CN107968975A - Audio frequency broadcast system based on bandpass filter - Google Patents
Audio frequency broadcast system based on bandpass filter Download PDFInfo
- Publication number
- CN107968975A CN107968975A CN201810007520.3A CN201810007520A CN107968975A CN 107968975 A CN107968975 A CN 107968975A CN 201810007520 A CN201810007520 A CN 201810007520A CN 107968975 A CN107968975 A CN 107968975A
- Authority
- CN
- China
- Prior art keywords
- resistance
- capacitance
- operational amplifier
- circuit
- audio
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- 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
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Amplifiers (AREA)
Abstract
The invention discloses a kind of audio frequency broadcast system based on bandpass filter, it is characterised in that：Including audio receiving module, it is connected with audio receiving module and frequency filtering is the bandwidth-limited circuit of 300~3000Hz, the audio amplifier circuit being connected with bandwidth-limited circuit, and the loudspeaker BT being connected with audio amplifier circuit；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 audio amplifier circuit.The present invention can be isolated the interfering noise outside setting range, effectively eliminate interfering noise, improve communication effect.
Description
Technical field
The present invention relates to a kind of audio system, in particular to a kind of audio frequency broadcast system based on bandpass filter.
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 audio frequency broadcast system based on bandpass filter.
The purpose of the present invention is achieved through the following technical solutions：Audio frequency broadcast system based on bandpass filter, including sound
Frequency receiving module, is connected with audio receiving module and frequency filtering is the bandwidth-limited circuit of 300~3000Hz, is filtered with band logical
The audio amplifier circuit that wave circuit is connected, and the loudspeaker BT being connected with audio amplifier circuit；The bandpass filtering electricity
Road includes the second order high-pass filtering circuit being connected with audio receiving module, is serially connected in second order high-pass filtering circuit and audio amplification
Second-order low-pass filter circuit between circuit.
Further, the second order high-pass filtering circuit includes operational amplifier A 1, and one end is connected with audio receiving module
Connect, capacitance C1, the P pole that the other end is connected after capacitance C2 with the cathode of operational amplifier A 1 is grounded after resistance R3, N poles with
The diode D1 that capacitance C1 is connected with the tie point of capacitance C2, be serially connected in diode D1 N poles and operational amplifier A 1 it is defeated
Resistance R2 between outlet, the resistance R4, Yi Jiyi being serially connected between the output terminal of operational amplifier A 1 and the P poles of diode D1
End is connected with the cathode of operational amplifier A 1, the resistance R1 of other end ground connection；The output terminal and two of the operational amplifier A 1
Rank low-pass filter 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 audio amplifier circuit.
The audio amplifier circuit includes amplification chip U1, and cathode is connected with 3 pins of amplification chip U1, anode ground connection
Polar capacitor C5, the resistance R13 being in parallel with polar capacitor C5, one end is connected with 3 pins of amplification chip U1, the other end
The resistance R11 of power supply is met, the capacitance C6 being serially connected between 2 pins of amplification chip U1 and 6 pins, the electricity being in parallel with capacitance C6
Hinder R12；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 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) present invention can be very good drive the speaker, improve the stability of sound.
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 audio frequency broadcast system based on bandpass filter of the present invention, including audio receiving module, with sound
The bandwidth-limited circuit that frequency receiving module is connected, the audio amplifier circuit being connected with bandwidth-limited circuit, and and audio
The loudspeaker BT that amplifying circuit is connected.
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 audio amplifier circuit.
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 audio amplifier circuit.
