CN106057189A - Indoor active noise reduction apparatus - Google Patents
Indoor active noise reduction apparatus Download PDFInfo
- Publication number
- CN106057189A CN106057189A CN201610492137.2A CN201610492137A CN106057189A CN 106057189 A CN106057189 A CN 106057189A CN 201610492137 A CN201610492137 A CN 201610492137A CN 106057189 A CN106057189 A CN 106057189A
- Authority
- CN
- China
- Prior art keywords
- circuit
- noise reduction
- active noise
- sound
- housing
- 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
- 230000009467 reduction Effects 0.000 title claims abstract description 49
- 239000011358 absorbing material Substances 0.000 claims abstract description 5
- 230000001681 protective effect Effects 0.000 claims description 8
- 230000000694 effects Effects 0.000 abstract description 6
- 230000009977 dual effect Effects 0.000 abstract description 3
- 230000003287 optical effect Effects 0.000 description 4
- 230000006872 improvement Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/162—Selection of materials
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
The invention relates to the technical field of noise reduction, and particularly relates to an indoor active noise reduction apparatus. The apparatus includes a casing, a passive noise reduction plate, and an active noise reduction circuit, the passive noise reduction plate is vertically arranged at the bottom of the casing and is attached to the side wall of the casing, the active noise reduction circuit is arranged in the casing, a plurality of grooves having sound absorbing materials are arranged in the passive noise reduction plate, the active noise reduction circuit includes a photosensitive circuit, a sound receiving circuit, a sound processing circuit, and a correction circuit, the electrical signal output by the photosensitive circuit is connected with the input end of the sound receiving circuit, the signal output by the sound receiving circuit is connected with the input end of the sound processing circuit, the signal in the opposite phase output by the sound processing circuit is connected with the input end of the correction circuit, and the error value output from the correction circuit is fed back to the sound processing circuit. The indoor active noise reduction apparatus is long in service life by means of light-operated noise reduction; and meanwhile, the noise reduction effect is improved by means of dual noise reduction.
Description
Technical field
The present invention relates to noise reduction technology field, be specifically related to a kind of indoor active noise reducing device.
Background technology
Along with the development in city, various noises have badly influenced the life of people, to this end, various respectively
The denoising device of sample arises at the historic moment.Current denoising device mostly is passive sound insulation and noise reduction, mainly by arrange sound-absorbing material and
Noise-reducing structure is set to carry out noise isolation, but to typically result in denoising device structure complicated for this quadrat method, and anti-acoustic capability is not
Preferably problem.Use active noise reduction technology to this end, in recent years more, sent and indoor noise opposite phase by electronic circuit
Sound wave, thus offset indoor noise, so can abate the noise from source, excellent noise reduction effect.
Existing active noise reducing device there is problems in that owing to electronic component and the speaker of active noise reduction part are continuous
Work, in 24 hours operation process, easily shortens the service life of active noise reduction part；Meanwhile, present active noise reduction dress
Put and can eliminate most noise, but there is also partial noise residual.
Summary of the invention
It is an object of the invention to provide the indoor active noise reduction dress of a kind of light-operated noise reduction, length in service life and Double-noise-reduction
Put.
For reaching above-mentioned purpose, the basic technology scheme of the present invention is to provide indoor active noise reducing device, including housing, nothing
Source noise reducing plate and active noise reduction circuit, passive noise control plate is vertically provided at the bottom of housing, and is affixed with the sidewall of housing, active
Dolby circuit is arranged in housing；Passive noise control plate is arranged above with multiple groove with sound-absorbing material；Active noise reduction circuit bag
Include photosensitive circuit, sound receives circuit, sound treatment circuit and correcting circuit, and the signal of telecommunication of photosensitive circuit output receives with sound
The input of circuit is connected, and sound receives the signal of circuit output and is connected with the input of sound treatment circuit, acoustic processing electricity
The signal of opposite phase of road output is connected with the input of correcting circuit, at the error value back of correcting circuit output to sound
Reason circuit.
