CN109462798B - Howling suppression audio power amplifier and method - Google Patents
Howling suppression audio power amplifier and method Download PDFInfo
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- CN109462798B CN109462798B CN201811336545.4A CN201811336545A CN109462798B CN 109462798 B CN109462798 B CN 109462798B CN 201811336545 A CN201811336545 A CN 201811336545A CN 109462798 B CN109462798 B CN 109462798B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2430/00—Signal processing covered by H04R, not provided for in its groups
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Abstract
The invention discloses a howling suppression audio power amplifier, which comprises: the pickup circuit is coupled with an external microphone; the power amplifying circuit is coupled with the pickup circuit and is also coupled with an external loudspeaker; the display circuit is coupled with a howling frequency detection circuit and a power calculation circuit, the howling frequency detection circuit is coupled with the pickup circuit, and the power calculation circuit is coupled with the power amplifier; a power supply circuit. The howling suppression audio power amplifier can effectively pick up the electric signal output by the external microphone through the arrangement of the pickup circuit, so that the electric signal output by the external microphone can be effectively picked up, then the electric signal is effectively amplified through the arrangement of the power amplification circuit to be provided for the external loudspeaker to make a sound, then the frequency and the power are displayed through the display circuit, so that the position of the external microphone can be adjusted through checking the frequency and the power, and howling can be effectively suppressed.
Description
Technical Field
The invention relates to a suppression circuit, in particular to a howling suppression audio power amplifier and a method.
Background
At present, various sound amplification systems in a theater, a conference hall, a sports stadium, a karaoke 0K hall and the like generally have a howling phenomenon, and the sound emitted by a sound box is transmitted into a microphone to cause the howling while the volume of the microphone is greatly increased. The existence of howling not only destroys the tone quality and limits the volume of the microphone, so that the sound picked up by the microphone cannot be reproduced well, but also the deep howling can cause the system signal to be too strong to burn out the power amplifier or the sound box, especially the high pitch loudspeaker of the sound box.
Howling is almost always caused by the high positive feedback of the audio signal. The sound of the loudspeaker is converted back to the microphone, the signal output by the microphone is sent to the sound amplifying system for amplification and then sent out through the loudspeaker, and then converted back to the microphone, and the operation is repeated. The signal causing the feedback is generally a single frequency signal, and after repeated times, the signal is overlapped in phase and gradually increased, so that self-oscillation is formed, and the self-oscillation frequency is reflected in the tone frequency of the howling.
However, in the above-mentioned suppression process, the location of the howling point is quite undefined, and people can only feel to avoid that the microphone is not located at the howling point, which may cause that in the process of suppressing the howling, people need to continuously move to find the howling point, so that the efficiency of suppressing the howling becomes very low.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a howling suppression audio power amplifier with high howling suppression efficiency and a method thereof.
In order to achieve the purpose, the invention provides the following technical scheme: a howling suppression audio power amplifier, comprising:
the pickup circuit is coupled with the external microphone and used for receiving the voice electric signal output by the external microphone after sound conversion and outputting the converted voice electric signal;
the power amplification circuit is coupled with the pickup circuit and the external loudspeaker and is used for receiving the voice electric signal output by the pickup circuit, amplifying the voice electric signal and outputting the amplified voice electric signal to the external loudspeaker to drive the external loudspeaker to produce sound;
the display circuit is coupled with a howling frequency detection circuit and a power calculation circuit, the howling frequency detection circuit is coupled with the pickup circuit and used for detecting the howling frequency in the voice electric signal output by the pickup circuit and inputting the howling frequency into the display circuit to be displayed, and the power calculation circuit is coupled with the power amplifier and used for receiving the amplified voice electric signal and calculating the power of the voice electric signal and inputting the power into the display circuit to be displayed;
and the power supply circuit is coupled with external commercial power and used for converting the commercial power into power and outputting the power to the pickup circuit, the power amplification circuit, the display circuit, the howling frequency detection circuit and the power calculation circuit for power supply.
As a further improvement of the present invention, a howling suppression circuit is further coupled between the sound pickup circuit and the power amplification circuit, and is configured to suppress howling of the voice electrical signal output from the sound pickup circuit to the power amplification circuit and input the voice electrical signal to the power amplification circuit.
