminal, the other end of the inductor L2 is connected to a resistor R3, the resistor R3 is connected to a capacitor C4, the other end of the capacitor C4 is connected to the right channel signal output terminal, a capacitor C3 is also connected between the inductor L2 and the resistor R3, one end of the capacitor C3 is connected to the ground terminal, a resistor R4 is also connected between the resistor R3 and the capacitor C4, and one end of the resistor R4 is connected between the capacitor C4 and the ground terminal.

3. A production test device for a building intercom motherboard with an audio amplifier output function as claimed in claim 2, characterized in that: The inductance value of the inductors L1 and L2 is 22 μH, the resistance value of the resistors R1 , R2 , R3 and R4 is 4.7 KΩ, and the capacitance value of the capacitors C1 , C2 , C3 and C4 is 1 μF.

4. A production test device for a building intercom motherboard with an audio amplifier output function as claimed in claim 2, characterized in that: The withstand voltage of the capacitors C1, C2, C3 and C4 is 25V.

5. A production test device for a building intercom motherboard with an audio amplifier output function as claimed in claim 1, characterized in that: The detection module includes an MCU, the MCU is connected to a low-pass filter module, the MCU is respectively connected to a red indicator light and a green indicator light, and the MCU is also connected to a main board of a building intercom to transmit the test results back to the main board of the building intercom.

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