A sound system

Abstract

The present invention discloses an audio system, belonging to the field of audio, including an audio source signal processing module, an amplifier module and a power supply module; the audio source signal processing module is used to receive the initial audio source signal output by the audio source device and decode the audio source signal; the amplifier module includes a filter pre-charge circuit, a full-frequency amplifier circuit, a fixed-frequency extraction area, a synthesis buffer circuit and a current amplifier circuit; the fixed-frequency extraction area is used to extract a signal of a set extraction frequency; the synthesis buffer circuit is used to synthesize the signal amplified by the full-frequency amplifier circuit and the signals of corresponding frequencies extracted by multiple fixed-frequency circuits. By setting the audio source signal processing module to receive the initial audio source signal of the audio source device and decode it, the present invention ensures a high pass rate of each frequency band signal of the signal source during the tone process, keeps the original flavor of the audio, extracts directionally at the frequency where excitation is required, performs excitation amplification, and realizes the high fidelity of the signal source during the transmission process.

Description

Technical Field

[0001] The present invention relates to the field of audio, and in particular to an audio system. Background Art

[0002] The preamplifier circuit in the existing audio system usually adopts an attenuation type or an operational amplifier to form a negative feedback circuit structure. Due to the characteristics of the negative feedback circuit structure, the sound source signal cannot be fully amplified before being input into the post-stage circuit, that is, the problem of partial loss of the sound source signal will occur. The most intuitive of which is the loss of the signal near 1kHz, which brings a dry and hard listening experience and a narrowed sound field, resulting in a higher level of distortion effect or a strong sense of irritation after amplification.

[0003] Traditional power amplifiers in existing audio systems usually use heavy silicon steel transformers in their power supplies to achieve voltage conversion, which results in larger mass and volume of the audio equipment and greater power loss. In addition, the high-frequency signal portion can only extend from the 50Hz AC power frequency through the full-bridge rectifier to the highest peak at 100Hz, resulting in dry, harsh, and non-magnetic high frequencies. Summary of the invention

[0004] The purpose of the present invention is to provide a sound system with a light power supply and capable of ensuring the integrity of sound source signals.

[0005] To achieve this purpose, the present invention adopts the following technical solution: including a sound source signal processing module, a power amplifier module and a power supply module; the sound source signal processing module is used to receive the initial sound source signal output by the sound source device and decode the sound source signal;

[0006] The power amplifier module includes a filter pre-thrust circuit, a full-frequency amplifier circuit, a fixed-frequency extraction area, a synthesis buffer circuit and a current amplifier circuit; the input end of the filter pre-thrust circuit is connected to the output end of the sound source signal processing module, the input end of the full-frequency amplifier circuit is connected to the output end of the filter pre-thrust circuit, the first output end of the full-frequency amplifier circuit is connected to the input end of the fixed-frequency extraction area, the output end of the fixed-frequency extraction area and the second output end of the full-frequency amplifier circuit are both connected to the input end of the synthesis buffer circuit, and the output end of the synthesis buffer circuit is connected to the input end of the current amplifier circuit;

[0007] The fixed frequency extraction area is used to extract a signal with a set extraction frequency;

[0008] The synthesis buffer circuit is used to synthesize the signal amplified by the full-frequency amplifier circuit and the signals of corresponding frequencies extracted by the plurality of fixed-frequency circuits;

[0009] The current amplifier circuit is used to amplify the signal synthesized by the synthesis buffer circuit;

[0010] The power supply module is used to convert the 220V power input from the mains power grid into power supply for the audio source processing module and the power amplifier module.

[0011] Preferably, the fixed-frequency extraction area includes a first fixed-frequency circuit, a second fixed-frequency circuit and a third fixed-frequency circuit, the first fixed-frequency circuit, the second fixed-frequency circuit and the third fixed-frequency circuit are all high-pass filter circuits, the first fixed-frequency circuit is used to pass a signal with a frequency of 12kHz, the second fixed-frequency circuit is used to pass a signal with a frequency of 120Hz, and the third fixed-frequency circuit is used to pass a signal with a frequency of 60Hz.

[0012] Preferably, the filter pre-thrust circuit includes an operational amplifier U101, a potentiometer W101, resistors R101, R102, R103, capacitors C101, C102, C103, and C104; the +IN input terminal of the operational amplifier U101 is connected to one end of the capacitor C103, one end of the capacitor C102, and one end of the resistor R101, one end of the capacitor C101 is connected to the signal input terminal, the other end of the capacitor C101 is connected to the other end of the resistor R101, the other end of the capacitor C102, and one end of the resistor R102, and the resistor R101 is connected to the signal input terminal. The other end of 02 is connected to the other end of capacitor C103, one end of resistor R104 and one end of resistor R103, the other end of resistor R014 is connected to the -IN input terminal of operational amplifier U101 and one end of capacitor C104, the other end of resistor R103 is connected to the other end of capacitor C104, the output terminal of operational amplifier U101 and I terminal of potentiometer W101, the G terminal of potentiometer W101 and the +IN input terminal of operational amplifier U101 are both connected to the GND terminal, and the O terminal of potentiometer W101 is connected to the input terminal of the full-frequency amplifier circuit.

[0013] Preferably, the full-frequency amplification circuit includes an operational amplifier U201, resistors R201, R202, R203, R204, and capacitors C201, C202, C203, and C204; one end of the capacitor C201 is connected to the input end of the filter pre-thrust circuit, the +IN input end of the operational amplifier U201 is connected to the other end of the capacitor C201, one end of the resistor R201, and one end of the capacitor C202, the other end of the resistor R201 is connected to the other end of the capacitor C202, one end of the resistor R202, one end of the resistor R204, and the GND end, and the operational amplifier U The -IN input terminal of 201 is connected to one end of capacitor C203, the other end of resistor R202 and one end of resistor R203, the other end of capacitor C203 is connected to the other end of resistor R203 and one end of capacitor C204, the other end of capacitor C204 is connected to the other end of resistor R204, the output terminal of operational amplifier U201 is connected to one end of capacitor C204, the input terminal of the first fixed frequency circuit, the input terminal of the second fixed frequency circuit and the input terminal of the third fixed frequency circuit, and the other end of capacitor C204 is also connected to the fourth input terminal of the synthetic buffer circuit.

