A multi-channel audio signal automatic gain adjustment circuit

Abstract

The utility model relates to the field of microphone switching, specifically a multi-channel audio signal automatic gain adjustment circuit. The circuit includes a microphone input unit, an identification unit, a gain adjustment unit and a mixing unit; wherein there are more than two microphone input units, each with a gain adjustment unit, and the adjusted audio output is simultaneously connected to the mixing unit; the identification unit acquires the current status of the microphone input unit through loop collection, and controls the working status of the gain adjustment unit and the mixing unit of each microphone input unit by hardware, so that multiple microphones can automatically adjust the circuit gain. This circuit is often used to detect the audio information of a mobile phone or computer, and sample it to provide a sound source for the sound and light synchronization of an RGB / RGBIC music controller; the collection environment is that when the sound source of the mobile phone or computer is unplugged, it automatically switches to the sound source information in the pickup mode of a capacitive electret microphone, and provides a sound source for the sound and light synchronization of the RGB / RGBIC music controller, and uses an interval power supply to ensure that faults are detected and that the circuit will not fail.

Description

Technical Field

[0001] The utility model relates to the field of microphone switching, specifically a multi-channel audio signal automatic gain adjustment circuit Background Art

[0002] Most conference venues have only one set of power amplifiers for sound playback, but there are many sound sources, such as microphones, projectors and recorders, among which there are often many microphones; each sound source has different gain requirements with the power amplifier; in order to automatically select and adjust the gain when switching microphones, a multi-channel audio signal automatic gain adjustment circuit is designed; this circuit includes a microphone input unit, an identification unit, a gain adjustment unit and a mixing unit; there are more than two microphone input units, each with a gain adjustment unit, and the adjusted audio output is simultaneously connected to the mixing unit; the identification unit obtains the current status of the microphone input unit through loop collection, and controls the working status of the gain adjustment unit and the mixing unit of each microphone input unit by hardware, so that the multi-microphone automatic gain adjustment circuit automatically adjusts the gain.

[0003] Similar circuits have the following disadvantages:

[0004] 1. In the e-sports atmosphere light, in order to achieve a better experience and adapt to a variety of usage scenarios, it is necessary to distinguish audio signals from different sources;

[0005] 2. For the electret condenser microphone, when it is working, it will pick up most of the external music spectrum, causing the received music spectrum to be disturbed and the sound signal to contain a large amount of clutter;

[0006] 3. Collecting audio signals directly through the audio cable can effectively avoid the noise when sampling with a microphone; at the same time, because the audio cable can only be used to collect the signal source, the experience will be lost;

[0007] 4. Each audio sampling circuit will have a different filtering bandwidth, amplitude, and phase; in this case, different negative feedback amplifier circuits are used to adapt to different circuit parameters.

[0008] This circuit is often used to detect audio information from a mobile phone or computer, and to sample the audio information to provide a sound source for the sound and light synchronization of an RGB / RGBI C music controller; the collection environment is that when the audio source of the mobile phone or computer is unplugged, the circuit automatically switches to the audio source information in the pickup mode of a core-type electret microphone to provide a sound source for the sound and light synchronization of the RGB / RGBI C music controller, and uses an interval power supply to ensure that a fault is detected and that the circuit does not fail; the utility model can detect audio signals from different sources and automatically adjust the gain of the corresponding audio signal. Utility Model Content

[0009] Most conference venues have only one set of power amplifiers for sound playback, which can be used with many sound sources, such as microphones, projectors and recorders, among which there are often many microphones; each sound source has different gain requirements with the power amplifier; in order to automatically select and adjust the gain when switching microphones, a multi-channel audio signal automatic gain adjustment circuit is designed; the purpose of the utility model is to address the defects and deficiencies of the prior art. The utility model is a multi-channel audio signal automatic gain adjustment circuit, the circuit includes a microphone input unit, an identification unit, a gain adjustment unit and a mixing unit; wherein there are two or more microphone input units, each with a gain adjustment unit, and the adjusted audio output is simultaneously connected to each input end of the mixing unit installed on the main circuit substrate; the identification unit obtains the current status of the microphone input unit through loop collection, and controls the working status of the gain adjustment unit and the mixing unit of each microphone input unit by hardware, so that the multi-microphone automatic gain adjustment circuit automatically adjusts the gain.