Operation principle and beneficial effect: the present invention is by arranging passive noise control plate and active noise reduction circuit, to room noise
Carry out dual noise reduction, expand the scope of noise reduction, strengthen noise reduction, optimize indoor environment.Meanwhile, active noise reduction circuit sets
There is photosensitive circuit, active noise reduction circuit can be turned on and off according to the change of light, make active noise reduction circuit open by day
Opening work, by active noise reduction circuit and the dual noise reduction of passive noise control plate, indoor people work in relatively quietly environment,
Improve work efficiency；Being in the time of having a rest of people evening, active noise reduction circuit quits work, and is only carried out by passive noise control plate
Noise reduction, it is ensured that the rest environment of people.By light-operated principle, can effectively control the work of active noise reduction circuit in denoising device
Make the time, extend the service life of denoising device.Meanwhile, according to light-operated principle, so automatically can adjust according to the difference in season
The full employment time, with existing by the set time divide compared with, use more flexible changeable.
The preferred version 1 obtaining the improvement of base case, photosensitive circuit includes light sensitive diode and protective resistance, photosensitive
Diode and protective resistance series connection.Light sensitive diode is the device converting optical signal into the signal of telecommunication, so can automatically control
The working time of active noise reduction circuit, the switch as circuit uses.Protective resistance primarily serves the effect of protection circuit.
The preferred version 2 obtaining the improvement of base case, sound treatment circuit includes delay circuit, amplifying circuit, sound
Sound contrast circuit and the speaker for opposite phase output, the outfan of delay circuit is connected with the input of amplifying circuit,
The output of amplifying circuit is amplified signal and is connected with the input of acoustic contrast's circuit, acoustic contrast's circuit output opposite phase telecommunications
Number, and be connected with speaker.The signal of telecommunication can effectively be amplified by amplifying circuit, and contrasts for this waveform, and output is contrary
The signal of telecommunication of phase place, sends sound eventually through speaker, and this sound is contrary with the waveform of noise, cancels out each other, thus plays
The effect of noise-reduction.
Base case is optimized preferred version 3 further that obtain, and the bottom of housing is provided with mounting groove, passive noise control plate
It is slidably connected with mounting groove.So it is easy to passive noise control plate is replaced and keeps in repair, convenient disassembly.
Base case is optimized preferred version 4 further that obtain, and the sidewall of housing is evenly distributed air vent.So
Be conducive to the heat radiation in housing and the propagation of sound.
Base case is optimized preferred version 5 further that obtain, and the bottom of housing is articulated with roller.So can so that
In the movement of denoising device, facilitate handy.
Accompanying drawing explanation
Fig. 1 is the structural representation of indoor of the present invention active noise reducing device embodiment；
Fig. 2 is the active noise reduction circuit block diagram in Fig. 1；
Fig. 3 is the sound treatment circuit block diagram in Fig. 2.
Detailed description of the invention
Below by detailed description of the invention and reference, the present invention is further detailed explanation:
Reference in Figure of description includes: housing 1, roller 2, air vent 3, mounting groove 4, passive noise control plate 5, groove 6,
Active noise reduction circuit 7, photosensitive circuit 8, light sensitive diode 81, protective resistance 82, sound treatment circuit 9, delay circuit 91, amplifies
Circuit 92, acoustic contrast's circuit 93, speaker 94, sound receives circuit 10, correcting circuit 11.
Embodiment is substantially as shown in accompanying drawing 1, Fig. 2 and Fig. 3: include that housing 1, housing 1 use aluminum alloy materials to make, housing
The cross section of 1 is rectangle, and the bottom of housing 1 is articulated with roller 2 by rotating shaft, and roller 2 is positioned at the corner of housing 1, roller 2
Obliquely downward is provided with fixture block, is used for making denoising device stop sliding.The top and bottom of its middle shell 1 are flat runner, the sidewall of housing 1
Evenly distributed have air vent 3, in order to dispels the heat denoising device, extends the service life of denoising device.The bottom of housing 1 leads to
Crossing screw and be fixed with mounting groove 4, the cross section of mounting groove 4 is U-shape structure, slidably connects passive noise control plate 5 in mounting groove 4.
The sidewall of passive noise control plate 5 and housing 1 is pressed close to mutually, offers groove 6, with sound absorber in groove 6 above passive noise control plate 5
Material, such as: acoustical cotton, Plant fiber etc..Being provided with active noise reduction circuit 7 in housing 1, wherein active noise reduction circuit 7 includes sense
Optical circuit 8, sound receive circuit 10, sound treatment circuit 9 and correcting circuit 11, and photosensitive circuit 8 includes light sensitive diode 81 He
Protective resistance 82, light sensitive diode 81 and protective resistance 82 are connected.Sound treatment circuit 9 includes delay circuit 91, amplifying circuit
92, acoustic contrast's circuit 93 and the speaker 94 for opposite phase output, the outfan of delay circuit 91 and amplifying circuit 92
Input be connected, the output of amplifying circuit 92 is amplified signal and is connected with the input of acoustic contrast's circuit 93, and acoustic contrast is electric
Road 93 exports the opposite phase signal of telecommunication, and is connected with speaker 94.