As a further improvement of the present invention, a conversion circuit is coupled between the power calculation circuit and the power amplification circuit, the conversion circuit including:
the rectifying circuit is coupled with the power amplifying circuit and is used for rectifying and outputting the amplified voice electric signal output by the power amplifying circuit;
the filter circuit is coupled to the rectifying circuit and used for filtering the output rectified voice electric signal;
and the A/D conversion circuit is coupled with the filter circuit and the power calculation circuit and is used for receiving the filtered electric signal, converting the electric signal into a digital signal and inputting the digital signal into the power calculation circuit.
As a further improvement of the present invention, the sound pickup circuit includes:
an operational amplifier U1A, wherein an inverting input terminal of the operational amplifier U1A is coupled to a resistor R4, then coupled to a capacitor C3, then coupled to an external microphone, the capacitor C3 is further coupled to a resistor R3, then coupled to a power supply, a non-inverting input terminal of the operational amplifier U1A is coupled to a resistor R7 and a resistor R9, then coupled to ground, and further coupled to a resistor R6, and an output terminal of the operational amplifier U1A is coupled to a capacitor C1 and a resistor R1, which are connected in parallel, then coupled to an inverting input terminal of the operational amplifier U1A;
an operational amplifier U1B, the inverting input terminal of the operational amplifier U1B is coupled to a variable resistor R5 and then to the output terminal of the operational amplifier U1A, the non-inverting input terminal of the operational amplifier U1B is coupled to a resistor R8 and then to one terminal of a resistor R7, the output terminal of the operational amplifier U1B is coupled to a capacitor C2 and a resistor R2 connected in parallel and then to the inverting input terminal of the operational amplifier U1B, and a capacitor C4 is coupled to a power amplifier circuit.
As a further improvement of the present invention, the howling suppression circuit includes:
an inverting input terminal of the operational amplifier U2 is coupled to the temperature sensitive resistor RW1 and then coupled to the pickup circuit, and is also coupled to the capacitor C100 and then grounded, a non-inverting input terminal of the operational amplifier U2 is coupled to the resistor R100 and then coupled to one end of the temperature sensitive resistor RW1 opposite to the pickup circuit, an output terminal of the operational amplifier U2 is coupled to the resistor R101 and then coupled to the other end of the resistor R100 opposite to the pickup circuit, and the output terminal is further coupled to the power amplification circuit. As a further improvement of the present invention, the howling frequency detection circuit includes:
an optocoupler relay U3, optocoupler relay U3 has input loop and output loop, the input loop includes first input and second input, the output loop includes first output and second output, be coupled with behind the variable resistance R36 coupling with resistance R31 and then be coupled in pickup circuit, second input ground connection, first output is coupled in the power, and ground connection behind the second output coupling with variable resistance R37 is still coupled in the coupling with behind resistance R34 and is coupled in display circuit.
As a further improvement of the present invention, the present invention further comprises a squeal suppressor, the squeal suppressor comprises a housing, a sound channel disposed in the housing, and a cut-off device disposed in the sound channel for cutting off or opening the sound channel, the external speaker is disposed in the sound channel, the cut-off device comprises a sound-insulating board and a driving motor, a storage slot is disposed on a channel wall of the sound channel, the sound-insulating board is slidably disposed in the storage slot and can slide into the storage slot to open the sound channel or slide out of the storage slot to cut off the sound channel, the driving motor is coupled to the squeal frequency detection circuit to receive the squeal frequency signal output by the squeal frequency detection circuit, and along with the rotation of the signal, a screw rod is coaxially fixed on a rotating shaft of the driving motor, the driving motor is fixed on a slot bottom of the storage slot, and the screw rod extends from the driving motor towards a slot opening of the storage slot, fixedly connected with sliding block on the acoustic celotex board, the lead screw penetrates in the sliding block and with sliding block threaded connection in order to drive the acoustic celotex board from the storage tank in the cunning or slide into the storage tank.
In another aspect, the present invention further provides a method for suppressing howling by using the above audio amplifier, including the following steps:
picking up an electric signal output after sound conversion by an external microphone by using a pickup circuit, detecting howling frequency in the electric signal by using a howling frequency detection circuit, and inputting the electric signal into a display circuit for display;
step two, amplifying the electric signal output by the pickup circuit by using a power amplifying circuit, inputting the electric signal into an external loudspeaker for playing, calculating the output power of the electric signal amplified by the power amplifying circuit by using a power calculating circuit, and inputting the output power into a display circuit for displaying;
and step three, adjusting the relative position of the external microphone and the loudspeaker box according to the howling frequency and the output power displayed by the display circuit, wherein the specific adjustment step is to move the position of the external microphone first, the display circuit displays an azimuth arrow when providing, if the howling frequency is reduced after the external microphone moves, the display circuit displays an azimuth arrow in the same direction as the original moving direction, and if the howling frequency is increased, the display circuit displays a direction arrow opposite to the original moving direction.
