CN110536195B - Dynamic noise reduction megaphone - Google Patents
Dynamic noise reduction megaphone Download PDFInfo
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- CN110536195B CN110536195B CN201910929585.8A CN201910929585A CN110536195B CN 110536195 B CN110536195 B CN 110536195B CN 201910929585 A CN201910929585 A CN 201910929585A CN 110536195 B CN110536195 B CN 110536195B
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- microphone
- pcb
- noise reduction
- megaphone
- sound
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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
- H04R1/083—Special constructions of mouthpieces
Abstract
The invention relates to a megaphone, in particular to a dynamic noise reduction megaphone which comprises a shell, wherein the shell is connected with a handle, a PCB (printed circuit board) is arranged in the shell, a sound pickup module, an operation amplification module, a data processing module, a power amplification module and a contact are arranged on the PCB, the power amplification module is connected with a loudspeaker, a cover plate used for protecting the PCB is arranged at the rear end of the shell, meshes corresponding to the sound pickup module and buttons matched with the contacts are arranged on the cover plate, the PCB is vertically arranged at the rear end of the shell, and a sound pickup device comprises a main microphone head, an auxiliary microphone head and at least one noise reduction microphone head which are arranged on the PCB.
Description
Technical Field
The invention relates to a megaphone, in particular to a dynamic noise reduction megaphone.
Background
The megaphone in the current market has a single microphone to pick up sound, the sound signal is converted into an electric signal and enters a main control controller, the main control controller has the functions of megaphone, recording or MP3 playing, and the electric signal enters power amplification through electronic volume control to push a loudspeaker to make sound; due to the principle of forward feedback, when the loud speaking sound is large, the megaphone generates a howling phenomenon, so that the loud speaking sound cannot be adjusted to the maximum position, the howling can be reduced only when the microphone is far away from the sounding port of the horn, but the size of the megaphone is increased, and the size of the sound is determined; when the current megaphone is used, the distance between a mouth and a microphone is about 2 centimeters, and if the sound emitted by a horn at a distance point is obviously reduced, inconvenience is brought to a user; in addition, when the megaphone is used, environmental noise or other sounds around the microphone can be picked up and emitted by a loudspeaker, so that the sound is noisy.
In order to reduce noise, the prior art discloses a technical scheme for eliminating noise through a plurality of microphones, and specifically includes receiving a first sound signal from a first direction; receiving a second sound signal from a second direction different from the first direction; comparing the sound volumes of the first sound signal and the second sound signal, and carrying out sound volume noise reduction treatment on the sound signals with the same volume in the first sound signal and the second sound signal; the stored sound frequency is compared with the sound frequencies in the first sound signal and the second sound signal, and the sound with the frequency outside the stored sound frequency range in the first sound signal and the second sound signal is subjected to frequency noise reduction processing, so that the noise can be effectively reduced.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a dynamic noise reduction megaphone which can effectively reduce noise, prevent howling and improve sound pickup precision.
The invention is realized by the following technical scheme: the utility model provides a megaphone of making an uproar falls in developments, includes the shell, the shell is connected with the handle, be provided with the PCB board in the shell, be provided with sound pickup module, operational amplification module, data processing module, power amplification module, contact on the PCB board, power amplification module is connected with loudspeaker, the shell rear end is provided with the apron that is used for protecting the PCB board, be provided with on the apron with the corresponding mesh of sound pickup module, with contact assorted button, the PCB board is vertical to be set up in the shell rear end, sound pickup module includes main miaow head, vice miaow head, at least one of setting on the PCB board and falling the miaow head of making an uproar, the interval between main miaow head and the vice miaow head is 45-50mm, main miaow head sets up in PCB board upper end, vice miaow head sets up at PCB board lower extreme, it sets up at the PCB board lateral part to fall the miaow head of making an uproar, the noise reduction microphone is in signal connection with the data processing module sequentially through the operational amplification module, and the data processing module comprises a gate value gate circuit, a phase shift circuit, an operational amplification subtraction circuit, a controller, an automatic gain control circuit and a volume control circuit which are in signal connection sequentially.