The present invention by day when, light becomes strong, and light sensitive diode 81 receives optical signal, and light sensitive diode 81 is unidirectional
Conducting, active noise reduction circuit 7 is open-minded.Sound receives circuit 10 and indoor sound is collected and is stored, and passes through delay circuit
When 91, after the setting time, acoustical signal continues through amplifying circuit 92, and acoustical signal is exaggerated.Now, by sound comparison
In circuit 93, the waveform of this acoustical signal is processed, and export the acoustical signal of opposite phase waveform, by speaker 94
Passing to indoor, wherein indoor sound cancels each other with this acoustical signal, thus serves the effect of noise reduction.At active noise reduction circuit
While 7 work, noise is absorbed by passive noise control plate 5 also by sound-absorbing material, and by groove 6, carries out sound
Reflection, thus reduce noise, it is ensured that the environment quiet of indoor people.The when of at night, light dies down, light sensitive diode 81
Do not receive optical signal, to this end, active noise reduction circuit 7 quits work, only carry out absorbing and anti-to noise by passive noise control plate 5
Penetrate, reach noise reduction.
Above-described is only embodiments of the invention, and in scheme, the known general knowledge such as concrete structure and/or characteristic is at this
Too much describe.It should be pointed out that, for a person skilled in the art, on the premise of without departing from present configuration, also
May be made that some deformation and improvement, these also should be considered as protection scope of the present invention, and these are real all without affecting the present invention
The effect executed and practical applicability.The protection domain that this application claims should be as the criterion with the content of its claim, description
In detailed description of the invention etc. record the content that may be used for explaining claim.
Claims (6)
1. indoor active noise reducing device, it is characterised in that include housing, passive noise control plate and active noise reduction circuit, described passive
Noise reducing plate is vertically provided at the bottom of housing, and is affixed with the sidewall of housing, and active noise reduction circuit is arranged in housing；Described nothing
Source noise reducing plate is arranged above with multiple groove with sound-absorbing material；Described active noise reduction circuit includes that photosensitive circuit, sound receive
Circuit, sound treatment circuit and correcting circuit, the signal of telecommunication of described photosensitive circuit output and sound receive the input phase of circuit
Even, sound receives the signal of circuit output and is connected with the input of sound treatment circuit, and it is mutually anti-phase that sound treatment circuit exports
The signal of position is connected with the input of correcting circuit, and the error value back of correcting circuit output is to sound treatment circuit.
Indoor active noise reducing device the most according to claim 1, it is characterised in that: described photosensitive circuit includes photosensitive two poles
Pipe and protective resistance, described light sensitive diode and protective resistance series connection.
Indoor active noise reducing device the most according to claim 1, it is characterised in that: described sound treatment circuit includes time delay
Circuit, amplifying circuit, acoustic contrast's circuit and for opposite phase output speaker, the outfan of described delay circuit with put
The input of big circuit is connected, and the output of amplifying circuit is amplified signal and is connected with the input of acoustic contrast's circuit, acoustic contrast
The circuit output opposite phase signal of telecommunication, and be connected with speaker.
4. according to the indoor active noise reducing device described in claim 1 or 2 or 3, it is characterised in that: the bottom of described housing is provided with
Mounting groove, described passive noise control plate is slidably connected with mounting groove.
5. according to the indoor active noise reducing device described in claim 1 or 2 or 3, it is characterised in that: the sidewall of described housing is uniform
It is arranged with air vent.