As a further improvement of the above method, the step of detecting the frequency by the howling frequency detection circuit in the step one is as follows:
and step one, judging whether the detected frequency is smaller than 2000HZ, if so, calculating the howling frequency by adopting a frequency measurement method, and if not, calculating the howling frequency by adopting a frequency measurement method.
As a further improvement of the above method, the steps of displaying the frequency and the power by the display circuit in the first step and the second step are as follows:
and 3, displaying the frequency value displayed in the step 2 in a delayed mode, and then clearing the screen to finish displaying the frequency and the power in the step one and the step two.
The invention has the advantages that the electric signal converted by the external sound output by the external microphone can be effectively received through the setting of the sound pick-up circuit, then the electric signal is input into the power amplifying circuit and amplified by the power amplifying circuit, thus realizing the sound power amplifying effect, the howling frequency output by the sound pick-up circuit can be effectively detected through the setting of the howling frequency detecting circuit and the power calculating circuit, the signal power finally output by the power amplifier is calculated, then the howling frequency and the signal power can be effectively displayed through the setting of the display circuit, thus people can judge whether the howling is about to be generated according to the displayed howling frequency and signal power, therefore, the same as the prior art is not needed, the howling point of the sound box is determined by adopting a feeling mode, the howling can be effectively inhibited before the howling is generated, therefore, the inhibition efficiency of howling is greatly improved, meanwhile, the effects of the sound pickup circuit, the howling frequency detection circuit and the power calculation circuit can be effectively utilized to detect the howling frequency and calculate the output power, and then the output power is displayed by the display circuit, so that people can move the position between the microphone and the sound source according to the displayed howling frequency and output power, the generation of the howling is effectively avoided.
Drawings
Fig. 1 is a block diagram of a howling suppression audio power amplifier according to the present invention;
FIG. 2 is a circuit diagram of the pickup circuit of FIG. 1;
FIG. 3 is a circuit diagram of the howling suppression circuit of FIG. 1;
fig. 4 is a circuit diagram of the howling frequency detection circuit in fig. 1;
FIG. 5 is a circuit diagram of a power circuit;
fig. 6 is a flow chart of the detection frequency of the howling suppression method of the present invention;
fig. 7 is a flow chart showing the frequency and power of the howling suppression method of the present invention;
fig. 8 is an overall configuration diagram of the howling suppressor.
Detailed Description
The invention will be further described in detail with reference to the following examples, which are given in the accompanying drawings.
Referring to fig. 1 to 8, a howling suppression audio power amplifier of the present embodiment includes:
the pickup circuit 1 is coupled to an external microphone, and is configured to receive a voice electrical signal output by the external microphone after sound conversion, convert the voice electrical signal, and output the converted voice electrical signal;
the power amplifying circuit 2 is coupled to the pickup circuit 1 and is also coupled to an external speaker, and is used for receiving the voice electric signal output by the pickup circuit 1, amplifying the voice electric signal and outputting the amplified voice electric signal to the external speaker, and driving the external speaker to sound;
the display circuit 3 is coupled with a howling frequency detection circuit 4 and a power calculation circuit 5, the howling frequency detection circuit 4 is coupled with the pickup circuit 1, and is used for detecting the howling frequency in the voice electric signal output by the pickup circuit 1 and inputting the howling frequency into the display circuit 3 for displaying, and the power calculation circuit 5 is coupled with the power amplifier 2 and is used for receiving the amplified voice electric signal and calculating the power of the voice electric signal and inputting the power into the display circuit 3 for displaying;
