CN110662128A - Microphone signal amplification system for active noise reduction - Google Patents
Microphone signal amplification system for active noise reduction Download PDFInfo
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- CN110662128A CN110662128A CN201910978971.6A CN201910978971A CN110662128A CN 110662128 A CN110662128 A CN 110662128A CN 201910978971 A CN201910978971 A CN 201910978971A CN 110662128 A CN110662128 A CN 110662128A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/08—Mouthpieces; Microphones; Attachments therefor
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2420/00—Details of connection covered by H04R, not provided for in its groups
- H04R2420/05—Detection of connection of loudspeakers or headphones to amplifiers
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Abstract
The invention provides a microphone signal amplification system for active noise reduction, which comprises an acoustic sensor, a two-terminal connector, a power supply filtering module, a carrier filtering module and an audio amplification module, wherein the acoustic sensor is connected with the two-terminal connector; the dual-terminal connector is sequentially connected with the power supply filtering module and the carrier filtering module, a first resistor and a second resistor are connected between the carrier filtering module and a power supply end of the sound sensor, a junction between the first resistor and the second resistor is connected with a first capacitor and a third resistor, a junction between the second resistor and the sound sensor is connected with one end of a second capacitor, an output end of the sound sensor is connected with the audio amplification module, a junction between the first resistor and the carrier filtering module is connected with a third capacitor, a fourth capacitor and a fourth resistor, and the third capacitor, the fourth capacitor and the fourth resistor are connected with the audio amplification module after being connected in parallel. The invention has good noise reduction performance, and the connector only needs to adopt a double-terminal structure, thereby effectively improving the design efficiency.
Description
Technical Field
The invention relates to an active noise reduction system, and particularly discloses a microphone signal amplification system for active noise reduction.
Background
The active noise reduction is to generate reverse sound waves opposite to external noise through a noise system to deteriorate the noise, so that the noise reduction effect is realized. The principle is that all sounds consist of a certain frequency spectrum, and if a sound can be found that has the same frequency spectrum as the noise to be cancelled, but with exactly the opposite phase, the noise can be completely cancelled.
The active noise reduction system mainly comprises an acoustic sensor, an audio amplification module and a connector, noise information is collected through the acoustic sensor to form a noise signal, then the noise signal is subjected to phase inversion and amplification through the audio amplification module to form an active noise reduction signal, and finally the corresponding active noise reduction signal is output through the connector. In the prior art, a connector in an active noise reduction system at least needs to have three terminals, which are respectively used for connecting a positive electrode and a negative electrode of a power supply and outputting an active noise reduction signal, and has a complex external connection structure and low design efficiency during application.
Disclosure of Invention
Therefore, it is necessary to provide a microphone signal amplifying system for active noise reduction, which has good noise reduction performance, and the connector adopts a two-terminal structure, so as to effectively improve the design efficiency.
In order to solve the problems of the prior art, the invention discloses a microphone signal amplification system for active noise reduction, which comprises an acoustic sensor, a two-terminal connector, a power supply filtering module, a carrier filtering module and an audio amplification module, wherein the two-terminal connector is connected with the power supply filtering module; the dual-terminal connector is sequentially connected with the power supply filtering module and the carrier filtering module, a first resistor and a second resistor are sequentially connected between the carrier filtering module and a power supply end of the acoustic sensor, a connection point between the first resistor and the second resistor is connected with a first capacitor and a third resistor, the first capacitor and the third resistor are grounded after being connected in parallel, the connection point between the second resistor and the acoustic sensor is connected with one end of a second capacitor, the other end of the second capacitor is grounded, an output end of the acoustic sensor is connected with the audio amplification module, the connection point between the first resistor and the carrier filtering module is connected with a third capacitor, a fourth capacitor and a fourth resistor, and the third capacitor, the fourth capacitor and the fourth resistor are connected in parallel and then are connected with the audio amplification module.
Further, the acoustic sensor is a silicon microphone.
Furthermore, a connecting point between the first resistor and the third capacitor is connected with one end of the electrostatic resistor, and the other end of the electrostatic resistor is grounded.
Furthermore, a connecting point between the output end of the acoustic sensor and the audio amplification module is connected with one end of a fifth capacitor, and the other end of the fifth capacitor is grounded.
Furthermore, the power supply filtering module comprises a first inductor, a sixth capacitor and a second inductor which are connected in sequence, and the first inductor and the second inductor are connected with two ends of the terminal connector respectively.
Furthermore, the carrier filtering module comprises a fifth resistor, a seventh capacitor and a sixth resistor which are connected in sequence, two ends of the seventh capacitor are respectively connected with the first resistor and the ground, one end of the fifth resistor is connected with one end of the sixth capacitor, and one end of the sixth resistor is connected with the other end of the sixth capacitor.