Further, the gate circuit, the phase shift circuit, the operational amplification subtraction circuit and the controller are integrated in the ML1901 chip.
Furthermore, the cover plate and the PCB are provided with dustproof noise reduction rings around the main microphone, the auxiliary microphone and the noise reduction microphone, and the inner end face of the mesh is provided with an annular clamping groove for mounting the dustproof noise reduction rings.
Furthermore, the dustproof noise reduction ring comprises a plurality of metal rings which are arranged in a stacked mode, annular grooves are formed in the upper end face and the lower end face of each metal ring, sound insulation and dust collection cotton is clamped between every two adjacent metal rings through the grooves, a conducting wire is arranged between every two adjacent metal rings, and an elastic supporting seat is arranged at one end, pointing to the PCB, of the dustproof noise reduction ring.
Further, the metal ring is one of a copper ring, an aluminum alloy ring and a stainless steel ring, and the cross section of the metal ring is rectangular.
Furthermore, the conducting wire is a copper wire which is arranged between the metal rings in a penetrating mode, through holes matched with the copper wire are formed in the bottom face of the groove, and a plurality of shock absorbing holes are evenly formed in the side wall of each metal ring.
Furthermore, the sound insulation dust absorption cotton comprises two layers of vertical sound absorption cotton, activated carbon cotton is arranged between the two layers of sound absorption cotton, and the thickness value of the activated carbon cotton is 2-3 times that of the sound absorption cotton.
Furthermore, the elastic support seat comprises a support ring, 3-4 support legs pointing to the PCB are uniformly and integrally formed on the support ring, and the support ring and the support legs are both made of PE materials.
Furthermore, there are two noise reduction microphone heads respectively arranged at two side parts of the PCB.
The beneficial effect of the invention is that,
1, howling suppression: the microphone squealing is caused by positive feedback, the suppression of the squealing is to solve the phenomenon of the positive feedback, and the suppression of the squealing is finished by a main microphone and an auxiliary microphone, namely a double-microphone circuit, wherein the main microphone is obvious in position, and the auxiliary microphone is arranged in a hidden mode at a position which is about 5 cm away from the main microphone; the shouting sound and the forward feedback sound are converted into electric signals through the main microphone and the auxiliary microphone, amplified and inverted through the operational circuit and enter the digital processing controller; a gate value gate circuit is arranged at the inlet of the controller, and is used for intercepting noise signals lower than normal signals and filtering a part of noise; the main microphone signal is subjected to phase shifting, the main microphone signal subjected to phase shifting and the auxiliary microphone signal are subjected to subtraction processing after comparison and operation, and the signal of the main microphone voice is larger than the signal value of the auxiliary microphone voice, so that the voice signal is extracted after the subtraction processing, the forward feedback signal can be eliminated after the subtraction processing, howling is avoided, and the gain of the shouting channel can be adjusted to the maximum. Therefore, on the premise of the same volume, the calling sound is greatly improved, and on the premise of the same sound, the distance between the microphone and the horn mouth is reduced, so that the volume of the calling device is reduced;
2, noise suppression: the method comprises the following steps that the megaphone clearly emits the sound of the megaphone in a noisy environment, sound signals except the megaphone are suppressed, two or more noise reduction microphone heads are additionally arranged on the left side and the right side of the megaphone to better collect external noise, the external noise enters a digital processing controller through an operational amplification circuit, the noise signals are compared with main microphone signals after being processed, subtraction processing is carried out after operation, the sound signals of the megaphone are extracted, and environmental noise signals are suppressed; therefore, the megaphone can carry out the megaphone in a noisy environment and can also clearly send out the sound of the megaphone;
3, automatic gain control: after the controller restrains the forward feedback signal and the noise signal, extracting a voice signal of a shout person and entering an automatic gain amplification control circuit, wherein the circuit sets the voltage value of an output signal in a negative feedback amplification state; when the voice of the shout is small or far away from the main microphone, the amplification gain is improved, and when the voice of the shout is large or near to the main microphone, the amplification gain is reduced, the voltage value of the output signal is set, and the phenomenon of power output distortion is ensured; the automatic gain control is set, the distance between the microphone port and the microphone is about 2 cm originally, and is increased to about 8 cm, so that the convenience of a user is greatly improved;
4, the installation is dustproof to fall and is fallen the ring and can keep apart other circuits of miaow head and PCB board, reduces the influence of the local noise of PCB board to the miaow head, and the noise that main miaow head, vice miaow head, the miaow head of making an uproar of falling receipt all is the noise that mainly comes from external environment, and the noise similarity of each miaow head is high, filtration that can be better guarantees the quality of sound production, can also adsorb the dust of miaow head department, guarantees that the miaow head is clean, reduces noise interference.