[0014] Preferably, the synthesis buffer circuit includes operational amplifiers U601, U602, resistors R601, R602, R603, R604, R605, R606, R607, and capacitor C601; one end of the resistor R601 is the first input end of the synthesis buffer circuit, one end of the resistor R602 is the second input end of the synthesis buffer circuit, one end of the resistor R603 is the third input end of the synthesis buffer circuit, and one end of the resistor R604 is the fourth input end of the synthesis buffer circuit; the -IN input end of the operational amplifier U601 is connected to the other end of the resistor R601, the other end of the resistor R602, and the capacitor C601; 3, the other end of resistor R604, one end of capacitor C601 and one end of resistor R606, the other end of resistor R606 is connected to the other end of capacitor C601, the output end of operational amplifier U601 and the +IN input end of operational amplifier U602, the +IN input end of operational amplifier U601 is connected to one end of resistor R605, the other end of resistor R605 is connected to GND, the -IN input end of operational amplifier U602 is connected to the output end of operational amplifier U602 and one end of resistor R607, the other end of resistor R607 is connected to the input end of the current amplifier circuit.

[0015] Preferably, the sound source processing module includes a DAC conversion circuit and an SRS processing circuit, the DAC conversion circuit includes an array chip U21, the input end of the array chip U11 is connected to the output end of the SRS processing circuit, and the array chip U21 adopts a ULN2003 chip;

[0016] The SRS processing circuit comprises an audio processing chip NJM2706, an input end of the SRS processing circuit is connected to an audio source device, and an output end of the SRS processing circuit is connected to an input end of the DAC conversion circuit.

[0017] Preferably, the sound source processing module also includes a TV decoding circuit and a PC decoding circuit, the TV decoding circuit includes a decoding chip U23, the input end of the decoding chip U23 is connected to the sound source device through a USB1 port, and the output end of the decoding chip U23 is connected to the input end of the DAC conversion circuit; the PC decoding circuit includes a decoding chip U24, the input end of the decoding chip U24 is connected to the sound source device through a USB2 port, and the output end of the decoding chip U24 is connected to the input end of the DAC conversion circuit, and the decoding chip U23 and the decoding chip U24 both use CM108 chips.

[0018] Preferably, the power module includes an EMI filter circuit and a half-bridge conversion circuit, the input end of the EMI filter circuit is connected to the mains power grid, the output end of the EMI filter circuit is connected to the input end of the half-bridge conversion circuit, and the half-bridge conversion circuit includes a rectifier D2, capacitors C1, C2, C7, C10, resistors R1, R2, R3, R4, R6, R11, R12, R13, R15, transistors Q1, Q22, diodes D1, D4, and a transformer T1; pin 1 of the rectifier D2 is sequentially connected to the positive electrode of the capacitor C1, one end of the resistor R4, the negative electrode of the diode D1, the collector of the transistor Q1, and one end of the resistor R1, the negative electrode of the capacitor C1 is sequentially connected to the positive electrode of the capacitor C10, one end of the resistor R12, one end of the capacitor C7, and the other end of the resistor R4, and pin 4 of the rectifier is sequentially connected to the positive electrode of the capacitor C10, one end of the resistor R12, one end of the capacitor C7, and the other end of the resistor R4. The cathode of capacitor C10, the other end of resistor R12, the anode of diode D4, the emitter of transistor Q2 and one end of resistor R15 are connected; the emitter of transistor Q1 is connected to the anode of diode D1, one end of resistor R6, one end of resistor R11, the collector of transistor Q2 and the cathode of transistor D4; the base of transistor Q1 is connected to one end of resistor R3, the other end of resistor R1, the other end of resistor R3 and the other end of resistor R6 are connected; the base of transistor Q2 is connected to one end of resistor R13, the other end of resistor R13 is connected to the other end of resistor R11 and the other end of resistor R15; the other end of capacitor C7 is connected to resistor R2 and one end of the primary coil of transformer T1, the other end of resistor R2 is connected to one end of capacitor C2, and the other end of capacitor C2 is connected to the other end of the primary coil of transformer T1.

[0019] Preferably, the power module further includes a push-pull conversion circuit, which includes NMOS tubes Q3, Q4, diodes D8, D9, D10, D11, D12, D13, resistors R18, R19, R20, R21, R22, R23, R24, R25, inductors L1, L2, L3, and a transformer T4;

[0020] The drain of the NMOS tube Q3 and the drain of the NMOS tube Q4 are respectively connected to the two ends of the primary coil of the transformer T4, the middle point of the primary coil of the transformer T4 is connected to the output end of the half-bridge conversion circuit, and the gates of the NMOS tube Q3 and the NMOS tube Q4 are both connected to the GND-2 terminal;

[0021] One end of the first secondary coil of the transformer T4 is connected to the positive electrode of the diode D8, the negative electrode of the diode D8 is connected to one end of the resistor R19, the positive electrode of the capacitor C18, one end of the capacitor C19 and one end of the inductor L1 in sequence, the other end of the inductor L1 is connected to one end of the resistor R18, the positive electrode of the capacitor C16, one end of the capacitor C17 and the V+ output terminal in sequence; the other end of the first secondary coil of the transformer T4 is connected to the negative electrode of the diode D9, the positive electrode of the diode D9 is connected to one end of the resistor R21, the negative electrode of the capacitor C22, one end of the capacitor C23, One end of the inductor L2, one end of the resistor R20, the negative electrode of the capacitor C20, one end of the capacitor C21 and the V- output end are connected; the midpoint of the first secondary coil of the transformer T4 is connected in sequence to the other end of the resistor R19, the other end of the resistor R21, the negative electrode of the capacitor C18, the positive electrode of the capacitor C22, the other end of the capacitor C19, the other end of the capacitor C23, the other end of the resistor R18, the other end of the resistor R20, the negative electrode of the capacitor C16, the positive electrode of the capacitor C20, the other end of the capacitor C17, the other end of the capacitor C21 and the GND-3 end.

[0022] Preferably, the power supply module also includes a first PWM regulation circuit and a second PWM regulation circuit, the first PWM regulation circuit includes a driving chip U1, the input end of the driving chip U1 is connected to the output end of the half-bridge conversion circuit, the first output end of the driving chip U1 is connected to the NMOS tube Q3, and the second output end of the driving chip U1 is connected to the NMOS tube Q4, the second PWM regulation circuit includes a driving chip U2, the input end of the driving chip U2 is connected to the output end of the half-bridge conversion circuit, and the output end of the driving chip U2 is connected to the transistor Q1 and the transistor Q2 of the half-bridge conversion circuit.

[0023] The beneficial effects of the present invention are as follows: 1. By setting up a sound source signal processing module to receive the initial sound source signal of the sound source device and decode it, it is possible to directly decode the sound source signal output by the sound source device, avoid decoding of low sound source quality, and filter pre-rush circuit to filter out digital unique signal glitches from the decoded sound source input signal to ensure signal integrity; then the signal is amplified several times by the full-frequency amplifier circuit, and then the signal of the corresponding frequency is extracted by the fixed-frequency extraction area, and then the signal amplified by the full-frequency amplifier circuit and the signal of the corresponding frequency extracted by the fixed-frequency extraction area are synthesized by the synthesis buffer circuit, thereby ensuring the high pass rate of the signal of each frequency band in the tone process of the signal source, keeping the original flavor of the audio, and directional extraction at the frequency where excitation is required, and excitation amplification, thereby achieving high fidelity of the signal source during transmission.