Further, the audio amplification module includes an eighth capacitor, a seventh resistor, an eighth resistor, a ninth capacitor, a ninth resistor and a triode, the output end of the acoustic sensor is connected to one end of the eighth capacitor, one end of the seventh resistor is connected to the other end of the eighth capacitor, the other end of the seventh resistor is respectively connected with one end of the eighth resistor, one end of the ninth capacitor, one end of the ninth resistor and the base of the triode are connected, one end of the fourth resistor is connected to the other end of the eighth resistor, the other end of the ninth capacitor, the other end of the ninth resistor and the emitter of the triode are grounded, and the collector of the triode is connected with the other end of the fourth resistor.
The invention has the beneficial effects that: the invention discloses a microphone signal amplification system for active noise reduction, which has good noise reduction performance, can realize reliable filtering on a direct current power supply through a power supply filtering module, has no influence on active noise reduction signals, can effectively realize fidelity and interference resistance on the active noise reduction signals by arranging a special carrier filtering module, thereby being capable of meeting the requirement of low-voltage carrier waves, wherein the positive pole of a direct current power supply end and the signal output end of the system share one terminal, and a connector only needs to adopt a double-terminal structure, so that the design efficiency can be effectively improved.
Drawings
Fig. 1 is a schematic structural diagram of the present invention.
Fig. 2 is a schematic structural diagram of a power filter module according to the present invention.
Fig. 3 is a schematic structural diagram of a carrier filtering module according to the present invention.
Fig. 4 is a schematic structural diagram of an audio amplifying module according to the present invention.
The reference signs are: the audio amplifier comprises an acoustic sensor 10, an electrostatic impeder 101, a first resistor 11, a second resistor 12, a first capacitor 13, a third resistor 14, a second capacitor 15, a third capacitor 16, a fourth capacitor 17, a fourth resistor 18, a fifth capacitor 19, a two-terminal connector 20, a power supply filtering module 30, a first inductor 31, a sixth capacitor 32, a second inductor 33, a carrier filtering module 40, a fifth resistor 41, a seventh capacitor 42, a sixth resistor 43, an audio amplifying module 50, an eighth capacitor 51, a seventh resistor 52, an eighth resistor 53, a ninth capacitor 54, a ninth resistor 55 and a triode 56.
Detailed Description
For further understanding of the features and technical means of the present invention, as well as the specific objects and functions attained by the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description.
Refer to fig. 1 to 4.
The embodiment of the invention discloses a microphone signal amplification system for active noise reduction, which comprises an acoustic sensor 10, a two-terminal connector 20, a power supply filtering module 30, a carrier filtering module 40 and an audio amplification module 50, wherein the positive terminal of the two-terminal connector 20 is a direct-current power supply positive terminal and a system signal output terminal, and the negative terminal of the two-terminal connector 20 is a direct-current power supply negative terminal; the two-terminal connector 20 is sequentially connected with the power supply filtering module 30 and the carrier filtering module 40, a first resistor 11 and a second resistor 12 are sequentially connected between the carrier filtering module 40 and a power supply end of the acoustic sensor 10, namely, an anode of the two-terminal connector 20 is connected with the first resistor 11 through the power supply filtering module 30 and the carrier filtering module 40, a connection point between the first resistor 11 and the second resistor 12 is connected with a first capacitor 13 and a third resistor 14, one end of the first capacitor 13 and the third resistor 14 are grounded after being connected in parallel, a connection point between the second resistor 12 and the power supply end of the acoustic sensor 10 is connected with one end of a second capacitor 15, the other end of the second capacitor 15 is grounded, an output end of the acoustic sensor 10 is connected with the audio amplification module 50, a ground end of the acoustic sensor 10 is connected with a cathode of the two-terminal connector 20 through the carrier filtering module 40 and the power supply filtering module 30, a connection point between the first resistor 11 and the carrier filtering module 40 is connected with a third, The third capacitor 16, the fourth capacitor 17 and the fourth resistor 18 are connected in parallel and then connected with the audio amplification module 50, and the low-frequency signals output from the audio amplification module 50 can be effectively filtered through the third capacitor 16, the fourth capacitor 17 and the fourth resistor 18, so that the high-frequency signals can smoothly pass through. Direct current is subjected to low-pass filtering by the power supply filtering module 30 from the two-terminal connector 20 to supply power to the acoustic sensor 10, the acoustic sensor 10 detects ambient sound waves and transmits noise signals to the audio amplification module 50 through an output end, the audio amplification module 50 amplifies the noise signals in opposite phases to form active noise reduction signals, and the active noise reduction signals are filtered and interfered by the carrier filtering module 40 and then are output from the two-terminal connector 20.
Preferably, the resistance values of the first resistor 11, the second resistor 12 and the fourth resistor 18 are 1K Ω, and the resistance value of the third resistor 14 is 200K Ω; the first capacitor 13, the second capacitor 15, the third capacitor 16, and the fourth capacitor 17 have a capacitance value of 19nF and a maximum withstand voltage of 16V.
