Audio filter testing device
By designing an audio filter testing device, utilizing inductor-capacitor filtering circuits and an oscilloscope to display waveforms, the problem of expensive and time-consuming audio signal testing equipment was solved, enabling fast and low-cost testing and troubleshooting.
Patent Information
- Application Number
- CN202422011853.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-08-19
AI Technical Summary
Existing audio signal testing equipment is expensive and time-consuming, making it difficult to quickly confirm whether the design meets the requirements, resulting in long troubleshooting times.
An audio filter testing device was designed, comprising a first circuit board, test wiring and an oscilloscope. The filter circuit is composed of inductors and capacitors to filter and test audio signals. The output waveform is displayed on the oscilloscope to determine signal abnormalities.
It enables rapid and low-cost audio signal testing, allowing for timely detection of design problems, simplified troubleshooting, prevention of equipment damage, and reduction of testing costs.
Smart Images
Figure CN223488405U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of signal testing, and more particularly to an audio filter testing apparatus. Background Technology
[0002] The project tests the audio signal output voltage and needs to calculate the maximum output power to confirm whether it meets design requirements. The current solution uses an Audio Precision System with an amplifier test filter (AUX-0025) to test the audio signal voltage and performance. This method has the following drawbacks: the testing equipment is expensive, requiring manufacturer assistance, the testing cycle is lengthy, and it cannot quickly and promptly confirm the design or identify problems, increasing debugging time. Utility Model Content
[0003] This disclosure provides an audio filter testing apparatus to at least solve the above-mentioned technical problems existing in the prior art.
[0004] According to a first aspect of this disclosure, an audio filter testing device is provided, comprising: a first circuit board, a first test connection, a second test connection, and a third test connection;
[0005] The first circuit board is provided with a first filtering circuit and a second filtering circuit, and each filtering circuit is provided with two independent audio input interfaces and audio output interfaces;
[0006] The test host is connected to the audio input interface on the first circuit board via the first test cable, and the audio device is connected to the audio output interface on the first circuit board via the second test cable.
[0007] The first circuit board is also provided with a first circuit board grounding port, which is connected to the grounding port of the test host based on the third test wiring.
[0008] In one embodiment, the first filter circuit includes: a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor;
[0009] The first inductor is connected in series with the second capacitor, the second inductor is connected in series with the third capacitor, the first capacitor is connected in parallel between the output terminals of the first inductor and the second inductor, and the second capacitor and the third capacitor are connected in parallel and connected to the grounding port of the first circuit board.
[0010] The audio input interface includes a first audio input interface and a second audio input interface disposed on the first filtering circuit, wherein the first audio input interface is located at the first inductor input terminal and the second audio input interface is located at the second inductor input terminal;
[0011] The audio output interface includes a first audio output interface and a second audio output interface disposed on the first filtering circuit. The first audio output interface is located at the output terminal of the first inductor, and the second audio output interface is located at the output terminal of the second inductor.
[0012] In one embodiment, the second filter circuit includes: a third inductor, a fourth inductor, a fourth capacitor, a fifth capacitor, and a sixth capacitor;
[0013] The third inductor is connected in series with the fifth capacitor, the fourth inductor is connected in series with the sixth capacitor, the fourth capacitor is connected in parallel between the third inductor and the output terminal of the fourth inductor, and the fifth capacitor and the sixth capacitor are connected in parallel and connected to the grounding port of the first circuit board.
[0014] The audio input interface includes a third audio input interface and a fourth audio input interface disposed on the second filter circuit. The third audio input interface is located at the input terminal of the third inductor, and the fourth audio input interface is located at the input terminal of the fourth inductor.
[0015] The two audio output interfaces include a third audio output interface and a fourth audio output interface disposed on the second filter circuit. The third audio output interface is located at the output terminal of the third inductor, and the fourth audio output interface is located at the output terminal of the fourth inductor.
[0016] In one embodiment, the first inductor, the second inductor, the third inductor, and the fourth inductor are rated at 8.2uH;
[0017] The first capacitor and the fourth capacitor have a specification of 1uF, and the second capacitor, the third capacitor, the fifth capacitor and the sixth capacitor have a specification of 0.22uF.
