Sound field controller

Abstract

The invention discloses a sound field controller. A power amplifier is connected with a sound field controller, the sound field controller is connected with three loudspeaker groups, the sound field controller comprises an MCU, a PHY and three partitions, one loudspeaker group is connected with one partition, the partitions comprise a first partition, a second partition and a third partition, and each partition comprises three relays. The relay comprises an initial relay, a first relay and a second relay, the relay comprises two groups of automatic switches, each automatic switch comprises two input interfaces and an output interface, the MCU comprises an I / O interface chip and an analog-to-digital converter, the MCU is connected with the PHY, and the PHY is used for transmitting external signals to the MCU; the power amplifier is connected with the initial relay, the initial relay is connected with the first relay, and the first relay is connected to the loudspeaker group. According to the invention, the problem that each sound field cannot be independently detected due to the fact that one power amplifier controls a plurality of sound fields in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of broadcast control, and in particular to a sound field controller. Background Art

[0002] The prior art generally uses one power amplifier to correspond to one sound field partition. When the business requires multiple small sound field partitions, multiple power amplifiers are needed to achieve it, resulting in unnecessary waste.

[0003] Therefore, the technical problem in the prior art that one power amplifier controls multiple sound fields, resulting in each sound field being unable to be detected individually, has not yet been effectively solved. Summary of the invention

[0004] The object of the present invention is to provide a sound field controller to solve the problem in the related art that one power amplifier controls multiple sound fields, resulting in that each sound field cannot be detected separately.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A sound field controller comprises a power amplifier connected to the sound field controller, the sound field controller is connected to three groups of speaker groups, the sound field controller comprises an MCU, a PHY and three partitions, one speaker group is connected to one partition, the partitions comprise a first partition, a second partition and a third partition, the partitions comprise three relays, the relays comprise an initial relay, a first relay and a second relay, the relays comprise two groups of automatic switches, the automatic switches comprise two input interfaces and one output interface, the MCU comprises an I / O interface chip and an analog-to-digital converter; the power amplifier is connected to the initial relay, the initial relay is connected to the first relay, the first relay is connected to the speaker group; the I / O interface chip is connected to the second relay via an I / O interface circuit, the analog-to-digital converter is connected to the second relay via a first analog-to-digital conversion circuit, the second relay is connected to the first relay; the analog-to-digital converter is connected to the output interface of the initial relay via a second analog-to-digital conversion circuit, the MCU is connected to the PHY, and the PHY is used to transmit external signals to the MCU.

[0007] It is further configured as follows: the output interface of the initial relay is connected to a voltage-dividing resistor, a capacitor and an inductor in sequence, one output interface of the inductor is grounded, the other output interface is connected to a third operational amplifier and a rectifier diode in sequence, and the rectifier diode is connected to an analog-to-digital converter; the two output interfaces of the first relay are connected in series with a sound field resistor, and a speaker unit of a speaker group is connected in parallel between the two output interfaces of the first relay.

[0008] It is further configured as follows: the voltage-dividing resistor includes a first resistor, a second resistor and a third resistor, the first resistor and the second resistor are respectively connected to two branch circuits corresponding to the two output interfaces of the initial relay; the third resistor is connected in parallel between the two branch circuits; the capacitor is connected in parallel between the third resistor and the inductor.

[0009] It is further configured as follows: the two output interfaces of the initial relay are respectively connected to one input interface of each of the two groups of automatic switches of the first relay, and the remaining two input interfaces of the first relay are respectively connected to the two output interfaces of the second relay; the second relay includes a first input interface, a second input interface, a third input interface and a fourth input interface, wherein the first input interface and the second input interface belong to the same group of automatic switches, and the third input interface and the fourth input interface belong to the same group of automatic switches; the first input interface is connected to a pull-up resistor; and the third input interface is grounded.

[0010] It is further configured as follows: the I / O interface chip is connected to the PE detection module, the two output interfaces of the PE detection module are respectively connected to the second input interface and the fourth input interface of the second relay; the analog-to-digital converter is connected to the fourth operational amplifier, the fourth operational amplifier is connected to the isolation operational amplifier, one output interface of the isolation operational amplifier is grounded, and the other output interface is connected to the first input interface of the second relay.

