CN107948867A - Bandpass filtering audio frequency broadcast system based on feedback interference - Google Patents
Bandpass filtering audio frequency broadcast system based on feedback interference Download PDFInfo
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- CN107948867A CN107948867A CN201810007781.5A CN201810007781A CN107948867A CN 107948867 A CN107948867 A CN 107948867A CN 201810007781 A CN201810007781 A CN 201810007781A CN 107948867 A CN107948867 A CN 107948867A
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- 238000001914 filtration Methods 0.000 title claims abstract description 34
- 239000003990 capacitor Substances 0.000 claims abstract description 18
- 230000003321 amplification Effects 0.000 claims description 17
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 17
- 230000005236 sound signal Effects 0.000 abstract description 10
- 230000002452 interceptive effect Effects 0.000 abstract description 5
- 238000004891 communication Methods 0.000 abstract description 2
- 230000000694 effects Effects 0.000 abstract description 2
- 230000005611 electricity Effects 0.000 description 5
- 239000000872 buffer Substances 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
Classifications
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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
- H04R2430/00—Signal processing covered by H04R, not provided for in its groups
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- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Amplifiers (AREA)
- Networks Using Active Elements (AREA)
Abstract
The invention discloses the bandpass filtering audio frequency broadcast system based on feedback interference, it is characterised in that：Including amplifier U2, audio receiving module, the bandwidth-limited circuit being connected with audio receiving module, the resistance R13 being serially connected between 1 pin of amplifier U2 and 3 pins, the polar capacitor C5 that cathode is connected with 1 pin of amplifier U2, anode is sequentially connected after polar capacitor C6, potentiometer R15 and resistance R14 with 11 pins of amplifier U2 etc.；The present invention can be isolated the interfering noise outside setting range, effectively eliminate interfering noise, improve communication effect.The interference signal that polar circuit and loudspeaker feedback are returned after the present invention can isolate, so as to improve the stability of audio signal.
Description
Technical field
The present invention relates to a kind of audio system, in particular to a kind of bandpass filtering audio based on feedback interference to play system
System.
Background technology
With the continuous development of electronic technology, electronics has been popularized, to bringing great convenience.But
The audio output system that existing electronics uses also existing defects, i.e. the sound noise of its output is more, and call is not
It is enough clear, it largely have impact on speech quality.
The content of the invention
It is an object of the invention to overcome the sound noise that audio output system exports more, call not enough clearly lacks
Fall into, there is provided a kind of bandpass filtering audio frequency broadcast system based on feedback interference.
The purpose of the present invention is achieved through the following technical solutions：Bandpass filtering audio frequency broadcast system based on feedback interference,
Managed including amplifier U2, audio receiving module, the bandwidth-limited circuit being connected with audio receiving module, be serially connected in amplifier U2 1
Resistance R13 between foot and 3 pins, cathode is connected with 1 pin of amplifier U2, anode is sequentially through polar capacitor C6, potentiometer R15
And the polar capacitor C5 being connected after resistance R14 with 11 pins of amplifier U2, one end are connected with 1 pin of amplifier U2, are another
The resistance R17 being connected after resistance R16 with the control terminal of potentiometer R15 is held, one end is connected with 3 pins of amplifier U2, the other end
The resistance R11 being connected after resistance R12 with 2 pins of amplifier U2, the audio amplifier circuit being connected with 1 pin of amplifier U2, with
And the loudspeaker BT being connected with audio amplifier circuit；2 pins of the amplifier U2 and the tie point of resistance R17 and resistance R16
Connection, 3 pins are connected with bandwidth-limited circuit.
Further, the bandwidth-limited circuit includes the second order high-pass filtering circuit being connected with audio receiving module,
The second-order low-pass filter circuit being serially connected between second order high-pass filtering circuit and 3 pins of amplifier U2.
The second order high-pass filtering circuit includes operational amplifier A 1, and one end is connected with audio receiving module, the other end
Capacitance C1, the P pole being connected after capacitance C2 with the cathode of operational amplifier A 1 is grounded after resistance R3, N poles and capacitance C1 and
The diode D1 that the tie point of capacitance C2 is connected, is serially connected between the N poles of diode D1 and the output terminal of operational amplifier A 1
Resistance R2, the resistance R4 being serially connected between the output terminal of operational amplifier A 1 and the P poles of diode D1, and one end and computing
The cathode of amplifier A1 is connected, the resistance R1 of other end ground connection；The output terminal of the operational amplifier A 1 is filtered with step low-pass
Wave circuit is connected, its anode is connected with the P poles of diode D1.
