CN100346669C - Non-microphone voice transmission device - Google Patents
Non-microphone voice transmission device Download PDFInfo
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- CN100346669C CN100346669C CNB031510329A CN03151032A CN100346669C CN 100346669 C CN100346669 C CN 100346669C CN B031510329 A CNB031510329 A CN B031510329A CN 03151032 A CN03151032 A CN 03151032A CN 100346669 C CN100346669 C CN 100346669C
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Abstract
The present invention belongs to the filed of information technology, and more specifically, the present invention relates to voice transmission equipment composed of optical fiber passive components. The voice transmission equipment can cancel a frequently used microphone and use voice signals to directly modulate optical signals. The voice transmission equipment has the advantages of high sensitivity (a receiver can be a plurality of meters away from a sound source), high stability, high security and no influence of electromagnetic radiation. The voice transmission equipment can be widely applied to class teaching, conferences, broadcasting stations, plays, microsound detection and civil or military occasions.
Description
Technical field
The invention belongs to the voice signal transmission field, be specifically related to a kind of no microphone speech transmission device.
Technical background
1875 Bel (Alexander Bell) invented telephone set, for the first time realized that electricity consumption transmits the analog communication of acoustic information.In communication process, the electric current in the lead constantly changes along with the power of sound and speed, promptly comes the variation of simulated sound power with the variation of current strength.
The course of work of phone can be summarized as follows: the sound wave of people's speech vibrates the vibrating membrane in the transmitter, and near the changes of magnetic field causing in the coil causes that then electric current changes; This is loaded with the transmission of the electric current of signal through electric wire, produces changes of magnetic field in the coil of receiver, promotes the film in the receiver then, and sound is reappeared in receiver.
Same principle can be used in public address equipment.(microphone microphone) replaces transmitter, and replaces receiver with the loud speaker with certain amplification (loudspeaker), just can work to use microphone herein.This is a well known fact: public address equipment, used very extensively, even can say and enrich human daily life to a certain extent.
After optical fiber development, replaced by broadband, anti-interference, lightweight optical cable as the cable of message transmission part.But this equipment still needs the link, particularly microphone of " sound → electricity → light → electricity → sound " not to lack, and also needs electrooptic modulator then.
Because sensitivity relation, sound source and microphone can not be at a distance of far away excessively.General microphone beyond 30～50 centimetres of sound sources, signal to noise ratio with regard to little to can not using, so produce during the having of microphone inconvenient.As use the fixedly public address equipment of microphone in the classroom, then teacher often will constantly change the position (when particularly projecting apparatus being arranged) of standing when giving lessons; If the use wireless microphone, then the microphone clip on that clothes will change its image to a certain extent.Particularly conspicuous when in stage or TV station, showing.A lot of for this reason people are being devoted to research and how are cancelling this microphone.
The present invention adopts fiber optic passive device to constitute interference system, has improved sensitivity greatly.Particularly importantly, under the situation of any electric link (sound → electricity, electricity → light), realize the long-distance transmissions of voice signal with the direct modulated light signal of voice signal.Because the operation principle of system is different fully with traditional light intensity modulation mode, increased the stable and repeatable of system works greatly.
Summary of the invention
The objective of the invention is to propose a kind of highly sensitive, effective, no microphone speech transmission device amplifies.
The no microphone voice device transmission that the present invention proposes is made up of sound reception probe, all-fiber interferometer and treatment circuit (being also primary circuit of voice signal), as shown in Figure 1.Wherein, sound reception probe 4 is wrapped in constituting on the responsive elastomer of the atmospheric pressure variation of sound generating by monomode fiber; All-fiber interferometer 2 is made of fiber coupler, and sound reception device 4 connects two port pins that place fiber coupler, specifically sees shown in Fig. 2,3; Treatment circuit is made up of preposition low noise signal amplifier and power amplifier.
