Audio filtering mainboard

Abstract

The utility model provides an audio filtering mainboard. The audio filtering mainboard comprises an input module, an amplification module, a filtering module and an output module, the output circuit is connected with the modulator and the filtering module; the modulation circuit is used for amplifying the audio signal output by the input module and removing noise coupled by the circuit to obtain a relatively pure initial signal, and the initial signal processed by the modulation circuit is converted from an analog signal to a digital signal, so that distortion of the signal in the transmission process is reduced, and the transmission efficiency is improved. And the filtering module is used for filtering the adjusted modulation signal, so that the negative influence of noise and EMI (Electro-Magnetic Interference) on the tone quality is reduced, the audio quality is improved, and the electronic sound equipment obtains a good tone quality effect.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of PCBA mainboard especially relates to an audio filtering mainboard. BACKGROUND

[0002] With the wide application of electronic products, most of the electronic products are provided with sound, and the audio of the electronic products needs to be filtered, has good tone quality, especially the audio power amplifier of the sound, also called audio power amplifier, is a kind of power amplifier device for pushing loudspeaker to sound, thereby reproducing sound. Its basic principle is to amplify the relatively small audio signal, increase its power, then, although the audio power amplifier can realize the amplification function, a large amount of electric energy is converted into heat energy and wasted, which not only increases the power consumption of the equipment, but also may cause the equipment to overheat and affect the performance, and high distortion rate will cause the audio signal to deviate in the amplification process, so that the tone quality is reduced.

[0003] The noise and EMI generated during modulation may have a negative impact on the tone quality, the filtering tone quality and noise filtering effect of the filtering audio circuit are not good, so that the tone quality becomes unclear, has noise or distortion. SUMMARY

[0004] The utility model provides an audio filtering mainboard, modulation circuit is connected with audio input module and modulator, output circuit is connected with modulator and filter module, modulation circuit is used for amplifying the audio signal of input module output, and removes the noise of circuit coupling to obtain initial signal, modulator is used for converting initial signal from analog signal to digital signal, and is recorded as adjustment signal, output circuit is used for voltage adjustment to the adjustment signal and obtains target signal, so that electronic sound obtains good tone quality effect.

[0005] To solve the above problems, the utility model provides an audio filtering mainboard, including audio input module, amplification module, filter module and output module, the amplification module includes modulation circuit, modulator and output circuit,

[0006] The modulation circuit is connected with the audio input module and the modulator,

[0007] The output circuit is connected with the modulator and the filter module, and the modulation circuit is used for amplifying the audio signal output by the input module and removing the noise coupled into the circuit to obtain an initial signal.

[0008] The filter module includes a seventh resistor, a first capacitor, a second capacitor and a second amplifier.

[0009] The output circuit is used for voltage adjustment to the filtered initial signal to obtain a target signal.

[0010] Preferably, the modulator is used to convert the initial signal from an analog signal to a digital signal, denoted as an adjusted signal.

[0011] Preferably, the input end of the seventh resistor is connected with the source of the first MOS tube and the drain of the first MOS tube respectively.

[0012] Preferably, the output end of the seventh resistor is connected with the negative pole of the second amplifier, one end of the first capacitor and one end of the second capacitor respectively.

[0013] Preferably, the other end of the first capacitor is connected with the positive pole of the second amplifier and the output end of the second amplifier respectively; and the other end of the second capacitor is grounded.

[0014] Preferably, the first capacitor and the second capacitor play the roles of coupling and decoupling, smooth the signal, reduce the mutation of the signal in the transmission process, and filter out high-frequency noise; the capacitor and the resistor can form a specific time constant, thereby determining the response of the circuit to different frequency signals.

[0015] Preferably, the modulation circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, an eighth sliding resistor, a first operational amplifier and a potentiometer.

[0016] Preferably, the positive pin of the first operational amplifier is connected with the output end of the first resistor; and the negative pin of the first operational amplifier is connected with the input end of the second resistor and the output end of the eighth sliding resistor respectively.

[0017] Preferably, the output end of the second resistor is connected with the output end of the first operational amplifier and the input end of the third resistor respectively; the output end of the third resistor is connected with the input end of the potentiometer; the power positive pin of the potentiometer is connected with the output end of the fourth resistor and the modulator respectively; and the output end of the first operational amplifier is connected with the modulator.

[0018] The audio filter mainboard adopts an input module, an amplification module, a filtering module and an output module; an output circuit is connected with a modulator and the filtering module; the modulation circuit is used to amplify the audio signal output by the input module, remove the noise coupled into the circuit to obtain a relatively pure initial signal, convert the initial signal processed by the modulation circuit from an analog signal to a digital signal, thereby reducing the distortion of the signal in the transmission process, filtering the adjusted modulation signal through the filtering module to reduce the negative influence of noise and EMI on the sound quality, improving the quality of the audio, and thereby the electronic sound system obtains good sound quality effect. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 The utility model discloses an audio filter's circuit structure schematic diagram;

[0020] Fig. 2 The utility model discloses an audio filter's circuit schematic diagram;

[0021] Fig. 3 The utility model discloses an audio filter's filter module's circuit diagram.

[0022] Reference signs

[0023] 1, input module, 2, amplification module, 3, filter module, 4, output module, R1, first resistance, R2, second resistance, R3, third resistance, R4, fourth resistance, R5, fifth resistance, R6, sixth resistance, R7, seventh resistance, R8, eighth slide resistance, L1, first external power supply, L2, second external power supply, L3, external voltage, Q1, potentiometer, Q2, first MOS tube, Q3, second MOS tube, C1, first capacitor, C2, second capacitor, D1, first diode, D2, second diode, F1, first operational amplifier, F2, second amplifier. DETAILED DESCRIPTION

[0024] In order to more fully understand the technical content of the utility model, the technical scheme of the utility model is further introduced and explained below in combination with the drawings and specific embodiments, but is not limited to this.

[0025] As Figs. 1 to 3 The utility model discloses an audio filter mainboard, including audio input module 1, amplification module 2, filter module 3 and output module 4, amplification module 2 includes modulation circuit, modulator and output circuit,

[0026] Modulation circuit is connected with audio input module 1 and modulator;

[0027] Output circuit is connected with modulator and filter module 3, and modulation circuit is used to amplify the audio signal of input module 1 output and removes the noise of circuit coupling to obtain initial signal;

[0028] Filter module 3 includes seventh resistance R7, first capacitor C1, second capacitor C2 and second amplifier F2;

[0029] Output circuit is used to carry out voltage regulation to the initial signal after filtering and obtains target signal.

[0030] Further, modulator is used to convert initial signal from analog signal to digital signal, and is recorded as adjustment signal.

[0031] Further, the input end of seventh resistance is connected with the source of first MOS tube Q2 and the drain of first MOS tube Q2 respectively.

[0032] Further, the output end of the seventh resistor R7 is connected with the negative pole of the second amplifier F2, one end of the first capacitor C1 and one end of the second capacitor C2 respectively.

[0033] Further, the other end of the first capacitor C1 is connected with the positive pole of the second amplifier F2 and the output end of the second amplifier F2 respectively; the other end of the second capacitor C2 is grounded.

[0034] Further, the first capacitor C1 and the second capacitor C2 play the role of coupling and decoupling, smooth the signal, reduce the mutation of the signal in the transmission process, and filter out high-frequency noise. The capacitor combined with the resistor can form a specific time constant, which determines the response of the circuit to different frequency signals.

[0035] Further, as shown in Fig. 3 , the modulation circuit 201 includes the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the eighth sliding resistor R8, the first external power supply L1, the second external power supply L2, the first operational amplifier F1 and the potentiometer Q1.

[0036] Further, the positive pin of the first operational amplifier F1 is connected with the output end of the first resistor R1; the negative pin of the first operational amplifier F1 is connected with the input end of the second resistor R2 and the output end of the eighth sliding resistor R8 respectively.

[0037] Further, the output end of the second resistor R2 is connected with the output end of the first operational amplifier F1 and the input end of the third resistor R3 respectively; the output end of the third resistor R3 is connected with the input end of the potentiometer Q1; the power supply positive pin of the potentiometer Q1 is connected with the output end of the fourth resistor R4 and the modulator respectively; the output end of the first operational amplifier F1 is connected with the modulator.