the power circuit 6 is coupled to an external commercial power, and is configured to convert a commercial power into a power and output the power to the sound pickup circuit 1, the power amplification circuit 2, the display circuit 3, the howling frequency detection circuit 4, and the power calculation circuit 5, when the audio power amplifier of this embodiment is used, only the audio power amplifier needs to be connected between an external microphone and a speaker, and the power circuit 6 is connected to the external commercial power, so that the audio power amplifier will operate, the sound pickup circuit 1 picks up a voice electrical signal output by the external microphone according to sound, and then inputs the voice electrical signal into the power amplification circuit 2, and then the power amplification circuit 2 performs power amplification on the voice electrical signal, and then inputs the voice electrical signal into the speaker, so that the speaker plays the amplified sound, and thus an effect of effectively amplifying the sound is achieved, the howling frequency of the voice electric signal output by the pickup circuit 1 can be effectively detected through the arrangement of the howling frequency detection circuit 4 and the power calculation circuit 5, the output power amplified by the power amplification circuit 2 is calculated at the same time, and then the obtained howling frequency and the obtained output power are effectively displayed through the display circuit 3, based on the principle of howling generation in the prior art, the howling is mainly caused when the howling frequency exceeds a certain numerical value and the output power exceeds a certain numerical value, so that the audio power amplifier of the embodiment can avoid moving to the howling point generating the howling frequency and the output power by changing the distance between a microphone and a sound source, compared with the howling suppression mode in the prior art, the howling point is searched in a sensing mode without waiting for the generation of the howling, and then realize and restrain the howling, so the inhibition efficiency of howling has been greatly increased, the display circuit 3 in this embodiment includes intelligent control chip circuit and LCD liquid crystal display, the power calculating circuit 5 is integrated into the intelligent control chip circuit at the same time, the LCD liquid crystal display is set up on the microphone outside, so people can look over the howling frequency of the speech electric signal that the pickup circuit 1 outputs and the output power of the power amplifier circuit 2 in real time, great convenience people restrain the howling, through the arrangement of the intelligent control chip circuit, the editability that can utilize the intelligent control chip, the effective calculation of power and cooperate with LCD and realize the howling frequency and output power.
As an improved specific embodiment, a howling suppression circuit 7 is further coupled between the sound pickup circuit 1 and the power amplification circuit 2, and is configured to suppress howling of the voice electrical signal output from the sound pickup circuit 1 to the power amplification circuit 2 and then input the voice electrical signal to the power amplification circuit 2, and by setting the howling suppression circuit 7, the voice electrical signal output from the sound pickup circuit 1 can be further subjected to howling suppression, so that the problem of howling of the audio power amplifier in the process of audio amplification can be further avoided, and the howling suppression of the audio amplifier is further improved.
As a specific embodiment of the improvement, a conversion circuit 8 is coupled between the power calculation circuit 5 and the power amplification circuit 2, and the conversion circuit 8 includes:
the rectifying circuit 81 is coupled to the power amplifying circuit 2, and is configured to rectify and output the amplified voice electrical signal output by the power amplifying circuit 2;
a filter circuit 82, coupled to the rectifying circuit 81, for filtering the output rectified speech electrical signal; the a/D conversion circuit 83 is coupled to the filter circuit 82 and also coupled to the power calculation circuit 5, for receiving the filtered electrical signal and converting the filtered electrical signal into a digital signal to be inputted into the power calculation circuit 5, because the voice signal required by the speaker to play the audio is an analog signal, but the signal recognized by the intelligent control chip is a digital signal, in this embodiment, the analog voice waveform signal is converted into a dc signal by the arrangement of the rectifier circuit 81, then the interference clutter on the voice electrical signal is effectively filtered by the arrangement of the filter circuit 82, the interference of the interference clutter on the calculation power of the intelligent control chip is avoided, so that the output power calculated by the intelligent control chip has a large error, and the dc voice electrical signal can be converted into a digital signal by the arrangement of the a/D conversion circuit 83 to be recognized and calculated by the intelligent control chip, therefore, compared with a mode of directly inputting the simulated voice electric signal into the intelligent control chip for calculation, the problem of inaccurate numerical value calculated by the output power caused by incomplete recognition of the voice electric signal by the intelligent control chip can be effectively avoided.