[0024] 2. In practical applications, the power module of the present invention has outstanding listening performance in terms of audio details and strong tube flavor. The annoying noise characteristic of modern digital audio equipment is greatly reduced. The low-frequency impact performance is due to the reasonable configuration of the power system. The multi-stage EMI filtering makes the power supply clutter filtering extremely clean, and the overall listening environment is not affected by fluctuations outside the power line. In addition, the application of the switching power supply in the overall listening use effectively increases the power utilization rate and reduces the power consumption, which meets the energy-saving requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings further illustrate the present invention, but the contents in the accompanying drawings do not constitute any limitation to the present invention.

[0026] Figure 1 is a schematic diagram of the overall circuit principle of one embodiment of the present invention;

[0027] Figure 2 is a circuit principle block diagram of a power module of one embodiment of the present invention;

[0028] Figure 3 is a circuit schematic diagram of a DAC conversion circuit according to one embodiment of the present invention;

[0029] Figure 4 is a circuit schematic diagram of an SRS processing circuit according to one embodiment of the present invention;

[0030] Figure 5 is a circuit schematic diagram of a TV decoding circuit according to one embodiment of the present invention;

[0031] Figure 6 is a circuit schematic diagram of a PC decoding circuit according to one embodiment of the present invention;

[0032] Figure 7 It is a circuit schematic diagram of a filter pre-thrust circuit and a full-frequency amplifier circuit in one embodiment of the present invention;

[0033] Figure 8 is a circuit schematic diagram of a first fixed frequency circuit of one embodiment of the present invention;

[0034] Fig. 9 is a circuit schematic diagram of a second fixed frequency circuit of one embodiment of the present invention;

[0035] Fig.10 is a circuit schematic diagram of a third fixed frequency circuit of one embodiment of the present invention;

[0036] Fig.11 is a circuit schematic diagram of a synthetic buffer circuit according to one embodiment of the present invention;

[0037] Fig.12 is a circuit schematic diagram of a current amplifier circuit according to one embodiment of the present invention;

[0038] Fig.13 is a circuit schematic diagram of a current amplifier circuit according to another embodiment of the present invention;

[0039] Fig.14 It is a circuit schematic diagram of an EMI filter circuit and a half-bridge converter circuit in one embodiment of the present invention;

[0040] Fig.15 is a circuit schematic diagram of a push-pull conversion circuit according to one embodiment of the present invention;

[0041] Fig.16 is a circuit schematic diagram of a first PWM regulation circuit according to one embodiment of the present invention;

[0042] Fig.17 It is a circuit schematic diagram of a second PWM regulation circuit according to one embodiment of the present invention.

[0043] Among them: power supply module 1, DAC conversion circuit 24, TV decoding circuit 22, PC decoding circuit 21, filter pre-thrust circuit 31, full-frequency amplifier circuit 32, fixed-frequency extraction area 33, synthesis buffer circuit 34, current amplifier circuit 35, EMI filter circuit 14, half-bridge conversion circuit 11, push-pull conversion circuit 12, first PWM regulation circuit 131, second PWM regulation circuit 132. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0045] A sound system of this embodiment, referring to the attached Figure 1 , 2, including an audio source signal processing module, an amplifier module and a power supply module 1; the audio source signal processing module is used to receive the initial audio source signal output by the audio source device and decode the audio source signal;

[0046] The power amplifier module includes a filter pre-thrust circuit 31, a full-frequency amplifier circuit 32, a fixed-frequency extraction area 33, a synthesis buffer circuit 34 and a current amplifier circuit 35; the input end of the filter pre-thrust circuit 31 is connected to the output end of the sound source signal processing module, the input end of the full-frequency amplifier circuit 32 is connected to the output end of the filter pre-thrust circuit 31, the first output end of the full-frequency amplifier circuit 32 is connected to the input end of the fixed-frequency extraction area 33, the output end of the fixed-frequency extraction area 33 and the second output end of the full-frequency amplifier circuit 32 are both connected to the input end of the synthesis buffer circuit 34, and the output end of the synthesis buffer circuit 34 is connected to the input end of the current amplifier circuit 35;

[0047] The fixed frequency extraction area 33 is used to extract the signal of the set extraction frequency;

[0048] The synthesis buffer circuit 34 is used to synthesize the signal amplified by the full-frequency amplifier circuit 32 and the signals of corresponding frequencies extracted by the multiple fixed-frequency circuits;

[0049] The current amplifier circuit 35 is used to amplify the signal synthesized by the synthesis buffer circuit 34;

[0050] The power module 1 is used to convert the 220V power input from the mains grid into power for the audio source processing module and the power amplifier module.

[0051] Preferably, the fixed-frequency extraction area 33 is respectively a first fixed-frequency circuit, a second fixed-frequency circuit and a third fixed-frequency circuit, the first fixed-frequency circuit, the second fixed-frequency circuit and the third fixed-frequency circuit are all high-pass filter circuits, the first fixed-frequency circuit is used to pass a signal with a frequency of 12kHz, the second fixed-frequency circuit is used to pass a signal with a frequency of 120Hz, and the third fixed-frequency circuit is used to pass a signal with a frequency of 60Hz.

[0052] Preferably, refer to the attached Figure 3-6 The sound source processing module includes a DAC conversion circuit 24 and an SRS processing circuit. The DAC conversion circuit 24 includes an array chip U21. The input end of the array chip U11 is connected to the output end of the SRS processing circuit. The array chip U21 uses a ULN2003 chip.

[0053] The SRS processing circuit includes an audio processing chip NJM2706. The input end of the SRS processing circuit is connected to the audio source device, and the output end of the SRS processing circuit is connected to the input end of the DAC conversion circuit 24.

[0054] By adding the PC decoding circuit 21 and TV decoding circuit 22 composed of the CM108 chip that can directly decode the USB signal, the two sets of decoding circuits are used independently, and the USB port of the audio source device such as a mobile phone or computer can be directly decoded through the USB line and the low-quality audio decoding at the source can be skipped. In addition, the SRS processing circuit that can accurately position the movie sound effect is added, which can be turned on and used when watching movies to achieve accurate positioning of a pair of main speakers, thereby creating surround sound effects, without the need to add additional surround speakers, saving space.