[0011] A sound field control method includes: the audio output of a power amplifier is connected to the initial relay of a partition, and an MCU controls the initial relay to close so that the partition outputs audio; the MCU detects whether there is audio input, including: a voltage-dividing resistor steps down the output voltage of the power amplifier and filters out clutter through a capacitor to obtain stepped-down audio, a third operational amplifier and a rectifier diode perform precise rectification on the stepped-down audio, and outputs it to an analog-to-digital converter of the MCU, and the MCU determines whether there is audio input.

[0012] Furthermore: when the MCU detects audio input or receives a zone opening instruction through the network, the first relay remains in a closed state, and the power amplifier outputs the audio to the speaker group corresponding to the partition through the initial relay and the first relay; when the MCU detects no audio input or receives a zone closing instruction through the network, the first relay switches to the sound field detection circuit to detect the sound field line, wherein the sound field detection circuit includes a second relay, a pull-up resistor, an isolation operational amplifier and a fourth operational amplifier.

[0013] Further: when the second relay is in a normally closed state and the sound field cable is in a normal state, the pull-up resistor, the sound field cable, and the sound field resistor form a DC path, the isolation operational amplifier detects the sum of the DC voltages of the sound field cable and the sound field resistor, and outputs it to the analog-to-digital converter of the MCU after adjustment through the fourth operational amplifier. The analog-to-digital converter determines that the sound field is normal based on a preset voltage threshold; when the sound field line is short-circuited, the sound field resistor is short-circuited, the upper resistor and the sound field line form a DC path, the isolation operational amplifier detects the DC voltage of the sound field cable, and outputs it to the analog-to-digital converter of the MCU after adjustment through the fourth operational amplifier. The analog-to-digital converter determines that the sound field is short-circuited based on a preset voltage threshold.

[0014] Furthermore: when the sound field circuit is open, the isolation operational amplifier detects the DC voltage of the upper resistor, which is adjusted by the fourth operational amplifier and output to the analog-to-digital converter of the MCU. The analog-to-digital converter determines that the sound field is open based on a preset voltage threshold.

[0015] Further: when the sound field line detection is completed, PE detection is performed, including: the second relay switches to the PE detection circuit, and the PE detection module detects whether the entire sound field loop is connected to PE. If so, the MCU is notified through the I / O interface chip, wherein the PE connection phenomenon is that the speaker group line of the partition output is connected to the PE protective ground wire.

[0016] Compared with the prior art, the beneficial technical effect of the present invention is as follows: the present invention integrates a power amplifier, a sound field controller and three groups of speaker groups, and realizes efficient and flexible audio partition management. The sound field controller is the core, with built-in MCU, PHY and three independent partitions, each partition accurately corresponds to a speaker group, ensuring the independence and controllability of the audio output. The audio output of the power amplifier first enters the sound field controller through the initial relay, and then is directly connected to the speaker group by the first relay to realize the transmission of the audio signal. As an intelligent control center, the MCU receives instructions through the network to accurately control each partition, and can detect and report the device status and the partition sound field status to the network management system in real time. The present invention is connected to the output of the initial relay through an analog-to-digital converter, so as to realize the detection and fault diagnosis function of the MCU on the audio signal. The present invention supports independent sound field detection for each partition, including multiple states such as open circuit, short circuit, normal and grounded, ensuring the stability and reliability of audio transmission. This refined partition management and detection mechanism enables the system to quickly discover and handle potential problems, ensuring the overall performance and user experience of the audio system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the partition control structure in the sound field controller of the present invention;

[0020] Figure 3 It is the control principle diagram of the present invention.

[0021] Figure numerals: 1. initial relay; 2. first relay; 3. second relay; 4. speaker unit; 5. sound field resistor; 6. I / O interface circuit; 7. first analog-to-digital conversion circuit; 8. second analog-to-digital conversion circuit; 9. pull-up resistor; 10. isolation amplifier; 11. PE detection module; 121. third operational amplifier; 122. fourth operational amplifier; 13. rectifier diode; 14. first resistor; 15. second resistor; 16. third resistor; 17. capacitor; 18. inductor. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Example

[0026] Reference Figure 1-Figure 3 , is a sound field controller disclosed in the present invention, the invention includes: a power amplifier connected to the sound field controller, the sound field controller is connected to three groups of speaker groups, the sound field controller includes an MCU, a PHY and three partitions, one speaker group is connected to one partition, the partition includes a first partition, a second partition and a third partition, the partition includes three relays, the relay includes an initial relay 1, a first relay 2 and a second relay 3, the relay includes two groups of automatic switches, the automatic switch includes two input interfaces and one output interface, the MCU includes an I / O interface chip and an analog-to-digital converter; the power amplifier is connected to the initial relay 1, the initial relay 1 is connected to the first relay 2, and the first relay 2 is connected to the speaker group; the I / O interface chip is connected to the second relay 3 through the I / O interface circuit 6, the analog-to-digital converter is connected to the second relay 3 through the first analog-to-digital conversion circuit 7, and the second relay 3 is connected to the first relay 2; the analog-to-digital converter is connected to the output interface of the initial relay 1 through the second analog-to-digital conversion circuit 8, the MCU is connected to the PHY, and the PHY is used to transmit external signals to the MCU.

[0027] Specifically, PHY is an external signal interface chip, which is used to transmit external signals to the MCU. The audio output of the power amplifier is connected to each partition respectively. The MCU controls the partitions through network control instructions. The MCU can send the device status to the network manager through the network. The MCU can send the sound field status of each partition to the network manager through the network.

[0028] When different sound fields need to be controlled, the power amplifier inputs the power amplifier to the sound field controller. The sound field controller includes multiple partitions, each partition corresponds to a group of speakers, and the MCU controls the partition to output signals to the corresponding speaker group. When detection is required, the MCU can detect any single partition and its corresponding speaker group.

[0029] In addition, through the three partitions (first partition, second partition, and third partition) in the sound field controller, the three groups of speakers can be independently controlled to achieve partitioned playback or independent adjustment of sound. This design is very suitable for application scenarios that require precise control of the sound propagation area and intensity. Each partition contains three relays (initial relay 1, first relay 2, and second relay 3). These relays can achieve fine adjustment of the volume of the speaker group by automatically switching the on and off of the circuit. In particular, the second relay 3 is controlled by the I / O interface chip and analog-to-digital converter (ADC) of the MCU (microcontroller unit), combined with the connection of the first relay 2, to provide more levels of volume control strategies.

[0030] It is further configured as follows: the output interface of the initial relay 1 is connected to the voltage-dividing resistor, the capacitor and the inductor 18 in sequence, one output interface of the inductor 18 is grounded, the other output interface is connected to the third operational amplifier 121 and the rectifier diode 13 in sequence, and the rectifier diode 13 is connected to the analog-to-digital converter; the two output interfaces of the first relay 2 are connected in series with the sound field resistor 5, and the speaker unit 4 is connected in parallel between the two output interfaces of the first relay 2. The voltage-dividing resistor includes a first resistor 14, a second resistor 15 and a third resistor 16, and the first resistor 14 and the second resistor 15 are respectively connected to the two branch circuits corresponding to the two output interfaces of the initial relay 1; the third resistor 16 is connected in parallel between the two branch circuits; the capacitor is connected in parallel between the third resistor 16 and the inductor 18.

[0031] Specifically, the voltage divider resistor steps down the output voltage of the power amplifier and filters out noise through the capacitor 17 to obtain the stepped-down audio. The third operational amplifier 121 and the rectifier diode 13 precisely rectify the stepped-down audio and output it to the analog-to-digital converter of the MCU. The MCU determines whether there is audio input.

[0032] It is further configured as follows: the two output interfaces of the initial relay 1 are respectively connected to one input interface of each of the two groups of automatic switches of the first relay 2, and the remaining two input interfaces of the first relay 2 are respectively connected to the two output interfaces of the second relay 3; the second relay 3 includes a first input interface, a second input interface, a third input interface and a fourth input interface, wherein the first input interface and the second input interface belong to the same group of automatic switches, and the third input interface and the fourth input interface belong to the same group of automatic switches; the first input interface is connected to the pull-up resistor 9; and the third input interface is grounded.

[0033] It is further configured as follows: the I / O interface chip is connected to the PE detection module 11, and the two output interfaces of the PE detection module 11 are respectively connected to the second input interface and the fourth input interface of the second relay 3; the analog-to-digital converter is connected to the fourth operational amplifier 122, the fourth operational amplifier 122 is connected to the isolation amplifier 10, one output interface of the isolation amplifier 10 is grounded, and the other output interface is connected to the first input interface of the second relay 3.

[0034] Specifically, after the sound field line detection is completed, PE detection is performed, including: the second relay 3 switches to the PE detection circuit, and the PE detection module 11 detects whether the entire sound field loop is connected to PE. If so, the MCU is notified through the I / O interface chip, where the PE connection phenomenon means that the speaker line of the partition output is connected to the PE protective ground wire.

[0035] The present invention also discloses a sound field control method, including connecting the audio output of the power amplifier to the initial relay 1 of the partition, and the MCU controlling the initial relay 1 to close so that the partition outputs audio; the MCU detects whether there is audio input, including: the voltage divider resistor steps down the output voltage of the power amplifier and filters out noise through the capacitor 17 to obtain the stepped-down audio, the third operational amplifier 121 and the rectifier diode 13 perform precise rectification on the stepped-down audio, and output it to the analog-to-digital converter of the MCU, and the MCU determines whether there is audio input.

[0036] Specifically, when controlling the audio output, after the MCU receives the control instruction through the network, the initial relay 1 of the partition is closed, and then the MCU sends a closing signal to the first relay 2, and the partition outputs audio at this time. The MCU can accurately control the closing and disconnection of the initial relay 1, thereby realizing independent control of different audio partitions. This flexibility enables the system to quickly adjust the audio output according to actual needs, and is suitable for multi-scene and multi-purpose audio playback needs. Through the combination of the voltage divider resistor and the capacitor 17, the system can effectively reduce the high-voltage audio signal output by the power amplifier, and filter out the clutter and noise therein, so as to obtain a purer buck audio signal. The precision rectifier circuit of the third operational amplifier 121 and the rectifier diode 13 further processes the buck audio signal and converts it into a DC signal suitable for processing by the analog-to-digital converter. This process improves the accuracy and reliability of audio signal detection. The analog-to-digital converter of the MCU converts the rectified DC signal into a digital signal, and judges it through an internal algorithm to accurately identify whether there is audio input. This digital processing method enhances the anti-interference ability and detection sensitivity of the system.

[0037] It is further configured as follows: when the MCU detects audio input or receives a zone opening instruction through the network, the first relay 2 remains in a closed state, and the power amplifier outputs the audio to the speaker group corresponding to the partition through the initial relay 1 and the first relay 2; when the MCU detects no audio input or receives a zone closing instruction through the network, the first relay 2 switches to the sound field detection circuit to detect the sound field line, wherein the sound field detection circuit includes a second relay 3, a pull-up resistor 9, an isolation operational amplifier 10 and a fourth operational amplifier 122.

[0038] Specifically, when the MCU detects audio input or receives a zone opening command, the first relay 2 remains in a closed state, ensuring that the audio output of the power amplifier can smoothly reach the speaker group corresponding to the zone through the initial relay 1 and the first relay 2. This intelligent management method improves the response speed and flexibility of the audio system. When the MCU detects no audio input or receives a zone closing command, the first relay 2 switches to the sound field detection circuit for line detection. This function helps to detect and solve line faults in a timely manner, ensuring the stability and reliability of the audio system. At the same time, it also supports line maintenance and inspection when the system is not in audio playback state.

[0039] It is further configured as follows: when the second relay 3 is in a normally closed state and the sound field cable is in a normal state, the pull-up resistor 9, the sound field cable, and the sound field resistor 5 form a DC path, the isolation operational amplifier 10 detects the sum of the DC voltages of the sound field cable and the sound field resistor 5, and outputs it to the analog-to-digital converter of the MCU after adjustment through the fourth operational amplifier 122, and the analog-to-digital converter determines that the sound field is normal according to a preset voltage threshold; when the sound field line is short-circuited, the sound field resistor 5 is short-circuited, the upper resistor and the sound field line form a DC path, the isolation operational amplifier 10 detects the DC voltage of the sound field cable, and outputs it to the analog-to-digital converter of the MCU after adjustment through the fourth operational amplifier 122, and the analog-to-digital converter determines that the sound field is short-circuited according to a preset voltage threshold.

[0040] Specifically, when the sound field cable is in a normal state, the pull-up resistor 9, the sound field cable and the sound field resistor 5 together form a DC path. The isolation amplifier 10 can detect the sum of the voltages at both ends of the sound field cable and the sound field resistor 5, and this voltage value reflects the normal state of the line. Through the adjustment of the fourth operational amplifier 122, this voltage value is converted into a digital signal suitable for the MCU analog-to-digital converter to read. The MCU can accurately determine whether the sound field circuit is normal according to a preset voltage threshold. When the sound field circuit is short-circuited, the sound field resistor 5 is short-circuited, and at this time, the pull-up resistor 9 is directly connected to the sound field circuit to form a new DC path. What the isolation amplifier 10 detects is the DC voltage on the sound field cable, and this voltage value is usually lower than the voltage value in the normal state (because the sound field resistor 5 is short-circuited, and its voltage divider effect disappears). Similarly, after adjustment by the fourth operational amplifier 122, this voltage value is converted into a digital signal, and the MCU can determine whether the sound field circuit is short-circuited according to a preset voltage threshold.

[0041] It is further configured as follows: when the sound field circuit is open, the isolation amplifier 10 detects the DC voltage of the upper resistor, and outputs it to the analog-to-digital converter of the MCU after adjustment through the fourth operational amplifier 122, and the analog-to-digital converter determines that the sound field is open according to the preset voltage threshold. After the sound field circuit detection is completed, PE detection is performed, including: the second relay 3 switches to the PE detection circuit, and the PE detection module 11 detects whether the entire loop of the sound field is connected to PE. If so, the MCU is notified through the I / O interface chip, wherein the PE connection phenomenon is that the speaker group line of the partition output is connected to the PE protective ground line.

[0042] The working principle and beneficial effects of the present invention are as follows: the present invention integrates a power amplifier, a sound field controller and three groups of speaker groups, and realizes efficient and flexible audio partition management. The sound field controller is the core, with built-in MCU, PHY and three independent partitions, each partition accurately corresponds to a speaker group, ensuring the independence and controllability of the audio output. The audio output of the power amplifier first enters the sound field controller through the initial relay 1, and then is directly connected to the speaker group by the first relay 2 to realize the transmission of the audio signal. As an intelligent control center, the MCU receives instructions through the network to accurately control each partition, and can detect and report the device status and the partition sound field status to the network management system in real time. The present invention is connected to the output of the initial relay 1 through an analog-to-digital converter, so as to realize the detection and fault diagnosis function of the MCU on the audio signal. The present invention supports independent sound field detection for each partition, including multiple states such as open circuit, short circuit, normal and grounded, ensuring the stability and reliability of audio transmission. This refined partition management and detection mechanism enables the system to quickly discover and deal with potential problems, ensuring the overall performance and user experience of the audio system.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sound field controller, characterized in that: include: The power amplifier is connected to a sound field controller, the sound field controller is connected to three groups of speaker groups, the sound field controller comprises an MCU, a PHY and three partitions, one of the speaker groups is connected to one of the partitions, the partitions comprise a first partition, a second partition and a third partition, the partitions comprise three relays, the relays comprise an initial relay (1), a first relay (2) and a second relay (3), the relays comprise two groups of automatic switches, the automatic switches comprise two input interfaces and one output interface, the MCU comprises an I / O interface chip and an analog-to-digital converter, the MCU is connected to the PHY, and the PHY is used to transmit external signals to the MCU; The power amplifier is connected to the initial relay (1), the initial relay (1) is connected to the first relay (2), and the first relay (2) is connected to the speaker group; The I / O interface chip is connected to the second relay (3) via an I / O interface circuit (6), the analog-to-digital converter is connected to the second relay (3) via a first analog-to-digital conversion circuit (7), and the second relay (3) is connected to the first relay (2); The analog-to-digital converter is connected to the output interface of the initial relay (1) via a second analog-to-digital conversion circuit (8).

2. A sound field controller according to claim 1, characterized in that: include: The output interface of the initial relay (1) is connected to a voltage-dividing resistor, a capacitor and an inductor (18) in sequence, one output interface of the inductor (18) is grounded, and the other output interface is connected to a third operational amplifier (121) and a rectifier diode (13) in sequence, and the rectifier diode (13) is connected to the analog-to-digital converter; The two output interfaces of the first relay (2) are connected in series with a sound field resistor (5), and a speaker group speaker unit (4) is connected in parallel between the two output interfaces of the first relay (2).

3. A sound field controller according to claim 2, characterized in that: include: The voltage-dividing resistor comprises a first resistor (14), a second resistor (15) and a third resistor (16), wherein the first resistor (14) and the second resistor (15) are respectively connected to two branch circuits corresponding to two output interfaces of the initial relay (1); The third resistor (16) is connected in parallel between the two branch circuits; The capacitor is connected in parallel between the third resistor (16) and the inductor (18).

4. A sound field controller according to claim 1, characterized in that: include: The two output interfaces of the initial relay (1) are respectively connected to one input interface of each of the two groups of automatic switches of the first relay (2), and the remaining two input interfaces of the first relay (2) are respectively connected to the two output interfaces of the second relay (3); The second relay (3) comprises a first input interface, a second input interface, a third input interface and a fourth input interface, wherein the first input interface and the second input interface belong to the same group of automatic switches, and the third input interface and the fourth input interface belong to the same group of automatic switches; The first input interface is connected to a pull-up resistor (9); The third input interface is grounded.

5. A sound field controller according to claim 4, characterized in that: include: The I / O interface chip is connected to a PE detection module (11), and two output interfaces of the PE detection module (11) are respectively connected to the second input interface and the fourth input interface of the second relay (3); The analog-to-digital converter is connected to a fourth operational amplifier (122), the fourth operational amplifier (122) is connected to an isolation operational amplifier (10), one output interface of the isolation operational amplifier (10) is grounded, and the other output interface is connected to the first input interface of the second relay (3).

6. A sound field control method, applied to a sound field controller as claimed in any one of claims 1 to 5, characterized in that: include: The audio output of the power amplifier is connected to the initial relay (1) of the partition, and the MCU controls the initial relay (1) to close so that the partition outputs audio; The MCU detects whether there is audio input, comprising: a voltage divider resistor steps down the output voltage of the power amplifier and filters out noise through a capacitor (17) to obtain stepped-down audio; a third operational amplifier (121) and a rectifier diode (13) precisely rectify the stepped-down audio and output it to an analog-to-digital converter of the MCU; and the MCU determines whether there is audio input.

7. A sound field control method according to claim 6, characterized in that: include: When the MCU detects audio input or receives a zone opening instruction through the network, the first relay (2) remains in a closed state, and the power amplifier outputs the audio to the speaker group corresponding to the zone through the initial relay (1) and the first relay (2); When the MCU detects that there is no audio input or receives a zone command through a network, the first relay (2) switches to a sound field detection circuit to detect a sound field line, wherein the sound field detection circuit comprises a second relay (3), a pull-up resistor (9), an isolation operational amplifier (10) and a fourth operational amplifier (122).

8. A sound field control method according to claim 7, characterized in that: include: When testing the sound field line, it includes: When the second relay (3) is in a normally closed state and the sound field cable is in a normal state, the pull-up resistor (9), the sound field cable, and the sound field resistor (5) form a DC path, the isolation amplifier (10) detects the sum of the DC voltages of the sound field cable and the sound field resistor (5), adjusts the sum through the fourth operational amplifier (122), and outputs the sum to the analog-to-digital converter of the MCU, and the analog-to-digital converter determines that the sound field is normal according to a preset voltage threshold; When the sound field line is short-circuited, the sound field resistor (5) is short-circuited, the upper resistor and the sound field line form a DC path, the isolation amplifier (10) detects the DC voltage of the sound field cable, and outputs it to the analog-to-digital converter of the MCU after adjustment through the fourth operational amplifier (122), and the analog-to-digital converter determines that the sound field is short-circuited according to a preset voltage threshold.

9. A sound field control method according to claim 7, characterized in that: include: When the sound field circuit is open-circuited, the isolation operational amplifier (10) detects the DC voltage of the upper resistor, adjusts it through the fourth operational amplifier (122), and outputs it to the analog-to-digital converter of the MCU. The analog-to-digital converter determines that the sound field is open-circuited based on a preset voltage threshold.

10. A sound field control method according to claim 7, characterized in that: include: After the sound field line detection is completed, PE detection is performed, including: the second relay (3) is switched to the PE detection circuit, and the PE detection module (11) detects whether the entire sound field loop is connected to PE. If so, the MCU is notified through the I / O interface chip, wherein: The PE connection phenomenon is that the speaker line of the zone output is connected to the PE protective ground wire.

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