As a specific embodiment of the improvement, the sound pickup circuit 1 includes:
an operational amplifier U1A, wherein an inverting input terminal of the operational amplifier U1A is coupled to a resistor R4, then coupled to a capacitor C3, then coupled to an external microphone, the capacitor C3 is further coupled to a resistor R3, then coupled to a power supply, a non-inverting input terminal of the operational amplifier U1A is coupled to a resistor R7 and a resistor R9, then coupled to ground, and further coupled to a resistor R6, and an output terminal of the operational amplifier U1A is coupled to a capacitor C1 and a resistor R1, which are connected in parallel, then coupled to an inverting input terminal of the operational amplifier U1A;
an operational amplifier U1B, the inverting input terminal of the operational amplifier U1B is coupled with a variable resistor R5 and then coupled with the output terminal of the operational amplifier U1A, the non-inverting input terminal of the operational amplifier U1B is coupled with a resistor R8 and then coupled with one terminal of a resistor R7, the output terminal of the operational amplifier U1B is coupled with a capacitor C2 and a resistor R2 which are connected in parallel and then coupled with the inverting input terminal of the operational amplifier U1B, and is also coupled with a capacitor C4 and coupled with the power amplifier circuit 2, through the arrangement of the operational amplifier U1A and the operational amplifier U1B, a two-stage amplifier circuit can be effectively formed, a preliminary amplification can be performed on the voice electrical signal output by the external microphone, so that the voice electrical signal output by the external microphone can be better amplified by the power amplifier circuit 2, and through the arrangement of the capacitor C3 and the resistor R4, a filtering effect can be performed on the voice electrical signal output by the external microphone, interference harmonics caused in the process of converting sound into a voice electric signal by an external microphone are filtered, so that the distortion rate of the voice electric signal is greatly reduced after the voice electric signal is subjected to secondary amplification, and the amplification factor of a secondary amplification circuit formed by combining an operational amplifier U1A and an operational amplifier U1B can be adjusted through the arrangement of a variable resistor R5 and a variable resistor R8, so that the situation that the output power is overlarge and howling is generated due to the fact that the subsequent amplification factor is further amplified through a power amplification circuit 2 caused by the overlarge factor before a power amplification circuit 2 is avoided, and therefore the effect of enough early amplification can be achieved and the howling effect cannot be generated through the arrangement of the variable resistor R5 and the variable resistor R8.
As an improved specific embodiment, the howling suppression circuit 7 includes:
an operational amplifier U2, the inverting input terminal of the operational amplifier U2 is coupled to a temperature-sensitive resistor RW1 and then coupled to the pickup circuit 1, and is also coupled to a capacitor C100 and then grounded, the non-inverting input terminal is coupled to a resistor R100 and then coupled to one end of the temperature-sensitive resistor RW1 opposite to the pickup circuit 1, the output terminal of the operational amplifier U2 is coupled to a resistor R101 and then coupled to the other end of the resistor R100 opposite to the pickup circuit 1, the output terminal is also coupled to the power amplification circuit 2, the operational amplifier U2, the capacitor C100, the resistor R100 and the resistor R101 cooperate to form a filter, through the arrangement of the temperature-sensitive resistor RW1, the pass frequency of the filter can be effectively adjusted and controlled according to the external temperature, therefore, if the frequency of the voice electrical signal output by the pickup circuit 1 reaches the howling frequency, the filter can effectively filter, and the whole circuit structure is simple and easy to realize.
As an improved specific implementation manner, the howling frequency detection circuit 4 includes:
the optical coupling relay U3, the optical coupling relay U3 has input return circuit and output return circuit, the input return circuit includes first input and second input, the output return circuit includes first output and second output, coupling behind the first input coupling with variable resistance R36 is coupled with resistance R31 behind the coupling and is coupled with pickup circuit 1, second input ground connection, first output is coupled with the power, ground connection behind the second output coupling with variable resistance R37, still coupling is coupled with behind resistance R34 and is coupled with display circuit 3, utilize the photoelectric conversion effect of optical coupling relay U3, just can convert the speech signal of sound pickup circuit 1 output into according to its digital signal that carries out frequency variation, so intelligent control chip alright discern this digital signal, and then realize the frequency detection's of a simple effectual speech signal effect, whole circuit structure device is few simultaneously, the realization is simple.
As an improved specific embodiment, the power circuit 6 includes a transformer T1, a rectifier D1 and a voltage stabilizing circuit 61, the transformer T1, the rectifier D1 and the voltage stabilizing circuit 61 are connected in series, wherein the transformer T1 is coupled to the external mains for outputting after reducing the voltage of the external mains, and the voltage stabilizing circuit 61 is used for outputting a stabilized voltage, and through the arrangement of the transformer T1, the rectifier D1 and the voltage stabilizing circuit 61, the voltage of the external mains can be effectively reduced, rectified and then stabilized, and then a stabilized power supply is output.