[0055] Preferably, the power amplifier module includes a filter pre-thrust circuit 31, a full-frequency amplification circuit 32, a fixed-frequency extraction area 33, a synthesis buffer circuit 34 and a current amplification circuit 35; the fixed-frequency extraction area 33 includes a first fixed-frequency circuit, a second fixed-frequency circuit and a third fixed-frequency circuit. For the filter pre-thrust circuit 31, refer to the attached Figure 7 Since there are generally two audio source input signals, the processing structure and principle of the two audio source signals in this embodiment are the same, so only one of the audio source input signals is described. One of the audio source input signals is input into the filter pre-thrust circuit 31 through the jumper L-IN. The filter pre-thrust circuit 31 includes an operational amplifier U101, a potentiometer W101, resistors R101, R102, R103, capacitors C101, C102, C103, and C104; the +IN input terminal of the operational amplifier U101 is connected to one end of the capacitor C103, one end of the capacitor C102, and one end of the resistor R101, one end of the capacitor C101 is connected to the jumper L-IN to receive the audio source signal, and the other end of the capacitor C101 is connected to the resistor R10 1, the other end of capacitor C102 and one end of resistor R102, the other end of resistor R102 is connected to the other end of capacitor C103, one end of resistor R104 and one end of resistor R103, the other end of resistor R014 is connected to the -IN input terminal of operational amplifier U101 and one end of capacitor C104, the other end of resistor R103 is connected to the other end of capacitor C104, the output terminal of operational amplifier U101 and I terminal of potentiometer W101, the G terminal of potentiometer W101 and the +IN input terminal of operational amplifier U101 are both connected to the GND terminal, and the O terminal of potentiometer W101 is connected to one end of capacitor C201 of full-frequency amplifier circuit 32, so as to output the signal to full-frequency amplifier circuit 32;

[0056] Therefore, by setting up the filter pre-shoot circuit 31, the audio source signal of the digital chip can be directly input without setting up filtering and buffering on the DAC or other digital chips; the filter pre-shoot circuit 31 plays a role in filtering and buffering the audio source signal, and is used to filter out the unique digital signal glitches, and adds a buffer structure after filtering to play an impedance matching role, thereby ensuring the integrity of the signal.

[0057] The full-frequency amplifier circuit 32 includes an operational amplifier U201, resistors R201, R202, R203, R204, and capacitors C201, C202, C203, and C204; the +IN input terminal of the operational amplifier U201 is connected to the other end of the capacitor C201, one end of the resistor R201, and one end of the capacitor C202, the other end of the resistor R201 is connected to the other end of the capacitor C202, one end of the resistor R202, one end of the resistor R204, and the GND terminal, and the -IN input terminal of the operational amplifier U201 is connected to one end of the capacitor C203, the resistor R202 The other end of the operational amplifier U201 is connected to one end of the capacitor C204, and the other end of the operational amplifier U201 is connected to the input end of the first fixed frequency circuit, the input end of the second fixed frequency circuit 32 and the input end of the third fixed frequency circuit through a jumper L-1. The other end of the capacitor C204 is connected to the fourth input end of the synthetic buffer circuit 34 through a jumper L-2.

[0058] Therefore, the full-frequency amplifier circuit 32 is used to amplify the signal output by the filter pre-shoot circuit 31 several times. The amplification factor of the full-frequency amplifier circuit 32 in this embodiment is 20 times, and its structure is changed from a traditional AC negative feedback circuit to a DC working state. Since the crossover distortion when amplifying high and low frequency signals in the DC working state is very low, the consistency of the overall signal is guaranteed.

[0059] The first fixed frequency circuit, the second fixed frequency circuit and the third fixed frequency circuit are all high-pass filter circuits. The first fixed frequency circuit is used to pass the signal with a frequency of 12kHz, the second fixed frequency circuit is used to pass the signal with a frequency of 120Hz, and the third fixed frequency circuit is used to pass the signal with a frequency of 60Hz. Figure 8 , 9, 10, the first fixed frequency circuit includes operational amplifiers U301, U302, resistors R301, R302, R303, R304, R305, capacitors C301, C302, C303, C304, and potentiometer W301; one end of capacitor C301 is connected to the output end of full-frequency amplifier circuit 32 through jumper L-1, the other end of capacitor C301 is connected to one end of resistor R301 and one end of capacitor C302, the other end of resistor R301 is connected to the -IN input end of operational amplifier U301, the output end of operational amplifier U301 and one end of resistor R303, the +IN input end of operational amplifier U301 is connected to the other end of capacitor C302 and resistor R30 2, the other end of the resistor R303 is connected to the +IN input terminal of the operational amplifier U302, the other end of the resistor R302 is connected to the GND terminal, one end of the resistor R304 and one end of the resistor R305, the -IN input terminal of the operational amplifier U302 is connected to the other end of the resistor R304, the I terminal and the O terminal of the potentiometer W301 and one end of the capacitor C303, the other end of the capacitor C303 is connected to the G terminal of the potentiometer W301, the output terminal of the operational amplifier U302 and one end of the capacitor C304, the other end of the capacitor C304 is connected to the other end of the resistor R305, and the capacitor C304 is also connected to the first input terminal of the synthesis buffer circuit 34 through the jumper 12kHz-L.

[0060] Therefore, the first fixed frequency circuit of this embodiment is for extracting the 12kHz signal. It first accurately extracts the 12kHz frequency signal through a high-pass filtering structure. After the extraction is completed, it is output through a feedback amplification setting circuit composed of a single-stage operational amplifier and an adjustable potentiometer, thereby ensuring that the 12kHz frequency signal is output to the synthesis buffer circuit 34.

[0061] The second fixed frequency circuit includes operational amplifiers U401, U402, capacitors C401, C402, C403, C404, C405, resistors R401, R402, R403, R404, R405, R406, and potentiometer W401; one end of capacitor C401 is connected to the output end of full-frequency amplifier circuit 322 through jumper L-1, the other end of capacitor C401 is connected to one end of resistor R402 and one end of resistor R401, the other end of resistor R402 is connected to one end of resistor R403 and one end of capacitor C402, the other end of resistor R403 is connected to the +IN input end of operational amplifier U401 and one end of capacitor R403, and the other end of resistor R401 is connected to the other end of capacitor C403, one end of resistor R403, and one end of resistor R404. 06 and the GND terminal, the other end of the resistor R405 is connected to the -IN input terminal of the operational amplifier U402, the I terminal and the O terminal of the potentiometer W401 and one end of the capacitor C404, the other end of the capacitor C404 is connected to the G terminal of the potentiometer W401, the output terminal of the operational amplifier U402 and one end of the capacitor C405, the other end of the capacitor C405 is connected to the other end of the resistor R406, the other end of the capacitor C405 is also connected to the third input terminal of the synthesis buffer circuit 344 through the jumper 120Hz-L, the other end of the capacitor C402 is connected to the -IN input terminal of the operational amplifier U401, the output terminal of the operational amplifier U401 and one end of the resistor R404, and the other end of the resistor R404 is connected to the +IN input terminal of the operational amplifier U402;

[0062] The second fixed frequency circuit of this embodiment is for extracting the 120Hz signal. It first accurately extracts the 120Hz frequency signal through a high-pass filtering structure. After the extraction is completed, it is output through a feedback amplification setting circuit composed of a single-stage operational amplifier and an adjustable potentiometer, thereby ensuring the output of the 120Hz frequency signal to the synthesis buffer circuit 34.