[0010] One is a microphone input unit, which has two or more units, each with a gain adjustment unit. After adjustment, the audio output is connected to each input end of the mixing unit and installed on the main circuit substrate; the identification unit can be connected individually or in groups according to the microphone input unit, and the current status of the microphone input unit can be obtained through loop collection, so that the multi-microphone automatic gain adjustment circuit can automatically adjust the gain.

[0011] The second is the identification unit, which uses the loop change generated by the microphone input unit and the identification unit to know the status of the microphone input unit, so that the multi-microphone automatic gain adjustment circuit can automatically adjust the gain; using the PIN1 of the audio interface PJ342, when the audio line is connected, due to mechanical reasons, the copper sheet on the PIN4 will contact the PIN1, so that the PIN1 has the same potential as the PIN4, thereby turning on the switch transistor;

[0012] The third is the gain adjustment unit. Different microphone input unit signals have different strengths and different output power requirements, which require different gain multiples. The gain multiple can be adjusted by using the appropriate resistor ratio of the transistor amplifier circuit. Using transistors, an exclusive OR (XOR) logic circuit is designed to automatically switch the amplifier circuit gain and adjust the high-pass filter.

[0013] The fourth is a mixing unit, which is a gain adjustment unit of each microphone input unit, and the adjusted audio output is simultaneously connected to the mixing unit.

[0014] Among them, the preferred solution is that in the process of multi-channel microphone input to audio output, the identification unit first obtains the current status of the microphone input unit through loop collection, and controls the working status of the gain adjustment unit and the mixing unit of each microphone input unit through hardware, so that the multi-microphone automatic gain adjustment circuit automatically adjusts the gain, and then connects to the audio output through the mixing unit.

[0015] Among them, the preferred solution is that the microphone input unit often detects the audio information of the mobile phone or computer, samples it, and provides the sound source for the sound and light synchronization of the RGB / RGBI C music controller; its collection environment is that when the sound source of the mobile phone or computer is unplugged, it automatically switches to the battery-type electret microphone pickup mode, and obtains the sound source information, and provides the sound source for the sound and light synchronization of the RGB / RGBI C music controller, and adopts interval power supply to ensure that the fault is detected and the circuit will not be damaged due to the fault.

[0016] Among them, the preferred solution is that this circuit is used for the sound and light synchronization lighting effect of the atmosphere lamp. ① In electrical logic, for the sound sources of different signal sources, an exclusive OR (XOR) electrical structure is adopted: that is, when the audio line is inserted, the microphone sampling is stopped; when the audio line is unplugged, the microphone sampling is started;

[0017] ② For audio sources with different signal sources, the same XOR electrical structure is used: when using audio line to pick up sound, the amplification factor and the audio bandwidth of audio pickup are one way; when using microphone sampling, the amplification factor and the audio bandwidth of audio pickup are another way.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. This circuit can detect audio signals from different sources and automatically adjust the gain of the corresponding audio signals.

[0020] 2. Realize the use of multiple audio sources: computer / mobile phone / speaker..., and expand the audio interface at the same time, when taking audio signals, it will not affect the media function.

[0021] 3. You can also set it to automatically switch to microphone pickup mode when the audio cable is not connected.

[0022] 4. Using the mechanical line of the audio interface P342, you can automatically switch between audio and microphone;

[0023] 5. Use transistors to design logic management circuits, which is low cost;

[0024] 6. The audio circuit amplification gain and audio bandwidth are designed separately, which greatly enriches the musical effect of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1A schematic diagram of a system framework of a multi-channel audio signal automatic gain adjustment circuit;

[0026] Figure 2 This is a schematic diagram of a multi-channel audio signal automatic gain adjustment circuit:

[0027] Figure 3 A schematic diagram of a microphone input unit circuit of a multi-channel audio signal automatic gain adjustment circuit;

[0028] Figure 4 A schematic diagram of a microphone input unit and a recognition unit circuit of a multi-channel audio signal automatic gain adjustment circuit;

[0029] Figure 5 A schematic diagram of a gain adjustment unit circuit of a multi-channel audio signal automatic gain adjustment circuit;

[0030] Figure 6 A schematic diagram of a mixing unit circuit of a multi-channel audio signal automatic gain adjustment circuit;

[0031] Description of the accompanying symbols:

[0032] 10-microphone input unit; 11-microphone audio output; 12-second microphone input unit; 13-gain adjustment unit audio output; 15-second microphone audio output; 17-second gain adjustment unit audio output; 20-identification unit; 22-microphone insertion detection point; 24-microphone insertion detection point; 28-control output; 30-gain adjustment unit; 32-gain adjustment unit; 40-mixing unit; 50-audio output; 60-input end; 70-circuit main substrate; DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] like Figures 1 to 6To achieve the above purpose, the utility model provides the following technical solutions: Most conference venues have only one set of power amplifiers for sound playback, but there are many sound sources, such as microphones, projectors and recorders, among which there are often many microphones; there are different gain requirements between each sound source and the power amplifier; in order to automatically select and adjust the gain when switching microphones, a multi-channel audio signal automatic gain adjustment circuit is designed; the purpose of the utility model is to address the defects and shortcomings of the prior art. The utility model is a multi-channel audio signal automatic gain adjustment circuit, such as Figure 1 As shown in the system framework diagram, the circuit includes a microphone input unit 10, an identification unit 20, a gain adjustment unit 30 and a mixing unit 40; wherein there are two or more microphone input units 10, each having a gain adjustment unit 30, and after adjustment, the microphone audio output 14 is simultaneously connected to each input end 60 of the mixing unit 40 installed on the circuit main substrate 70; the identification unit 20 obtains the current status of the microphone input unit 10 through loop collection, and controls the working status of the gain adjustment unit 30 and the mixing unit 40 of each microphone input unit 10 by hardware, so that the multi-microphone automatic gain adjustment circuit automatically adjusts the gain.

[0035] One is a microphone input unit 10, such as Figure 1 As shown in the schematic diagram of the system framework, there are two or more, one is a microphone input unit 10 and the other is a second microphone input unit 14 with a microphone audio output 11 and a second microphone audio output 15; connected to the gain adjustment unit 30 and the second gain adjustment unit 30, the adjusted gain adjustment unit audio output 13, the second gain adjustment unit audio output 17 and the input terminal 60, and connected to the mixing unit 40 at the same time, and the above are installed on the main circuit substrate 70; as shown in FIG. Figure 2 As shown, the identification unit 20 can be connected simultaneously according to the microphone insertion detection point 22 of the microphone input unit 10 and the second microphone insertion detection point 24 of the second microphone input unit 12, and the current status of the microphone input unit 10 and the second microphone input unit 10 can be obtained through loop collection, so that the multi-microphone automatic gain adjustment circuit can automatically adjust the gain.

[0036] The second is the identification unit 20, such as Figure 3 As shown, the loop change generated by the microphone input unit 10 and the identification unit 20 is to know the current status of the microphone input unit 10 and the second microphone input unit 12 through the microphone insertion detection point 22 and the second microphone insertion detection point 24, so that the multi-microphone automatic gain adjustment circuit can automatically adjust the gain; using the PIN1 of the audio interface PJ342, when the audio line is connected, due to mechanical reasons, the copper sheet on the PIN4 will contact the PIN1, so that PIN1 has the same potential as the PIN4, thereby turning on the switch transistor. Figure 3As shown, R13 controls Q3 to select the mixing unit (40).

[0037] The third is the gain adjustment unit 30. Different microphone input units 10 have different signal strengths and different output power requirements, which require different gain multiples. The gain multiple can be adjusted by using a suitable resistor ratio of the transistor amplifier circuit (80). Using transistors, an XOR logic circuit is designed to automatically switch the amplifier circuit gain and adjust the high-pass filter. Figure 5 As shown, the sound signal points of the microphone input unit 10 and the second microphone input unit 12 are connected, and are connected to the B-stage of Q2 through R11, and are also connected to the B-stage of Q4 through R13, and the C-stage of Q2 is connected to the I N- of the mixing unit 40 through C6 and R6; and the C-stage of Q4 is connected to the B-stage of Q1 through R, and the C-stage of Q1 is connected to the I N- of the mixing unit 40 through C7 and R7; because there is an additional Q4 at the front end of Q1, only one group between Q1 and Q2 will be turned on.

[0038] When the connection point of R11 and R13 is at a high level, the Q2C stage is connected to the E stage and also to the ground; the Q4C stage is connected to the E stage and also to the ground; which is equivalent to C6 and R8 being grounded, forming an amplification gain for the mixing unit 40.