The second-order low-pass filter circuit includes operational amplifier A 2, and one end is connected with the output terminal of operational amplifier A 1
Connect, the resistance R5 that the other end is connected after resistance R7 with the cathode of operational amplifier A 2, one end is with resistance R5's and resistance R7
The capacitance C4 that tie point is connected, the other end is connected with the output terminal of operational amplifier A 2, the resistance being in parallel with capacitance C4
R8, one end is connected with the cathode of operational amplifier A 2, capacitance C3, the resistance R6 being in parallel with capacitance C3 of other end ground connection,
And the resistance R9 that one end is connected with the output terminal of operational amplifier A 2, the other end is grounded after resistance R10；The computing is put
The anode of big device P2 is connected with the tie point of resistance R9 and resistance R10, its output terminal is then connected with 3 pins of amplifier U2.
The audio amplifier circuit includes amplification chip U1, and cathode is connected with 3 pins of amplification chip U1, anode ground connection
Polar capacitor C7, the resistance R20 being in parallel with polar capacitor C7, one end is connected with 3 pins of amplification chip U1, the other end
The resistance R18 of power supply is met, the capacitance C8 being serially connected between 2 pins of amplification chip U1 and 6 pins, the electricity being in parallel with capacitance C8
Hinder R19；2 pins of institute amplification chip U1 are connected with the output terminal of operational amplifier A 2, its 7 pin connects power supply, 4 pins connect
Ground, 6 pins are connected with loudspeaker BT.
The centre frequency of the second order high-pass filtering circuit isThe second-order low-pass filter
The centre frequency of circuit is
The gain A of the second order high-pass filtering circuitF1Equal to the gain A of second-order low-pass filter circuitF2, i.e.,：The gain A of the bandwidth-limited circuitF=AF1AF2。
The frequency filtering of the bandwidth-limited circuit is 300~3000Hz.
The present invention compared with the prior art, has the following advantages and beneficial effect：
(1) present invention can be isolated the interfering noise outside setting range, effectively eliminate interfering noise, be improved
Communication effect.
(2) interference signal that polar circuit and loudspeaker feedback are returned after the present invention can isolate, so as to improve audio signal
Stability.
Brief description of the drawings
Fig. 1 is the overall structure diagram of the present invention.
Embodiment
The present invention is described in further detail with reference to embodiment, but embodiments of the present invention are not limited to
This.
Embodiment
As shown in Figure 1, the bandpass filtering audio frequency broadcast system based on feedback interference of the present invention, including amplifier U2, audio
Receiving module, the bandwidth-limited circuit being connected with audio receiving module, is serially connected between 1 pin of amplifier U2 and 3 pins
Resistance R13, cathode is connected with 1 pin of amplifier U2, anode sequentially after polar capacitor C6, potentiometer R15 and resistance R14 with
The polar capacitor C5 that 11 pins of amplifier U2 are connected, one end is connected with 1 pin of amplifier U2, the other end after resistance R16 with
Potentiometer R15 control terminal connection resistance R17, one end is connected with 3 pins of amplifier U2, the other end after resistance R12 with fortune
Put the resistance R11 of the 2 pins connection of U2, the audio amplifier circuit being connected with 1 pin of amplifier U2, and and audio amplifier circuit
The loudspeaker BT being connected；2 pins of the amplifier U2 are connected with the tie point of resistance R17 and resistance R16,3 pins and band logical
Filter circuit connects.
Specifically, the audio receiving module is used to receive audio signal, it can be realized using existing antenna.The band logical
The frequency filtering of filter circuit is 300~3000Hz, it effectively can filter interfering noise and retain the audio signal spoken,
So that the sound that the present invention exports becomes apparent from.
In order to filter interference signal, as shown in Figure 1, the bandwidth-limited circuit includes two to be connected with audio receiving module
Rank high-pass filtering circuit, the second-order low-pass filter circuit being serially connected between second order high-pass filtering circuit and 3 pins of amplifier U2.
Specifically, the second order high-pass filtering circuit includes operational amplifier A 1, capacitance C1, capacitance C2, resistance R1, resistance
R2, resistance R3, resistance R4 and diode D1.