[0063] The third fixed frequency circuit includes operational amplifiers U501, U502, U503, capacitors C501, C502, C503, C504, C505, C506, C507, C508, resistors R501, R502, R503, R504, R505, R506, R507, R508, R509, R510, R511, R512, R513, R514, R515, and potentiometer W501; one end of capacitor C501 is connected to the output end of full-frequency amplifier circuit 322 through jumper L-1, the other end of capacitor C501 is connected to one end of resistor R502 and one end of resistor R501, and the other end of resistor R501 is connected to resistor R502 and one end of resistor R501. 04, one end of capacitor C503, one end of resistor R509, one end of capacitor C505, GND, G end of potentiometer W501 and one end of resistor R515, the other end of resistor R502 is connected to one end of capacitor C502 and one end of resistor R503, the other end of resistor R503 is connected to the other end of capacitor C503 and the +IN input terminal of operational amplifier U501, the other end of resistor R504 is connected to the other end of capacitor C502, the -IN input terminal of operational amplifier U501 and one end of resistor R505, the other end of resistor R505 is connected to one end of resistor R506, the other end of resistor R506 is connected to the operational amplifier U501 The output end of the operational amplifier U502 is connected to one end of the resistor R510, the other end of the resistor R510 is connected to one end of the resistor R511, the other end of the resistor R511 is connected to the output end of the operational amplifier U502 and one end of the resistor R513, the other end of the resistor R513 is connected to the output end of the operational amplifier U502 and one end of the resistor R513, the other end of the resistor R513 is connected to the output end of the operational amplifier U502 and one end of the resistor R513, and the other end of the resistor R513 is connected to the output end of the operational amplifier U502 and one end of the resistor R513. The -IN input terminal of U503, one end of capacitor C507 and one end of resistor R514 are connected, the other end of resistor R514 is connected to the other end of capacitor C507, the output terminal of operational amplifier U503 and the I terminal of potentiometer W501, the +IN output terminal of operational amplifier U503 is connected to one end of capacitor C506 and one end of resistor R512, the other end of resistor R512 is connected to the other end of capacitor 506 and the GND terminal, the O terminal of potentiometer W501 is connected to one end of capacitor C508, the other end of capacitor C508 is connected to the other end of resistor R515, and capacitor C508 is also connected to the second input terminal of synthesis buffer circuit 34 through jumper 60Hz-L;

[0064] The third fixed frequency circuit of this embodiment is for extracting the 60Hz signal. It first accurately extracts the 120Hz frequency signal through the high-pass filter structure. After the extraction is completed, it is output through the feedback amplifier setting circuit composed of a single-stage operational amplifier and an adjustable potentiometer, thereby ensuring that the 60Hz frequency signal is output to the synthesis buffer circuit 344. This level of circuit reflects the weak subwoofer signal on the signal source very strongly. Because the fixed frequency extraction and each level have 10 times amplification, the super low frequency signal is extremely strong in the sense of hearing. Therefore, the present invention meets the hearing needs of most people and only sets 12KHz, 120Hz and the super heavy bass frequency band 60Hz (the air wave feeling of guns and cannons) required by the sound source of most video programs.

[0065] The synthesis buffer circuit 34 includes operational amplifiers U601, U602, resistors R601, R602, R603, R604, R605, R606, R607, and a capacitor C601; the output end of the first fixed frequency circuit, the output end of the second fixed frequency circuit, the output end of the third fixed frequency circuit, and the output end of the synthesis buffer circuit 34 are connected to one end of the resistor R601, one end of the resistor R602, one end of the resistor R603, and one end of the resistor R604 through jumpers 12kHz-L, 60Hz-L, 120Hz-L, and L-2 respectively; the -IN input end of the operational amplifier U601 is connected to the other end of the resistor R601 and the other end of the resistor R604. 02, the other end of resistor R603, the other end of resistor R604, one end of capacitor C601 and one end of resistor R606, the other end of resistor R606 is connected to the other end of capacitor C601, the output end of operational amplifier U601 and the +IN input end of operational amplifier U602, the +IN input end of operational amplifier U601 is connected to one end of resistor R605, the other end of resistor R605 is connected to the GND end, the -IN input end of operational amplifier U602 is connected to the output end of operational amplifier U602 and one end of resistor R607, and the other end of resistor R607 is connected to the input end of current amplifier circuit 35.

[0066] The synthesis buffer circuit 34 uses an adder circuit structure composed of an operational amplifier to amplify and synthesize the original signal of the full-frequency amplifier circuit 32 and the 12kHz, 120Hz, and 60Hz frequency signals extracted by the first fixed-frequency circuit, the second fixed-frequency circuit, and the third fixed-frequency circuit, and then adds a buffer to complete the impedance matching with the current amplifier stage.

[0067] Preferably, refer to the attached Fig.12 The current amplifier circuit 35 includes power amplifier chips U11, U12, and U13. The power amplifier chip U11 is connected in parallel with the power amplifier chip U12 and the power amplifier chip U13. The power amplifier chips U11, U12, and U13 all use TDA7293 chips to amplify each signal processed by the synthesis buffer circuit 34 and finally output it to the speaker.

[0068] This embodiment uses three master-slave parallel TDA7293 power amplifier chips to form a current amplifier circuit 35 to enhance the control of the speaker. The TDA7293 chip is a single-row dual-row (Multiwatt15) 15-pin package. Its operating voltage range: ±12V-±60V; output current peak value 10A; output power: 100W at ±40V, 8Ω; 140W at ±45V, 8Ω; 100W at ±29V, 4Ω; total harmonic distortion (Po=5W, f=1KHz) 0.005%; conversion rate 15V / μs, so the richer the sound quality; input impedance 100KΩ; frequency response 20Hz-20Kz; working in Class A and B state. The internal structure is divided into three levels: the differential input stage is composed of bipolar transistors, the driving stage and the power output stage use field effect tubes. This structure can combine the advantages of low noise of bipolar transistors and power field effect tubes in linearity, temperature coefficient, and timbre. It has beautiful tone and takes into account the advantages of bipolar signal processing circuit and MOS power tube. It has the advantages of low distortion, low noise, high voltage resistance, silent switching, overheat protection, short circuit protection, etc.