[0039] When the connection point of R11 and R13 is at a low level, Q2C and E are not conducting, and are not conducting with the ground, Q4Q2C and E are not conducting, and are not conducting with the ground; while R9 has a high level, Q1C and E are conducting, and are also conducting with the ground; which is equivalent to C7 and R7 being grounded, forming an amplification gain for the mixing unit 40. The amplification gain can be adjusted according to whether the microphone is inserted or not.

[0040] The fourth is a mixing unit 40, which connects the gain adjustment unit 30 of each microphone input unit 10, the adjusted microphone audio output 14 and the second microphone audio output 16 to the mixing unit 40 at the same time. Figure 6 As shown, when the point where R11 and R13 are connected is at a high level, it is equal to that C6 and R6 are grounded; when the point where R11 and R13 are connected is at a low level, it is equal to that C7 and R7 are grounded. Because the grounding resistance and capacitance are different, the gain of the mixing unit 40 is different.

[0041] Among them, the preferred solution is that the microphone input unit 10 often detects the audio information of the mobile phone or computer, samples it, and provides the sound source for the sound and light synchronization of the RGB / RGBI C music controller; its collection environment is that when the sound source of the mobile phone or computer is unplugged, it automatically switches to the battery-type electret microphone pickup mode, and the sound source information provides the sound source for the sound and light synchronization of the RGB / RGBI C music controller, and adopts interval power supply to ensure that the fault is detected and the circuit will not be damaged due to the fault.

[0042] Among them, the preferred solution is as follows Figure 2 As shown, this circuit is used for the sound and light synchronization lighting effect of the atmosphere lamp. ① In electrical logic, for the sound sources of different signal sources, an exclusive OR (XOR) electrical structure is adopted: that is, when the audio line is inserted, the microphone sampling is stopped; when the audio line is unplugged, the microphone sampling is started;

[0043] ② For audio sources with different signal sources, the same XOR electrical structure is used: when using audio line to pick up sound, the amplification factor and the audio bandwidth of audio pickup are one way; when using microphone sampling, the amplification factor and the audio bandwidth of audio pickup are another way.

[0044] Among them, the preferred scheme is: ① When the audio line is connected to PJ342A, the audio line will hit the spring on PJ342A, causing the spring to deform and contact with the copper sheet of PI N1, so that PI N1 is charged; the audio signal line will have a bias voltage, and this bias voltage is used to turn on the transistor Q3 through the bias resistor R12; ② When Q3 is turned on, the collector of Q3 is connected to the ground, where the potential is 0, so Q2 / Q4 is turned off; when Q2 is turned off, the path formed by R6 / C6 is turned off;

[0045] a. When Q4 is cut off, 3V3 makes the collector potential of Q4 high level through R8, and the high level makes Q1 high pass through the bias resistor R9, so that the R7 / C7 path is turned on; when this branch path is turned on, the AC signal is amplified through C7, and the amplification factor Av=R5 / R7≈7; this is because the signal from the audio line is relatively robust;

[0046] b. The signal line is bandpass designed through R7 / C7 to meet the richness of the music spectrum and make the sound and light synchronization richer;

[0047] ③When the audio line is unplugged from PJ342A, the spring on PIN1 is restored, the contact between PIN4 and PIN1 is disconnected, PIN1 becomes low level; Q3 is cut off; the collector of Q3 becomes high level, and the transistor Q2 / Q4 is turned on through the bias resistor R11 / R13;

[0048] a. Q2 is turned on, and the R6 / C6 path is turned on;

[0049] b. When PJ342A restores the deformed PI N4 / PI N4 contact, it automatically switches to the electret condenser microphone to collect audio signals;

[0050] c. When Q4 is turned on, the collector of Q4 is connected to the ground, making Q1 cut off; then the R7 / C7 path is turned on; d. When the Q2 transistor is turned on, the amplification factor of the microphone sampling Av=R5 / R6=200 times; e. The cutoff frequency of the high-pass filter is set to ≈100Hz through R6 / C6, and the audio signal of >100Hz can be passed through C6. In this range, the sound and light synchronization reaction is very sensitive;

[0051] ④R5 and the transistor circuit form a negative feedback circuit;

[0052] ⑤Amplify the audio signal through the ADC chip ME321; R3 / R4 provides the bias voltage

[0053] Among them, the preferred solution is that the circuit can detect audio signals from different sources and automatically adjust the gain of the corresponding audio signals, so as to realize the use of multiple audio sources: computer / mobile phone / speaker..., and at the same time expand the audio interface, and when the audio signal is used, the media function is not affected.

