Diagnostic method for an audio amplifier and diagnostic circuit therefor

Abstract

The application provides a diagnosis method of an audio amplifier and a diagnosis circuit thereof. In the diagnosis method, the voltage differential signal and the current signal of the load after the diagnosis differential signal passes through the load are detected, so that the modulus and the phase of the impedance of the load can be obtained according to the voltage differential signal and the current signal. Then, whether the load is normally connected can be judged by comparing the modulus of the impedance of the load with the size of a preset threshold, according to the size of the phase of the impedance of the load, or by combining the comparison of the modulus of the impedance of the load with the size of a preset threshold and the size of the phase of the impedance of the load. Therefore, the diagnosis method of the audio amplifier comprises various methods for diagnosing whether the load of the audio amplifier is normally connected. These methods are simple in determination logic and can accurately diagnose, so that the convenience of diagnosis is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic circuit, in particular to a diagnosis method of an audio amplifier and a diagnosis circuit thereof. BACKGROUND

[0002] Since the design of an audio amplifier is usually based on specific load conditions (such as impedance matching), abnormal connection of the load may directly cause overcurrent or overvoltage of the device, thereby causing physical damage. For example, in the case of open circuit of the load, i.e. the load is not normally connected, the sound effect cannot be presented, thereby affecting the user experience. Moreover, in the case of short circuit of the load, there is a risk of burning the loudspeaker.

[0003] However, the prior art method for determining whether the audio amplifier is normally connected is very complex. SUMMARY

[0004] The present application provides a diagnosis method of an audio amplifier and a diagnosis circuit thereof to provide an accurate and simple diagnosis method for determining the connection state of a tweeter.

[0005] According to a first aspect of the present application, a diagnosis method of an audio amplifier is provided, wherein the load of the audio amplifier includes a tweeter, and the method comprises:

[0006] outputting a diagnosis differential signal to both ends of the load of the audio amplifier, wherein the diagnosis differential signal is an alternating current signal;

[0007] after outputting the diagnosis differential signal to both ends of the load of the audio amplifier, collecting a voltage differential signal and a current signal at both ends of the load;

[0008] obtaining a modulus and a phase of the impedance of the load of the audio amplifier according to the voltage differential signal and the current signal;

[0009] determining the connection state of the tweeter according to the impedance parameters of the load, including: comparing the modulus of the impedance of the load with a preset modulus threshold value to determine the connection state of the tweeter; and / or, comparing the phase of the impedance of the load with a preset phase threshold value to determine the connection state of the tweeter.

[0010] Optionally, the method for obtaining the modulus and the phase of the impedance of the load of the audio amplifier according to the voltage differential signal and the current signal comprises: performing quadrature demodulation on the voltage differential signal and the current signal to obtain the modulus and the phase of the impedance of the load.

[0011] Optionally, the method for obtaining the preset modulus threshold value comprises:

[0012] providing a sample audio amplifier;

[0013] obtaining a first mode of impedance of the first load under a first load condition, the first load condition being used to characterize a first load of the sample audio amplifier as a woofer;

[0014] obtaining a second mode of impedance of the second load under a second load condition, the second load condition being used to characterize a second load of the sample audio amplifier as a woofer and a tweeter in parallel;

[0015] obtaining a mean value of the first mode and the second mode as the preset mode threshold.

[0016] Optionally, the method of obtaining the first mode of impedance of the first load comprises: outputting a first diagnostic differential signal to both ends of the first load under a first load condition; collecting a first voltage signal and a first current signal at both ends of the first load after outputting the first diagnostic differential signal to both ends of the first load; and obtaining the first mode of impedance of the first load according to the first voltage signal and the first current signal.

[0017] The method of obtaining the second mode of impedance of the second load comprises: outputting a second diagnostic differential signal to both ends of the second load; collecting a second voltage signal and a second current signal at both ends of the second load after outputting the second diagnostic differential signal to both ends of the second load; and obtaining the second mode of impedance of the second load according to the second voltage signal and the second current signal.