As an improved specific embodiment, the squeal suppressor 9 further comprises a squeal suppressor 9, the squeal suppressor 9 comprises a housing 91, a sound channel 92 arranged in the housing 91 and a cut-off device 93 arranged in the sound channel 92 for cutting off or opening the sound channel 92, the external speaker is arranged in the sound channel 92, the cut-off device 93 comprises a sound-insulating board 931 and a driving motor 932, a storage slot 921 is arranged on a channel wall of the sound channel 92, the sound-insulating board 931 is slidably arranged in the storage slot 921 and can slide into the storage slot 921 to open the sound channel, or can slide out of the storage slot 921 to cut off the sound channel, the driving motor 932 is coupled with the squeal frequency detection circuit 4 to receive the squeal frequency signal output by the squeal frequency detection circuit 4, and as the signal rotates, a screw rod 932 is coaxially fixed on a rotating shaft of the driving motor 932, the driving motor 932 is fixed at the bottom of the storage slot 921, the lead screw extends from the driving motor 932 to the slot opening of the storage slot 921, the baffle 931 is fixedly connected with a sliding block, the lead screw penetrates into the sliding block and is in threaded connection with the sliding block to drive the baffle 931 to slide out of the storage slot 921 or slide into the storage slot 921, because the sound is transmitted through the air, when the sound channel 92 is cut off, the sound generated by the speaker is cut off and cannot be transmitted to the outside through the sound channel 92, so that the sound channel 92 is cut off or opened by the cooperation of the baffle 931 and the driving motor 932 in the embodiment, so that when the squealing frequency detection circuit 4 detects the squealing, the driving motor 932 can effectively drive the baffle 931 to slide out of the storage slot 921 to cut off the sound channel 92, so that the squealing sound generated by the speaker cannot be transmitted to the outside, so also effectual effect of realizing a squeal suppression, travelling comfort when having promoted people and using microphone and speaker adopts the motor controller to realize detecting the signal of squeal and then drive septum 931 gliding of acoustic baffle 931 and cut off sound passageway 92 with the supporting mode of driving motor 932 in this embodiment.
The invention also provides a method for suppressing howling by using the components, which comprises the following steps:
firstly, a pickup circuit 1 is used for picking up an electric signal output after an external microphone converts sound, then a howling frequency detection circuit 4 is used for detecting the howling frequency in the electric signal, and the electric signal is input into a display circuit 3 for display;
step two, the electric signal output by the pickup circuit 1 is amplified by the power amplifying circuit 2 and then input into an external loudspeaker for playing, and meanwhile, the output power of the electric signal amplified by the power amplifying circuit 2 is calculated by the power calculating circuit 5 and is input into the display circuit 3 for displaying;
step three, adjusting the relative position of the external microphone and the sound box according to the howling frequency and the output power displayed by the display circuit 3, wherein the specific adjustment step is to move the position of the external microphone first, when providing, the display circuit 3 displays an azimuth arrow, if the howling frequency is reduced after the external microphone is moved, the display circuit 3 displays the azimuth arrow in the same direction as the original moving direction, if the howling frequency is increased, the display circuit 3 displays a direction arrow opposite to the original moving direction, thus, the howling frequency and the output power on the voice electric signal can be effectively displayed through the arrangement of the step one and the step two, so that people can judge whether the position of the microphone at the moment is at a howling point by checking the numerical values of the howling frequency and the output power, thus, the same as the prior art is not needed, after the howling is generated, the howling point is searched in a sensory mode, the efficiency of howling suppression is greatly improved, and the indication effect of a directional arrow is adopted, so that people can be further assisted to adjust the relative position between the microphone and the loudspeaker box, and the efficiency of howling suppression is improved.
As a specific implementation of the improvement of the above method, the step of detecting the frequency by the howling frequency detection circuit 4 in the step one is as follows:
the method comprises the steps of judging whether the detected frequency is smaller than 2000HZ, if so, calculating the howling frequency by adopting a frequency measurement method, if not, calculating the howling frequency by adopting a frequency measurement method, wherein the frequency measurement method is suitable for detecting low frequency, and the frequency measurement method is suitable for detecting high frequency.
As a specific implementation manner of the above method, the steps of displaying the frequency and the power by the display circuit 3 in the first step and the second step are as follows:
and 3, performing delayed display on the frequency value displayed in the step 2, and then clearing the screen to finish the display of the frequency and the power in the step one and the step two, wherein the voltage display characters can be sequentially displayed through the setting in the step 1, then the voltage and the display power display characters and then the power display effect are displayed, so that the voltage display characters and the power display characters are available before the voltage and the power are displayed, people can effectively know whether the displayed value is the voltage value or the power value, the step 2 and the step 3 can also effectively realize that people know that the displayed value is the frequency, and meanwhile, once zero clearing is performed between the power and the frequency, so that the alternate display effect can be realized, and the intelligent control chip can better display the frequency and the power.