[0054] Among them, the preferred solution is that it can be set to automatically switch to microphone pickup mode when the audio line is not connected. The mechanical line of the audio interface P342 can automatically switch between audio and microphone;

[0055] Among them, the preferred solution is to use triodes to design the logic management circuit, which is low in cost;

[0056] Among them, the preferred solution is to separately design the audio circuit amplification gain and audio bandwidth, which greatly enriches the musical effect of the product.

[0057] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

[0058] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multi-channel audio signal automatic gain adjustment circuit, characterized in that: The circuit comprises a microphone input unit (10), an identification unit (20), a gain adjustment unit (30) and a mixing unit (40); wherein there are two or more microphone input units (10), each of which has a gain adjustment unit (30); after adjustment, the microphone audio output (14) is simultaneously connected to each input end (60) of the mixing unit (40) installed on a circuit main substrate (70); the identification unit (20) acquires the current status of the microphone input unit (10) through loop collection, and controls the working status of the gain adjustment unit (30) and the mixing unit (40) of each microphone input unit (10) by hardware, so that the multi-microphone automatic gain adjustment circuit automatically adjusts the gain, and outputs the audio (50) through the mixing unit (40).

2. A multi-channel audio signal automatic gain adjustment circuit according to claim 1, characterized in that: The microphone input units (10) have two or more, each having a gain adjustment unit (30). After adjustment, the microphone audio output (14) is simultaneously connected to each input end (60) of the mixing unit (40) installed on the circuit main substrate (70); the identification unit (20) can be connected individually or in groups according to the microphone input unit (10), and the current status of the microphone input unit (10) can be obtained through loop collection, so that the multi-microphone automatic gain adjustment circuit automatically adjusts the gain through the mixing unit (40) to output the audio (50).

3. The multi-channel audio signal automatic gain adjustment circuit according to claim 1, characterized in that: The identification unit (20) uses the microphone input unit (10) and the identification unit (20) to generate a loop change to obtain the current status of the microphone input unit (10), so that the multi-microphone automatic gain adjustment circuit automatically adjusts the gain; using PIN1 of the audio interface PJ342, when the audio line is connected, due to mechanical reasons, the copper sheet on PIN4 will contact PIN1, so that PIN1 has the same potential as PIN4, thereby turning on the switch transistor.

4. The multi-channel audio signal automatic gain adjustment circuit according to claim 1, characterized in that: The gain adjustment unit (30) requires different gain multiples due to the different signal strengths and output power requirements of different microphone input units (10). The gain multiples can be adjusted by using a suitable resistor ratio of the triode amplifier circuit (80); a triode is used to design an exclusive OR (XOR) logic circuit to automatically switch the gain of the amplifier circuit and adjust the high-pass filter.

5. The multi-channel audio signal automatic gain adjustment circuit according to claim 1, characterized in that: The mixing unit (40) adjusts each microphone input unit (10) through the gain adjustment unit (30), and the obtained audio output (50) is then connected to the mixing unit (40).

6. The multi-channel audio signal automatic gain adjustment circuit according to claim 1, characterized in that: The microphone input unit (10) usually detects the audio information of the mobile phone or computer, samples it, and provides the sound source for the sound and light synchronization of the RGB / RGBIC music controller; The collection environment is that when the audio source of the mobile phone or computer is unplugged, it automatically switches to the battery-type electret microphone pickup mode, intermediate sound source information, and provides sound source for the sound and light synchronization of the RGB / RGBIC music controller. It uses interval power supply to ensure that faults are detected and the circuit will not be damaged due to faults.

7. The multi-channel audio signal automatic gain adjustment circuit according to claim 1, characterized in that: This circuit is used for the sound and light synchronization lighting effect of the atmosphere lamp; ① In the electrical logic, for the sound sources of different signal sources, an exclusive OR (XOR) electrical structure is adopted; that is, when the audio line is inserted, the microphone sampling is stopped; when the audio line is unplugged, the microphone sampling is started; ② For audio sources with different signal sources, the same XOR electrical structure is used: when using audio line to pick up sound, the amplification factor and the audio bandwidth of audio pickup are one way; when using microphone sampling, the amplification factor and the audio bandwidth of audio pickup are another way.

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