[0018] Optionally, the load is a woofer and a tweeter in parallel.

[0019] Optionally, before judging the connection state of the tweeter according to the impedance parameter of the load, the method further comprises:

[0020] obtaining a difference between the mode of impedance of the load and the preset mode threshold as a preset margin;

[0021] selecting a diagnostic method according to the preset margin, comprising: if the preset margin is less than or equal to a preset error, judging the connection state of the tweeter according to a size between a phase of the impedance of the load and a preset phase threshold; and if the preset margin is greater than the preset error, judging the connection state of the tweeter according to a size between the mode of the impedance of the load and the preset mode threshold.

[0022] Optionally, the method of judging the connection state of the tweeter by comparing the mode of the impedance of the load with the preset mode threshold comprises: if the mode of the impedance of the load is greater than the preset mode threshold, judging that the connection state of the tweeter is abnormal; and if the mode of the impedance of the load is less than or equal to the preset mode threshold, judging that the connection state of the tweeter is normal.

[0023] Optionally, the load is a tweeter.

[0024] Optionally, the preset phase threshold is -45°~ -30°, and according to the size of the phase of the impedance of the load and the preset phase threshold, the method for judging the connection state of the tweeter comprises: if the phase of the impedance of the load is greater than the preset phase threshold, judging that the connection state of the tweeter is abnormal; and if the phase of the impedance of the load is less than or equal to the preset phase threshold, judging that the connection state of the tweeter is normal.

[0025] According to the second aspect of the present application, a diagnostic circuit of an audio amplifier is provided, characterized by being used to implement the diagnostic method of the audio amplifier, and the diagnostic circuit comprises:

[0026] a driving module, configured to output a diagnostic differential signal to both ends of a load of the audio amplifier, the diagnostic differential signal being an alternating current signal;

[0027] a collecting module, configured to collect a voltage differential signal and a current signal at both ends of the load;

[0028] a calculating module, configured to judge the connection state of the tweeter according to an impedance parameter of the load, comprising: judging the connection state of the tweeter by comparing the size of the impedance of the load with a preset impedance threshold; and / or judging the connection state of the tweeter according to the size of the phase of the impedance of the load and a preset phase threshold.

[0029] Optionally, the diagnostic differential signal comprises a first diagnostic signal and a second diagnostic signal, the driving module comprises an amplifying unit and an inverting unit, the amplifying unit is configured to receive an initial diagnostic signal output by the calculating module and amplify the initial diagnostic signal to output the first diagnostic signal to one end of the load and an input end of the inverting unit, and the inverting unit is configured to invert the first diagnostic signal to output the second diagnostic signal to the other end of the load, the first diagnostic signal and the second diagnostic signal being in phase opposition.

[0030] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0031] In the diagnosis method of the audio amplifier provided in the technical solution, the voltage differential signal and the current signal at both ends of the load after the diagnostic differential signal passes through the load are detected, so that the modulus and the phase of the impedance of the load can be obtained according to the voltage differential signal and the current signal, and then whether the load is normally connected can be determined by comparing the modulus of the impedance of the load with the size of the preset threshold, according to the size of the phase of the impedance of the load, or by combining the comparison of the modulus of the impedance of the load with the size of the preset threshold and the size of the phase of the impedance of the load. Therefore, the diagnosis method of the audio amplifier includes various methods for diagnosing whether the load of the audio amplifier is normally connected, which can accurately diagnose and has simple determination logic, so that the convenience of diagnosis is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 FIG. 1 is a circuit structure diagram of a diagnosis circuit of an audio amplifier provided in an embodiment of the present application;

[0033] Figure 2 FIG. 2 is a flowchart of a diagnosis method of an audio amplifier provided in an embodiment of the present application; Figure 1 ;

[0034] Figure 3 FIG. 3 is a flowchart of a diagnosis method of an audio amplifier provided in another embodiment of the present application; Figure 2 ;

[0035] Figure 4 FIG. 4 is a flowchart of a method for obtaining a preset modulus threshold provided in an embodiment of the present application;

[0036] Figure 5 FIG. 5 is a circuit structure diagram of a diagnosis circuit of an audio amplifier provided in another embodiment of the present application. DETAILED DESCRIPTION

[0037] As described in the background, there is no clear determination method for determining whether the audio amplifier is normally connected in the prior art.