[0018] In one possible implementation, the first filtering circuit and the second filtering circuit have a symmetrical structure.
[0019] In one possible implementation, the test host and the first audio input interface, the second audio input interface, the third audio input interface and the fourth audio input interface on the first circuit board are connected through the first test wiring.
[0020] In one embodiment, the audio device and the first audio output interface, the second audio output interface, the third audio output interface and the fourth audio output interface on the first circuit board are connected through the second test wiring.
[0021] In one embodiment, the second test wiring is further provided with a connection point for an oscilloscope, wherein the carbon rod of the oscilloscope is connected to the test fulcrum of the second test wiring.
[0022] In one embodiment, the third test connection is provided with a grounding point, and the oscilloscope grounding port is connected to the grounding point of the third test connection.
[0023] In one embodiment, the audio input signal is connected to the audio input interface on the first circuit board through the first test connection. After being filtered by the first filter circuit and the second filter circuit, the processed audio signal is output to the second test connection through the audio output.
[0024] An oscilloscope is connected to the second test wiring to acquire the audio output signal and display the output waveform. Based on the output waveform, it is determined whether the audio output signal is abnormal and the output voltage is measured. Based on the output voltage, the rated output power of the audio output signal is calculated.
[0025] This disclosure discloses an audio filtering test device that, through the aforementioned capacitor-inductor connection method, can filter out high-frequency signals and glitches from PWM modulation. Using an oscilloscope, when playing a standard 1kHz audio source, it can display a 1kHz sine wave. The output power can be calculated from the waveform, and the device can also check for signal jitter, noise, and other anomalies to aid in troubleshooting. The fixture is lightweight and inexpensive, eliminating the need for expensive dedicated testing equipment. Furthermore, the fixture is applicable to various projects, and a test fixture can be easily made by hand. The testing operation is simple: the audio precision system sends the audio source input signal using its own equipment; the fixture only needs to play a 1kHz standard audio source on its own device, and then, in conjunction with the fixture and oscilloscope, it can perform testing quickly and efficiently to verify the initial design power of the audio signal, avoiding damage to the audio signal and allowing for early troubleshooting. It can also assist in troubleshooting some audio signal problems.
[0026] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description
[0027] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood by reading the detailed description below with reference to the accompanying drawings, in which several embodiments of the present disclosure are shown by way of example and not limitation, wherein:
[0028] In the drawings, the same or corresponding reference numerals denote the same or corresponding parts.
[0029] Figure 1 A schematic diagram of the composition structure of an audio filtering test apparatus according to an embodiment of the present disclosure is shown.
[0030] The following are the labeling options in the diagram: 101-1 First audio input interface, 101-2 Second audio input interface, 101-3 Third audio input interface, 101-4 Fourth audio input interface, 102-1 First audio output interface, 102-2 Second audio output interface, 102-3 Third audio output interface, 102-4 Fourth audio output interface, 103 First circuit board grounding port, 104-1 First inductor, 104-2 Second inductor, 104-3 Third inductor, 104-4 Fourth inductor, 105-1 First capacitor, 105-2 Fourth capacitor, 106-1 Second capacitor, 106-2 Third capacitor, 106-3 Fifth capacitor, 106-4 Sixth capacitor, 107 First circuit board. Detailed Implementation
[0031] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.
[0032] Figure 1 A schematic diagram of the composition structure of an audio filtering test apparatus according to an embodiment of the present disclosure is shown, such as... Figure 1 As shown, a first inductor 104-1, a second inductor 104-2, a third inductor 104-3, and a fourth inductor 104-4 are mounted on the first circuit board 107. A first capacitor 105-1, a second capacitor 106-1, a third capacitor 106-2, a fourth capacitor 105-2, a fifth capacitor 106-3, and a sixth capacitor 106-4 are also mounted on the first circuit board 107. The first inductor 104-1, the second inductor 104-2, the third inductor 104-3, and the fourth inductor 104-4 have a capacitance of 8.2uH; the first capacitor 105-1 and the fourth capacitor 105-2 have a capacitance of 1uF; and the second capacitor 106-1, the third capacitor 106-2, the fifth capacitor 106-3, and the sixth capacitor 106-4 have a capacitance of 0.22uF.