Drawings
FIG. 1 is a schematic view of the control principle of embodiment 1
FIG. 2 is a schematic view of the structure of embodiment 1;
FIG. 3 is a schematic diagram of a PCB structure;
FIG. 4 is a schematic view of a cover plate structure;
FIG. 5 is a schematic cross-sectional view of a dust and noise reduction ring;
FIG. 6 is a schematic enlarged view of a portion A of FIG. 5;
FIG. 7 is a diagram of ML1901 chip pin;
fig. 8 is a schematic view of the respective microphone circuits;
FIG. 9 is a schematic diagram of a four operational amplifier circuit;
FIG. 10 is a schematic diagram of a class D power amplifier circuit;
FIG. 11 is a schematic diagram of a communication interface circuit;
FIG. 12 is a schematic diagram of contacts and USB interface circuitry;
wherein: the microphone comprises a shell, a handle, a cover plate, a 4-mesh, a button, a 6-switch, an indicator light, a USB interface 12-ML1901 chip, a USB interface.
Detailed Description
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
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.
In the following embodiments, the pilot microphone, the subsidiary microphone and the noise reduction microphone are all selected from 4015 single-direction microphones of Weifang Delhi Fuyun electronics Limited company, and have small volume and high precision;
the gate circuit, the phase shift circuit, the operational amplification subtraction circuit and the controller are integrated in the ML1901 chip 12 of Shenzhen Hengsheng technology Limited, and the working stability and the integration level are high.
Example 1
As shown in fig. 1-10, a dynamic noise reduction megaphone comprises a housing 1, the housing is connected with a handle 2, the housing and the handle are both made of ABS plastic, the hardness is high, the wear resistance is high, a PCB 14 is installed in the housing, the PCB is connected with the housing through a mounting hole 10, a sound pickup module, an operational amplification module, a data processing module, a power amplification module, and a contact 15 are installed on the PCB, the power amplification module is connected with a loudspeaker, the sound pickup module comprises a main microphone 9, an auxiliary microphone 13, and two noise reduction microphones 24 installed on the PCB, the distance between the main microphone and the auxiliary microphones is 45-50mm, the main microphone is installed on the upper end of the PCB, the auxiliary microphones are installed on the lower end of the PCB, the noise reduction microphones are installed on both sides of the PCB, the main microphone, the auxiliary microphones and the noise reduction microphones are connected with the data processing module through the operational amplification module in sequence, the operational amplification module is a four operational amplifier, the data processing module comprises a gate value gate circuit, a phase shift circuit, an operational amplification subtraction circuit, a controller, an automatic gain control circuit and a volume control circuit which are sequentially connected in a signal mode, the gate value gate circuit, the phase shift circuit, the operational amplification subtraction circuit and the controller are integrated in the ML1901 chip 12, the integration degree is high, and the working stability is high.
The microphone squealing is caused by positive feedback, the suppression of the squealing is to solve the phenomenon of the positive feedback, and the suppression of the squealing is finished by a main microphone and an auxiliary microphone, namely a double-microphone circuit, wherein the main microphone is obvious in position, and the auxiliary microphone is arranged in a hidden mode at a position which is about 5 cm away from the main microphone; the shouting sound and the forward feedback sound are converted into electric signals through the main microphone and the auxiliary microphone, amplified and inverted through the operational circuit and enter the digital processing controller; a gate value gate circuit is arranged at the inlet of the controller, and is used for intercepting noise signals lower than normal signals and filtering a part of noise; the main microphone signal is subjected to phase shifting, the main microphone signal subjected to phase shifting and the auxiliary microphone signal are subjected to subtraction processing after comparison and operation, and the signal of the main microphone voice is larger than the signal value of the auxiliary microphone voice, so that the voice signal is extracted after the subtraction processing, the forward feedback signal can be eliminated after the subtraction processing, howling is avoided, and the gain of the shouting channel can be adjusted to the maximum. Therefore, on the premise of the same volume, the microphone is greatly improved in sound, and on the premise of the same sound, the distance between the microphone and the horn mouth is reduced, so that the volume of the microphone is reduced.