[0038] Therefore, the present application creatively provides a diagnosis method of an audio amplifier, which comprises:

[0039] outputting a diagnostic differential signal to both ends of a load of the audio amplifier, the diagnostic differential signal being an alternating current signal;

[0040] after the diagnostic differential signal is output to both ends of the load of the audio amplifier, collecting a voltage differential signal and a current signal at both ends of the load;

[0041] obtaining the modulus and the phase of the impedance of the load of the audio amplifier according to the voltage differential signal and the current signal;

[0042] According to the impedance parameter of the load, the connection state of the tweeter is determined, including: comparing the modulus of the impedance of the load with a preset threshold to determine the connection state of the tweeter; and / or determining the connection state of the tweeter according to the phase of the impedance of the load.

[0043] The diagnostic method of the audio amplifier includes various methods for diagnosing whether the load of the audio amplifier is normally connected, which can accurately diagnose and has simple determination logic, thereby further improving the convenience of diagnosis.

[0044] To make the above-mentioned purposes, features and benefits of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. The terms "second", "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0045] Figure 1 Fig. 1 is a circuit structure diagram of the diagnostic circuit of the audio amplifier provided by the embodiments of the present application.

[0046] Please refer to Figure 1 The embodiments of the present application provide a diagnostic circuit of an audio amplifier, which comprises a driving module, an acquisition module and a calculation module.

[0047] The driving module is used to output the diagnostic differential signal to both ends of the load of the audio amplifier.

[0048] The diagnostic differential signal includes a first diagnostic signal and a second diagnostic signal, the driving module includes an amplification unit and an inverting unit K, the amplification unit is used for receiving an initial diagnostic signal output by the calculation module and amplifying to output the first diagnostic signal to one end of the load and an input end of the inverting unit K, the inverting unit K is used for inverting the first diagnostic signal and outputting the second diagnostic signal to the other end of the load, and the first diagnostic signal and the second diagnostic signal are in phase opposition.

[0049] The acquisition module is used for acquiring a voltage differential signal and a current signal between the two ends of the load.

[0050] The calculation module is used for obtaining a modulus and a phase of the impedance of the load according to the voltage differential signal and the current signal, and the calculation module is also used for outputting a judgment result according to the modulus and / or the phase of the impedance of the load to judge the connection state of the load.

[0051] In the embodiment, please refer to Figure 1 The load of the audio amplifier is the parallel connection of the tweeter P1 and the woofer P2.

[0052] Figure 2 The diagnostic method of the audio amplifier provided in the embodiment Figure 1 .

[0053] Please refer to Figure 2 The diagnostic method of the audio amplifier provided in the embodiment, comprising:

[0054] Step S1, outputting a diagnostic differential signal to the two ends of the load of the audio amplifier;

[0055] The diagnostic differential signal is an alternating signal, for example, a sine wave, and the frequency of the diagnostic differential signal is 10-20 mA, and the amplitude of the diagnostic differential signal is 20 Hz-20 kHz.

[0056] In the embodiment, the woofer P2 has been diagnosed and judged to be normally connected before the tweeter P1 is diagnosed. The tweeter P1 is mainly responsible for playing back high-frequency signals, and the frequency range is generally 2000-20000 Hz. The woofer P2 is responsible for low-frequency sound restoration, and the frequency response range is generally 16-256 Hz.