In summary, the audio power amplifier and the method of the present embodiment can effectively adjust the distance between the microphone and the sound source by preferentially displaying the frequency and the output power, so as to avoid the howling problem, and thus compared with the howling suppression method in the prior art, the method and the device can achieve the effect of pre-suppression, and greatly increase the howling suppression efficiency.
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.
Claims (9)
1. A howling suppression audio power amplifier, characterized by: the method comprises the following steps:
the pickup circuit (1) is coupled with the external microphone and used for receiving the voice electric signal output by the external microphone after sound conversion and outputting the voice electric signal after conversion;
the power amplification circuit (2) is coupled with the pickup circuit (1) and is also coupled with an external loudspeaker and used for receiving the voice electric signal output by the pickup circuit (1), amplifying the voice electric signal and outputting the amplified voice electric signal to the external loudspeaker to drive the external loudspeaker to produce sound;
the display circuit (3), the howling frequency detection circuit (4) and the power calculation circuit (5) are coupled to the display circuit (3), the howling frequency detection circuit (4) is coupled to the pickup circuit (1) and is used for detecting the howling frequency in the voice electric signal output by the pickup circuit (1) and inputting the howling frequency into the display circuit (3) to be displayed, and the power calculation circuit (5) is coupled to the power amplifier (2) and is used for receiving the amplified voice electric signal and calculating the power of the voice electric signal and inputting the power into the display circuit (3) to be displayed;
the power supply circuit (6) is coupled with external commercial power and used for converting the commercial power into a power supply and outputting the power supply to the pickup circuit (1), the power amplification circuit (2), the display circuit (3), the howling frequency detection circuit (4) and the power calculation circuit (5) for power supply;
the squealing device comprises a housing (91), a sound channel (92) arranged in the housing (91) and a cut-off device (93) arranged in the sound channel (92) and used for cutting off or opening the sound channel (92), wherein an external loudspeaker is arranged in the sound channel (92), the cut-off device (93) comprises a sound insulation board (931) and a driving motor (932), a storage groove (921) is formed in the channel wall of the sound channel (92), the sound insulation board (931) is slidably arranged in the storage groove (921) and can slide into the storage groove (921) to open the sound channel or slide out of the storage groove (921) to cut off the sound channel, the driving motor (932) is coupled with a squealing frequency detection circuit (4) to receive a squealing frequency signal output by the squealing frequency detection circuit (4), and along with the signal rotation, the coaxial lead screw that is fixed with in the pivot of driving motor (932), this driving motor (932) are fixed in the tank bottom of storing groove (921), and the lead screw extends towards the notch of storing groove (921) from driving motor (932), fixedly connected with sliding block on acoustic celotex board (931), the lead screw penetrates in the sliding block and with sliding block threaded connection in order to drive acoustic celotex board (931) from storing groove (921) in the roll-out or slide in storing groove (921).
2. The howling suppression audio power amplifier according to claim 1, wherein: a howling suppression circuit (7) is further coupled between the sound pickup circuit (1) and the power amplification circuit (2) and is used for suppressing howling of the voice electric signal output from the sound pickup circuit (1) to the power amplification circuit (2) and then inputting the voice electric signal to the power amplification circuit (2).
3. A howling suppressing audio power amplifier according to claim 1 or 2, characterized in that: a conversion circuit (8) is coupled between the power calculation circuit (5) and the power amplification circuit (2), the conversion circuit (8) comprising:
the rectifying circuit (81) is coupled with the power amplifying circuit (2) and is used for rectifying and outputting the amplified voice electric signal output by the power amplifying circuit (2);
a filter circuit (82), coupled to the rectifying circuit (81), for filtering the output rectified speech electrical signal;
and the A/D conversion circuit (83) is coupled with the filter circuit (82) and is also coupled with the power calculation circuit (5) and is used for receiving the filtered electric signal, converting the electric signal into a digital signal and inputting the digital signal into the power calculation circuit (5).
