An audio signal DC abnormality monitoring circuit

Abstract

The present application belongs to the technical field of audio signal DC anomaly monitoring design, and specifically relates to an audio signal DC anomaly monitoring circuit, which uses a fifth capacitor C5 to block the DC components of the audio signal left channel AUDIO-L and the audio signal right channel AUDIO-R, and controls the conduction of the first transistor N1 and the second transistor N2 to output a low level to the STM32F103CBT6 microcontroller U4, thereby realizing the detection of audio signal anomalies.

Description

Technical Field

[0001] The present application belongs to the technical field of audio signal DC anomaly monitoring design, and in particular relates to an audio signal DC anomaly monitoring circuit. Background Art

[0002] Due to manufacturing defects, malfunctions and other factors in audio equipment, the audio signals generated usually contain DC components. The DC components can cause sound distortion and even damage the speakers.

[0003] Currently, capacitors are mostly used to isolate the DC components in audio equipment. However, this technical solution cannot monitor the DC components and effectively protect the speakers from damage.

[0004] This application is proposed in view of the above-mentioned technical defects. Utility Model Content

[0005] The purpose of the present application is to provide an audio signal DC anomaly monitoring circuit to overcome or alleviate at least one aspect of the known technical defects.

[0006] The technical solution of this application is:

[0007] An audio signal DC abnormality monitoring circuit includes: a first transistor N1, a second transistor N2, an STM32F103CBT6 microcontroller U4, and a fifth capacitor C5;

[0008] The base of the first transistor N1 and the emitter of the second transistor N2 are grounded through the fifth capacitor C5, and the connection line between the fifth capacitor C5 and the base of the first transistor N1 and the emitter of the second transistor N2 is connected to the audio signal left channel AUDIO-L through the forty-sixth resistor R46, and is connected to the audio signal right channel AUDIO-R through the forty-seventh resistor R47;

[0009] The collector of the first transistor N1 is connected to the power supply through the forty-eighth resistor R48 and the forty-ninth resistor R49, the emitter of the first transistor N1 is grounded, the collector of the second transistor N2 is connected to the collector of the first transistor N1 and the line through the forty-eighth resistor R48, and the emitter of the second transistor N2 is grounded;

[0010] Pin 29 of the STM32F103CBT6 microcontroller U4 is connected to the line between the forty-eighth resistor R48 and the forty-ninth resistor R49.

[0011] Optionally, in the above-mentioned audio signal DC abnormality monitoring circuit, pin 1 of the STM32F103CBT6 microcontroller U4 is connected to the power supply and is grounded through the forty-second resistor R42 and the thirty-seventh capacitor C37; pin 7 of the STM32F103CBT6 microcontroller U4 is connected to the power supply and is grounded through the thirty-seventh capacitor C37.

[0012] Optionally, in the above-mentioned audio signal DC abnormality monitoring circuit, pin 8 of the STM32F103CBT6 microcontroller U4 is grounded, pin 35 of the STM32F103CBT6 microcontroller U4 is grounded, pin 44 of the STM32F103CBT6 microcontroller U4 is grounded through the twenty-fifth resistor, and pin 47 of the STM32F103CBT6 microcontroller U4 is grounded.

[0013] Optionally, in the above-mentioned audio signal DC abnormality monitoring circuit, pin 24 of the STM32F103CBT6 microcontroller U4 is connected to the power supply, pin 36 of the STM32F103CBT6 microcontroller U4 is connected to the power supply, and pin 48 of the STM32F103CBT6 microcontroller U4 is connected to the power supply.

[0014] Optionally, in the above-mentioned audio signal DC anomaly monitoring circuit, the 11th pin of the STM32F103CBT6 microcontroller U4 is connected to an indicator light.

[0015] Optionally, in the above audio signal DC anomaly monitoring circuit, pin 18 of the STM32F103CBT6 microcontroller U4 is connected to a speaker control switch.

[0016] This application has at least the following beneficial technical effects:

[0017] Provided is an audio signal DC anomaly monitoring circuit, which uses a fifth capacitor C5 to block the DC components of the left channel AUDIO-L and the right channel AUDIO-R of the audio signal, and controls the conduction of the first transistor N1 and the second transistor N2 to output a low level to the STM32F103CBT6 microcontroller U4, thereby realizing the detection of audio signal anomalies. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of an audio signal DC anomaly monitoring circuit provided in an embodiment of the present application.

[0019] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0020] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0021] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0022] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0023] An audio signal DC abnormality monitoring circuit, such as Figure 1 As shown, it includes a first transistor N1, a second transistor N2, an STM32F103CBT6 microcontroller U4, and a fifth capacitor C5.

[0024] The base of the first transistor N1 and the emitter of the second transistor N2 are grounded through the fifth capacitor C5, and the connection line between the fifth capacitor C5 and the base of the first transistor N1 and the emitter of the second transistor N2 is connected to the audio signal left channel AUDIO-L through the forty-sixth resistor R46, and is connected to the audio signal right channel AUDIO-R through the forty-seventh resistor R47.

[0025] The collector of the first transistor N1 is connected to the power supply through the forty-eighth resistor R48 and the forty-ninth resistor R49, the emitter of the first transistor N1 is grounded, the collector of the second transistor N2 is connected to the collector of the first transistor N1 and the line through the forty-eighth resistor R48, and the emitter of the second transistor N2 is grounded.

[0026] Pin 29 of the STM32F103CBT6 microcontroller U4 is connected to the line between the forty-eighth resistor R48 and the forty-ninth resistor R49.

[0027] The audio signal DC abnormality monitoring circuit disclosed in the above embodiment, when the audio signal left channel AUDIO-L and the audio signal right channel AUDIO-R are normal, the DC component carried is small, and is given to the fifth capacitor C5 through the forty-sixth resistor R46 and the forty-seventh resistor R47. Due to the characteristics of the fifth capacitor C5 passing AC and blocking DC, the maximum voltage on it will not exceed the positive DC voltage threshold, the first transistor N1 is not conducting, and the minimum voltage on it will not be lower than the negative DC voltage threshold, the second transistor N2 is not conducting, and there is no voltage drop between the forty-ninth resistor R49 and the forty-eighth resistor R48, and the high level is output to the 29th pin of the STM32F103CBT6 microcontroller U4. It is detected that the audio signal is normal, and the positive DC voltage threshold and the negative DC voltage threshold can be set by adjusting the values ​​of the forty-sixth resistor R46, the forty-seventh resistor R47, and the fifth capacitor C5, and can be specifically +0.6V and -0.6V.

[0028] In the audio signal DC abnormality monitoring circuit disclosed in the above embodiment, when the audio signal left channel AUDIO-L and the audio signal right channel AUDIO-R are abnormal, the DC component they carry is relatively large, and is supplied to the fifth capacitor C5 through the forty-sixth resistor R46 and the forty-seventh resistor R47. Due to the characteristics of the fifth capacitor C5 that passes AC and blocks DC, the maximum voltage on it may exceed the positive DC voltage threshold. At this time, the first transistor N1 is turned on, or the minimum voltage on it may be lower than the negative DC voltage threshold. At this time, the second transistor N2 is turned on, and a voltage drop is generated between the forty-ninth resistor R49 and the forty-eighth resistor R48, which is output to the low level of the 29th pin of the STM32F103CBT6 microcontroller U4, and the audio signal abnormality is detected.

[0029] The audio signal DC anomaly monitoring circuit disclosed in the above embodiment uses the fifth capacitor C5 to block the DC components of the audio signal left channel AUDIO-L and the audio signal right channel AUDIO-R, and controls the conduction of the first transistor N1 and the second transistor N2 to output a low level to the STM32F103CBT6 microcontroller U4, thereby realizing the detection of audio signal anomalies.

[0030] Furthermore, in the audio signal DC anomaly monitoring circuit disclosed in the above embodiment, pin 1 of the STM32F103CBT6 microcontroller U4 is connected to the power supply and is grounded through the forty-second resistor R42 and the thirty-seventh capacitor C37; pin 7 of the STM32F103CBT6 microcontroller U4 is connected to the power supply and is grounded through the thirty-seventh capacitor C37.