[0057] Step S2, after the diagnostic differential signal is output to the two ends of the load of the audio amplifier, acquiring a voltage differential signal and a current signal between the two ends of the load;

[0058] Step S3, obtaining the modulus and phase of the impedance of the load of the audio amplifier according to the voltage differential signal and the current signal;

[0059] In the embodiment, step S3 specifically comprises: performing quadrature demodulation on the voltage differential signal and the current signal to obtain the modulus and phase of the impedance of the load.

[0060] Step S4: judging the connection state of the tweeter P1 according to the impedance parameter of the load.

[0061] Wherein, please refer to Figure 3 , Figure 3 is the flow of the diagnosis method of the audio amplifier provided by the embodiment of the application Figure 2 , step S4 specifically comprises:

[0062] Step S41, obtaining a preset modulus threshold;

[0063] Wherein, please refer to Figure 4 , Figure 4 is the flow of the method for obtaining a preset modulus threshold provided by the embodiment of the application, and step S41 specifically comprises:

[0064] Step S411, providing a sample audio amplifier;

[0065] Step S412, obtaining a first modulus of the impedance of the first load under a first load condition, the first load condition being used to represent that the first load of the sample audio amplifier is a woofer P2;

[0066] Wherein, step S412 specifically comprises:

[0067] Step S4121, outputting a first diagnosis differential signal to both ends of the first load under the first load condition;

[0068] Wherein, the requirements of the first diagnosis differential signal are the same as those of the diagnosis differential signal, which will not be repeated here.

[0069] Step S4122, after outputting the first diagnosis differential signal to both ends of the first load, collecting a first voltage signal and a first current signal at both ends of the first load;

[0070] Step S4123, obtaining a first modulus of the impedance of the first load according to the first voltage signal and the first current signal.

[0071] Specifically, performing quadrature demodulation on the first voltage signal and the first current signal to obtain the first modulus of the impedance of the first load.

[0072] Step S413, obtaining a second mode of the impedance of the second load under a second load condition, the second load condition being used to characterize the second load of the sample audio amplifier as the high-pitched loudspeaker P1 and the bass loudspeaker P2 in parallel;

[0073] In the step S413, the step S413 specifically comprises:

[0074] Step S4131, outputting a second diagnostic differential signal to both ends of the second load;

[0075] The second diagnostic differential signal has the same requirements as the diagnostic differential signal, which will not be repeated here.

[0076] Step S4132, after outputting the second diagnostic differential signal to both ends of the second load, collecting a second voltage signal and a second current signal at both ends of the second load;

[0077] Step S4133, obtaining a second mode of the impedance of the second load according to the second voltage signal and the second current signal.

[0078] Specifically, the second voltage signal and the second current signal are quadrature demodulated to obtain the second mode of the impedance of the second load.

[0079] Step S414, obtaining the mean value of the first mode and the second mode as the preset mode threshold. Specifically, the preset mode threshold is (the first mode + the second mode).

[0080] It should be noted that only when the diagnostic method is used for the first time, the steps S411-S413 are needed to obtain the preset mode threshold, and in subsequent use of the diagnostic method, the preset mode threshold can be directly obtained from the register.

[0081] Step S42, obtaining the difference between the mode of the impedance of the load and the preset mode threshold as a preset margin;

[0082] Step S43, selecting a diagnostic method according to the preset margin, comprising: if the preset margin is less than or equal to a preset error, performing step S45; if the preset margin is greater than the preset error, performing step S44.

[0083] In the embodiment, the preset error is greater than or equal to 5.

[0084] Since in actual situation, there are errors in any circuit system and measurement process, for example: the precision limit of measurement tool, environmental interference, manufacturing or assembly tolerance, etc., therefore, judging whether the preset margin meets the preset error can further determine the accuracy of judging the connection state of the tweeter P1 according to the size of the modulus of the impedance of the load and the preset modulus threshold, so as to ensure the rationality, robustness and practicability of the judgment result.