[0033] In this invention, a first inductor 104-1, a second inductor 104-2, a first capacitor 105-1, a second capacitor 106-1, and a third capacitor 106-2 are connected to form a first filter circuit. The output of the first inductor 104-1 is connected in series with the input of the second capacitor 106-1, and the output of the second inductor 104-2 is connected in series with the input of the third capacitor 106-2. The two ends of the first capacitor 105-1 are connected in parallel with the outputs of the first inductor 104-1 and the first inductor 104-2, respectively. The first and second filter circuits are connected in series: the third inductor 104-3, the fourth inductor 104-4, the fourth capacitor 105-2, the fifth capacitor 106-3, and the sixth capacitor 106-4. The output of the third inductor 104-3 is connected in series with the input of the fifth capacitor 106-3, and the output of the fourth inductor 104-4 is connected in series with the input of the sixth capacitor 106-4. The two ends of the fourth capacitor 105-2 are connected in parallel between the outputs of the first inductor 104-3 and the first inductor 104-4. The capacitors and inductors in the first and second filter circuits are installed in a symmetrical configuration.
[0034] In this invention, the first circuit board 107 is provided with a first circuit board grounding port 103 and the third test wiring. This test wiring is a ground wire and is provided with a grounding support point. Specifically, the output terminals of the second capacitor 106-1, the third capacitor 106-2, the fifth capacitor 106-3, and the sixth capacitor 106-4 are all connected to the first circuit board grounding port 103. During testing, the grounding port of the test host is connected to the first circuit board grounding port 103 through the third test wiring, and the grounding port of the oscilloscope is also connected to the grounding support point of the third test wiring.
[0035] In this invention, the test host is connected to the first audio input interface 101-1, the second audio input interface 101-2, the third audio input interface 101-3, and the fourth audio input interface 101-4 on the first circuit board 107 via a first test cable. The first audio output interface 102-1, the second audio output interface 102-2, the third audio output interface 102-3, and the fourth audio output interface 102-4 on the first circuit board 107 are connected to external audio devices via a third test cable.
[0036] In this invention, the first audio input interface 101-1 is located at the input terminal of the first inductor 104-1, the second audio input interface 101-2 is located at the input terminal of the second inductor 104-2, the third audio input interface 101-3 is located at the input terminal of the third inductor 104-3, and the fourth audio interface 101-4 is located at the input terminal of the fourth inductor 104-4. The first audio output interface 102-1 is located at the output terminal of the first inductor 104-1, the second audio output interface 102-2 is located at the output terminal of the second inductor 104-2, the third audio output interface 102-3 is located at the output terminal of the third inductor 104-3, and the fourth audio output interface 102-4 is located at the output terminal of the fourth inductor 104-4.
[0037] In this invention, the signal carbon rod of the oscilloscope is connected to the test fulcrum on the second test wiring, and the grounding port of the oscilloscope is connected to the test fulcrum on the third test wiring.
[0038] In this invention, the filter can pass low frequencies and block high frequencies, with a cutoff frequency of fc = 1 / (2π*√(LC)) = 120kHz. A 1kHz pulse width modulation (PWM) digital pulse signal audio, after being filtered by the audio filtering test device of this invention, has its high frequencies removed, resulting in a 1kHz sine wave. The original 1kHz audio source signal consists of a fundamental frequency and multiple high-frequency harmonics; after being filtered by the audio filtering test device, the high-frequency harmonics and noise signals are removed, resulting in the fundamental frequency.
[0039] In this invention, the audio signal (1kHz or other audio source) is input to the first circuit board 107 through the first test connection, filtered, and then output to external audio devices and oscilloscopes through the second test connection.
[0040] The oscilloscope acquires the audio output signal of the audio device based on the connection pivot point, and displays the L / R output waveform of the audio signal obtained after subtracting the P / N signal. The volume is turned up to the maximum, and the output waveform is used to determine whether the audio output signal is abnormal and measure the output voltage. Based on the output voltage and the impedance between P / N, the rated output power of the audio output signal is calculated to determine whether it meets the usage conditions of the device.