In addition, the megaphone needs to clearly send out the voice of the megaphone in a noisy environment, the voice signals except the megaphone need to be suppressed, two or more noise reduction microphone heads are additionally arranged on the left side and the right side of the megaphone to better collect external noise, the external noise enters a digital processing controller through an operational amplification circuit, the noise signals are compared with main microphone signals after being processed, subtraction processing is carried out after operation, the voice signals of the megaphone are extracted, and environmental noise signals are suppressed; therefore, the megaphone can carry out megaphone in noisy environment and can clearly emit the sound of the megaphone.
After the controller restrains the forward feedback signal and the noise signal, extracting a voice signal of a shout person and entering an automatic gain amplification control circuit, wherein the circuit sets the voltage value of an output signal in a negative feedback amplification state; when the voice of the shout is small or far away from the main microphone, the amplification gain is improved, and when the voice of the shout is large or near to the main microphone, the amplification gain is reduced, the voltage value of the output signal is set, and the phenomenon of power output distortion is ensured; the automatic gain control is arranged, the distance between the microphone port and the microphone is about 2 cm originally, the distance is increased to about 8 cm, and the convenience of a user is greatly improved.
The apron 3 that is used for protecting the PCB board is installed to the shell rear end, processing has mesh 4 corresponding with the sound pickup module on the apron, 5 with contact assorted button, the jog button can trigger the contact, and then the adjustment parameter, the vertical installation of PCB board is in the shell rear end, encircle main miaow head between apron and the PCB board, vice miaow head, it falls the ring of making an uproar all to fall to make an uproar the miaow head, terminal surface integrated into one piece has the ring groove 16 that is used for installing dustproof ring of making an uproar in the mesh, it includes a plurality of becket 17 that range upon range of arranging to fall the ring of making an uproar to prevent dust, the up end and the lower terminal surface of becket all process annular slot, it has syllable-dividing dust absorption cotton 18 to clamp through the slot between two adjacent becket, install conductor wire 22 between two adjacent becket.
In the embodiment, the metal ring is a copper ring, the cross section of the metal ring is rectangular, the conductive wire is a copper wire which is arranged between the metal rings in a penetrating way, the metal rings can be connected into a complete conductor through the copper wire, the electromagnetic shielding effect is achieved, the electromagnetic interference generated by local vibration is avoided, a through hole matched with the copper wire is processed on the bottom surface of the groove, a plurality of shock absorption holes 23 are uniformly processed on the side wall of the metal ring, shock absorption holes are processed in the metal rings and are through holes, the shock absorption holes can play a buffering role in vibration of the metal rings and reduce the amplitude, the sound insulation and dust absorption cotton comprises two layers of vertical sound absorption cotton 20, activated carbon cotton 21 is bonded between the two layers of sound absorption cotton, the thickness value of the activated carbon cotton is 2-3 times of that of the sound absorption cotton, the activated carbon cotton is clamped between the sound absorption cotton, the dust can be gathered, secondary dust raising in the vibration process is, the elastic support seat comprises a support ring 19, 3-4 supporting legs 25 pointing to a PCB are uniformly and integrally formed on the support ring, the support ring and the supporting legs are made of PE materials, the PCB is provided with electronic elements of printed circuits, the supporting legs can effectively avoid the electronic elements, and meanwhile, the dustproof noise reduction ring is clamped in the annular clamping groove to avoid falling.