6. according to the indoor active noise reducing device described in claim 1 or 2 or 3, it is characterised in that: the bottom pivot joint of described housing
There is roller.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610492137.2A CN106057189A (en) | 2016-06-29 | 2016-06-29 | Indoor active noise reduction apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610492137.2A CN106057189A (en) | 2016-06-29 | 2016-06-29 | Indoor active noise reduction apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106057189A true CN106057189A (en) | 2016-10-26 |
Family
ID=57166055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610492137.2A Pending CN106057189A (en) | 2016-06-29 | 2016-06-29 | Indoor active noise reduction apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106057189A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106639013A (en) * | 2016-11-28 | 2017-05-10 | 南京大学 | Mixed soundproof wall |
| CN107909992A (en) * | 2017-12-04 | 2018-04-13 | 成都星达微科技有限公司 | A kind of campus dormitory active noise reduction system of powered stable |
| CN107978309A (en) * | 2017-12-04 | 2018-05-01 | 成都星达微科技有限公司 | A kind of campus dormitory active noise reduction system based on demographics |
| CN107993645A (en) * | 2017-12-04 | 2018-05-04 | 成都星达微科技有限公司 | A kind of campus dormitory active noise reduction system based on Noise Acquisition |
| CN107993644A (en) * | 2017-12-04 | 2018-05-04 | 成都星达微科技有限公司 | A kind of campus dormitory active noise reduction system based on time switch |
| CN108399911A (en) * | 2017-02-06 | 2018-08-14 | 北京市劳动保护科学研究所 | A kind of ventilation and heat sound insulating structure of broad band low frequency |
| CN109994099A (en) * | 2019-03-18 | 2019-07-09 | 佛山市云米电器科技有限公司 | A kind of bedroom active noise reducing device and the bedroom with the active noise reducing device |
| CN111591308A (en) * | 2020-05-14 | 2020-08-28 | 北京交通大学 | Vibration-damping noise-reducing shielding door for urban rail transit station platform |
| CN112164385A (en) * | 2020-09-21 | 2021-01-01 | 深圳市三德大康电子有限公司 | Indoor adjustable equipment of making an uproar that disappears |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2247394Y (en) * | 1995-04-26 | 1997-02-12 | 李纪训 | Light controlled switch |
| CN2772124Y (en) * | 2005-01-18 | 2006-04-12 | 临海爱迪节日装饰品有限公司 | Light-operated switch |
| CN201407533Y (en) * | 2009-05-18 | 2010-02-17 | 厦门海莱照明有限公司 | Optically-controlled induction energy-saving lamp |
| CN101852056A (en) * | 2010-06-28 | 2010-10-06 | 四川正升声学科技有限公司 | Active ventilated and soundproof window |
| CN202102262U (en) * | 2011-05-11 | 2012-01-04 | 王小峰 | Humanized intelligent alarm clock |
| CN202855037U (en) * | 2012-11-17 | 2013-04-03 | 陈世红 | Noise warning device |
| CN202889748U (en) * | 2012-11-16 | 2013-04-17 | 深圳市中航楼宇科技有限公司 | LED (light emitting diode) lamp |
| CN203134364U (en) * | 2012-10-29 | 2013-08-14 | 郑力铭 | Door and window active noise reduction device |
| CN203433806U (en) * | 2013-09-12 | 2014-02-12 | 国家电网公司 | Long-life active sound barrier for transformer station |
| CN204896412U (en) * | 2015-08-14 | 2015-12-23 | 深圳承轩浩业科技发展有限公司 | Intelligence garbage bin with function of making an uproar falls in initiative |
| CN205827914U (en) * | 2016-06-29 | 2016-12-21 | 广州恒成智道信息科技有限公司 | Indoor active noise reducing device |
-
2016
- 2016-06-29 CN CN201610492137.2A patent/CN106057189A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2247394Y (en) * | 1995-04-26 | 1997-02-12 | 李纪训 | Light controlled switch |
| CN2772124Y (en) * | 2005-01-18 | 2006-04-12 | 临海爱迪节日装饰品有限公司 | Light-operated switch |
| CN201407533Y (en) * | 2009-05-18 | 2010-02-17 | 厦门海莱照明有限公司 | Optically-controlled induction energy-saving lamp |
| CN101852056A (en) * | 2010-06-28 | 2010-10-06 | 四川正升声学科技有限公司 | Active ventilated and soundproof window |
| CN202102262U (en) * | 2011-05-11 | 2012-01-04 | 王小峰 | Humanized intelligent alarm clock |
| CN203134364U (en) * | 2012-10-29 | 2013-08-14 | 郑力铭 | Door and window active noise reduction device |
| CN202889748U (en) * | 2012-11-16 | 2013-04-17 | 深圳市中航楼宇科技有限公司 | LED (light emitting diode) lamp |
| CN202855037U (en) * | 2012-11-17 | 2013-04-03 | 陈世红 | Noise warning device |
| CN203433806U (en) * | 2013-09-12 | 2014-02-12 | 国家电网公司 | Long-life active sound barrier for transformer station |