The invention has good noise reduction performance, can realize reliable filtering on a direct current power supply through the power supply filtering module 30, has no influence on active noise reduction signals, can effectively realize fidelity and anti-interference on the active noise reduction signals by arranging the special carrier filtering module 40, thereby being capable of meeting the requirement of low-voltage carrier, and the positive pole of a direct current power supply end and the signal output end of a system share one terminal.
In this embodiment, the acoustic sensor 10 is a silicon microphone, preferably, the silicon microphone is an MK1 patch element, the silicon microphone has the advantages of small volume, suitability for surface mounting and the like, and the active noise reduction system for the automobile has excellent performance.
In the embodiment, a connection point between the first resistor 11 and the third capacitor 16 is connected to one end of the electrostatic impedance 101, the electrostatic impedance 101 is also called ESD, specifically, PESD5V0S1BA is adopted, and the other end of the electrostatic impedance 101 is grounded.
In the present embodiment, the connection point between the output terminal of the acoustic sensor 10 and the audio amplification module 50 is connected to one end of the fifth capacitor 19, the other end of the fifth capacitor 19 is grounded, the capacitance of the fifth capacitor 19 is 19nF, and the maximum withstand voltage is 16V.
In this embodiment, as shown in fig. 2, the power filter module 30 includes a first inductor 31, a sixth capacitor 32, and a second inductor 33, which are connected in sequence, where the first inductor 31 and the second inductor 33 are respectively connected to two ends of the terminal connector, one end of the first inductor 31, which is far away from the sixth capacitor 32, is connected to the positive electrode of the two-terminal connector 20, and one end of the second inductor 33, which is far away from the sixth capacitor 32, is connected to the negative electrode of the two-terminal connector 20. Direct current is input from the positive pole of the two-terminal connector, LC filtering is adopted for the positive pole of the direct current power supply, and independent L filtering is adopted for the negative pole. Preferably, the inductance values of the first inductor 31 and the second inductor 33 are 10 μ H, the capacitance value of the sixth capacitor 32 is 19nF, and the maximum withstand voltage value is 16V. When a direct current input of 20Hz is adopted, the first inductor 31 and the second inductor 33 generate inductive reactance, and the inductive reactance of the first inductor 31 and the inductive reactance of the second inductor 33 are both WL 2 pi 20 10-6The capacitance reactance of the sixth capacitor 32 is 0.012 Ω, 1/WC 1/2 pi 20 19 10-979.6K Ω, has no effect on the active noise reduction signal.
Based on the above embodiment, as shown in fig. 3, the carrier filtering module 40 includes a fifth resistor 41, a seventh capacitor 42, and a sixth resistor 43 that are connected in sequence, two ends of the seventh capacitor 42 are respectively connected to the first resistor 11 and the ground, one end of the fifth resistor 41, which is far away from the seventh capacitor 42, is connected to one end of the sixth capacitor 32, one end of the sixth resistor 43, which is far away from the seventh capacitor 42, is connected to the other end of the sixth capacitor 32, the active noise reduction signal needs to be output from the positive electrode of the two-terminal connector 20, which belongs to a low-voltage carrier technology, a large number of high-frequency components exist in the active noise reduction signal, where the fifth resistor 41 and the sixth resistor 43 can effectively prevent the signal from being emitted, and the seventh capacitor 42 plays a role in filtering differential mode interference. Preferably, the resistance values of the fifth resistor 41 and the sixth resistor 43 are both 10 Ω, the capacitance value of the seventh capacitor 42 is 19nF, and the maximum withstand voltage value is 16V.
Based on any of the above embodiments, as shown in fig. 4, the audio amplifying module 50 includes an eighth capacitor 51, a seventh resistor 52, an eighth resistor 53, a ninth capacitor 54, a ninth resistor 55, and a transistor 56, one end of the eighth capacitor 51 is connected to the output terminal of the acoustic sensor 10, the other end of the eighth capacitor 51 is connected to one end of the seventh resistor 52, the other end of the seventh resistor 52 is respectively connected to one end of the eighth resistor 53, one end of the ninth capacitor 54, and one end of the ninth resistor 55, and the base of the transistor 56, the other end of the eighth resistor 53 is connected to one end of the fourth resistor 18, the other end of the ninth capacitor 54, and the emitter of the transistor 56 are grounded, the collector of the transistor 56 is connected to the other end of the fourth resistor 18, the output terminal of the acoustic sensor 10 couples the noise signal to the base of the transistor 56 through the eighth capacitor 51 as the input of the audio amplifying module 50, the eighth resistor 53 and the ninth resistor 55 provide a bias voltage for the audio amplifier module 50, and a signal passing through the seventh resistor 52 is superimposed with the bias voltage to effectively prevent distortion at a low voltage, so that the transistor 56 is ensured to be located near a static operating point. Preferably, the capacitance of the eighth capacitor 51 is 170nF, the maximum withstand voltage is 50V, the resistance of the seventh resistor 52 is 36K Ω, the resistance of the eighth resistor 53 is 200K Ω, the resistance of the ninth resistor 55 is 19K Ω, the capacitance of the ninth capacitor 54 is 19nF, and the maximum withstand voltage is 16V. Base voltage of transistor 56 is Vb＝Vcc*[200/(200+19)]＝0.667VccTransistor 56 is ensured to be near the quiescent operating point.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (7)
1. A microphone signal amplification system for active noise reduction, comprising an acoustic sensor (10), a two-terminal connector (20), a power supply filtering module (30), a carrier filtering module (40) and an audio amplification module (50); the two-terminal connector (20) is sequentially connected with the power supply filtering module (30) and the carrier filtering module (40), a first resistor (11) and a second resistor (12) are sequentially connected between the carrier filtering module (40) and a power end of the sound sensor (10), a connection point between the first resistor (11) and the second resistor (12) is connected with a first capacitor (13) and a third resistor (14), the first capacitor (13) and the third resistor (14) are grounded after being connected in parallel, the connection point between the second resistor (12) and the sound sensor (10) is connected with one end of a second capacitor (15), the other end of the second capacitor (15) is grounded, an output end of the sound sensor (10) is connected with the audio amplification module (50), and a connection point between the first resistor (11) and the carrier filtering module (40) is connected with a third capacitor (16), The audio amplifier comprises a fourth capacitor (17) and a fourth resistor (18), wherein the third capacitor (16), the fourth capacitor (17) and the fourth resistor (18) are connected in parallel and then are connected with an audio amplification module (50).
2. A microphone signal amplification system for active noise reduction according to claim 1, characterized in that the acoustic sensor (10) is a silicon microphone.
3. A microphone signal amplification system for active noise reduction according to claim 1, characterized in that the junction between the first resistor (11) and the third capacitor (16) is connected to one end of an electrostatic impeder (101), the other end of the electrostatic impeder (101) being connected to ground.
4. A microphone signal amplification system for active noise reduction according to claim 1, characterized in that the junction between the output of the acoustic sensor (10) and the audio amplification module (50) is connected to one end of a fifth capacitor (19), the other end of the fifth capacitor (19) being connected to ground.
5. The microphone signal amplification system for active noise reduction according to claim 1, wherein the power filter module (30) comprises a first inductor (31), a sixth capacitor (32) and a second inductor (33) connected in sequence, and the first inductor (31) and the second inductor (33) are respectively connected with two ends of the terminal connector.
6. The microphone signal amplifying system for active noise reduction according to claim 5, wherein the carrier filtering module (40) comprises a fifth resistor (41), a seventh capacitor (42) and a sixth resistor (43) which are connected in sequence, two ends of the seventh capacitor (42) are respectively connected with the first resistor (11) and the ground, one end of the fifth resistor (41) is connected with one end of the sixth capacitor (32), and one end of the sixth resistor (43) is connected with the other end of the sixth capacitor (32).
7. The microphone signal amplifying system for active noise reduction according to any of claims 1 to 6, wherein the audio amplifying module (50) comprises an eighth capacitor (51), a seventh resistor (52), an eighth resistor (53), a ninth capacitor (54), a ninth resistor (55) and a transistor (56), one end of the eighth capacitor (51) is connected to the output end of the acoustic sensor (10), the other end of the eighth capacitor (51) is connected to one end of the seventh resistor (52), the other end of the seventh resistor (52) is connected to one end of the eighth resistor (53), one end of the ninth capacitor (54), one end of the ninth resistor (55) and the base of the transistor (56), the other end of the eighth resistor (53) is connected to one end of the fourth resistor (18), the other end of the ninth capacitor (54), and the transistor (56), respectively, The other end of the ninth resistor (55) is grounded with the emitter of the triode (56), and the collector of the triode (56) is connected with the other end of the fourth resistor (18).
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910978971.6A CN110662128A (en) | 2019-10-15 | 2019-10-15 | Microphone signal amplification system for active noise reduction |
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| CN201910978971.6A CN110662128A (en) | 2019-10-15 | 2019-10-15 | Microphone signal amplification system for active noise reduction |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112118501A (en) * | 2020-09-15 | 2020-12-22 | 陕西宝成航空仪表有限责任公司 | Airborne microphone signal amplifying circuit with howling suppression function |
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2019
- 2019-10-15 CN CN201910978971.6A patent/CN110662128A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112118501A (en) * | 2020-09-15 | 2020-12-22 | 陕西宝成航空仪表有限责任公司 | Airborne microphone signal amplifying circuit with howling suppression function |
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