CN102291662A - High-sensitivity sound detector made by operation amplifier - Google Patents
High-sensitivity sound detector made by operation amplifier Download PDFInfo
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- CN102291662A CN102291662A CN2011101099025A CN201110109902A CN102291662A CN 102291662 A CN102291662 A CN 102291662A CN 2011101099025 A CN2011101099025 A CN 2011101099025A CN 201110109902 A CN201110109902 A CN 201110109902A CN 102291662 A CN102291662 A CN 102291662A
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Abstract
The invention relates to a high-sensitivity sound detector made by an operation amplifier, which consists of a direct current (DC) power supply, a sound picking circuit, a primary amplification circuit and a secondary amplification circuit, and is characterized in that the type of an operation amplifier integrated circuit (IC) 1 in two stages of amplification circuits is LM324, and a negative feedback resistor R4 and a negative feedback resistor R5 are respectively connected into the two stages of amplification circuits. The circuit of the high-sensitivity sound detector is formed by combining the operation amplifier and a small quantity of discrete elements. The sound detector has the characteristics that the circuit structure is simple, the peripheral elements are few, the cross distortion is little, in addition, the work voltage range is wide, the static current is little, the electricity consumption is little, the distortion is small, and the like. The sound detector has strong directivity and high sensitivity, the sound picking sensitivity of the high-sensitivity sound detector is much higher than that of an ordinary hearing aid, and the high-sensitivity sound detector can detect very weak sound which can not be directly heard by human ears in remote places.
Description
Technical field
The invention belongs to electronic technology and audio frequency amplifying technique field, is to make the high sensitivity sound-detection gear about a kind of with operational amplifier.
Background technology
It is exactly a highly sensitive pick-up to sound-detection gear of the present invention in fact, its circuit structure has a lot of similar places with operation principle to general hearing aids, different is that sound-detection gear has extremely strong directive property and high sensitivity, it is more much higher than common hearing aid sensitivity, can snoop the atomic weak sound that far people from place ear can't directly be heard.The present invention is through field trial, and it can receive eardrum to the greatest extent with the conversation content that move field player and coach have a buzz of talk.It can be widely used in outdoor news interview, production of film and TV, public security officer and handle a case, monitors at a distance and work such as bulk storage plant is antitheft.
Characteristics such as circuit of the present invention uses common operational amplifier LM324 integrated circuit as core parts, and that its circuit has is simple in structure, peripheral component is few and operating voltage range broad, quiescent current are little, little power consumption, distortion are little.
Below describe in detail and of the present inventionly make high sensitivity sound-detection gear related relevant technologies content in manufacturing process with operational amplifier.
Summary of the invention
Goal of the invention and beneficial effect: of the present inventionly make the high sensitivity sound-detection gear with operational amplifier and adopt operational amplifier and a small amount of discrete component to combine.This sound-detection gear has characteristics such as circuit structure is simple, peripheral cell is few, cross distortion is little and operating voltage range is wide, quiescent current is little, little power consumption.Sound-detection gear has extremely strong directive property and high sensitivity, and its common hearing aids of pickup remolding sensitivity wants nice and high many, can snoop far people from place ear easily and can't directly hear atomic weak sound.
Technical scheme: make the high sensitivity sound-detection gear with operational amplifier, be made up of DC power supply DC, pickup circuit, one-level amplifying circuit and second amplifying circuit, the model of operational amplifier IC1 is LM324 in the two-stage amplifying circuit.
Connection features in the composition of each several part circuit and the circuit between the components and parts
The pickup circuit is made up of Electret condenser microphone MIC, resistance R 1, capacitor C 1, its connection features is: the end of the output D connecting resistance R1 of Electret condenser microphone MIC and an end of capacitor C 1, the metal shell termination circuit ground GND of Electret condenser microphone MIC, the anodal VCC of the other end connection circuit of resistance R 1,3 pin of another termination operational amplifier IC1-A of capacitor C 1.
The one-level amplifying circuit is by operational amplifier IC1-A, resistance R 2, resistance R 3, electrochemical capacitor C2, capacitor C 3 and negative feedback resistor R4 form, its connection features is: 2 pin of operational amplifier IC1-A and an end of resistance R 2, one end of resistance R 3 and the positive pole of electrochemical capacitor C2 link to each other, the anodal VCC of the other end connection circuit of resistance R 2, the negative pole connection circuit ground GND of the other end of resistance R 3 and electrochemical capacitor C2,1 pin of the termination operational amplifier IC1-A of negative feedback resistor R4 and an end of capacitor C 3,3 pin of another termination operational amplifier IC1-A of negative feedback resistor R4,13 pin of another termination operational amplifier IC1-D of capacitor C 3.
Second amplifying circuit is made up of operational amplifier IC1-D, negative feedback resistor R5, electrochemical capacitor C4 and earphone SP, its connection features is: the anodal VCC of the 4 pin connection circuits of operational amplifier IC1-D, the 11 pin connection circuit ground GND of operational amplifier IC1-D, 14 pin of operational amplifier IC1-D link to each other with the end of the positive pole of electrochemical capacitor C4, negative feedback resistor R5, connection circuit ground GND behind the negative pole serial connection earphone SP of electrochemical capacitor C4,13 pin of another termination operational amplifier IC1-D of negative feedback resistor R5,12 pin of operational amplifier IC1-D connect 2 pin of operational amplifier IC1-A.
The circuit working principle: Electret condenser microphone MIC requires to be contained in the special poly-sound bobbin in the accompanying drawing, and purpose is assigned direction sound at a distance to be received come, and the sound of other directions is significantly suppressed.Voice signal is transformed into tone currents by Electret condenser microphone MIC, and audio signal is amplified to amplifier by capacitor C 1 coupling then.Amplifier is made up of the two-stage amplifying circuit, the first order is made of one group of operational amplifier among four groups of operational amplifier IC1, the amplification quantity that 120 multiplication benefits are arranged approximately, the second level is made of another group operational amplifier among four groups of operational amplifier IC1, and the amplification quantity of 500 multiplication benefits is arranged approximately.So big multiplication factor is enough to atomic weak audio signal is amplified, and exports earphone SP at last to.Utilize it can snoop the faint sound that far people from place ear can't directly be heard.
Description of drawings
Accompanying drawing is to the invention provides an embodiment circuit working schematic diagram of making the high sensitivity sound-detection gear of operational amplifier; Integrated four groups of operational amplifiers in the operational amplifier IC1 in the accompanying drawing, the present invention has only used two of four operational amplifier LM324 IC1-A, IC1-D wherein.
Embodiment
According to implementing with the circuit working schematic diagram of operational amplifier making high sensitivity sound-detection gear and the components and parts specification requirement of description of drawings and the following stated shown in the accompanying drawing, can realize the present invention.
The selection of components and parts and technical parameter thereof
IC1 is an operational amplifier, and model is selected LM324 for use, and it adopts 14 pin dual-in-line Plastic Package forms.Internal circuit at it comprises four groups of identical operational amplifiers of form, except that power sharing, four groups of amplifiers are separate, and present embodiment has only been used two of IC1-A, IC1-D among four groups of operational amplifier LM324;
MIC is an Electret condenser microphone, requires to select for use two ends output type Electret condenser microphone, and its drain electrode be the audio signal output end D of microphone MIC, the metal shell end of the Electret condenser microphone connection circuit ground GND afterwards that links to each other with source S.Field effect transistor is connected into drain electrode is output, its output signal has certain voltage gain, can make the sensitivity of Electret condenser microphone higher.Electret condenser microphone MIC select for use the CM-18W type (the high sensitivity Electret condenser microphone of Ф 10mm * 6.5mm), its sensitivity is divided into five retainings, represents with color dot respectively, present embodiment is selected the product of white point for use;
Resistance uses RTX-1/16W type metalfilmresistor, and the resistance of resistance R 1～R3 is 12K Ω; The resistance of resistance R 4, R5 is 910K Ω;
C1, C3 select electric capacity of the dacron for use, and its capacity is respectively 0.47 μ F, 0.33 μ F;
C2, C4 select the withstand voltage electrochemical capacitor of 16V that is, its capacity is respectively 22 μ F, 470 μ F;
SP is an earphone, selects moving coil earphone for use, and its impedance is 36 Ω, and the impedance that earphone is selected for use is more little, and the power of audio signal output is big more, but tonequality slightly descends;
The voltage of DC power supply DC is 6～9V, and available four joints or the series connection of five batteries are used.
Circuit production and debugging
The installation of Electret condenser microphone MIC should be as much as possible away from the two-stage amplifying circuit, the lead-in wire of Electret condenser microphone MIC should adopt shielding conductor and unsuitable long, purpose is to reduce the interference that the previous stage amplifying signal is caused back one-level amplifying circuit, otherwise causing easily that extraneous various noise signal is responded to lead-out wire causes audio distortion, even causes disagreeable howling.For further reducing the interference of electromagnetic signal, require the shell connection circuit ground GND of Electret condenser microphone MIC.
For Electret condenser microphone MIC can be received assigned direction sound at a distance, Electret condenser microphone MIC should be contained in the special poly-sound bobbin, and requires the appearance of poly-sound bobbin should be attached with sound-absorbing material.
Conscientiously detect the performance of each components and parts, each components and parts all can not wrong, pay special attention to polarized component and can not connect instead, as DC power supply DC, Electret condenser microphone MIC and electrochemical capacitor etc., and will guarantee the welding quality of components and parts.
When circuit debugging, if find that circuit working is stable inadequately, at first can take to strengthen filtering to DC power supply DC, secondly be suitably to reduce the resistance of resistance R 4 in the negative-feedback circuit or resistance R 5 and reduce gain amplifier.Improve the operating voltage of DC power supply DC, can effectively increase the power output of sound-detection gear sensitivity and audio signal.
High because of the sensitivity of this sound-detection gear, when circuit debugging, cut and can not be too near to Electret condenser microphone MIC speech! General speech requires more than 6m apart from Electret condenser microphone MIC.
Claims (1)
1. make the high sensitivity sound-detection gear with operational amplifier for one kind, be made up of DC power supply DC, pickup circuit, one-level amplifying circuit and second amplifying circuit, the model of operational amplifier IC1 is LM324 in the two-stage amplifying circuit, it is characterized in that:
The pickup circuit is made up of Electret condenser microphone MIC, resistance R 1, capacitor C 1, its connection features is: the end of the output D connecting resistance R1 of Electret condenser microphone MIC and an end of capacitor C 1, the metal shell termination circuit ground GND of Electret condenser microphone MIC, the anodal VCC of the other end connection circuit of resistance R 1,3 pin of another termination operational amplifier IC1-A of capacitor C 1.
The one-level amplifying circuit is by operational amplifier IC1-A, resistance R 2, resistance R 3, electrochemical capacitor C2, capacitor C 3 and negative feedback resistor R4 form, its connection features is: 2 pin of operational amplifier IC1-A and an end of resistance R 2, one end of resistance R 3 and the positive pole of electrochemical capacitor C2 link to each other, the anodal VCC of the other end connection circuit of resistance R 2, the negative pole connection circuit ground GND of the other end of resistance R 3 and electrochemical capacitor C2,1 pin of the termination operational amplifier IC1-A of negative feedback resistor R4 and an end of capacitor C 3,3 pin of another termination operational amplifier IC1-A of negative feedback resistor R4,13 pin of another termination operational amplifier IC1-D of capacitor C 3.
Second amplifying circuit is made up of operational amplifier IC1-D, negative feedback resistor R5, electrochemical capacitor C4 and earphone SP, its connection features is: the anodal VCC of the 4 pin connection circuits of operational amplifier IC1-D, the 11 pin connection circuit ground GND of operational amplifier IC1-D, 14 pin of operational amplifier IC1-D link to each other with the end of the positive pole of electrochemical capacitor C4, negative feedback resistor R5, connection circuit ground GND behind the negative pole serial connection earphone SP of electrochemical capacitor C4,13 pin of another termination operational amplifier IC1-D of negative feedback resistor R5,12 pin of operational amplifier IC1-D connect 2 pin of operational amplifier IC1-A.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101099025A CN102291662A (en) | 2011-04-28 | 2011-04-28 | High-sensitivity sound detector made by operation amplifier |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101099025A CN102291662A (en) | 2011-04-28 | 2011-04-28 | High-sensitivity sound detector made by operation amplifier |
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| CN102291662A true CN102291662A (en) | 2011-12-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2011101099025A Pending CN102291662A (en) | 2011-04-28 | 2011-04-28 | High-sensitivity sound detector made by operation amplifier |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102355621A (en) * | 2011-06-01 | 2012-02-15 | 刘喆 | High-sensitivity sound detector manufactured by operational amplifiers |
| CN104977869A (en) * | 2015-07-15 | 2015-10-14 | 成都陌云科技有限公司 | Special processor in intelligent sound recognition robot |
-
2011
- 2011-04-28 CN CN2011101099025A patent/CN102291662A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102355621A (en) * | 2011-06-01 | 2012-02-15 | 刘喆 | High-sensitivity sound detector manufactured by operational amplifiers |
| CN104977869A (en) * | 2015-07-15 | 2015-10-14 | 成都陌云科技有限公司 | Special processor in intelligent sound recognition robot |
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| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20111221 |