阅读说明：本技术 一种低频衰减四阶高通滤波幻象输出电路 (Low-frequency attenuation fourth-order high-pass filtering phantom output circuit ) 是由 沈生猛 张平 张军波 于 2021-07-14 设计创作，主要内容包括：本发明公开了一种低频衰减四阶高通滤波幻象输出电路,包括声音传感器、四阶高通滤波器电路、一级音频放大器电路、二级音频放大幻象输出电路和电源滤波电路,其中四阶高通滤波器电路的输入端与声音传感器连接,输出端与一级音频放大器电路连接,一级音频放大器电路的输出端与二级音频放大幻象输出电路连接,电源滤波电路分别与声音传感器、四阶高通滤波器电路、一级音频放大器电路和二级音频放大幻象输出电路连接。本发明通过将麦克风信号前级放大为四阶高通滤波,后级采用两个三极管跟随做幻象输出与导航主机连接,使电源与信号叠加,达到单线双向传输降噪的目的。(The invention discloses a low-frequency attenuation fourth-order high-pass filtering phantom output circuit, which comprises a sound sensor, a fourth-order high-pass filter circuit, a first-order audio amplifier circuit, a second-order audio amplifying phantom output circuit and a power supply filter circuit, wherein the input end of the fourth-order high-pass filter circuit is connected with the sound sensor, the output end of the fourth-order high-pass filter circuit is connected with the first-order audio amplifier circuit, the output end of the first-order audio amplifier circuit is connected with the second-order audio amplifying phantom output circuit, and the power supply filter circuit is respectively connected with the sound sensor, the fourth-order high-pass filter circuit, the first-order audio amplifier circuit and the second-order audio amplifying phantom output circuit. The invention amplifies the front stage of the microphone signal into four-order high-pass filtering, and the rear stage adopts two triodes to follow the signal and make a phantom output to be connected with a navigation host computer, so that a power supply is superposed with the signal, and the aim of single-wire bidirectional transmission and noise reduction is achieved.)

1. A low frequency attenuating fourth order high pass filtering phantom output circuit, characterized by: comprises a sound sensor (1), a fourth-order high-pass filter circuit (2), a first-stage audio amplifier circuit (3), a second-stage audio amplification phantom output circuit (4) and a power supply filter circuit (5), the input end of the fourth-order high-pass filter circuit (2) is connected with the sound sensor (1), the output end is connected with the first-order audio amplifier circuit (3), the output end of the primary audio amplifier circuit (3) is connected with a secondary audio amplification phantom output circuit (4), the power supply filter circuit (5) is respectively connected with the sound sensor (1), the fourth-order high-pass filter circuit (2), the first-stage audio amplifier circuit (3) and the second-stage audio amplification phantom output circuit (4), and provides electric energy for the sound sensor (1), the fourth-order high-pass filter circuit (2), the first-stage audio amplifier circuit (3) and the second-stage audio amplification phantom output circuit (4).

2. A low frequency attenuating fourth order high pass filtering phantom output circuit according to claim 1, characterized in that: the sound sensor (1) can pick up an audio signal between 50Hz-10 KHZ.

3. A low frequency attenuating fourth order high pass filtering phantom output circuit according to claim 1, characterized in that: the fourth-order high-pass filter circuit (2) is composed of a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, an operational amplifier U1 and an operational amplifier U2, the same-direction input end of an operational amplifier U1 is connected with a resistor R5 and a capacitor C4 respectively, the reverse input end of the operational amplifier U1 is connected with the output end of an operational amplifier U1, the output end of the operational amplifier U1 is connected with a capacitor C5 and a resistor R4 respectively, one end of the capacitor C3 is connected with a sound sensor (1), the other end of the capacitor C4 is connected with a capacitor C4 respectively, the same-direction input end of the operational amplifier U2 is connected with a resistor R6 and a capacitor C6 respectively, the reverse input end of the operational amplifier U2 is connected with the output end of the operational amplifier U2, and the output end of the operational amplifier U2 is connected with a resistor R3 and a primary audio amplifier circuit (3) respectively.