[0041] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this disclosure can be achieved, and this is not limited herein.
[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.
[0043] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.
Claims
1. An audio filter testing device, characterized in that, The device includes: First circuit board, first test wiring, second test wiring, and third test wiring; The first circuit board is provided with a first filtering circuit and a second filtering circuit, and each filtering circuit is provided with two independent audio input interfaces and audio output interfaces; The test host is connected to the audio input interface on the first circuit board via the first test cable, and the audio device is connected to the audio output interface on the first circuit board via the second test cable. The first circuit board is also provided with a first circuit board grounding port, which is connected to the grounding port of the test host based on the third test wiring.
2. The apparatus according to claim 1, characterized in that, The first filtering circuit includes: a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor; The first inductor is connected in series with the second capacitor, the second inductor is connected in series with the third capacitor, the first capacitor is connected in parallel between the output terminals of the first inductor and the second inductor, and the second capacitor and the third capacitor are connected in parallel and connected to the grounding port of the first circuit board. The audio input interface includes a first audio input interface and a second audio input interface disposed on the first filtering circuit, wherein the first audio input interface is located at the first inductor input terminal and the second audio input interface is located at the second inductor input terminal; The audio output interface includes a first audio output interface and a second audio output interface disposed on the first filter circuit. The first audio output interface is located at the output terminal of the first inductor, and the second audio output interface is located at the output terminal of the second inductor. The second filter circuit includes: a third inductor, a fourth inductor, a fourth capacitor, a fifth capacitor, and a sixth capacitor; The third inductor is connected in series with the fifth capacitor, the fourth inductor is connected in series with the sixth capacitor, the fourth capacitor is connected in parallel between the third inductor and the output terminal of the fourth inductor, and the fifth capacitor and the sixth capacitor are connected in parallel and connected to the grounding port of the first circuit board. The audio input interface includes a third audio input interface and a fourth audio input interface disposed on the second filter circuit. The third audio input interface is located at the input terminal of the third inductor, and the fourth audio input interface is located at the input terminal of the fourth inductor. The audio output interface includes a third audio output interface and a fourth audio output interface disposed on the second filter circuit. The third audio output interface is located at the output terminal of the third inductor, and the fourth audio output interface is located at the output terminal of the fourth inductor.
3. The apparatus according to claim 2, characterized in that, The first inductor, the second inductor, the third inductor, and the fourth inductor are all rated at 8.2uH. The first capacitor and the fourth capacitor have a specification of 1uF, and the second capacitor, the third capacitor, the fifth capacitor and the sixth capacitor have a specification of 0.22uF.
4. The apparatus according to claim 1, characterized in that, The first filter circuit and the second filter circuit have a symmetrical structure.
5. The apparatus according to claim 2, characterized in that, The test host and the first audio input interface, the second audio input interface, the third audio input interface and the fourth audio input interface on the first circuit board are connected through the first test wiring.
6. The apparatus according to claim 2, characterized in that, The audio device and the first audio output interface, the second audio output interface, the third audio output interface and the fourth audio output interface on the first circuit board are connected through the second test wiring.
7. The apparatus according to claim 1, characterized in that, The second test connection is also provided with a test fulcrum for an oscilloscope, and the carbon rod of the oscilloscope is connected to the test fulcrum of the second test connection.
8. The apparatus according to claim 1, characterized in that, The third test connection is equipped with a grounding point, and the oscilloscope grounding port is connected to the grounding point of the third test connection.
9. The apparatus according to claim 1, characterized in that, The audio input signal is connected to the audio input interface on the first circuit board through the first test connection. After being filtered by the first filter circuit and the second filter circuit, the processed audio signal is output to the second test connection through the audio output. An oscilloscope is connected to the second test wiring to acquire the audio output signal and display the output waveform. Based on the output waveform, it is determined whether the audio output signal is abnormal and the output voltage is measured. Based on the output voltage, the rated output power of the audio output signal is calculated.