[0069] In another embodiment, referring to the attached Fig.13 The current amplifier stage includes a discrete differential input unit and a push-pull output unit. The input end of the differential input unit is connected to the output end of the synthetic buffer circuit 34, the output end of the discrete differential input unit is connected to the input end of the push-pull output unit, and the output end of the push-pull output unit is connected to the speaker.

[0070] The current amplifier circuit 35 is composed of a discrete differential input unit and a push-pull output unit. The current amplifier circuit 35 of this embodiment has a strong control over the speaker 6 and a relatively high performance for large dynamic audio.

[0071] The power module 1 includes an EMI filter circuit 14, a half-bridge conversion circuit 11, a first PWM regulation circuit 131, a second PWM regulation circuit 132 and a push-pull conversion circuit 12; Fig.14 , the EMI filter circuit 144 includes common mode inductors T2 and T3, the input end of the common mode inductor T2 is connected to the mains power grid, the output end of the common mode inductor T2 is connected to the input end of the common mode inductor T3, and the output end of the common mode inductor T3 is connected to the AC input end of the rectifier D2. The half-bridge conversion circuit 111 includes a rectifier D2, which adopts a KB810 bridge rectifier, and the AC input end of the rectifier D2 is connected to the output end of the EMI filter circuit 144. The rectifier D2 is used to rectify the 220V mains power grid input after filtering by the EMI filter circuit 144.

[0072] Furthermore, the half-bridge conversion circuit 111 also includes capacitors C1, C2, C7, C10, resistors R1, R2, R3, R4, R6, R11, R12, R13, R15, transistors Q1, Q22, diodes D1, D4, and transformer T1; pin 1 of the rectifier D2 is connected to the positive electrode of the capacitor C1, one end of the resistor R4, the negative electrode of the diode D1, the collector of the transistor Q1, and one end of the resistor R1 in sequence, the negative electrode of the capacitor C1 is connected to the positive electrode of the capacitor C10, one end of the resistor R12, one end of the capacitor C7, and the other end of the resistor R4 in sequence, and pin 4 of the rectifier is connected to the negative electrode of the capacitor C10, the other end of the resistor R12, the positive electrode of the diode D4, the emitter of the transistor Q2, and One end of the resistor R15 is connected; the emitter of the transistor Q1 is connected to the positive electrode of the diode D1, one end of the resistor R6, one end of the resistor R11, the collector of the transistor Q2 and the negative electrode of the D4; the base of the transistor Q1 is connected to one end of the resistor R3, the other end of the resistor R1, the other end of the resistor R3 and the other end of the resistor R6 are connected; the base of the transistor Q2 is connected to one end of the resistor R13, the other end of the resistor R13 is connected to the other end of the resistor R11 and the other end of the resistor R15; the other end of the capacitor C7 is connected to the resistor R2 and one end of the primary coil of the transformer T1, the other end of the resistor R2 is connected to one end of the capacitor C2, and the other end of the capacitor C2 is connected to the other end of the primary coil of the transformer T1. Thus, high-frequency inversion of the rectified 220V input is achieved.

[0073] Furthermore, the half-bridge conversion circuit 111 also includes an inductor L4, capacitors C3, C8, C9, C11, resistors R5, R7, R10, R14, diodes D3, D5, one end of the first secondary coil of the transformer T1 is connected to one end of the capacitor C3 and the positive electrode of the diode D3, the middle point of the first secondary coil of the transformer TI is connected to one end of the inductor L4, the other end of the first secondary coil of the transformer TI is connected to one end of the capacitor C11 and the positive electrode of the diode D5, the other end of the capacitor C3 is connected to one end of the resistor R7, the other end of the capacitor C11 is connected to one end of the resistor R14, the other end of the inductor L4 is connected to one end of the resistor R5, the other end of the resistor R5 is connected to one end of the resistor R10, one end of the capacitor C8 and one end of the capacitor C9 in sequence, and the other end of the resistor R7 is connected to the negative electrode of the diode D3, the other end of the resistor R14, the negative electrode of the diode D5, the other end of the resistor R10, the other end of the capacitor C8 and the other end of the capacitor C9 are interconnected. It plays the role of rectification and filtering on the output after the voltage is stepped down by transformer T1.

[0074] Reference Fig.15The push-pull conversion circuit 122 includes NMOS tubes Q3, Q4, diodes D8, D9, D10, D11, D12, D13, resistors R18, R19, R20, R21, R22, R23, R24, R25, inductors L1, L2, L3, and a transformer T4;

[0075] The drain of the NMOS transistor Q3 and the drain of the NMOS transistor Q4 are respectively connected to the two ends of the primary coil of the transformer T4, the middle point of the primary coil of the transformer T4 is connected to the output end of the half-bridge conversion circuit 111, and the gates of the NMOS transistor Q3 and the NMOS transistor Q4 are both connected to the GND-2 terminal;

[0076] One end of the first secondary coil of the transformer T4 is connected to the positive electrode of the diode D8, the negative electrode of the diode D8 is connected to one end of the resistor R19, the positive electrode of the capacitor C18, one end of the capacitor C19 and one end of the inductor L1 in sequence, the other end of the inductor L1 is connected to one end of the resistor R18, the positive electrode of the capacitor C16, one end of the capacitor C17 and the V+ output terminal in sequence; the other end of the first secondary coil of the transformer T4 is connected to the negative electrode of the diode D9, the positive electrode of the diode D9 is connected to one end of the resistor R21, the negative electrode of the capacitor C22, one end of the capacitor C23, One end of the inductor L2, one end of the resistor R20, the negative electrode of the capacitor C20, one end of the capacitor C21 and the V- output end are connected; the middle point of the first secondary coil of the transformer T4 is connected to the other end of the resistor R19, the other end of the resistor R21, the negative electrode of the capacitor C18, the positive electrode of the capacitor C22, the other end of the capacitor C19, the other end of the capacitor C23, the other end of the resistor R18, the other end of the resistor R20, the negative electrode of the capacitor C16, the positive electrode of the capacitor C20, the other end of the capacitor C17, the other end of the capacitor C21 and the GND-3 end. The V+ output end and the V- output end are respectively output to the load of the audio, and the main frequency is increased to 100kHz. The push-pull conversion circuit 122 replaces the heavy silicon steel transformer to reduce the weight of the audio switch power supply.

[0077] The capacitor C17 and the capacitor C21 are high-frequency capacitors with low ESR value and small capacity, which ensure that the output of the push-pull conversion circuit 122 has extremely low power ripple factor and high transient response.

