Active noise reduction display system

Abstract

The present invention relates to the field of signal processing technology, specifically to an active noise reduction and noise display system, including hardware noise reduction and software noise reduction. The hardware noise reduction uses a low-frequency power amplifier to reduce energy consumption, and the software noise reduction uses a single-chip microcomputer as a controller to display the noise collected by the noise collection circuit on a liquid crystal screen. The hardware noise reduction circuit of the present invention uses a low-frequency power amplifier to minimize energy consumption, and the software part uses a single-chip microcomputer as a controller to display the noise collected by the noise collection circuit on a liquid crystal screen. This system can realize a noise display circuit based on active noise reduction technology, can monitor the noise status in real time, can realize a noise display circuit based on active noise reduction technology, can monitor the noise status in real time, and the active noise reduction technology can filter out noise more effectively and conveniently; active noise reduction has better performance characteristics.

Description

Technical Field

[0001] The invention relates to the technical field of signal processing design, in particular to an active noise reduction noise display system. Background Art

[0002] In our daily lives, almost everyone will encounter noises such as air conditioners, vacuum cleaners, snoring, and decoration noises. The "Law of the People's Republic of China on the Prevention and Control of Noise Pollution" will come into effect on June 5, 2022. Based on this, active noise reduction technology can reduce these noises, but it was previously expensive and did not enter the public.

[0003] Publication (Announcement) No.: CN112153505A discloses a noise reduction system for an electronic device. The electronic device includes a shell. The noise reduction system includes a first microphone, a second microphone and a processor circuit. The first and second microphones are arranged in the shell. The first microphone is used to generate a first sound signal. The second microphone is away from the shell relative to the first microphone. The second microphone is used to generate a second sound signal. The processor circuit is coupled to the first microphone and the second microphone. The processor circuit receives a first sound signal from the first microphone and a second sound signal from the second microphone. The processor circuit is used to calculate the difference between the first sound signal and the second sound signal to obtain an equalization gain, and adjust the first sound signal according to the equalization gain to generate a third sound signal. In addition, a noise reduction method is also proposed. The noise reduction system and noise reduction method of the present invention can effectively reduce the impact of noise on electronic devices.

[0004] Publication (Announcement) No.: CN107564509A discloses a noise reduction system for reducing the noise generated by medical imaging equipment in a scanning room. The noise reduction system sends a noise reduction signal corresponding to the noise signal to the target area based on the detected noise signal to reduce or offset the noise generated by the medical imaging equipment in the target area. The above-mentioned noise reduction system reduces the noise in the target area in real time, that is, it performs targeted noise reduction on the noise in the scanning room. The noise reduction is targeted and not only easy to implement, but also has a good noise reduction effect and a good noise protection effect on personnel.

[0005] The effects of active noise reduction and passive noise reduction on different sound frequencies are very different. Passive noise reduction is better in eliminating mid- and high-frequency noise, but it is less effective for lower-frequency sounds. This is due to the characteristics of sound: high frequencies can only penetrate and can be blocked by materials, while low frequencies can be diffracted, diffused, and resonated and bypassed, and cannot be blocked. Active noise reduction technology works better in the low-frequency segment (50-2000HZ), but it is powerless for high frequencies and may even intensify the noise. This is because the higher the frequency, the faster the device must react to keep up, and if it can't keep up, it will even be superimposed instead of weakened. Most of the noise in daily life is low-frequency noise, which is suitable for active noise reduction technology. Summary of the invention

[0006] The object of the present invention is to provide an active noise reduction noise display system to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An active noise reduction and noise display system includes hardware noise reduction and software noise reduction. The hardware noise reduction uses a low-frequency power amplifier to reduce energy loss, and the software noise reduction uses a single-chip microcomputer as a controller to display the noise collected by a noise collection circuit on a liquid crystal screen.

[0009] Preferably, the circuits for hardware noise reduction and software noise reduction include an LM324 operational amplifier circuit, an AD\DA converter, a 12864 LCD screen, a single-chip microcomputer and a microphone.

[0010] Preferably, the operational amplifier circuit includes a first LM324 operational amplifier, a second LM324 operational amplifier and a third LM324 operational amplifier, the communication input terminal of the first LM324 operational amplifier is externally connected to a 0.01uF capacitor, the capacitor is externally connected to the output terminal of the microphone, the output terminal of the first LM324 operational amplifier is connected to the reverse input terminal of the second LM324 operational amplifier through a resistor R4, and the output terminal of the second LM324 operational amplifier is connected to the reverse input terminal of the third LM324 operational amplifier through a resistor R5.

[0011] Preferably, the inverting input terminal of the first LM324 operational amplifier is connected to the output terminal of the first LM324 operational amplifier through a resistor R6, the inverting input terminal of the first LM324 operational amplifier is grounded through a resistor R7 and a 10uF capacitor, and a resistor R8 is arranged between the resistor R6 and the 10uF capacitor.