[0085] In step S44, the connection state of the tweeter P1 is judged according to the size of the modulus of the impedance of the load and the preset modulus threshold.

[0086] In step S44, the connection state of the tweeter P1 is judged according to the size of the modulus of the impedance of the load and the preset modulus threshold.

[0087] In step S45, the connection state of the tweeter P1 is judged according to the size of the phase of the impedance of the load and the preset phase threshold.

[0088] In the embodiment, the preset phase threshold is -45°~ -30°, and in step S45, if the phase of the impedance of the load is greater than the preset phase threshold, it is judged that the connection state of the tweeter P1 is abnormal; if the phase of the impedance of the load is less than or equal to the preset phase threshold, it is judged that the connection state of the tweeter P1 is normal. Specifically, when the connection state of the tweeter P1 is abnormal, the phase of the impedance of the load is about -90°, and when the connection state of the tweeter P1 is normal, the phase of the impedance of the load is about 0°.

[0089] It should be noted that step S4 can only include step S45.

[0090] Figure 5 is a circuit structure diagram of a diagnostic circuit of an audio amplifier provided by another embodiment of the application.

[0091] In another embodiment, the load of the audio amplifier is a tweeter P1. On this basis, step S4 only includes step S45.

[0092] In summary, in the audio amplifier diagnosis method provided by the embodiment of the present application, the voltage differential signal across the load and the current signal after the diagnosis differential signal passes through the load are detected, so that the modulus and phase of the impedance of the load can be obtained according to the voltage differential signal and the current signal, and then whether the load is normally connected can be determined by comparing the modulus of the impedance of the load with the size of the preset threshold, according to the size of the phase of the impedance of the load, or by combining the comparison of the modulus of the impedance of the load with the size of the preset threshold and the size of the phase of the impedance of the load. Therefore, the audio amplifier diagnosis method includes various methods for diagnosing whether the load of the audio amplifier is normally connected, and the determination logic is simple on the basis of accurate diagnosis, so that the convenience of diagnosis is further improved.

[0093] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and the protection scope of the present application should be defined by the scope defined by the claims.

Claims

1. A diagnostic method for an audio amplifier, characterized by, The load of the audio amplifier comprises a tweeter, and the method comprises: outputting a diagnostic differential signal to both ends of the load of the audio amplifier, the diagnostic differential signal being an alternating signal; after outputting the diagnostic differential signal to both ends of the load of the audio amplifier, collecting a voltage differential signal and a current signal at both ends of the load; obtaining a modulus and a phase of the impedance of the load of the audio amplifier according to the voltage differential signal and the current signal; judging the connection state of the tweeter according to the impedance parameters of the load, comprising: judging the connection state of the tweeter by comparing the modulus of the impedance of the load with a preset modulus threshold; and / or judging the connection state of the tweeter according to the phase of the impedance of the load and a preset phase threshold; when the load comprises a tweeter and a woofer in parallel, before judging the connection state of the tweeter according to the impedance parameters of the load, further comprising: obtaining a difference between the modulus of the impedance of the load and the preset modulus threshold as a preset margin; selecting a diagnostic method according to the preset margin, comprising: if the preset margin is less than or equal to a preset error, judging the connection state of the tweeter according to the phase of the impedance of the load and the preset phase threshold; and if the preset margin is greater than the preset error, judging the connection state of the tweeter according to the modulus of the impedance of the load and the preset modulus threshold.

2. The diagnostic method of an audio amplifier according to claim 1, wherein, The method for obtaining the modulus and the phase of the impedance of the load of the audio amplifier according to the voltage differential signal and the current signal comprises: performing quadrature demodulation on the voltage differential signal and the current signal to obtain the modulus and the phase of the impedance of the load.