| CN204896412U (en) * | 2015-08-14 | 2015-12-23 | 深圳承轩浩业科技发展有限公司 | Intelligence garbage bin with function of making an uproar falls in initiative |
| CN205827914U (en) * | 2016-06-29 | 2016-12-21 | 广州恒成智道信息科技有限公司 | Indoor active noise reducing device |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106639013A (en) * | 2016-11-28 | 2017-05-10 | 南京大学 | Mixed soundproof wall |
| CN106639013B (en) * | 2016-11-28 | 2019-09-27 | 南京大学 | Mix sound-proof wall |
| CN108399911A (en) * | 2017-02-06 | 2018-08-14 | 北京市劳动保护科学研究所 | A kind of ventilation and heat sound insulating structure of broad band low frequency |
| CN108399911B (en) * | 2017-02-06 | 2024-03-22 | 北京市劳动保护科学研究所 | Ventilating, radiating and sound insulating structure of low-frequency broadband |
| CN107909992A (en) * | 2017-12-04 | 2018-04-13 | 成都星达微科技有限公司 | A kind of campus dormitory active noise reduction system of powered stable |
| CN107978309A (en) * | 2017-12-04 | 2018-05-01 | 成都星达微科技有限公司 | A kind of campus dormitory active noise reduction system based on demographics |
| CN107993645A (en) * | 2017-12-04 | 2018-05-04 | 成都星达微科技有限公司 | A kind of campus dormitory active noise reduction system based on Noise Acquisition |
| CN107993644A (en) * | 2017-12-04 | 2018-05-04 | 成都星达微科技有限公司 | A kind of campus dormitory active noise reduction system based on time switch |
| CN109994099A (en) * | 2019-03-18 | 2019-07-09 | 佛山市云米电器科技有限公司 | A kind of bedroom active noise reducing device and the bedroom with the active noise reducing device |
| CN111591308A (en) * | 2020-05-14 | 2020-08-28 | 北京交通大学 | Vibration-damping noise-reducing shielding door for urban rail transit station platform |
| CN112164385A (en) * | 2020-09-21 | 2021-01-01 | 深圳市三德大康电子有限公司 | Indoor adjustable equipment of making an uproar that disappears |
| CN112164385B (en) * | 2020-09-21 | 2024-02-20 | 深圳市三德大康电子有限公司 | Indoor adjustable noise elimination equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106057189A (en) | Indoor active noise reduction apparatus | |
| CN205827914U (en) | Indoor active noise reducing device | |
| BR0015585A (en) | Electronic sound shielding system, device to acoustically improve an environment, and method to manufacture a curtain for use in the device, and active noise cancellation system | |
| CN203134364U (en) | Door and window active noise reduction device | |
| CN103244465B (en) | For the active fans noise control system of portable computer | |
| CN110473544A (en) | A kind of low-power consumption voice awakening method and device | |
| CN105449934A (en) | Motor noise reduction system and method and range hood | |
| CN107240404B (en) | Noise reduction method for prefabricated cabin type transformer substation | |
| CN205141927U (en) | Motor noise reduction system and range hood | |
| CN204626680U (en) | Generator room noise eliminating silencer | |
| CN106328116A (en) | Robot indoor noise control system | |
| CN202673791U (en) | Muffling fan | |
| CN204732142U (en) | A kind of railway other family expenses noise reduction electronic equipment | |
| CN109559732A (en) | A kind of low noise power supply noise reduction system and method | |
| CN205280207U (en) | Integrate into communication technology's noise decibel detection device | |
| CN107993645A (en) | A kind of campus dormitory active noise reduction system based on Noise Acquisition | |
| CN205142521U (en) | Carbon nanotube film sound source system based on clamp circuit | |
| CN204189448U (en) | A kind of acoustic hood | |
| CN111816154A (en) | Integrated kitchen with function of making an uproar falls in initiative | |
| CN203022250U (en) | Music stairs with novel framework | |
| CN202721748U (en) | Volume adjuster | |
| CN104952441A (en) | Household electronic noise reducing equipment used beside railway | |
| CN107123731B (en) | A kind of piezoelectric ceramic piece and preparation method by collecting noise power generation | |
| CN206877690U (en) | A kind of electronics muffler | |
| CN204377116U (en) | The little cavity audio amplifier of a kind of mix mode low frequency |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20161026 |
|
| RJ01 | Rejection of invention patent application after publication |