Fig. 1 is the fundamental diagram of no microphone audio amplifying equipment.Voice signal is not by sound reception device (being common microphone), the physical quantity of carrying acoustic information is gathered by all-fiber interferometer and is carried out detection and handle, the voice signal of gained reduces the voice signal that reducible one-tenth is original through the treatment circuit signal after tentatively extracting.The key of whole device is that the sound reception probe is to the collection sensitivity of voice signal and the detection effect of all-fiber interferometer.The sensitivity of receiving transducer has determined the no microphone transmission range of whole device.
Sound wave transmits in air and will cause that the air ambient acoustic pressure changes, and utilizes this physical characteristic, and the present invention has designed by the surface and twined the elastomer (as column) of monomode fiber as the sound reception device.Acoustic pressure changes the change that will cause elastomer shape, and according to elasto-optical effect, fiber lengths and refractive index will change.Defining this change in optical path length amount that causes owing to the fiber lengths and the refraction index changing of acoustic pressure formation is L, and L and acoustic pressure are proportional.
According to the operation principle of all-fiber interferometer, the interferometric phase (t) that the variation of optical path difference forms in interference system can be expressed as
In the following formula,
The change in optical path length rate that the expression acoustic pressure causes, relevant with optical fiber bullet light characteristic with the elastic cylinder characteristic, be proportional to acoustic velocity V (t).
According to the all-fiber interferometer characteristic that is made of 3 * 3 fiber couplers, interference signal can be expressed as respectively
I
1(t)＝I
0cos[(t)+
0] (2)
I
2(t)＝I
0cos[(t)-
0] (3)
According to top two formulas, can calculate interferometric phase, obtain (t) by formula (1), thereby the physical quantity L ' that obtains reflecting wave speed is (t), by integration, obtains the acoustic pressure that sound wave causes, finally realize the voice signal reduction.
Treatment circuit 9 (being also primary circuit of voice signal) is made up of preposition low noise amplifier (being voltage amplifier circuit) 11 and main amplifier (being power amplifier) 12 two parts, as shown in Figure 5.The effect of preamplifier 11 is faint voice signal to be carried out low noise amplify and the adjustment of volume tonequality, and provides input signal to main amplifier 12.Main amplifier 12 provides and drives the loud speaker power demand, and its final stage requires the sizable power of output, so adopt power amplification circuit.
The present invention adopts fiber optic passive device to constitute interference system, under the situation of electric link, directly realizes the modulation of voice signal to light signal, transmits then, detection and processing, is reduced into original voice signal.Because the common microphone of remolding sensitivity of complete machine wants high hundreds of to several thousand times, therefore only need outside several meters, to place one or several sound reception device, just can obtain graceful acoustics.
Characteristics of the present invention are to need not microphone, and the distortion factor is little, therefore all can use at aspects such as classroom instruction, meeting, broadcasting, performance, little acoustic detections.Simultaneously because the anti-electromagnetic interference of optical fiber itself and radiation resistance is good, good confidentiality (anti-eavesdrop), be more suitable in the open air with use in particular cases such as military exercises.
Description of drawings
Fig. 1 fundamental diagram.
The interference system that Fig. 2 is made of 3 * 3 fiber couplers.
The interference system that Fig. 3 is made of 2 * 2 fiber couplers.
The formation block diagram of Fig. 4 treatment circuit.
The preposition low noise amplifier of Fig. 5.
Fig. 6 main amplifier.
Fig. 7 sound waveform.
Waveform after Fig. 8 system modulation.
Waveform after Fig. 9 reduction.
Number in the figure: 1 is stabilized light source, and 2 is fiber coupler, and 3 is fibre delay line, and 4 are the sound reception device, 5,6 is photodetector, and 7,8 is two ports of fiber coupler, and 9 is treatment circuit, 10 is loudspeaker, and 11 is the pre-amplification circuit of treatment circuit, and 12 is main amplifier.
Embodiment
In this nothing microphone voice transfer equipment, all-fiber interferometer has multiple implementation:
Example 1: be made of 3 * 3 fiber couplers, its structure is seen shown in Figure 2.
Light that stabilized light source 1 sends connects through wire jumper FC/PC, enters 3 * 3 fiber couplers 2, and after beam split, the light that sends from the port 7 of coupler is transferred to port 8 through sound reception device 4 more clockwise through behind the fibre delay line 3.The light of port 8 is earlier by being transferred to port 7 by fibre delay line 3 inhours again behind the sound reception device 4.Two light beams form the light signal that carries sound reception device physical feature in 3 * 3 fiber couplers 2, be detected device 5,6 and receive.By the inverting interference signal, finally obtain the physical characteristic of sound reception device 4.
Example 2: be made of 2 * 2 fiber couplers, its structure as shown in Figure 3.
The light that stabilized light source 1 sends is through 2 * 2 fiber couplers 2, after beam split, the light of port 7 is transferred to port 8 through behind the fibre delay line 3 clockwise through sound reception device 4, and the light of port 8 is transferred to port 7 by sound reception device 4 backs by fibre delay line 3 inhours earlier.Two light beams form the light signal that carries sound reception device physical feature in 2 * 2 fiber couplers 2, be detected device 5 and receive.By the inverting interference signal, finally obtain the physical characteristic of sound reception device 4.
Example 1 is identical with the operation principle of 2 two kinds of structures of example, just in the structure shown in the example 1 (Fig. 2), has two-way to have the output signal of certain phase difference; And in the structure shown in the example 2 (Fig. 3), have only one tunnel output signal.Just output signal is under identical work light situation, and is big 3/2 times.And output signal is compared with formula (2), does not have initial phase 0.
The output signal of photodetector 5 is coupled into triode G1 by capacitor C 1 and resistance R 1, resistance R 2 provides bias voltage, be coupled into the amplifying circuit that constitutes by resistance R 3, R4, capacitor C 4 and triode G2 from the signal of triode G1 output by capacitor C 3 and C2, arrive power amplification circuit by capacitor C 5 output signals at last.The supply power voltage of amplification system can be 12 volts of voltages of direct current.
Audio signal by preposition amplification enters the coupling circuit of being made up of two constant-current source M1 and M2, two diode D1 and D2 with the form of difference, by the power amplifying part that constitutes by two NPN triode G3 and G4, export powerful audio signal at last, promote loudspeaker or stereo set, realize the playing process of voice signal.Owing to will obtain big output, final stage adopts the class B push-pull circuit.When with transistor or FET forming circuit, often adopt SEPP (Signal-ended push pull) circuit.Two transistors of SEPP circuit are the half period of an amplification input signal respectively, and synthesizes a signal at output, because two transistors are in parallel to load, and power supply is connected, so can connect the little load of impedance.Therefore, it can directly connect loud speaker without output transformer, becomes OTL (output transformer less) circuit, makes frequency characteristic and distortion rate improve.
The utility model is tested the performance of system.All-fiber interferometer adopts 3 * 3 couplers, and as shown in Figure 2, treatment circuit adopts Fig. 5 and circuit shown in Figure 6.It is the LED source of 1.31 μ m, spectrum width 20nm that system uses centre wavelength.Leaving the sound reception device at source speech signal is 4 meters, the sound signal waveform that system acquisition arrives as shown in Figure 7, through the signal waveform after the system modulation as shown in Figure 8; The waveform of reduction as shown in Figure 9.Can see that full optical fiber interferometer has well been finished the collection of voice signal, realize no microphone audio amplifying function.
Claims (5)
1, a kind of no microphone speech transmission device, it is characterized in that forming by sound reception probe, all-fiber interferometer and voice signal reduction circuit, wherein, sound reception probe (4) is wrapped in constituting on the responsive elastomer of the atmospheric pressure variation of sound generating by monomode fiber; All-fiber interferometer (2) is made of fiber coupler, and sound reception device (4) connects two port pins that place fiber coupler, and voice signal also primary circuit is made up of preposition low noise signal amplifier and main amplifier.
2, device according to claim 1 is characterized in that all-fiber interferometer is made of 3 * 3 fiber couplers.
3, device according to claim 1 is characterized in that all-fiber interferometer is made of 2 * 2 fiber couplers.
4, device according to claim 1, it is characterized in that in the described preposition low noise amplifying circuit, connect to form signal coupling circuit by triode G1, resistance R 1 and R2, capacitor C 1 through circuit, connect to form amplifier section by triode G2, resistance R 3 and R4, capacitor C 4 through circuit, coupling circuit is connected with amplifier section with C3 by capacitor C 2, optical signal detection device (5) is connected in the loop of preposition low noise amplifying circuit, by capacitor C 5 output signals to power amplification circuit (12).
5, device according to claim 1, it is characterized in that in the described main amplifier, connect to form coupling circuit by constant-current source M1, diode D1, diode D2, constant-current source M2 circuit successively, triode G3, resistance R 5 and R6, triode G4 circuit successively connect to form amplifier section, and its final stage adopts the class B push-pull circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB031510329A CN100346669C (en) | 2003-09-18 | 2003-09-18 | Non-microphone voice transmission device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB031510329A CN100346669C (en) | 2003-09-18 | 2003-09-18 | Non-microphone voice transmission device |
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| Publication Number | Publication Date |
|---|---|
| CN1525792A CN1525792A (en) | 2004-09-01 |
| CN100346669C true CN100346669C (en) | 2007-10-31 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB031510329A Expired - Lifetime CN100346669C (en) | 2003-09-18 | 2003-09-18 | Non-microphone voice transmission device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11333573B2 (en) | 2014-08-28 | 2022-05-17 | Adelos, Inc. | Noise management for optical time delay interferometry |
| USRE49680E1 (en) | 2013-08-12 | 2023-10-03 | Adelos, Llc | Systems and methods for spread spectrum distributed acoustic sensor monitoring |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4714299B1 (en) * | 2010-10-14 | 2011-06-29 | 彰 福島 | Pseudo triode characteristic amplifying device for acoustic and push-pull amplifier for pseudo triode characteristic for acoustic |
| CN102355621A (en) * | 2011-06-01 | 2012-02-15 | 刘喆 | High-sensitivity sound detector manufactured by operational amplifiers |
| CN109348368A (en) * | 2018-12-12 | 2019-02-15 | 黄高 | A kind of every class way system for protecting student's sense of hearing |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01168199A (en) * | 1987-12-24 | 1989-07-03 | Mitsubishi Heavy Ind Ltd | Optical audio microphone |
| JPH10150692A (en) * | 1996-11-18 | 1998-06-02 | N H K Technical Service:Kk | Digital wireless microphone device, transmitter and receiver |
| JP2002101486A (en) * | 2000-05-23 | 2002-04-05 | Daimler Chrysler Ag | Audio system |
| CN2678297Y (en) * | 2003-09-18 | 2005-02-09 | 复旦大学 | Voice transmission device without microphone |
-
2003
- 2003-09-18 CN CNB031510329A patent/CN100346669C/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01168199A (en) * | 1987-12-24 | 1989-07-03 | Mitsubishi Heavy Ind Ltd | Optical audio microphone |
| JPH10150692A (en) * | 1996-11-18 | 1998-06-02 | N H K Technical Service:Kk | Digital wireless microphone device, transmitter and receiver |
| JP2002101486A (en) * | 2000-05-23 | 2002-04-05 | Daimler Chrysler Ag | Audio system |
| CN2678297Y (en) * | 2003-09-18 | 2005-02-09 | 复旦大学 | Voice transmission device without microphone |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE49680E1 (en) | 2013-08-12 | 2023-10-03 | Adelos, Llc | Systems and methods for spread spectrum distributed acoustic sensor monitoring |
| US11333573B2 (en) | 2014-08-28 | 2022-05-17 | Adelos, Inc. | Noise management for optical time delay interferometry |
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| Publication number | Publication date |
|---|---|
| CN1525792A (en) | 2004-09-01 |
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Application publication date: 20040901 Assignee: Dongguan advanced optical fiber Application Technology Research Institute Co.,Ltd. Assignor: Fudan University Contract record no.: 2018310000016 Denomination of invention: Non-microphone voice transmission device Granted publication date: 20071031 License type: Exclusive License Record date: 20180529 |
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Granted publication date: 20071031 |