3. The diagnostic method of an audio amplifier according to claim 1, wherein, The method for obtaining the preset modulus threshold comprises: providing a sample audio amplifier; under a first load condition, obtaining a first modulus of the impedance of a first load, the first load condition being used to represent that the first load of the sample audio amplifier is a woofer; under a second load condition, obtaining a second modulus of the impedance of a second load, the second load condition being used to represent that the second load of the sample audio amplifier is a tweeter and a woofer in parallel; obtaining a mean value of the first modulus and the second modulus as the preset modulus threshold.

4. The diagnostic method of an audio amplifier according to claim 3, wherein The method for obtaining the first modulus of the impedance of the first load comprises: under the first load condition, outputting a first diagnostic differential signal to both ends of the first load; after outputting the first diagnostic differential signal to both ends of the first load, collecting a first voltage signal and a first current signal at both ends of the first load; and obtaining the first modulus of the impedance of the first load according to the first voltage signal and the first current signal. The method for obtaining the second modulus of the impedance of the second load comprises: outputting a second diagnostic differential signal to both ends of the second load; after outputting the second diagnostic differential signal to both ends of the second load, collecting a second voltage signal and a second current signal at both ends of the second load; and obtaining the second modulus of the impedance of the second load according to the second voltage signal and the second current signal.

5. The diagnostic method for an audio amplifier according to claim 1, wherein The method for determining the connection state of the tweeter by comparing the modulus of the impedance of the load with a preset modulus threshold value comprises: if the modulus of the impedance of the load is greater than the preset modulus threshold value, determining that the connection state of the tweeter is abnormal; and if the modulus of the impedance of the load is less than or equal to the preset modulus threshold value, determining that the connection state of the tweeter is normal.

6. The diagnostic method for an audio amplifier according to claim 1, wherein The load is a tweeter.

7. The diagnostic method for an audio amplifier according to claim 1, wherein The preset phase threshold value ranges from -45° to -30°, and the method for determining the connection state of the tweeter according to the phase of the impedance of the load and the size of the preset phase threshold value comprises: if the phase of the impedance of the load is greater than the preset phase threshold value, determining that the connection state of the tweeter is abnormal; and if the phase of the impedance of the load is less than or equal to the preset phase threshold value, determining that the connection state of the tweeter is normal.

8. A diagnostic circuit for an audio amplifier, characterized by The diagnostic circuit for implementing the diagnostic method of the audio amplifier according to any one of claims 1-7 comprises: a driving module configured to output a diagnostic differential signal to both ends of the load of the audio amplifier, the diagnostic differential signal being an alternating signal; a collecting module configured to collect a voltage differential signal and a current signal at both ends of the load; a calculating module configured to determine the connection state of the tweeter according to the impedance parameters of the load, comprising: determining the connection state of the tweeter by comparing the modulus of the impedance of the load with a preset modulus threshold value; and / or determining the connection state of the tweeter according to the phase of the impedance of the load and the size of a preset phase threshold value; when the load is a parallel connection of a tweeter and a woofer, before determining the connection state of the tweeter according to the impedance parameters of the load, the calculating module is further configured to: obtain a difference between the modulus of the impedance of the load and the preset modulus threshold value as a preset margin; and select a diagnostic method according to the preset margin, comprising: if the preset margin is less than or equal to a preset error, determining the connection state of the tweeter according to the phase of the impedance of the load and the size of the preset phase threshold value; and if the preset margin is greater than the preset error, determining the connection state of the tweeter according to the modulus of the impedance of the load and the size of the preset modulus threshold value.

9. The diagnostic circuit for an audio amplifier of claim 8, wherein, The diagnostic differential signal comprises a first diagnostic signal and a second diagnostic signal, the driving module comprises an amplifying unit and an inverting unit, the amplifying unit is configured to receive an initial diagnostic signal output by the calculating module and amplify the initial diagnostic signal to output a first diagnostic signal to one end of the load and an input end of the inverting unit, and the inverting unit is configured to invert the first diagnostic signal to output a second diagnostic signal to the other end of the load, the first diagnostic signal being inverted with respect to the second diagnostic signal.

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