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 audio amplifier circuit includes amplification chip U1, cathode is connected with 3 pins of amplification chip U1, bears
Polar capacitor C5, the resistance R13 being in parallel with polar capacitor C5 of pole ground connection, one end is connected with 3 pins of amplification chip U1,
Resistance R11, the capacitance C6 being serially connected between 2 pins of amplification chip U1 and 6 pins of another termination 12V voltages, with capacitance C6
The resistance R12 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 C5 and resistance R13 forms a wave filter, it can be filtered input voltage processing, make to put
Large chip U1 work is more stablized；Resistance R11 plays partial pressure, and the resistance value of resistance R11 and resistance R13 is 10K Ω, pole
The capacitance of property capacitance C5 is 0.1 μ F, and the resistance value of resistance R12 is 1K Ω, and the capacitance of capacitance C6 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 (6)
1. the audio frequency broadcast system based on bandpass filter, it is characterised in that：Including audio receiving module, with audio receiving module
It is connected and frequency filtering is the bandwidth-limited circuit of 300~3000Hz, the audio amplification electricity being connected with bandwidth-limited circuit
Road, and the loudspeaker BT being connected with audio amplifier circuit；The bandwidth-limited circuit includes being connected with audio receiving module
The second order high-pass filtering circuit connect, the second-order low-pass filter electricity being serially connected between second order high-pass filtering circuit and audio amplifier circuit
Road.
2. the audio frequency broadcast system according to claim 1 based on bandpass filter, it is characterised in that：The second order high pass
Filter circuit includes operational amplifier A 1, one end is connected with audio receiving module, the other end after capacitance C2 with operation amplifier
Capacitance C1, the P pole that the cathode of device A1 is connected is grounded after resistance R3, N poles are connected with the tie point of capacitance C1 and capacitance C2
Diode D1, 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 computing and puts
Resistance R4 between the output terminal of big device A1 and the P poles of diode D1, and one end be connected with the cathode of operational amplifier A 1,
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 with
The P poles of diode D1 are connected.
3. the audio frequency broadcast system according to claim 2 based on bandpass filter, it is characterised in that：The step low-pass
Filter circuit includes operational amplifier A 2, one end is connected with the output terminal of operational amplifier A 1, the other end after resistance R7 with
The resistance R5 that the cathode of operational amplifier A 2 is connected, one end is connected with the tie point of resistance R5 and resistance R7, the other end with
The capacitance C4 that the output terminal of operational amplifier A 2 is connected, the resistance R8 being in parallel with capacitance C4, one end and operational amplifier A 2
Cathode be connected, capacitance C3, the resistance R6 being in parallel with capacitance C3 of other end ground connection, and one end and operational amplifier A 2
Output terminal be connected, the resistance R9 that the other end is grounded after resistance R10；The anode of the operational amplifier P2 and resistance R9 and
The tie point of resistance R10 is connected, its output terminal is then connected with audio amplifier circuit.
4. the audio frequency broadcast system according to claim 3 based on bandpass filter, it is characterised in that：The audio amplification
Circuit includes amplification chip U1, and cathode is connected with 3 pins of amplification chip U1, the polar capacitor C5 of anode ground connection, with polarity
The resistance R13 that capacitance C5 is in parallel, one end is connected with 3 pins of amplification chip U1, the resistance R11 of another termination power, string
The capacitance C6 being connected between 2 pins of amplification chip U1 and 6 pins, the resistance R12 being in parallel with capacitance C6；Institute amplification chip U1
2 pins be connected with the output terminal of operational amplifier A 2, its 7 pin connects power supply, 4 pins ground connection, 6 pins and loudspeaker BT company
Connect.