4. A low frequency attenuating fourth order high pass filtering phantom output circuit according to claim 1, characterized in that: the primary audio amplifier circuit (3) is composed of a capacitor C10, a capacitor C11, a capacitor C15, a capacitor C16, a resistor R9, a resistor R11, a resistor R12, a resistor R13, a resistor R14 and a triode Q1A, wherein the resistor R11 and the capacitor C10 are connected in series and then connected in parallel with the resistor R12, one end of the capacitor C11 is connected with the output end of the operational amplifier U2, the other end of the capacitor C11 is connected with the resistor R13, the resistor R14 and the capacitor C16 are connected in parallel, the emitter and the collector of the triode Q1A are respectively connected with the capacitor C15, one end of the resistor R9 is grounded, and the other end of the resistor R9 is connected with the collector of the triode Q1A.

5. A low frequency attenuating fourth order high pass filtering phantom output circuit according to claim 1, characterized in that: the two-stage audio amplification phantom output circuit (4) is composed of a capacitor C12, a capacitor C13, a capacitor C14, an inductor FB1, an inductor FB2, a bidirectional transient suppression diode D1 and a triode Q1B, wherein the capacitor C12, the capacitor C13, the capacitor C14, the bidirectional transient suppression diode D1 and the triode Q1B are connected in parallel, the base of the triode Q1B is connected with the primary audio amplifier circuit (3), and the inductor FB1 and the inductor FB2 are respectively connected with an output port CN 1.

6. A low frequency attenuating fourth order high pass filtering phantom output circuit according to claim 1, characterized in that: the power supply filter circuit (5) is composed of a resistor R1, a capacitor C1, a capacitor C2 and a voltage-stabilizing diode Z1, wherein the capacitor C1, the capacitor C2 and the voltage-stabilizing diode Z1 are connected in parallel and then connected in series with the resistor R1.

Technical Field

The invention relates to the technical field of vehicle-mounted microphones, in particular to a low-frequency attenuation fourth-order high-pass filtering phantom output circuit.

Background

With the rapid development of automobile intelligent networking and the continuous increase of the personalized demands of consumers, the utilization rate of a vehicle-mounted microphone on an automobile is higher and higher, but with the continuous upgrading and optimization of an intelligent system of the automobile by an automobile enterprise, the electrical property characteristics of a common microphone used at present cannot more perfectly meet the requirements of an updated vehicle-mounted intelligent interaction system. The electrical characteristics of the common vehicle-mounted microphone are not specially processed due to the low frequency of 50 Hz-200 Hz, so that the noise signal with the low frequency of 50 Hz-200 Hz is picked up by the microphone and introduced into the voice interaction system, while the sound frequency range of the common person is 300 Hz' 6KHz, the function of the intelligent voice interaction system of the automobile is influenced due to the low-frequency noise, so that the problems of low voice recognition rate, large vehicle-mounted hands-free call noise, insufficient precision in sound source positioning and the like are caused.

Disclosure of Invention

The invention aims to provide a low-frequency attenuation four-order high-pass filtering phantom output circuit, which amplifies a microphone signal into four-order high-pass filtering in the front stage, and adopts two triodes in the rear stage to follow the signal to output a phantom to be connected with a navigation host computer, so that a power supply is superposed with the signal, the aim of single-wire bidirectional transmission noise reduction is fulfilled, and the technical problems of low voice recognition rate, high vehicle-mounted hands-free conversation noise, insufficient accuracy in sound source positioning and the like caused by the influence on the functions of an automobile intelligent voice interaction system due to the generation of low-frequency noise of the conventional vehicle-mounted microphone are solved.

In order to achieve the purpose, the invention provides the following technical scheme: a low-frequency attenuation fourth-order high-pass filtering phantom output circuit comprises a sound sensor, a fourth-order high-pass filter circuit, a first-order audio amplifier circuit, a second-order audio amplifying phantom output circuit and a power supply filter circuit, wherein the input end of the fourth-order high-pass filter circuit is connected with the sound sensor, the output end of the fourth-order high-pass filter circuit is connected with the first-order audio amplifier circuit, the output end of the first-order audio amplifier circuit is connected with the second-order audio amplifying phantom output circuit, and the power supply filter circuit is respectively connected with the sound sensor, the fourth-order high-pass filter circuit, the first-order audio amplifier circuit and the second-order audio amplifying phantom output circuit and supplies electric energy to the sound sensor, the fourth-order high-pass filter circuit, the first-order audio amplifier circuit and the second-order audio amplifying phantom output circuit.

Preferably, the sound sensor can pick up an audio signal between 50Hz-10 KHZ.

Preferably, the fourth-order high-pass filter circuit is composed of a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, an operational amplifier U1 and an operational amplifier U2, wherein a same-direction input end of the operational amplifier U1 is connected with the resistor R5 and the capacitor C4, a reverse-direction input end of the operational amplifier U1 is connected with an output end of the operational amplifier U1, an output end of the operational amplifier U1 is connected with the capacitor C5 and the resistor R4, one end of the capacitor C3 is connected with the sound sensor, the other end of the capacitor C3 is connected with the capacitor C4 and the resistor R4, a same-direction input end of the operational amplifier U2 is connected with the resistor R6 and the capacitor C6, a reverse-direction input end of the operational amplifier U2 is connected with an output end of the operational amplifier U2, and an output end of the operational amplifier U2 is connected with the resistor R3 and the first-stage audio amplifier circuit.

Preferably, the primary audio amplifier circuit is composed of a capacitor C10, a capacitor C11, a capacitor C15, a capacitor C16, a resistor R9, a resistor R11, a resistor R12, a resistor R13, a resistor R14 and a triode Q1A, wherein the resistor R11 and the capacitor C10 are connected in series and then connected in parallel with the resistor R12, one end of the capacitor C11 is connected with the output end of the operational amplifier U2, the other end of the capacitor C11 is connected with the resistor R13, the resistor R14 is connected in parallel with the capacitor C16, the emitter and the collector of the triode Q1A are respectively connected with the capacitor C15, one end of the resistor R9 is grounded, and the other end of the resistor R9 is connected with the collector of the triode Q1A.

Preferably, the two-stage audio amplification phantom output circuit is composed of a capacitor C12, a capacitor C13, a capacitor C14, an inductor FB1, an inductor FB2, a bidirectional transient suppression diode D1 and a triode Q1B, wherein the capacitor C12, the capacitor C13, the capacitor C14, the bidirectional transient suppression diode D1 and the triode Q1B are connected in parallel, a base of the triode Q1B is connected with the primary audio amplifier circuit, and the inductor FB1 and the inductor FB2 are respectively connected with the output port CN 1.

Preferably, the power filter circuit is composed of a resistor R1, a capacitor C1, a capacitor C2 and a zener diode Z1, wherein the capacitor C1, the capacitor C2 and the zener diode Z1 are connected in parallel and then connected in series with the resistor R1.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention provides a low-frequency attenuation fourth-order high-pass filtering phantom output circuit, which comprises a sound sensor, a fourth-order high-pass filter circuit, a first-order audio amplifier circuit, a second-order audio amplifying phantom output circuit and a power supply filter circuit, wherein the sound sensor picks up a microphone signal, the fourth-order high-pass filter circuit amplifies the front stage of the picked-up microphone signal into fourth-order high-pass filtering, the first-order audio amplifier circuit amplifies the microphone signal, the second-order audio amplifying phantom output circuit outputs a phantom, the processed microphone signal is connected with a vehicle-mounted navigation host, the power supply and the signal are superposed, the purpose of single-wire two-way transmission noise reduction is achieved, the problems that the function of an automobile intelligent voice interaction system is influenced due to the generation of low-frequency noise, the voice recognition rate is low, the vehicle-mounted hands-free conversation noise is high, the sound source positioning is not accurate enough, and the like.

Drawings

FIG. 1 is a schematic block diagram of the present invention;

fig. 2 is a schematic circuit diagram of the present invention.

The reference numerals and names in the figures are as follows:

1. a sound sensor; 2. a fourth order high pass filter circuit; 3. a first stage audio amplifier circuit; 4. a secondary audio amplification phantom output circuit; 5. and a power supply filter circuit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, an embodiment of the present invention: a low-frequency attenuation fourth-order high-pass filtering phantom output circuit comprises a sound sensor 1, a fourth-order high-pass filter circuit 2, a first-order audio amplifier circuit 3, a second-order audio amplifying phantom output circuit 4 and a power supply filter circuit 5, wherein the input end of the fourth-order high-pass filter circuit 2 is connected with the sound sensor 1, the output end of the fourth-order high-pass filter circuit 2 is connected with the first-order audio amplifier circuit 3, the output end of the first-order audio amplifier circuit 3 is connected with the second-order audio amplifying phantom output circuit 4, the power supply filter circuit 5 is respectively connected with the sound sensor 1, the fourth-order high-pass filter circuit 2, the first-order audio amplifier circuit 3 and the second-order audio amplifying phantom output circuit 4, and electric energy is supplied to the sound sensor 1, the fourth-order high-pass filter circuit 2, the first-order audio amplifier circuit 3 and the second-order audio amplifying phantom output circuit 4.

Specifically, the audio signal that can be picked up by the sound sensor 1 is between 50HZ and 10KHZ, and when the audio signal that can be picked up by the sound sensor 1 is between 50HZ and 200HZ, the audio signal is subjected to noise reduction processing by sequentially passing through the fourth-order high-pass filter circuit 2, the first-order audio amplifier circuit 3 and the second-order audio amplification phantom output circuit 4, so that the use requirement of a user is met.

Referring to fig. 2, the fourth-order high-pass filter circuit 2 comprises a resistor R3, a resistor R4, a resistor R5, a resistor R6, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, an operational amplifier U1 and an operational amplifier U2, the same-direction input end of an operational amplifier U1 is connected with a resistor R5 and a capacitor C4 respectively, the reverse input end of the operational amplifier U1 is connected with the output end of the operational amplifier U1, the output end of the operational amplifier U1 is connected with a capacitor C5 and a resistor R4 respectively, one end of the capacitor C3 is connected with the sound sensor 1, the other end of the capacitor C4 is connected with the capacitor R4 respectively, the same-direction input end of the operational amplifier U2 is connected with the resistor R6 and the capacitor C6 respectively, the reverse input end of the operational amplifier U2 is connected with the output end of the operational amplifier U2, and the output end of the operational amplifier U2 is connected with the resistor R3 and the primary audio amplifier circuit 3 respectively.

Referring to fig. 2 again, the primary audio amplifier circuit 3 is composed of a capacitor C10, a capacitor C11, a capacitor C15, a capacitor C16, a resistor R9, a resistor R11, a resistor R12, a resistor R13, a resistor R14, and a transistor Q1A, wherein the resistor R11 and the capacitor C10 are connected in series and then connected in parallel with the resistor R12, one end of the capacitor C11 is connected to the output end of the operational amplifier U2, the other end is connected to the resistor R13, the resistor R14 is connected in parallel with the capacitor C16, the emitter and the collector of the transistor Q1A are connected to the capacitor C15, respectively, one end of the resistor R9 is grounded, and the other end is connected to the collector of the transistor Q1A.

Referring to fig. 2 again, the two-stage audio amplifying phantom output circuit 4 is composed of a capacitor C12, a capacitor C13, a capacitor C14, an inductor FB1, an inductor FB2, a bidirectional transient suppression diode D1, and a transistor Q1B, wherein the capacitor C12, the capacitor C13, the capacitor C14, the bidirectional transient suppression diode D1, and the transistor Q1B are connected in parallel, a base of the transistor Q1B is connected to the primary audio amplifier circuit 3, and the inductor FB1 and the inductor FB2 are connected to the output port CN1, respectively.

Referring to fig. 2 again, the power filter circuit 5 is composed of a resistor R1, a capacitor C1, a capacitor C2 and a zener diode Z1, wherein the capacitor C1, the capacitor C2 and the zener diode Z1 are connected in parallel and then connected in series with the resistor R1.

In conclusion, the low-frequency attenuation fourth-order high-pass filtering phantom output circuit in the embodiment amplifies the front stage of a microphone signal into the fourth-order high-pass filtering, and the rear stage adopts two triodes to follow the two triodes to output the phantom to be connected with a navigation host, so that a power supply is superposed with the signal, the purpose of single-wire bidirectional transmission noise reduction is achieved, and the technical problems that the existing vehicle-mounted microphone influences the function of an automobile intelligent voice interaction system due to the generation of low-frequency noise, the voice recognition rate is low, the vehicle-mounted hands-free call noise is large, the sound source positioning is not accurate enough and the like are solved.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.