The dustproof ring of making an uproar of falling of installation can keep apart the miaow head with other circuits of PCB board, reduces the influence of the local noise of PCB board to the miaow head, and main miaow head, vice miaow head, the noise that the miaow head of making an uproar of falling received all are the noise that mainly comes from external environment, and the noise similarity of each miaow head is high, filtration that can be better guarantees the quality of sound production, can also adsorb the dust of miaow head department, guarantees that the miaow head is clean, reduces noise interference.
And a switch 6, an indicator light 7 and a USB interface 8 are also arranged on the PCB, so that the use is convenient.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.
Claims (6)
1. A dynamic noise reduction megaphone comprises a shell, the shell is connected with a handle, a PCB is arranged in the shell, a sound pickup module, an operational amplification module, a data processing module, a power amplification module and a contact are arranged on the PCB, the power amplification module is connected with a loudspeaker, a cover plate used for protecting the PCB is arranged at the rear end of the shell, a mesh corresponding to the sound pickup module and a button matched with the contact are arranged on the cover plate, the dynamic noise reduction megaphone is characterized in that the PCB is vertically arranged at the rear end of the shell, the sound pickup module comprises a main microphone, an auxiliary microphone and at least one noise reduction microphone which are arranged on the PCB, the distance between the main microphone and the auxiliary microphone is 45-50mm, the main microphone is arranged at the upper end of the PCB, the auxiliary microphone is arranged at the lower end of the PCB, and the noise reduction microphone is arranged at the side part of the PCB, the main microphone, the auxiliary microphone and the noise reduction microphone are sequentially connected with the data processing module through the operational amplification module by signals, the data processing module comprises a gate value gate circuit, a phase-shifting circuit, an operational amplification subtraction circuit, a controller, an automatic gain control circuit and a volume control circuit which are sequentially connected by signals,
the dustproof and noise-reducing rings are arranged between the cover plate and the PCB around the main microphone, the auxiliary microphone and the noise-reducing microphone, the inner end surface of the mesh is provided with an annular clamping groove for mounting the dustproof and noise-reducing rings,
the dustproof noise reduction ring comprises a plurality of metal rings which are arranged in a laminated manner, annular grooves are formed in the upper end surface and the lower end surface of each metal ring, sound-insulation dust-absorption cotton is clamped between every two adjacent metal rings through the grooves, a conductive wire is arranged between every two adjacent metal rings, an elastic supporting seat is arranged at one end, pointing to the PCB, of the dustproof noise reduction ring,
the conductor wire is a copper wire which is arranged between the metal rings in a penetrating mode, through holes matched with the copper wire are formed in the bottom surfaces of the grooves, and a plurality of shock absorbing holes are uniformly formed in the side walls of the metal rings.
2. The dynamic noise reduction megaphone of claim 1, wherein the gate circuit, phase shift circuit, operational amplification subtraction circuit, controller are integrated in a ML1901 chip.
3. The dynamic noise reducing megaphone of claim 1, wherein the metal ring is one of a copper ring, an aluminum alloy ring, and a stainless steel ring, and the cross section of the metal ring is rectangular.
4. The dynamic noise reduction megaphone as claimed in claim 1, wherein the sound insulation and dust absorption cotton comprises two layers of vertical sound absorption cotton, activated carbon cotton is arranged between the two layers of sound absorption cotton, and the thickness value of the activated carbon cotton is 2-3 times of the thickness value of the sound absorption cotton.
5. The dynamic noise reduction megaphone of claim 1, wherein the elastic support base comprises a support ring, 3-4 legs pointing to the PCB are uniformly integrated on the support ring, and the support ring and the legs are made of PE material.
6. The dynamic noise-reducing megaphone as claimed in claim 1, wherein the noise-reducing microphone has two, respectively disposed at two sides of the PCB.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201910929585.8A CN110536195B (en) | 2019-09-29 | 2019-09-29 | Dynamic noise reduction megaphone |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910929585.8A CN110536195B (en) | 2019-09-29 | 2019-09-29 | Dynamic noise reduction megaphone |
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| CN110536195A CN110536195A (en) | 2019-12-03 |
| CN110536195B true CN110536195B (en) | 2021-07-02 |
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| CN110536195A (en) | 2019-12-03 |
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