[0012] Preferably, the resistance value of the resistor R4 is 10 kΩ, the resistance value of the resistor R5 is 100 kΩ, the resistance value of the resistor R6 is 100 kΩ, the resistance value of the resistor R7 is 510 Ω, and the resistance value of the resistor R8 is 10 kΩ.

[0013] Preferably, the inverting input terminal of the second LM324 operational amplifier is further connected to the output terminal of the second LM324 operational amplifier via a resistor R1.

[0014] Preferably, the inverting input terminal of the third LM324 operational amplifier is also connected to the output terminal of the third LM324 operational amplifier through a resistor R2 and a sliding resistor RW1, and the output terminal of the third LM324 operational amplifier is connected to the same-direction input terminal of the third LM324 operational amplifier through a 0.1uF capacitor.

[0015] Preferably, the resistance value of the resistor R1 is 100 kΩ, the resistance value of the resistor R2 is 100 kΩ, and the resistance value of the sliding resistor RW1 is 0-500 kΩ, so the operational amplifier circuit is externally connected to +12V and -12V DC power supplies.

[0016] Preferably, the single chip microcomputer is externally connected to a +5V voltage.

[0017] Preferably, the microphone is externally connected to a +5V pull-up voltage, and a resistor R3 is provided between the pull-up voltage and the microphone, and the resistance value of the resistor R3 is 1KΩ.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The active noise reduction and noise display system of the present invention adopts a low-frequency power amplifier in the hardware noise reduction circuit to minimize energy loss. The software part uses a single-chip microcomputer as a controller to display the noise collected by the noise collection circuit on a liquid crystal screen. This system can realize a noise display circuit based on active noise reduction technology, can monitor the noise status in real time, and can realize a noise display circuit based on active noise reduction technology, which can monitor the noise status in real time.

[0020] 2. In the active noise reduction display system of the present invention, active noise reduction technology can filter out noise more effectively and conveniently; active noise reduction has better performance characteristics: active noise reduction will adjust its own parameters to remove noise according to changes in the input signal, while passive noise reduction will not; the algorithm complexity of active noise reduction is low, while the algorithm complexity of passive noise reduction is high; the output signal-to-noise ratio of active noise reduction is high, while that of passive noise reduction is relatively low, especially when the background noise changes drastically. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flowchart of the implementation process of the present invention.

[0022] Figure 2 It is a schematic diagram of the circuit principle of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Example 1

[0025] An active noise reduction and noise display system includes hardware noise reduction and software noise reduction. The hardware noise reduction uses a low-frequency power amplifier to reduce energy loss. The software noise reduction uses a single-chip microcomputer as a controller to display the noise collected by the noise collection circuit on a liquid crystal screen. The collected noise enters the noise display circuit after noise reduction and is displayed in real time through a circuit controlled by the single-chip microcomputer. The flow chart is as follows Figure 1 shown.

[0026] Further, such as Figure 2 As shown, the circuits of hardware noise reduction and software noise reduction include LM324 operational amplifier circuit, AD\DA converter, 12864 LCD screen, single chip microcomputer and microphone.

[0027] Specifically, the operational amplifier circuit includes a first LM324 operational amplifier, a second LM324 operational amplifier and a third LM324 operational amplifier. The communication input terminal of the first LM324 operational amplifier is externally connected to a 0.01uF capacitor, and the capacitor is externally connected to the output terminal of the microphone. The output terminal of the first LM324 operational amplifier is connected to the reverse input terminal of the second LM324 operational amplifier through a resistor R4, the output terminal of the second LM324 operational amplifier is connected to the reverse input terminal of the third LM324 operational amplifier through a resistor R5, the reverse input terminal of the first LM324 operational amplifier is connected to the output terminal of the first LM324 operational amplifier through a resistor R6, the reverse input terminal of the first LM324 operational amplifier is grounded through a resistor R7 and a 10uF capacitor, and a resistor R8 is arranged between the resistor R6 and the 10uF capacitor.

[0028] It is worth noting that the resistance value of the resistor R4 is 10 kΩ, the resistance value of the resistor R5 is 100 kΩ, the resistance value of the resistor R6 is 100 kΩ, the resistance value of the resistor R7 is 510 Ω, and the resistance value of the resistor R8 is 10 kΩ.

[0029] In addition, the reverse input terminal of the second LM324 operational amplifier is also connected to the output terminal of the second LM324 operational amplifier through a resistor R1, the reverse input terminal of the third LM324 operational amplifier is also connected to the output terminal of the third LM324 operational amplifier through a resistor R2 and a sliding resistor RW1, and the output terminal of the third LM324 operational amplifier is connected to the same-direction input terminal of the third LM324 operational amplifier through a 0.1uF capacitor.