[0031] Furthermore, in the audio signal DC anomaly monitoring circuit disclosed in the above embodiment, pin 8 of the STM32F103CBT6 microcontroller U4 is grounded, pin 35 of the STM32F103CBT6 microcontroller U4 is grounded, pin 44 of the STM32F103CBT6 microcontroller U4 is grounded through the twenty-fifth resistor, and pin 47 of the STM32F103CBT6 microcontroller U4 is grounded.

[0032] Furthermore, in the audio signal DC anomaly monitoring circuit disclosed in the above embodiment, pin 24 of the STM32F103CBT6 microcontroller U4 is connected to the power supply, pin 36 of the STM32F103CBT6 microcontroller U4 is connected to the power supply, and pin 48 of the STM32F103CBT6 microcontroller U4 is connected to the power supply.

[0033] In order to be able to indicate audio signal abnormalities, in the audio signal DC abnormality monitoring circuit disclosed in the above embodiment, the 11th pin of the STM32F103CBT6 microcontroller U4 can be further designed to be connected to an indicator light. When the audio signal is detected to be normal, the control indicator light is turned off, and when the audio signal is detected to be abnormal, the control indicator light is turned on.

[0034] In order to effectively protect the speaker from damage when the audio signal is abnormal, in the audio signal DC abnormality monitoring circuit disclosed in the above embodiment, the 18th pin of the STM32F103CBT6 microcontroller U4 can be further designed to be connected to the speaker control switch. When the audio signal is detected to be normal, the speaker control switch is controlled to be turned off, and when the audio signal is detected to be abnormal, the speaker control switch is controlled to be turned on.

[0035] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other. In the absence of conflict, the embodiments in this application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0036] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. An audio signal DC abnormality monitoring circuit, characterized in that: include: A first transistor N1, a second transistor N2, a STM32F103CBT6 microcontroller U4, and a fifth capacitor C5; The base of the first transistor N1 and the emitter of the second transistor N2 are grounded through the fifth capacitor C5, and the connection line between the fifth capacitor C5 and the base of the first transistor N1 and the emitter of the second transistor N2 is connected to the audio signal left channel AUDIO-L through the forty-sixth resistor R46, and is connected to the audio signal right channel AUDIO-R through the forty-seventh resistor R47; The collector of the first transistor N1 is connected to the power supply through the forty-eighth resistor R48 and the forty-ninth resistor R49, the emitter of the first transistor N1 is grounded, the collector of the second transistor N2 is connected to the collector of the first transistor N1 and the line through the forty-eighth resistor R48, and the emitter of the second transistor N2 is grounded; Pin 29 of the STM32F103CBT6 microcontroller U4 is connected to the line between the forty-eighth resistor R48 and the forty-ninth resistor R49.

2. The audio signal DC anomaly monitoring circuit according to claim 1, characterized in that: Pin 1 of the STM32F103CBT6 microcontroller U4 is connected to a power supply and is grounded through the forty-second resistor R42 and the thirty-seventh capacitor C37. Pin 7 of the STM32F103CBT6 microcontroller U4 is connected to a power supply and is grounded through the thirty-seventh capacitor C37.

3. The audio signal DC anomaly monitoring circuit according to claim 1, characterized in that: Pin 8 of the STM32F103CBT6 microcontroller U4 is grounded, pin 35 of the STM32F103CBT6 microcontroller U4 is grounded, pin 44 of the STM32F103CBT6 microcontroller U4 is grounded through the twenty-fifth resistor, and pin 47 of the STM32F103CBT6 microcontroller U4 is grounded.

4. The audio signal DC anomaly monitoring circuit according to claim 1, characterized in that: Pin 24 of the STM32F103CBT6 microcontroller U4 is connected to a power supply, pin 36 of the STM32F103CBT6 microcontroller U4 is connected to a power supply, and pin 48 of the STM32F103CBT6 microcontroller U4 is connected to a power supply.

5. The audio signal DC anomaly monitoring circuit according to claim 1, characterized in that: Pin 11 of the STM32F103CBT6 microcontroller U4 is connected to an indicator light.

6. The audio signal DC anomaly monitoring circuit according to claim 1, characterized in that: Pin 18 of the STM32F103CBT6 microcontroller U4 is connected to the speaker control switch.

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