4. A howling suppressing audio power amplifier according to claim 1 or 2, characterized in that: the sound pickup circuit (1) includes:
an operational amplifier U1A, wherein an inverting input terminal of the operational amplifier U1A is coupled to a resistor R4, then coupled to a capacitor C3, then coupled to an external microphone, the capacitor C3 is further coupled to a resistor R3, then coupled to a power supply, a non-inverting input terminal of the operational amplifier U1A is coupled to a resistor R7 and a resistor R9, then coupled to ground, and further coupled to a resistor R6, and an output terminal of the operational amplifier U1A is coupled to a capacitor C1 and a resistor R1, which are connected in parallel, then coupled to an inverting input terminal of the operational amplifier U1A;
an operational amplifier U1B, the inverting input terminal of the operational amplifier U1B is coupled to a variable resistor R5 and then to the output terminal of the operational amplifier U1A, the non-inverting input terminal of the operational amplifier U1B is coupled to a resistor R8 and then to one terminal of a resistor R7, the output terminal of the operational amplifier U1B is coupled to a capacitor C2 and a resistor R2 which are connected in parallel and then to the inverting input terminal of the operational amplifier U1B, and a capacitor C4 is coupled to the power amplifier circuit (2).
5. The howling suppressing audio power amplifier according to claim 2, wherein: the howling suppression circuit (7) includes:
an inverting input terminal of the operational amplifier U2 is coupled to the temperature sensitive resistor RW1 and then coupled to the sound pickup circuit (1), and is further coupled to the capacitor C100 and then grounded, a non-inverting input terminal of the operational amplifier U2 is coupled to the resistor R100 and then coupled to one end of the temperature sensitive resistor RW1 opposite to the sound pickup circuit (1), an output terminal of the operational amplifier U2 is coupled to the resistor R101 and then coupled to the other end of the resistor R100 opposite to the sound pickup circuit (1), and the output terminal is further coupled to the power amplification circuit (2).
6. The howling suppressing audio power amplifier according to claim 1 or 2, characterized in that: the howling frequency detection circuit (4) includes:
an optical coupling relay U3, optical coupling relay U3 has input loop and output loop, the input loop includes first input and second input, the output loop includes first output and second output, coupling is coupled after first input has variable resistance R36 and is coupled in pickup circuit (1) behind the resistance R31, second input ground connection, first output is coupled in the power, and coupling is coupled behind the second output has variable resistance R37 and is grounded, still is coupled in behind the resistance R34 and is coupled in display circuit (3).
7. A method of suppressing howling using the audio power amplifier of any of claims 1 to 6, characterized by: the method comprises the following steps:
picking up an electric signal output after sound conversion by an external microphone by using a pickup circuit (1), detecting howling frequency in the electric signal by using a howling frequency detection circuit (4), and inputting the electric signal into a display circuit (3) for display;
secondly, amplifying the electric signal output by the pickup circuit (1) by using the power amplifying circuit (2), inputting the electric signal into an external loudspeaker for playing, calculating the output power of the electric signal amplified by the power amplifying circuit (2) by using the power calculating circuit (5), and inputting the output power into the display circuit (3) for displaying;
and step three, adjusting the relative position of the external microphone and the loudspeaker box according to the howling frequency and the output power displayed by the display circuit (3), wherein the specific adjustment step is that the position of the external microphone is moved firstly, the display circuit (3) displays an azimuth arrow when providing, if the howling frequency is reduced after the external microphone is moved, the display circuit (3) displays an azimuth arrow in the same direction as the original moving direction, and if the howling frequency is increased, the display circuit (3) displays a direction arrow opposite to the original moving direction.
8. The method of claim 7, wherein: the step of detecting the frequency by the howling frequency detection circuit (4) in the step one is as follows:
and step one, judging whether the detected frequency is smaller than 2000HZ, if so, calculating the howling frequency by adopting a frequency measurement method, and if not, calculating the howling frequency by adopting a frequency measurement method.
9. The method of claim 7, wherein: the display circuit (3) in the first step and the second step displays the frequency and the power as follows:
step 1, displaying variable assignment by using a display circuit (3), setting a coordinate first line, displaying a voltage measurement character, setting a coordinate second line, displaying a voltage value, setting a coordinate third line, and displaying a power measurement character; setting a fourth row coordinate and displaying the power value;
step 2, the power value displayed in the step 1 is displayed in a delayed mode and then is cleared, then a first line of coordinates is set, frequency measurement characters are displayed, a second line of coordinates is set, and frequency numerical values are displayed;
and 3, displaying the frequency value displayed in the step 2 in a delayed mode, and then clearing the screen to finish displaying the frequency and the power in the step one and the step two.
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| CN111464930B (en) * | 2020-05-12 | 2022-02-25 | 歌尔智能科技有限公司 | Howling detection method and device for earphone and storage medium |
| CN112511948B (en) * | 2021-02-08 | 2021-06-11 | 江西联创宏声电子股份有限公司 | Earphone set |
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