[0030] It is worth noting that the resistance value of resistor R1 is 100kΩ, the resistance value of resistor R2 is 100kΩ, and the resistance value of sliding resistor RW1 is 0-500kΩ, so the operational amplifier circuit is connected to +12V and -12V DC power supplies, the microcontroller is connected to a +5V voltage, the microphone is connected to a +5V pull-up voltage, and a resistor R3 is provided between the pull-up voltage and the microphone, and the resistance value of resistor R3 is 1KΩ.

[0031] After installing the active noise reduction circuit, supply +12V and -12V DC power supplies to the noise reduction circuit and LM324 operational amplifier circuit, supply +5V pull-up voltage to the microphone, and +5V voltage to the microcontroller, then it can be used normally.

[0032] The working principle of the active noise reduction and noise display system of the present invention is as follows:

[0033] (1) This part first amplifies the collected noise through an LM324 operational amplifier circuit.

[0034] (2) The collected audio analog signal is then converted into a digital signal through an AD\DA converter, which is controlled by a single-chip microcomputer.

[0035] (3) The audio signal after noise reduction processing is input into the AD\DA converter, the audio analog signal is converted into a digital signal, and then the digital signal is displayed on the 12864 LCD screen through the single chip microcomputer.

[0036] (4) The microcontroller displays the converted digital signal through a 12864 LCD screen with a display accuracy of two decimal places.

[0037] The active noise reduction and noise display system of the present invention adopts a low-frequency power amplifier in the hardware noise reduction circuit to minimize energy loss. The software part uses a single-chip microcomputer as a controller to display the noise collected by the noise collection circuit on a liquid crystal screen. The system can realize a noise display circuit based on active noise reduction technology, can monitor the noise status in real time, and can realize a noise display circuit based on active noise reduction technology, and can monitor the noise status in real time.

[0038] In the active noise reduction display system of the present invention, the active noise reduction technology can filter out noise more effectively and conveniently; the active noise reduction has better performance characteristics: the active noise reduction will adjust its own parameters according to the change of the input signal to remove noise, while the passive noise reduction will not; the algorithm complexity of the active noise reduction is low, while the algorithm complexity of the passive noise reduction is high; the output signal-to-noise ratio of the active noise reduction is high, while the passive noise reduction ratio is relatively low, especially when the background noise changes drastically.

[0039] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An active noise reduction display system, characterized in that: It includes hardware noise reduction and software noise reduction. The hardware noise reduction uses a low audio power amplifier to reduce energy loss. The software noise reduction uses a single-chip microcomputer as a controller to display the noise collected by the noise collection circuit on a liquid crystal screen. The circuits of hardware noise reduction and software noise reduction include LM324 operational amplifier circuit, AD\DA converter, 12864 LCD screen, single chip microcomputer and microphone; The operational amplifier circuit includes a first LM324 operational amplifier, a second LM324 operational amplifier and a third LM324 operational amplifier, the communication input end of the first LM324 operational amplifier is externally connected to a 0.01uF capacitor, the capacitor is externally connected to the output end of the microphone, the output end of the first LM324 operational amplifier is connected to the reverse input end of the second LM324 operational amplifier through a resistor R4, and the output end of the second LM324 operational amplifier is connected to the reverse input end of the third LM324 operational amplifier through a resistor R5; The inverting input terminal of the first LM324 operational amplifier is connected to the output terminal of the first LM324 operational amplifier through a resistor R6, and the inverting input terminal of the first LM324 operational amplifier is grounded through a resistor R7 and a 10uF capacitor, and a resistor R8 is provided between the resistor R6 and the 10uF capacitor; The resistance value of the resistor R4 is 10 kΩ, the resistance value of the resistor R5 is 100 kΩ, the resistance value of the resistor R6 is 100 kΩ, the resistance value of the resistor R7 is 510 Ω, and the resistance value of the resistor R8 is 10 kΩ.

2. The active noise reduction display system according to claim 1, characterized in that: The inverting input terminal of the second LM324 operational amplifier is also connected to the output terminal of the second LM324 operational amplifier through the resistor R1.

3. The active noise reduction display system according to claim 2, characterized in that: The inverting input terminal of the third LM324 operational amplifier is also connected to the output terminal of the third LM324 operational amplifier through the resistor R2 and the sliding resistor RW1, and the output terminal of the third LM324 operational amplifier is connected to the non-inverting input terminal of the third LM324 operational amplifier through a 0.1uF capacitor.

4. The active noise reduction display system according to claim 3, characterized in that: The resistance value of resistor R1 is 100kΩ, the resistance value of resistor R2 is 100kΩ, and the resistance value of sliding resistor RW1 is 0-500kΩ, so the operational amplifier circuit is externally connected to +12V and -12V DC power supplies.

5. The active noise reduction display system according to claim 1, characterized in that: The single chip microcomputer is externally connected to a +5V voltage.

6. The active noise reduction display system according to claim 1, characterized in that: The microphone is externally connected to a +5V pull-up voltage, and a resistor R3 is provided between the pull-up voltage and the microphone, and the resistance value of the resistor R3 is 1KΩ.

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