During connection, one end of capacitance C1 is connected with audio receiving module, the other end after capacitance C2 with operation amplifier
The cathode of device A1 is connected.The P poles of diode D1 are grounded after resistance R3, N poles are connected with the tie point of capacitance C1 and capacitance C2
Connect.Resistance R2 is serially connected between the N poles of diode D1 and the output terminal of operational amplifier A 1.Resistance R4 is serially connected in operational amplifier
Between the output terminal of A1 and the P poles of diode D1.One end of resistance R1 is connected with the cathode of operational amplifier A 1, another termination
Ground.The output terminal of the operational amplifier A 1 is connected with second-order low-pass filter circuit, its anode is extremely connected with the P of diode D1
Connect.
The audio signal of audio receiving module output inputs to operational amplifier after capacitance C1 and capacitance C2 are filtered
A1, the operational amplifier A 1, capacitance C1, capacitance C2, resistance R4 and resistance R3 are collectively forming high-pass filter；The operation amplifier
Device A1 is negative-feedback, it can be with the gain of stabilizing circuit.The centre frequency of the second order high-pass filtering circuit isIn the present embodiment, the capacitance of capacitance C1 and capacitance C2 be 0.068 μ F, resistance R1 and
The resistance value of resistance R2 is 8.2K Ω；It can be drawn by above-mentioned formula, the centre frequency of second order high-pass filtering circuit in the present embodiment
f1=286Hz.In addition, the model 14001 of diode D1, the resistance value of resistance R4 is 27K Ω, and the resistance value of resistance R3 is 47K Ω,
The model OP07 of operational amplifier A 1.The audio signal that operational amplifier A 1 exports is input to second-order low-pass filter circuit.
As shown in Figure 1, the second-order low-pass filter circuit includes operational amplifier A 2, resistance R5, resistance R7, resistance R6, electricity
Hinder R8, resistance R9, resistance R10, capacitance C3 and capacitance C4.During specific connection, one end and the operational amplifier A 1 of resistance R5
Output terminal be connected, cathode of the other end with operational amplifier A 2 after resistance R7 is connected.One end of capacitance C4 and resistance
The tie point of R5 and resistance R7 are connected, the other end is connected with the output terminal of operational amplifier A 2.Resistance R8 and capacitance C4 phases
It is in parallel.One end of capacitance C3 is connected with the cathode of operational amplifier A 2, other end ground connection.Resistance R6 is in parallel with capacitance C3.
One end of resistance R9 is connected with the output terminal of operational amplifier A 2, the other end is grounded after resistance R10.The operational amplifier
The anode of P2 is connected with the tie point of resistance R9 and resistance R10, its output terminal is then connected with 3 pins of amplifier U2.
The audio signal that operational amplifier A 1 exports inputs to operational amplifier A 2, while electricity after resistance R5 and resistance R7
Audio signal can be filtered by holding C3 and capacitance C4；The operational amplifier A 2, resistance R5, resistance R7, capacitance C3, resistance R6,
Capacitance C4 and resistance R8 are collectively forming low-pass filter.Operational amplifier A 2 is also negative-feedback, it can be with the increasing of stabilizing circuit
Benefit.The centre frequency of the second-order low-pass filter circuit isIn the present embodiment, resistance R5 and
The resistance value of resistance R7 is that the capacitance of 8.2K Ω, capacitance C3 and capacitance C4 are 0.0068 μ F；It can be drawn by above-mentioned formula, this reality
Apply the centre frequency f of second-order low-pass filter circuit in example2=2856Hz.In addition, the resistance value of resistance R6 is 10K Ω, resistance R8
Resistance value be 1K Ω, the resistance value of resistance R9 is 27K Ω, and the resistance value of resistance R10 is 47K Ω, the model of operational amplifier A 2
OP07。
Obtained by above-mentioned, the cutoff frequency of the bandwidth-limited circuit of the present embodiment is 286Hz~2856Hz, so that effectively
Interference signal beyond one's voice in speech frequency signal is isolated, improves speech quality.