[0078] Further, the push-pull conversion circuit 122 also includes three-terminal voltage regulators 7812, 7912, inductor L3, diodes D10, D11, D12 and D13, one end of the second secondary coil of the transformer T4 is respectively connected to the positive electrode of the diode D11 and the negative electrode of the diode D12, the negative electrode of the diode D11 is respectively connected to the negative electrode of the diode D10 and the input end of the three-terminal voltage regulator 7812, the other end of the second secondary coil of the transformer T4 is respectively connected to the positive electrode of the diode D12 and the negative electrode of the diode D13, the positive electrode of the diode D13 is respectively connected to the positive electrode of the diode D12 and the input end of the three-terminal voltage regulator 7912, the middle point of the second secondary coil of the transformer T4 is connected to one end of the inductor L3, and the other end of the inductor L3 is connected to the GND-3 terminal. By connecting the three-terminal voltage regulators 7812 and 7912 to the second secondary coil of the transformer T4, the voltage stabilization protection of the push-pull conversion circuit 122 is achieved.

[0079] Reference Fig.16 The first PWM regulation circuit 13131 includes a driver chip U1, the input end of the driver chip U1 is connected to the output end of the half-bridge conversion circuit 111, the first output end of the driver chip U1 is connected to the NMOS tube Q3 through a jumper V1, and the second output end of the driver chip U1 is connected to the NMOS tube Q4 through a jumper V2. The driver chip U1 adopts a TL494 chip, the input end of the driver chip U1 is connected to the output end of the half-bridge conversion circuit 111, and is used to supply power to the driver chip U1 and input feedback signals, and the output end of the driver chip U1 is connected to the NMOS tubes Q3 and Q4 in the push-pull circuit, which plays a role in driving and controlling the NMOS tubes Q3 and Q4.

[0080] Reference Fig.17 The second PWM regulation circuit 13232 includes a driving chip U2, the input end of the driving chip U2 is connected to the output end of the half-bridge conversion circuit 11 through a jumper, and the output end of the driving chip U2 is connected to the transistor Q1 and the transistor Q2 of the half-bridge conversion circuit 11. The driving chip U2 adopts a TL494 chip, and the input end of the driving chip U2 is connected to the output end of the half-bridge conversion circuit 111, which is used to supply power to the driving chip U2 and input feedback signals, and the output end of the driving chip U2 is connected to the transistors Q1 and Q2 in the half-bridge conversion circuit 11, which plays a role in driving and controlling the transistors Q1 and Q2.

[0081] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A sound system, characterized in that: It includes an audio source signal processing module, an amplifier module and a power supply module; the audio source signal processing module is used to receive the initial audio source signal output by the audio source device and decode the audio source signal; The power amplifier module includes a filter pre-thrust circuit, a full-frequency amplifier circuit, a fixed-frequency extraction area, a synthesis buffer circuit and a current amplifier circuit; the input end of the filter pre-thrust circuit is connected to the output end of the sound source signal processing module, the input end of the full-frequency amplifier circuit is connected to the output end of the filter pre-thrust circuit, the first output end of the full-frequency amplifier circuit is connected to the input end of the fixed-frequency extraction area, the output end of the fixed-frequency extraction area and the second output end of the full-frequency amplifier circuit are both connected to the input end of the synthesis buffer circuit, and the output end of the synthesis buffer circuit is connected to the input end of the current amplifier circuit; The fixed frequency extraction area is used to extract the signal of the set frequency; The fixed-frequency extraction area includes a first fixed-frequency circuit, a second fixed-frequency circuit and a third fixed-frequency circuit, wherein the first fixed-frequency circuit, the second fixed-frequency circuit and the third fixed-frequency circuit are all high-pass filter circuits, the first fixed-frequency circuit is used to pass a signal with a frequency of 12kHz, the second fixed-frequency circuit is used to pass a signal with a frequency of 120Hz, and the third fixed-frequency circuit is used to pass a signal with a frequency of 60Hz; The synthesis buffer circuit is used to synthesize the signal amplified by the full-frequency amplifier circuit and the signals of corresponding frequencies extracted by the plurality of fixed-frequency circuits; The current amplifier circuit is used to amplify the signal synthesized by the synthesis buffer circuit; The power supply module is used to convert the 220V power input from the mains power grid into power supply for the audio signal processing module and the power amplifier module; The filter pre-thrust circuit includes an operational amplifier U101, a potentiometer W101, resistors R101, R102, R103, capacitors C101, C102, C103, and C104; the +IN input terminal of the operational amplifier U101 is connected to one end of the capacitor C103, one end of the capacitor C102, and one end of the resistor R101, one end of the capacitor C101 is connected to the signal input terminal, the other end of the capacitor C101 is connected to the other end of the resistor R101, the other end of the capacitor C102, and one end of the resistor R102, and the resistor R102 is connected to the +IN input terminal of the operational amplifier U101. The other end of is connected to the other end of capacitor C103, one end of resistor R104 and one end of resistor R103, the other end of resistor R014 is connected to the -IN input terminal of operational amplifier U101 and one end of capacitor C104, the other end of resistor R103 is connected to the other end of capacitor C104, the output terminal of operational amplifier U101 and the I terminal of potentiometer W101, the G terminal of potentiometer W101 and the +IN input terminal of operational amplifier U101 are both connected to the GND terminal, and the O terminal of potentiometer W101 is connected to the input terminal of the full-frequency amplifier circuit; The full-frequency amplification circuit includes an operational amplifier U201, resistors R201, R202, R203, R204, and capacitors C201, C202, C203, and C204; one end of the capacitor C201 is connected to the input end of the filter pre-thrust circuit, the +IN input end of the operational amplifier U201 is connected to the other end of the capacitor C201, one end of the resistor R201, and one end of the capacitor C202, the other end of the resistor R201 is connected to the other end of the capacitor C202, one end of the resistor R202, one end of the resistor R204, and the GND end, and the operational amplifier U201 is connected to the input end of the filter pre-thrust circuit. The -IN input terminal of the operational amplifier U201 is connected to one end of the capacitor C203, the other end of the resistor R202 and one end of the resistor R203, the other end of the capacitor C203 is connected to the other end of the resistor R203 and one end of the capacitor C204, the other end of the capacitor C204 is connected to the other end of the resistor R204, the output terminal of the operational amplifier U201 is connected to one end of the capacitor C204, the input terminal of the first fixed frequency circuit, the input terminal of the second fixed frequency circuit and the input terminal of the third fixed frequency circuit, and the other end of the capacitor C204 is also connected to the fourth input terminal of the synthesis buffer circuit; The synthesis buffer circuit includes operational amplifiers U601, U602, resistors R601, R602, R603, R604, R605, R606, R607, and capacitor C601; one end of the resistor R601 is the first input end of the synthesis buffer circuit, one end of the resistor R602 is the second input end of the synthesis buffer circuit, one end of the resistor R603 is the third input end of the synthesis buffer circuit, and one end of the resistor R604 is the fourth input end of the synthesis buffer circuit; the -IN input end of the operational amplifier U601 is connected to the other end of the resistor R601, the other end of the resistor R602, and the fourth input end of the resistor R603. The other end of the operational amplifier U601 is connected to the other end of the resistor R604, one end of the capacitor C601 and one end of the resistor R606, the other end of the resistor R606 is connected to the other end of the capacitor C601, the output end of the operational amplifier U601 and the +IN input end of the operational amplifier U602, the +IN input end of the operational amplifier U601 is connected to one end of the resistor R605, the other end of the resistor R605 is connected to the GND end, the -IN input end of the operational amplifier U602 is connected to the output end of the operational amplifier U602 and one end of the resistor R607, and the other end of the resistor R607 is connected to the input end of the current amplifier circuit.