[0038] As shown in Fig. 3 , the output circuit 202 of the modulator includes the fifth resistor R5, the sixth resistor R6, the first diode D1, the second diode D2, the external voltage L3, the first MOS tube Q2 and the second MOS tube Q3. The input end of the fifth resistor R5 is connected with the modulator and the negative pole of the second diode D2 respectively; the output end of the fifth resistor R5 is connected with the positive pole of the second diode D2 and the gate of the second MOS tube Q3 respectively; the input end of the sixth resistor R6 is connected with the modulator and the negative pole of the first diode D1 respectively; the output end of the sixth resistor R6 is connected with the positive pole of the first diode D1 and the gate of the first MOS tube Q2 respectively; the drain of the first MOS tube is connected with the input voltage, the source of the first MOS tube Q2 is connected with the drain of the second MOS tube Q3; the source of the second MOS tube Q3 is grounded.

[0039] The utility model discloses an audio filter circuit, including audio input module 1, amplification module 2, filter module 3 and output module 4, through the modulation circuit to the audio signal of input module 1 signal amplification, remove the noise of circuit coupling simultaneously, obtain relatively pure initial signal, the initial signal of having passed modulation circuit processing is converted from analog signal to digital signal, thereby reduce the distortion of signal in transmission process, and through filter module 3 to the modulation signal of adjustment good filtering processing to reduce the negative influence of noise and EM I to the sound quality, improved the quality of audio.

[0040] The above only is the patent preferred implementation, and not limit the patent range, and all equivalent structures or equivalent process transformations of using the contents of specification and drawings, direct or indirect application in other related technical fields, all belong to the patent protection range.

Claims

1. An audio filtering motherboard, characterized in that, It includes an audio input module, an amplification module, a filtering module, and an output module. The amplification module includes a modulation circuit, a modulator, and an output circuit. The modulation circuit is connected to the audio input module and the modulator; The output circuit is connected to the modulator and the filter module. The modulation circuit is used to amplify the audio signal output by the input module and remove noise coupled into the circuit to obtain the initial signal. The filtering module includes a seventh resistor, a first capacitor, a second capacitor, and a second amplifier; The output circuit is used to adjust the voltage of the filtered initial signal to obtain the target signal.

2. The audio filtering motherboard as described in claim 1, characterized in that, The modulator is used to convert the initial signal from an analog signal into a digital signal, denoted as the modulation signal.

3. The audio filtering motherboard as described in claim 1, characterized in that, The input terminal of the seventh resistor is connected to the source and drain of the first MOS transistor, respectively.

4. The audio filtering motherboard as described in claim 1, characterized in that, The output terminal of the seventh resistor is connected to the negative terminal of the second amplifier, one end of the first capacitor, and one end of the second capacitor, respectively.

5. The audio filtering motherboard as described in claim 1, characterized in that, The other end of the first capacitor is connected to the positive terminal of the second amplifier and the output terminal of the second amplifier, respectively; the other end of the second capacitor is grounded.

6. The audio filtering motherboard as described in claim 1, characterized in that, The first and second capacitors serve to couple and decouple, smooth the signal, reduce abrupt changes in the signal during transmission, and filter out high-frequency noise. The combination of capacitors and resistors can form a specific time constant, which in turn determines the circuit's response to signals of different frequencies.

7. The audio filtering motherboard as described in claim 1, characterized in that, The modulation circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, an eighth sliding resistor, a first operational amplifier, and a potentiometer.

8. The audio filtering motherboard as described in claim 7, characterized in that, The positive pin of the first operational amplifier is connected to the output terminal of the first resistor; the negative pin of the first operational amplifier is connected to the input terminal of the second resistor and the output terminal of the eighth sliding resistor, respectively.

9. The audio filtering motherboard as described in claim 7, characterized in that, The output terminal of the second resistor is connected to the output terminal of the first operational amplifier and the input terminal of the third resistor, respectively; the output terminal of the third resistor is connected to the input terminal of the potentiometer; the positive power supply pin of the potentiometer is connected to the output terminal of the fourth resistor and the modulator, respectively. The output of the first operational amplifier is connected to the modulator.

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