In addition, the gain A of the second order high-pass filtering circuitF1Equal to the gain A of second-order low-pass filter circuitF2, i.e.,：The gain A of the bandwidth-limited circuitF=AF1AF2。
In addition, the amplifier U2, polar capacitor C5, polar capacitor C6, resistance R17, resistance R16, potentiometer R15 and resistance
R14 is collectively forming an isolation buffers；The isolation buffers can isolate rear class low distortion audio amplifier circuit and loudspeaker
The feedback interference signal of BT, so as to improve the stability of system.In the present embodiment, the model LM324 of amplifier U2, polarity electricity
The capacitance for holding C5 is 1 μ F, and the capacitance of polar capacitor C6 is 4.7 μ F, and the resistance value of resistance R17 is 10K Ω, and the resistance value of resistance R16 is
The resistance value of 100K Ω, potentiometer R15 are 10K Ω, and the resistance value of resistance R14 is 4.7K Ω, and the resistance value of resistance R12 is 100K Ω, electricity
The resistance value for hindering R11 is 4.7K Ω, and the resistance value of resistance R13 is 22K Ω.Audio signal is exported from 1 pin of amplifier U2 and put to audio
Big circuit.
In addition, the audio amplifier circuit includes amplification chip U1, cathode is connected with 3 pins of amplification chip U1, bears
Polar capacitor C7, the resistance R20 being in parallel with polar capacitor C7 of pole ground connection, one end is connected with 3 pins of amplification chip U1,
Resistance R18, the capacitance C8 being serially connected between 2 pins of amplification chip U1 and 6 pins of another termination 12V voltages, with capacitance C8
The resistance R19 being in parallel.2 pins of the amplification chip U1 are connected with the output terminal of operational amplifier A 2, its 7 pin connects
12V voltages, 4 pins ground connection, 6 pins are connected with loudspeaker BT.
The audio signal that operational amplifier A 2 exports is input in amplification chip U1, is driven and is raised after being amplified by amplification chip U1
Sound device BT.Polar capacitor C7 and resistance R20 forms a wave filter, it can be filtered input voltage processing, make to put
Large chip U1 work is more stablized；Resistance R18 plays partial pressure, and the resistance value of resistance R18 and resistance R20 is 10K Ω, pole
The capacitance of property capacitance C7 is 0.1 μ F, and the resistance value of resistance R19 is 1K Ω, and the capacitance of capacitance C8 is 4.7 μ F, the type of amplification chip U1
Number it is LM74.
As described above, the present invention can be realized well.
Claims (8)
1. the bandpass filtering audio frequency broadcast system based on feedback interference, it is characterised in that：Including amplifier U2, audio receiving module,
The bandwidth-limited circuit being connected with audio receiving module, the resistance R13 being serially connected between 1 pin of amplifier U2 and 3 pins, just
Pole is connected with 1 pin of amplifier U2, anode sequentially after polar capacitor C6, potentiometer R15 and resistance R14 with amplifier U2 11
The polar capacitor C5 that pin is connected, one end is connected with 1 pin of amplifier U2, the other end after resistance R16 with potentiometer R15's
The resistance R17 of control terminal connection, one end is connected with 3 pins of amplifier U2,2 pins of the other end after resistance R12 with amplifier U2
The resistance R11 of connection, the audio amplifier circuit being connected with 1 pin of amplifier U2, and what is be connected with audio amplifier circuit raise
Sound device BT；2 pins of the amplifier U2 are connected with the tie point of resistance R17 and resistance R16,3 pins and bandwidth-limited circuit connect
Connect.
2. the bandpass filtering audio frequency broadcast system according to claim 1 based on feedback interference, it is characterised in that：The band
Bandpass filter circuit includes the second order high-pass filtering circuit that is connected with audio receiving module, be serially connected in second order high-pass filtering circuit and
Second-order low-pass filter circuit between 3 pins of amplifier U2.
3. the bandpass filtering audio frequency broadcast system according to claim 2 based on feedback interference, it is characterised in that：Described two
Rank high-pass filtering circuit includes operational amplifier A 1, one end is connected with audio receiving module, the other end after capacitance C2 with fortune
Calculate capacitance C1, the P pole that the cathode of amplifier A1 is connected be grounded after resistance R3, the tie point of N poles and capacitance C1 and capacitance C2
The diode D1 being connected, the resistance R2 being serially connected between the N poles of diode D1 and the output terminal of operational amplifier A 1, is serially connected in
Resistance R4 between the output terminal of operational amplifier A 1 and the P poles of diode D1, and one end and the cathode of operational amplifier A 1
It is connected, the resistance R1 of other end ground connection；The output terminal of the operational amplifier A 1 is connected with second-order low-pass filter circuit, its
Anode is connected with the P poles of diode D1.
4. the bandpass filtering audio frequency broadcast system according to claim 3 based on feedback interference, it is characterised in that：Described two
Rank low-pass filter circuit includes operational amplifier A 2, and one end is connected with the output terminal of operational amplifier A 1, the other end is through resistance
The resistance R5 being connected after R7 with the cathode of operational amplifier A 2, one end are connected, separately with the tie point of resistance R5 and resistance R7
The capacitance C4 that one end is connected with the output terminal of operational amplifier A 2, the resistance R8 being in parallel with capacitance C4, one end is put with computing
The cathode of big device A2 is connected, capacitance C3, the resistance R6 being in parallel with capacitance C3 of other end ground connection, and one end is put with computing
The output terminal of big device A2 is connected, the resistance R9 that the other end is grounded after resistance R10；The operation amplifier
The anode of device P2 is connected with the tie point of resistance R9 and resistance R10, its output terminal is then connected with 3 pins of amplifier U2
Connect.
5. the bandpass filtering audio frequency broadcast system according to claim 4 based on feedback interference, it is characterised in that：The sound
Frequency amplifying circuit includes amplification chip U1, and cathode is connected with 3 pins of amplification chip U1, the polar capacitor C7 of anode ground connection,
The resistance R20 being in parallel with polar capacitor C7, one end is connected with 3 pins of amplification chip U1, the resistance of another termination power
R18, the capacitance C8 being serially connected between 2 pins of amplification chip U1 and 6 pins, the resistance R19 being in parallel with capacitance C8；Amplified
2 pins of chip U1 are connected with the output terminal of operational amplifier A 2, its 7 pin connects power supply, 4 pins are grounded, 6 pins are with raising one's voice
Device BT connections.
6. the bandpass filtering audio frequency broadcast system according to claim 5 based on feedback interference, it is characterised in that：Described two
The centre frequency of rank high-pass filtering circuit isThe centre frequency of the second-order low-pass filter circuit
For
7. the bandpass filtering audio frequency broadcast system according to claim 6 based on feedback interference, it is characterised in that：Described two
The gain A of rank high-pass filtering circuitF1Equal to the gain A of second-order low-pass filter circuitF2, i.e.,：Institute
State the gain A of bandwidth-limited circuitF=AF1 AF2。
8. the bandpass filtering audio frequency broadcast system according to claim 7 based on feedback interference, it is characterised in that：The band
The frequency filtering of bandpass filter circuit is 300~3000Hz.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810007781.5A CN107948867B (en) | 2018-01-04 | 2018-01-04 | Band-pass filtering audio playing system based on feedback interference |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810007781.5A CN107948867B (en) | 2018-01-04 | 2018-01-04 | Band-pass filtering audio playing system based on feedback interference |
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| Publication Number | Publication Date |
|---|---|
| CN107948867A true CN107948867A (en) | 2018-04-20 |
| CN107948867B CN107948867B (en) | 2024-04-09 |
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| CN201810007781.5A Active CN107948867B (en) | 2018-01-04 | 2018-01-04 | Band-pass filtering audio playing system based on feedback interference |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070269055A1 (en) * | 2006-05-17 | 2007-11-22 | Erath Louis W | Feedback System for a Multiple Element Loudspeaker |
| CN105763162A (en) * | 2015-01-05 | 2016-07-13 | 音乐集团公司 | Power Amplifiers Coupled In Series |
| CN107948866A (en) * | 2018-01-04 | 2018-04-20 | 成都威邦科技有限公司 | A kind of feedback interference low distortion audio frequency broadcast system |
| CN208402102U (en) * | 2018-01-04 | 2019-01-18 | 成都威邦科技有限公司 | Bandpass filtering audio frequency broadcast system based on feedback interference |
-
2018
- 2018-01-04 CN CN201810007781.5A patent/CN107948867B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070269055A1 (en) * | 2006-05-17 | 2007-11-22 | Erath Louis W | Feedback System for a Multiple Element Loudspeaker |
| CN105763162A (en) * | 2015-01-05 | 2016-07-13 | 音乐集团公司 | Power Amplifiers Coupled In Series |
| CN107948866A (en) * | 2018-01-04 | 2018-04-20 | 成都威邦科技有限公司 | A kind of feedback interference low distortion audio frequency broadcast system |
| CN208402102U (en) * | 2018-01-04 | 2019-01-18 | 成都威邦科技有限公司 | Bandpass filtering audio frequency broadcast system based on feedback interference |
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| Publication number | Publication date |
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| CN107948867B (en) | 2024-04-09 |
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