2. A sound system according to claim 1, characterized in that: The audio source signal processing module includes a DAC conversion circuit and an SRS processing circuit. The DAC conversion circuit includes an array chip U21. The input end of the array chip U21 is connected to the output end of the SRS processing circuit. The array chip U21 adopts a ULN2003 chip. The SRS processing circuit comprises an audio processing chip NJM2706, an input end of the SRS processing circuit is connected to an audio source device, and an output end of the SRS processing circuit is connected to an input end of the DAC conversion circuit.

3. A sound system according to claim 2, characterized in that: The sound source signal processing module also includes a TV decoding circuit and a PC decoding circuit. The TV decoding circuit includes a decoding chip U23, the input end of the decoding chip U23 is connected to the sound source device through a USB1 port, and the output end of the decoding chip U23 is connected to the input end of the DAC conversion circuit; the PC decoding circuit includes a decoding chip U24, the input end of the decoding chip U24 is connected to the sound source device through a USB2 port, and the output end of the decoding chip U24 is connected to the input end of the DAC conversion circuit. Both the decoding chip U23 and the decoding chip U24 use CM108 chips.

4. The sound system according to claim 1, characterized in that: The power module includes an EMI filter circuit and a half-bridge conversion circuit, wherein the input end of the EMI filter circuit is connected to the mains power grid, and the output end of the EMI filter circuit is connected to the input end of the half-bridge conversion circuit, and the half-bridge conversion circuit includes a rectifier D2, capacitors C1, C2, C7, C10, resistors R1, R2, R3, R4, R6, R11, R12, R13, R15, transistors Q1, Q22, diodes D1, D4, and a transformer T1; pin 1 of the rectifier D2 is connected to the positive electrode of the capacitor C1, one end of the resistor R4, the negative electrode of the diode D1, the collector of the transistor Q1, and one end of the resistor R1 in sequence, the negative electrode of the capacitor C1 is connected to the positive electrode of the capacitor C10, one end of the resistor R12, one end of the capacitor C7, and the other end of the resistor R4 in sequence, and pin 4 of the rectifier is connected to the positive electrode of the capacitor C10, one end of the resistor R12, one end of the capacitor C7, and the other end of the resistor R4 in sequence. The cathode of transistor Q1 is connected to the cathode of diode D10, the other end of resistor R12, the anode of diode D4, the emitter of transistor Q2 and one end of resistor R15; the emitter of transistor Q1 is connected to the anode of diode D1, one end of resistor R6, one end of resistor R11, the collector of transistor Q2 and the cathode of transistor D4; the base of transistor Q1 is connected to one end of resistor R3, the other end of resistor R1, the other end of resistor R3 and the other end of resistor R6 are connected; the base of transistor Q2 is connected to one end of resistor R13, the other end of resistor R13 is connected to the other end of resistor R11 and the other end of resistor R15; the other end of capacitor C7 is connected to resistor R2 and one end of the primary coil of transformer T1, the other end of resistor R2 is connected to one end of capacitor C2, and the other end of capacitor C2 is connected to the other end of the primary coil of transformer T1.

5. A sound system according to claim 4, characterized in that: The power module also includes a push-pull conversion circuit, which includes NMOS tubes Q3, Q4, diodes D8, D9, D10, D11, D12, D13, resistors R18, R19, R20, R21, R22, R23, R24, R25, inductors L1, L2, L3, and a transformer T4; The drain of the NMOS tube Q3 and the drain of the NMOS tube Q4 are respectively connected to the two ends of the primary coil of the transformer T4, the middle point of the primary coil of the transformer T4 is connected to the output end of the half-bridge conversion circuit, and the gates of the NMOS tube Q3 and the NMOS tube Q4 are both connected to the GND-2 terminal; One end of the first secondary coil of the transformer T4 is connected to the positive electrode of the diode D8, the negative electrode of the diode D8 is connected to one end of the resistor R19, the positive electrode of the capacitor C18, one end of the capacitor C19 and one end of the inductor L1 in sequence, the other end of the inductor L1 is connected to one end of the resistor R18, the positive electrode of the capacitor C16, one end of the capacitor C17 and the V+ output terminal in sequence; the other end of the first secondary coil of the transformer T4 is connected to the negative electrode of the diode D9, the positive electrode of the diode D9 is connected to one end of the resistor R21, the negative electrode of the capacitor C22, one end of the capacitor C23, One end of the inductor L2, one end of the resistor R20, the negative electrode of the capacitor C20, one end of the capacitor C21 and the V- output end are connected; the midpoint of the first secondary coil of the transformer T4 is connected in sequence to the other end of the resistor R19, the other end of the resistor R21, the negative electrode of the capacitor C18, the positive electrode of the capacitor C22, the other end of the capacitor C19, the other end of the capacitor C23, the other end of the resistor R18, the other end of the resistor R20, the negative electrode of the capacitor C16, the positive electrode of the capacitor C20, the other end of the capacitor C17, the other end of the capacitor C21 and the GND-3 end.

6. The sound system according to claim 4, characterized in that: The power supply module also includes a first PWM regulation circuit and a second PWM regulation circuit. The first PWM regulation circuit includes a driving chip U1, the input end of the driving chip U1 is connected to the output end of the half-bridge conversion circuit, the first output end of the driving chip U1 is connected to the NMOS tube Q3, and the second output end of the driving chip U1 is connected to the NMOS tube Q4. The second PWM regulation circuit includes a driving chip U2, the input end of the driving chip U2 is connected to the output end of the half-bridge conversion circuit, and the output end of the driving chip U2 is connected to the transistors Q1 and Q2 of the half-bridge conversion circuit.

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