5. the audio frequency broadcast system according to claim 4 based on bandpass filter, it is characterised in that：The second order high pass
The centre frequency of filter circuit isThe centre frequency of the second-order low-pass filter circuit is
6. the audio frequency broadcast system according to claim 5 based on bandpass filter, it is characterised in that：The second order high pass
The gain A of filter circuitF1Equal to the gain A of second-order low-pass filter circuitF2, i.e.,：The band logical
The gain A of filter circuitF=AF1AF2。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810007520.3A CN107968975A (en) | 2018-01-04 | 2018-01-04 | Audio frequency broadcast system based on bandpass filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810007520.3A CN107968975A (en) | 2018-01-04 | 2018-01-04 | Audio frequency broadcast system based on bandpass filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107968975A true CN107968975A (en) | 2018-04-27 |
Family
ID=61993978
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810007520.3A Pending CN107968975A (en) | 2018-01-04 | 2018-01-04 | Audio frequency broadcast system based on bandpass filter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107968975A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108900176A (en) * | 2018-09-20 | 2018-11-27 | 无锡吉兴汽车声学部件科技有限公司 | A kind of adjustable bandpass filter of two channel central frequencies |
| CN110956977A (en) * | 2019-12-31 | 2020-04-03 | 青岛海之声科技有限公司 | Real-time positioning system and method for automobile whistling |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204290889U (en) * | 2014-12-05 | 2015-04-22 | 杭州海康威视数字技术股份有限公司 | A kind of filtering and amplifying circuit |
| CN105232040A (en) * | 2015-09-29 | 2016-01-13 | 武汉工程大学 | Muscle fatigue detection system and method |
| CN107301029A (en) * | 2017-06-19 | 2017-10-27 | 北京小米移动软件有限公司 | Dio Output Modules, method and terminal device |
| CN208015982U (en) * | 2018-01-04 | 2018-10-26 | 成都威邦科技有限公司 | Audio frequency broadcast system based on bandpass filter |
-
2018
- 2018-01-04 CN CN201810007520.3A patent/CN107968975A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204290889U (en) * | 2014-12-05 | 2015-04-22 | 杭州海康威视数字技术股份有限公司 | A kind of filtering and amplifying circuit |
| CN105232040A (en) * | 2015-09-29 | 2016-01-13 | 武汉工程大学 | Muscle fatigue detection system and method |
| CN107301029A (en) * | 2017-06-19 | 2017-10-27 | 北京小米移动软件有限公司 | Dio Output Modules, method and terminal device |
| CN208015982U (en) * | 2018-01-04 | 2018-10-26 | 成都威邦科技有限公司 | Audio frequency broadcast system based on bandpass filter |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108900176A (en) * | 2018-09-20 | 2018-11-27 | 无锡吉兴汽车声学部件科技有限公司 | A kind of adjustable bandpass filter of two channel central frequencies |
| CN110956977A (en) * | 2019-12-31 | 2020-04-03 | 青岛海之声科技有限公司 | Real-time positioning system and method for automobile whistling |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107968975A (en) | Audio frequency broadcast system based on bandpass filter | |
| CN208015982U (en) | Audio frequency broadcast system based on bandpass filter | |
| CN205793138U (en) | A kind of Radix Saposhnikoviae is made an uproar mike monomer and earphone | |
| CN207895428U (en) | Audio frequency broadcast system based on voltage follow | |
| CN205900092U (en) | Echo elimination circuit | |
| CN208402102U (en) | Bandpass filtering audio frequency broadcast system based on feedback interference | |
| CN208015983U (en) | A kind of low distortion audio frequency broadcast system | |
| CN104270698A (en) | Multifunctional power amplification audio device and method thereof | |
| CN201774652U (en) | Microphone of mobile terminal, mobile terminal employing same | |
| CN208402103U (en) | A kind of feedback interference low distortion audio frequency broadcast system | |
| CN107948866A (en) | A kind of feedback interference low distortion audio frequency broadcast system | |
| CN208061666U (en) | A kind of voltage follow low distortion audio frequency broadcast system | |
| CN107911097A (en) | A kind of bandpass filter | |
| CN203104383U (en) | High Q quality band pass filter used for audio frequency near field payment | |
| CN102325288A (en) | De-noising device and method for audio circuit of mobile terminal earphone | |
| CN207926548U (en) | A kind of bandpass filter | |
| CN107948867A (en) | Bandpass filtering audio frequency broadcast system based on feedback interference | |
| CN204721585U (en) | Receiver amplifier | |
| CN108021352A (en) | Audio frequency broadcast system based on voltage follow | |
| CN205123720U (en) | Novel on -vehicle wireless data terminal | |
| CN202111843U (en) | Sound for suppressing TDMA noises | |
| CN108010543A (en) | A kind of voltage follow low distortion audio frequency broadcast system | |
| CN107968976A (en) | A kind of low distortion audio frequency broadcast system | |
| CN209517434U (en) | A kind of noise reduction folder neck microphone | |
| CN106817644A (en) | A kind of mobile terminal and head circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |