CN217116403U - Automatic volume control circuit for power amplification microphone and electronic equipment - Google Patents
Automatic volume control circuit for power amplification microphone and electronic equipment Download PDFInfo
- Publication number
- CN217116403U CN217116403U CN202123029680.4U CN202123029680U CN217116403U CN 217116403 U CN217116403 U CN 217116403U CN 202123029680 U CN202123029680 U CN 202123029680U CN 217116403 U CN217116403 U CN 217116403U
- Authority
- CN
- China
- Prior art keywords
- resistor
- signal
- circuit
- microphone
- input
- 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.)
- Active
Links
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model discloses a power amplifier microphone volume automatic control circuit and electronic equipment, power amplifier microphone volume automatic control circuit includes: the microphone amplifying circuit is used for outputting the amplified microphone signal; a signal detection circuit that outputs a high level when a microphone signal is detected; a gain control circuit for controlling an amplification gain of a music signal; and the signal mixing circuit is used for mixing the microphone signal and the music signal and then outputting the mixture in an inverted manner. The utility model discloses an adopt automatic control circuit, with the gain control part of first detected signal output for music signal to music signal's gain reduces when the sound is input, realizes that the background music of sound system output reduces when the microphone is spoken, makes microphone sound discern more easily.
Description
Technical Field
The utility model relates to a microphone control technology field, in particular to power amplifier microphone volume automatic control circuit and electronic equipment.
Background
The sound box has long become one of the necessary electrical appliances for people in daily life. At present, when the volume of playing music is adjusted by a common sound system on the market, two adjusting modes are usually provided, one mode is to adjust the sound power amplifier, the volume adjusting knob of the power amplifier needs to be rotated for adjusting the sound power amplifier, a vehicle-mounted power amplifier is generally arranged in a trunk, the yacht power amplifier is generally arranged at a position where water is not easy to enter, and the adjustment is inconvenient; another way is to adjust on the audio source: for example, there is on-vehicle CD in the car console, adjust the volume knob on the on-vehicle CD also can reduce the volume, but the user can influence safe driving in the operation console of in-process of traveling, and yacht power amplifier CD machine also generally installs in the region of being difficult to intake, adjusts inconveniently, still influences simultaneously and controls the yacht.
In practical use, when people use the sound system with the microphone function, sometimes the use scenes that the microphone needs to be used for speaking when music is played or voice is broadcasted are met, but the speaking content of the microphone and the played music are overlapped, so that the speaking content of the microphone is not easy to identify. Therefore, in order to make the speaking content of the microphone clearer, the music played needs to be reduced or even turned off.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a power amplifier microphone volume automatic control circuit aims at realizing that the microphone sound is discerned more easily.
In order to achieve the above object, the utility model provides a power amplifier microphone volume automatic control circuit includes:
the input end of the microphone amplifying circuit is connected with a first input end of a microphone signal; the microphone amplifying circuit is used for amplifying and outputting an input microphone signal;
the input end of the signal detection circuit is connected with the second input end of the microphone signal; the signal detection circuit is used for outputting a first detection signal when detecting that a voice signal is input into the microphone;
the first input end of the gain control circuit is used for inputting music signals, the second input end of the gain control circuit is connected with the output end of the signal detection circuit, the gain control circuit is used for performing gain amplification on the input music signals and then outputting the amplified music signals, and when the first detection signal is received, the gain of the input music signals is reduced;
the first input end of the signal mixing circuit is connected with the output end of the microphone amplifying circuit, the second input end of the signal mixing circuit is connected with the output end of the gain control circuit, and the signal mixing circuit is used for mixing the amplified microphone signal and the amplified music signal and then outputting the mixed signal to the power amplifier circuit to drive the loudspeaker to produce sound.
Optionally, the microphone amplification circuit comprises:
the input end of the in-phase amplifying circuit is the input end of the microphone amplifying circuit, the output end of the in-phase amplifying circuit outputs an in-phase amplified microphone signal, and the in-phase amplifying circuit is used for amplifying the input microphone signal in phase;
the microphone signal processing circuit comprises a first inverting amplifying circuit, wherein the input end of the first inverting amplifying circuit is connected with the output end of the in-phase amplifying circuit, the output end of the first inverting amplifying circuit outputs a microphone signal after inverting amplification, and the first inverting amplifying circuit is used for inverting-amplifying the microphone signal after in-phase amplification and outputting the microphone signal.
Optionally, the signal detection circuit includes a first triode, a second triode, a fifth capacitor, a sixth capacitor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, and an eleventh resistor;
the first end of the seventh resistor is a signal input end of the signal detection circuit, the second end of the seventh resistor is respectively connected with the first end of the eighth resistor and the base electrode of the first triode, the emitter of the first triode is respectively connected with the second end of the eighth resistor and the first end of the tenth resistor, the collector of the first triode is connected with the base of the second triode through the ninth resistor, the collector of the second triode is respectively connected with a direct current power supply and the first end of the fifth capacitor, and is connected with a first input end of a microphone signal through the eleventh resistor, a second end of the fifth capacitor is connected with a first end of the sixth capacitor, and an emitting electrode of the second triode is connected with the second end of the sixth capacitor, and an emitting electrode of the second triode is an output end of the signal detection circuit.
Optionally, the signal detection circuit further comprises a voltage stabilizing circuit;
the voltage stabilizing circuit comprises a voltage stabilizing diode and a seventh capacitor, wherein the cathode of the voltage stabilizing diode is respectively connected with the emitter of the first triode, the second end of the eighth resistor, the first end of the tenth resistor and the first end of the seventh capacitor, and the anode of the voltage stabilizing diode is respectively grounded with the second end of the seventh capacitor.
Optionally, the gain control circuit comprises:
the input end of the second inverting amplifying circuit is used for inputting music signals, the output end of the second inverting amplifying circuit is the output end of the gain control circuit, and the second inverting amplifying circuit is used for inverting and amplifying the input music signals;
and the input end of the feedback adjusting circuit is connected with the output end of the signal detection circuit, the output end of the feedback adjusting circuit is connected with the negative feedback end of the second inverting amplifying circuit, and the feedback adjusting circuit is used for controlling the amplification gain of the second inverting amplifying circuit.
Optionally, the second inverting amplifying circuit includes a third operational amplifier, a third coupler, a variable resistor, an eighth capacitor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, and a fifteenth resistor;
a first end of the twelfth resistor is used for inputting a music signal, a second end of the twelfth resistor is connected with a first end of the potentiometer, the second end of the potentiometer is connected with the first end of the potentiometer, the second end of the potentiometer is grounded, a moving end of the potentiometer is connected with a first end of the third coupler, a second end of the third coupler is connected with a first end of the fourteenth resistor, a second end of the fourteenth resistor is connected to the inverting input terminal of the third operational amplifier, a first end of the eighth capacitor, and a first end of the fifteenth resistor, the non-inverting input end of the third operational amplifier is grounded, the output end of the third operational amplifier is respectively connected with the second end of the eighth capacitor and the second end of the fifteenth resistor, and the output end of the third operational amplifier outputs music signals after reverse-phase amplification.
Optionally, the feedback regulation circuit includes a fourth coupler, a sixteenth resistor, and a seventeenth resistor;
the cathode of the light emitting diode of the fourth coupler is grounded, the anode of the light emitting diode of the fourth coupler is connected with the first end of the seventeenth resistor, the second end of the seventeenth resistor is the input end of the second inverting amplifying circuit, the first end of the photoresistor of the fourth coupler is connected with the first end of the sixteenth resistor, the second end of the photoresistor of the fourth coupler is respectively connected with the output end of the third operational amplifier, the second end of the eighth capacitor and the second end of the fifteenth resistor, and the first end of the fifteenth resistor is respectively connected with the inverting input end of the third operational amplifier, the first end of the eighth capacitor and the second end of the sixteenth resistor.
Optionally, the signal mixing circuit includes a fourth operational amplifier, a ninth capacitor, an eighteenth resistor, a nineteenth resistor, and a twentieth resistor;
the first end of eighteenth resistance does the first input of signal hybrid, the second end of eighteenth resistance with the inverting input of fourth operational amplifier the first end of ninth electric capacity the second end of nineteenth resistance reaches the first end of twentieth resistance is connected respectively, the noninverting input ground connection of fourth operational amplifier, the output of fourth operational amplifier with the second end of ninth electric capacity reaches the second end of twentieth resistance is connected respectively, the output of fourth operational amplifier is the output of signal hybrid, the first end of nineteenth resistance does the second input of signal hybrid for connect the microphone sound signal.
In order to achieve the above object, the utility model discloses still provide an electronic equipment, reach as above including power amplifier circuit, speaker power amplifier microphone volume automatic control circuit, power amplifier microphone volume automatic control circuit's signal output part with the speaker sound production is redriven after power amplifier circuit connects.
The utility model discloses technical scheme detects the microphone through signal detection circuit and has when voice signal input, transfers the gain of input music signal through gain control circuit to hang down, has reduced the signal volume of input music promptly for the volume of the microphone sound of the relative broadcast of the volume of the music signal that the speaker finally broadcasts reduces, thereby makes microphone sound discern more easily.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
Fig. 1 is a circuit functional block diagram of an embodiment of the automatic volume control circuit of the power amplifier microphone of the present invention;
fig. 2 is a schematic diagram of a circuit structure of an embodiment of the automatic volume control circuit of the power amplifier microphone of the present invention;
fig. 3 is a schematic diagram of a circuit structure according to another embodiment of the automatic volume control circuit of the power amplifier microphone of the present invention.
The reference numbers illustrate:
| reference numerals | Name (R) | Reference numerals | Name (R) |
| 10 | Microphone amplifying |
40 | |
| 11 | In-phase amplifying circuit | U1～U4 | First to fourth |
| 12 | First inverting amplifier circuit | PC1～PC4 | First to |
| 20 | Signal detection circuit | Q1～Q2 | First to |
| 21 | Voltage stabilizing circuit | D1 | |
| 30 | Gain control circuit | VR1 | Potentiometer with |
| 31 | Second inverting amplifier circuit | C1～C9 | First to |
| 32 | Feedback regulation circuit | R1～R20 | First to twentieth resistors |
The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
It should be noted that, if directional indications (such as upper, lower, left, right, front and rear … …) are involved in the embodiments of the present invention, the directional indications are only used for explaining the relative position relationship between the components, the motion situation, etc. under a certain posture (as shown in the drawings), and if the certain posture is changed, the directional indications are changed accordingly.
In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.
The utility model provides a power amplifier microphone volume automatic control circuit is applicable to the sound system.
Referring to fig. 1, in an embodiment, the utility model provides a power amplifier microphone volume automatic control circuit includes:
the microphone amplification circuit 10, an input end of the microphone amplification circuit 10 is connected with a first input end of a microphone signal, and an output end of the microphone amplification circuit 10 outputs the amplified microphone signal, so as to amplify and output the input microphone signal;
the input end of the signal detection circuit 20 is connected with a second input end of the microphone signal; the signal detection circuit 20 is configured to output a first detection signal when detecting that a voice signal is input into the microphone;
a gain control circuit 30, a first input end of the gain control circuit 30 is used for inputting a music signal, a second input end of the gain control circuit 30 is connected with an output end of the signal detection circuit 20, the gain control circuit 30 is used for performing gain amplification on the input music signal and outputting the amplified music signal, and when receiving the first detection signal, reducing the gain of the input music signal;
the signal mixing circuit 40, the first input of signal mixing circuit 40 with the output of microphone amplifier circuit 10 is connected, the second input of signal mixing circuit 40 with the output of gain control circuit 30 is connected, signal mixing circuit 40 is used for exporting the speaker sound production again behind the power amplifier circuit after microphone signal after will amplifying and music signal mix.
In this embodiment, the amplitude of the input music signal is limited, so that the microphone sound is easier to identify. It is needless to say that whether the second input terminal of the microphone is inputted with the voice signal is detected before the inputted music signal is amplitude-limited, therefore, the present embodiment limits the connection of the output terminal of the signal detection circuit 20 and the second input terminal of the microphone to detect whether the microphone is inputted with the voice signal, and when it is determined that the current circuit is inputted with the microphone signal, the gain of the inputted music signal is adjusted to be low, that is, the volume of the music signal is reduced relative to the volume of the played microphone sound, so that the microphone sound is easier to be identified.
In this embodiment, when the signal detection circuit 20 detects that a voice signal is input to the microphone, the gain control circuit 30 turns down the gain of the input music signal, that is, the volume of the input music signal is reduced, so that the volume of the music signal finally played by the speaker is reduced relative to the volume of the microphone sound played, and the microphone sound is easier to identify.
Referring to fig. 2, in an embodiment, the microphone amplification circuit 10 includes:
the input end of the in-phase amplifying circuit 11 is the input end of the microphone amplifying circuit 10, the output end of the in-phase amplifying circuit 11 outputs a microphone signal after in-phase amplification, and the in-phase amplifying circuit 11 is used for performing in-phase amplification on the input microphone signal;
the input end of the first inverting amplifying circuit 12 is connected with the output end of the in-phase amplifying circuit 11, the output end of the first inverting amplifying circuit 12 outputs a microphone signal after inverting amplification, and the first inverting amplifying circuit 12 is used for inverting-amplifying the input microphone signal after in-phase amplification and outputting the microphone signal;
specifically, the non-inverting amplification circuit 11 includes a first coupler PC1, a first operational amplifier U1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4;
a first terminal of the first coupler PC1 is connected to a first terminal of a first capacitor C1, a first terminal of a first resistor R1 and a first microphone signal input terminal, a second terminal of the first capacitor C1 is connected to a second terminal of the first resistor R1 and ground, a second terminal of the first coupler PC1 is connected to a non-inverting input terminal of the first operational amplifier U1 and a first terminal of the second resistor R2, the second end of the second resistor is connected to the first end of the second capacitor C2 and ground, respectively, the second end of the second capacitor C2 is connected to the first end of the third resistor R3, a second end of the third resistor R3 is connected to an inverting input terminal of the first operational amplifier U1, a first end of the fourth resistor R4 and a first end of the third capacitor C3, an output end of the first operational amplifier U1 is connected to a second end of the fourth resistor R4 and a second end of the third capacitor C3, respectively.
The first inverting amplifying circuit 12 comprises a second coupler PC2, a second operational amplifier U2, a fourth capacitor C4, a fifth resistor R5 and a sixth resistor R6;
a first end of the fifth resistor R5 is an input end of the first inverting amplifier circuit 12, a second end of the fifth resistor R5 is connected to an inverting input end of the second operational amplifier U2, a first end of the fourth capacitor C4 and a first end of the sixth resistor R6, a non-inverting input end of the second operational amplifier U2 is grounded, an output end of the second operational amplifier U2 is connected to a first end of the second coupler PC2, a second end of the fourth capacitor C4 and a second end of the sixth resistor R6, and a second end of the second coupler PC2 is an output end of the first inverting amplifier circuit 12 and outputs the amplified microphone sound signal.
In this embodiment, the first operational amplifier U1 is a non-inverting amplifier, and the second operational amplifier U2 is an inverting amplifier for amplifying the input microphone signal.
Furthermore, the first resistor and the first capacitor C1 are connected in parallel to play a role in filtering, so as to filter noise of an input microphone signal, the second resistor R2 is a positive phase pull-down resistor of the first operational amplifier U1, so as to allow a zero drift to occur at the output end of the first operational amplifier U1, the third resistor and the fourth resistor R4 control the in-phase amplification factor of the first operational amplifier U1, so that the amplified microphone signal is output at the output end of the first operational amplifier U1, and the third capacitor C3 is connected in parallel to two ends of a feedback circuit of the first operational amplifier U1, so as to filter noise of the output microphone signal, thereby clearly outputting a sound signal of the microphone in a sound system.
The input end of the first inverting amplifying circuit 12 inputs the microphone signal amplified in phase, the amplification factor of the second operational amplifier U2 is determined by the fifth resistor and the sixth resistor, the microphone signal amplified in phase opposite and output by the second operational amplifier U2 is coupled by the second coupler PC2 and then output to the post-stage amplifying circuit for mixed output, and the fourth capacitor C4 and the feedback circuit of the second operational amplifier U2 are used for filtering the noise of the output microphone sound signal, so that the sound signal of the microphone can be clearly output in the sound system.
Referring to fig. 2, in an embodiment, the signal detection circuit 20 includes a first transistor Q1, a second transistor Q2, a fifth capacitor C5, a sixth capacitor C6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R11, and an eleventh resistor R11;
a first end of the seventh resistor R7 is a signal input end of the signal detection circuit 20, a second end of the seventh resistor R7 is connected to a first end of the eighth resistor R8 and a base of the first transistor Q1 respectively, an emitter of the first transistor Q1 is connected to a second terminal of an eighth resistor R8 and a first terminal of the tenth resistor R11, the collector of the first triode Q1 is connected with the base of the second triode Q2 through the ninth resistor R9, the collector of the second triode Q2 is connected with the dc power supply and the first end of the fifth capacitor C5 respectively, and is connected with the first input end of the microphone through the eleventh resistor R11, the second end of the fifth capacitor C5 is connected with the first end of the sixth capacitor C6, an emitter of the second transistor Q2 is connected to the second terminal of the sixth capacitor C6, and an emitter of the second transistor Q2 is an output terminal of the signal detection circuit 20.
In this embodiment, when the signal detection circuit 20 does not detect that a microphone signal is input at the second input terminal of the microphone, a low level is output; when the signal detection circuit 20 detects that a microphone signal is input at the second input terminal of the microphone, a high level is output to control the gain of the input music signal, so that the amplitude of the waveform of the music signal output after gain control is reduced, where the output high level is used to represent the first detection signal.
Specifically, the first input end of the microphone is connected to a +15V dc power supply through the eleventh resistor R11 to provide a +15V bias voltage for the microphone socket, wherein the eleventh resistor R11 plays a role in current limiting and voltage dividing, the second input end of the microphone is a control pin of the microphone, when the microphone is in use, the second input end of the microphone is connected to the third input end of the microphone through the microphone switch, and at this time, the second input end of the microphone is at a low potential, so that the base of the first triode Q1 is at a low level; the dc power supply is regulated to provide a high level to the emitter of the first transistor Q1, so that the first transistor Q1 is turned on.
Further, after the first transistor Q1 is turned on, the collector of the first transistor Q1 is divided by the ninth resistor R9 to provide a voltage to the base of the second transistor Q2, since U is a resistor 1e -U 1b >U 1c -U 1b ，U 1e <+15, so U 2e <U 2c +15V, thereby turning on the second transistor Q2, andthe emitter of the second triode Q2 outputs a first detection signal to control the post gain automatic control circuit to adjust the gain of the music signal, so that when the signal detection circuit 20 detects that the microphone signal is input, the amplification gain of the music signal is automatically reduced, and the sound input by the microphone is more prominent when being output in the sound system.
Referring to fig. 2, in an embodiment, the signal detection circuit 20 further includes a voltage regulator circuit 21;
the voltage stabilizing circuit comprises a voltage stabilizing diode D1 and a seventh capacitor C7, wherein the cathode of the voltage stabilizing diode D1 is respectively connected with the emitter of the first triode Q1, the second end of the eighth resistor R8, the first end of the tenth resistor R11 and the first end of the seventh capacitor C7, and the anode of the voltage stabilizing diode D1 and the second end of the seventh capacitor C7 are respectively grounded.
In this embodiment, the zener diode D1 and the seventh resistor R7 are connected in parallel to form an 8.2V voltage stabilizing circuit, so that the dc power supply can provide a stable voltage for the emitter of the zener diode D1, and can more accurately detect the input of the microphone signal, so that the first detection signal is accurately output to the subsequent gain automatic control circuit, thereby realizing the automatic control of the signal gain in the audio system.
Referring to fig. 3, in an embodiment, the gain control circuit 30 includes:
a second inverting amplifier circuit 31, an input end of the second inverting amplifier circuit 31 is used for inputting a music signal, an output end of the second inverting amplifier circuit 31 is an output end of the gain control circuit 30, and the second inverting amplifier circuit 31 is used for inverting and amplifying the input music signal;
the input end of the feedback adjusting circuit 32 is connected to the output end of the signal detecting circuit 20, the output end of the feedback adjusting circuit 32 is connected to the negative feedback end of the second inverting amplifying circuit 31, and the feedback adjusting circuit 32 is configured to control the amplification gain of the second inverting amplifying circuit 31.
In this embodiment, the gain of the music signal input to the gain control circuit 30 is determined by two feedback branches, the first feedback branch amplifies the input music signal, and the second feedback branch reduces the gain of the input music signal by the control of the signal detection circuit 20, so that the gain of the music signal output through the gain control circuit 30 is reduced.
When the signal detection circuit 20 does not detect that a microphone signal is input, the resistance of the feedback resistor in the gain control circuit 30 is determined by the first feedback branch, and at this time, the input music signal is amplified; when the signal detection circuit 20 detects that a microphone signal is input, the resistance of the feedback resistor in the gain control circuit 30 is determined by the second feedback branch, and at this time, the gain of the input music signal is reduced, and the amplitude of the waveform is reduced after the input music signal is output through the gain control circuit 30.
Specifically, the second inverting amplifier circuit 31 performs inverting amplification on the input music signal, the feedback adjusting circuit 32 is configured to adjust a gain of the music signal when the music signal passes through the second inverting amplifier circuit 31, the feedback adjusting circuit 32 is configured to be open when the signal detection circuit 20 does not detect the input of the microphone signal, the gain of the second inverting amplifier circuit 31 is determined by a fixed resistor, and the feedback adjusting circuit 32 is turned on to reduce the gain of the second inverting amplifier circuit 31 when the signal detection circuit 20 detects the input of the microphone signal, so that the sound system normally outputs music when the microphone voice is not input, and the music sound output by the sound system is automatically reduced when the user inputs the voice signal by using the telephone microphone.
Referring to fig. 3, in an embodiment, the second inverting amplifier circuit 31 includes a third operational amplifier U3, a third coupler PC3, a potentiometer VR1, an eighth capacitor C8, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, and a fifteenth resistor R15;
a first end of the twelfth resistor R12 is connected to an input of a music signal, a second end of the twelfth resistor R12 is connected to a first end of the potentiometer VR1, a second end of the potentiometer VR1 is connected to a first end of the thirteenth resistor R13, a second end of the thirteenth resistor R13 is grounded, a moving end of the potentiometer VR1 is connected to a first end of the third coupler PC3, a second end of the third coupler PC3 is connected to a first end of the fourteenth resistor R14, a second end of the fourteenth resistor R14 is connected to an inverting input terminal of the third operational amplifier U3, a first end of the eighth capacitor C8 and a first end of the fifteenth resistor R15, a non-inverting input terminal of the third operational amplifier U3 is grounded, an output terminal of the third operational amplifier U3 is connected to a second end of the eighth capacitor C8 and a second end of the fifteenth resistor R15, the output end of the third operational amplifier U3 outputs the music signal after the inverted amplification.
In this embodiment, the third operational amplifier U3 is an inverting amplifier.
Specifically, the music signal is divided by the twelfth resistor R12, the potentiometer VR1 and the thirteenth resistor R13, then coupled to the third operational amplifier U3 by the third coupler PC3 for inverse amplification, and output by the output end of the third operational amplifier U3, wherein the potentiometer VR1 can adjust the power amplifier of the music signal to control the sound size of the sound source in the sound system, and the third operational amplifier U3 can amplify and output the music signal, so that the output of the sound source in the sound system is controlled more clearly.
Referring to fig. 3, in an embodiment, the feedback regulation circuit 32 includes a fourth coupler PC4, a sixteenth resistor R16, and a seventeenth resistor R17;
the cathode of the light emitting diode of the fourth coupler PC4 is grounded, the anode of the light emitting diode of the fourth coupler PC4 is connected to the first end of the seventeenth resistor R17, the second end of the seventeenth resistor R17 is the input end of the second inverting amplifier circuit 31, the first end of the photo resistor of the fourth coupler PC4 is connected to the first end of the sixteenth resistor R16, the second end of the photo resistor of the fourth coupler PC4 is connected to the output end of the third operational amplifier U3, the second end of the eighth capacitor C8 and the second end of the fifteenth resistor R15, respectively, and the first end of the fifteenth resistor R15 is connected to the inverting input end of the third operational amplifier U3, the first end of the eighth capacitor C8 and the second end of the sixteenth resistor R16, respectively.
In this embodiment, the fourth coupler PC4 is a linear photocoupler; the feedback resistance between the output terminal and the inverting input terminal of the third operational amplifier U3 in the feedback adjusting circuit 32 is determined by two feedback branches, the first feedback branch includes the fifteenth resistor R15, and the second feedback branch is formed by connecting the photoresistor of the fourth coupler PC4 in series with the sixteenth resistor R16 and then in parallel with the fifteenth resistor R15.
When the signal detection circuit 20 does not detect that a microphone signal is input at the second microphone input terminal, the fourth coupler PC4 is not turned on, the resistance of the feedback resistor in the feedback adjustment circuit 32 is determined by the first feedback branch, and the input music signal is amplified; when the signal detection circuit 20 detects that a microphone signal is input to the second input terminal of the microphone, the fourth coupler PC4 is turned on, the resistance of the feedback resistor in the feedback adjustment circuit 32 is determined by the second feedback branch, the gain of the input music signal is reduced, and the amplitude of the waveform is reduced after the input music signal is output through the feedback adjustment circuit 32.
Specifically, when the signal detection circuit 20 does not detect the input of the microphone signal, the input terminal of the feedback adjustment circuit 32 is at a low level, the photo-resistor of the fourth coupler PC4 is controlled by the light emitting diode of the fourth coupler PC4, when the light emitting diode of the fourth coupler PC4 is at a low level, the resistance of the photo-resistor of the fourth coupler PC4 is greater than 1 megaohm, which is approximately an open circuit, and the amplification gain of the music signal is determined by the fourteenth resistor R14 and the fifteenth resistor R15; when the input end of the feedback adjusting circuit 32 inputs the first detection signal, the light emitting diode of the fourth coupler PC4 receives a high level to be lighted, the light sensitive resistor of the fourth coupler PC4 senses light to reduce the resistance, and the light sensitive resistor of the fourth coupler PC4 is connected in series with the sixteenth resistor R16 and then connected in parallel with the fifteenth resistor R15, so that the gain of the music signal passing through the third operational amplifier U3 is reduced, and the amplification factor of the output music signal is reduced. Therefore, the sound system can realize normal output of music sound when no microphone voice is input, and when a user inputs a voice signal using the microphone, the music sound output by the sound system is reduced, thereby ensuring that the microphone sound can be clearly output.
Referring to fig. 3, in an embodiment, the signal mixing circuit 40 includes a fourth operational amplifier U4, a ninth capacitor C9, an eighteenth resistor R18, a nineteenth resistor R19, and a twentieth resistor R20;
the first end of the eighteenth resistor R18 is the first input end of the signal mixing circuit 40, the second end of the eighteenth resistor R18 is connected to the inverting input end of the fourth operational amplifier U4, the first end of the ninth capacitor C9, the second end of the nineteenth resistor R19 and the first end of the twentieth resistor R20, the non-inverting input end of the fourth operational amplifier U4 is grounded, the output end of the fourth operational amplifier U4 is connected to the second end of the ninth capacitor C9 and the second end of the twentieth resistor R20, the output end of the fourth operational amplifier U4 is the output end of the signal mixing circuit 40, and the first end of the nineteenth resistor R19 is the second input end of the signal mixing circuit 40 and is used for receiving a microphone signal.
In this embodiment, the fourth operational amplifier U4 is an inverting amplifier.
Specifically, the amplified microphone signal and the amplified music signal are mixed and input to the inverting input terminal of the fourth amplifier U4, and are mixed and output after being inverted again by the fourth operational amplifier U4, wherein the ninth capacitor C9 plays a role of filtering, and is used for filtering sharp noise. Therefore, the sound system can output the amplified microphone signal and simultaneously output the music signal after gain adjustment, so that the sound system can simultaneously output the music signal at relatively low volume under the condition that the microphone has voice input, and the effect that the sound system can automatically reduce the background music without adjusting a power amplifier knob at the back of the sound system when voice communication is carried out can be achieved.
The utility model also provides an electronic equipment, this electronic equipment include power amplifier circuit, speaker and power amplifier microphone volume automatic control circuit, power amplifier microphone volume automatic control circuit's signal output part with the speaker sound production is redriven after the power amplifier circuit is connected. The specific structure of the automatic volume control circuit of the power amplifier microphone refers to the above embodiments, and since the electronic device adopts all the technical solutions of all the embodiments, at least all the beneficial effects brought by the technical solutions of the embodiments are achieved, and no further description is given here.
The above is only the optional embodiment of the present invention, and not therefore the limit to the patent scope of the present invention, all the concepts of the present invention utilize the equivalent structure transformation of the content of the specification and the attached drawings, or the direct/indirect application in other related technical fields is included in the patent protection scope of the present invention.
Claims (9)
1. The utility model provides a power amplifier microphone volume automatic control circuit for adjust the microphone volume, its characterized in that, power amplifier microphone volume automatic control circuit includes:
the input end of the microphone amplifying circuit is connected with a first input end of a microphone signal; the microphone amplifying circuit is used for amplifying and outputting an input microphone signal;
the input end of the signal detection circuit is connected with the second input end of the microphone signal; the signal detection circuit is used for outputting a first detection signal when detecting that a voice signal is input into the microphone;
the first input end of the gain control circuit is used for inputting music signals, the second input end of the gain control circuit is connected with the output end of the signal detection circuit, the gain control circuit is used for performing gain amplification on the input music signals and then outputting the amplified music signals, and when the first detection signal is received, the gain of the input music signals is reduced;
the first input end of the signal mixing circuit is connected with the output end of the microphone amplifying circuit, the second input end of the signal mixing circuit is connected with the output end of the gain control circuit, and the signal mixing circuit is used for mixing the amplified microphone signal and the amplified music signal and then outputting the mixed signal to the power amplifier circuit to drive the loudspeaker to produce sound.
2. The power amplifier microphone volume automatic control circuit of claim 1, wherein the microphone amplifying circuit comprises:
the input end of the in-phase amplifying circuit is the input end of the microphone amplifying circuit, the output end of the in-phase amplifying circuit outputs a microphone signal after in-phase amplification, and the in-phase amplifying circuit is used for amplifying the input microphone signal in phase;
the microphone signal processing circuit comprises a first inverting amplifying circuit, wherein the input end of the first inverting amplifying circuit is connected with the output end of the in-phase amplifying circuit, the output end of the first inverting amplifying circuit outputs a microphone signal after inverting amplification, and the first inverting amplifying circuit is used for inverting-amplifying the microphone signal after in-phase amplification and outputting the microphone signal.
3. The automatic volume control circuit of a power amplifier microphone according to claim 1, wherein the signal detection circuit comprises a first triode, a second triode, a fifth capacitor, a sixth capacitor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor and an eleventh resistor;
the first end of the seventh resistor is a signal input end of the signal detection circuit, the second end of the seventh resistor is respectively connected with the first end of the eighth resistor and the base electrode of the first triode, the emitter of the first triode is respectively connected with the second end of the eighth resistor and the first end of the tenth resistor, the collector of the first triode is connected with the base of the second triode through the ninth resistor, the collector of the second triode is respectively connected with a direct current power supply and the first end of the fifth capacitor, and is connected with a first input end of a microphone signal through the eleventh resistor, a second end of the fifth capacitor is connected with a first end of the sixth capacitor, and an emitting electrode of the second triode is connected with the second end of the sixth capacitor, and an emitting electrode of the second triode is an output end of the signal detection circuit.
4. The power amplifier microphone volume automatic control circuit of claim 3, wherein the signal detection circuit further comprises a voltage stabilizing circuit;
the voltage stabilizing circuit comprises a voltage stabilizing diode and a seventh capacitor, wherein the cathode of the voltage stabilizing diode is respectively connected with the emitter of the first triode, the second end of the eighth resistor, the first end of the tenth resistor and the first end of the seventh capacitor, and the anode of the voltage stabilizing diode is respectively grounded with the second end of the seventh capacitor.
5. The power amplifier microphone volume automatic control circuit of claim 1, wherein the gain control circuit comprises:
the input end of the second inverting amplifying circuit is used for inputting music signals, the output end of the second inverting amplifying circuit is the output end of the gain control circuit, and the second inverting amplifying circuit is used for inverting and amplifying the input music signals;
and the input end of the feedback adjusting circuit is connected with the output end of the signal detection circuit, the output end of the feedback adjusting circuit is connected with the negative feedback end of the second inverting amplifying circuit, and the feedback adjusting circuit is used for controlling the amplification gain of the second inverting amplifying circuit.
6. The automatic volume control circuit for power amplification microphone according to claim 5, wherein the second inverting amplifying circuit comprises a third operational amplifier, a third coupler, a potentiometer, an eighth capacitor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor and a fifteenth resistor;
a first end of the twelfth resistor is used for inputting a music signal, a second end of the twelfth resistor is connected with a first end of the potentiometer, the second end of the potentiometer is connected with the first end of the potentiometer, the second end of the potentiometer is grounded, a moving end of the potentiometer is connected with a first end of the third coupler, a second end of the third coupler is connected with a first end of the fourteenth resistor, a second end of the fourteenth resistor is connected to the inverting input terminal of the third operational amplifier, a first end of the eighth capacitor, and a first end of the fifteenth resistor, the non-inverting input end of the third operational amplifier is grounded, the output end of the third operational amplifier is respectively connected with the second end of the eighth capacitor and the second end of the fifteenth resistor, and the output end of the third operational amplifier outputs music signals after reverse-phase amplification.
7. The power amplifier microphone volume automatic control circuit of claim 6, wherein the feedback adjusting circuit comprises a fourth coupler, a sixteenth resistor and a seventeenth resistor;
the cathode of the light emitting diode of the fourth coupler is grounded, the anode of the light emitting diode of the fourth coupler is connected with the first end of the seventeenth resistor, the second end of the seventeenth resistor is the input end of the second inverting amplifying circuit, the first end of the photoresistor of the fourth coupler is connected with the first end of the sixteenth resistor, the second end of the photoresistor of the fourth coupler is respectively connected with the output end of the third operational amplifier, the second end of the eighth capacitor and the second end of the fifteenth resistor, and the first end of the fifteenth resistor is respectively connected with the inverting input end of the third operational amplifier, the first end of the eighth capacitor and the second end of the sixteenth resistor.
8. The automatic volume control circuit of a power amplifier microphone according to claim 1, wherein the signal mixing circuit comprises a fourth operational amplifier, a ninth capacitor, an eighteenth resistor, a nineteenth resistor and a twentieth resistor;
the first end of eighteenth resistance does the first input of signal mixing circuit, the second end of eighteenth resistance with the inverting input of fourth operational amplifier the first end of ninth electric capacity the second end of nineteenth resistance reaches the first end of twentieth resistance is connected respectively, the noninverting input ground connection of fourth operational amplifier, the output of fourth operational amplifier with the second end of ninth electric capacity reaches the second end of twentieth resistance is connected respectively, the output of fourth operational amplifier is the output of signal mixing circuit, the first end of nineteenth resistance does the second input of signal mixing circuit for connect the microphone signal after the inverting amplification.
9. An electronic device, characterized in that the electronic device comprises a power amplifier circuit, a loudspeaker and the power amplifier microphone volume automatic control circuit according to any one of claims 1 to 8; and the signal output end of the power amplification microphone volume automatic control circuit is connected with the power amplification circuit and then drives the loudspeaker to produce sound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123029680.4U CN217116403U (en) | 2021-12-03 | 2021-12-03 | Automatic volume control circuit for power amplification microphone and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123029680.4U CN217116403U (en) | 2021-12-03 | 2021-12-03 | Automatic volume control circuit for power amplification microphone and electronic equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217116403U true CN217116403U (en) | 2022-08-02 |
Family
ID=82589566
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123029680.4U Active CN217116403U (en) | 2021-12-03 | 2021-12-03 | Automatic volume control circuit for power amplification microphone and electronic equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217116403U (en) |
-
2021
- 2021-12-03 CN CN202123029680.4U patent/CN217116403U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8320587B2 (en) | Audio device and volume adjusting circuit for the audio device | |
| CN104093095B (en) | It is a kind of can automatic regulating volume singing device | |
| KR100242336B1 (en) | Sound volume control circuit using pwm(pulse width modulation) signal | |
| CA2014499A1 (en) | Battery powered in-line amplifier | |
| CN217116403U (en) | Automatic volume control circuit for power amplification microphone and electronic equipment | |
| CN201928424U (en) | Sound source frequency adjusting system and terminal | |
| CN207427395U (en) | Multi-phone microphone | |
| CN208905194U (en) | Silent sound reverberation one power amplifier | |
| US20080247570A1 (en) | Sound output device with earphone mode and speaker mode | |
| CN203205048U (en) | Multifunctional portable electric guitar | |
| US20120192703A1 (en) | Two-stage musical instrument effects pedal | |
| CN218830588U (en) | Power amplifier voltage regulating circuit, power amplifier and electroacoustic equipment | |
| CN211406261U (en) | Computer multimedia loudness control circuit | |
| CN212367526U (en) | Teaching sound amplification infrared transmission system and teaching equipment | |
| CN204721590U (en) | Wireless headset audio output control circuit and wireless headset | |
| CN207589130U (en) | A kind of earphone power amplifier | |
| CN219041961U (en) | Amplifying circuit and audio equipment | |
| CN204993809U (en) | Dual track audio power amplifier circuit | |
| CN213472945U (en) | Novel automobile-used voice alarm that turns to | |
| CN214591944U (en) | Audio frequency amplitude limiting circuit of stereo set | |
| CN220896832U (en) | Earphone control circuit and audio equipment | |
| CN216490833U (en) | Multifunctional live broadcast sound card circuit capable of realizing anti-interference | |
| CN201051755Y (en) | A transmitter amplifier for automatically adjusting output volume | |
| CN214315522U (en) | Multifunctional electrified education active loudspeaker system | |
| CN214045985U (en) | Audio gain switching circuit and sound equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |