CN201243374Y - Earphone volume adjusting control device - Google Patents

Abstract

The utility model relates to an earphone volume adjustment controlling means, including manual volume adjustment potentiometre, sample detection circuit, level comparison circuit, controllable gain amplifier, wherein: the manual volume adjustment potentiometer is used for adjusting the size of an audio signal at the audio signal input end; the sampling detection circuit samples the audio signal regulated by the manual volume regulating potentiometer, then carries out rectification filtering on the sampling signal and converts an alternating current signal into a direct current level; a level comparison circuit which is internally provided with a reference level, receives the direct current level of the sampling detection circuit, compares the direct current level with the reference level and outputs a comparison signal to the controllable gain amplifier; and the controllable gain amplifier is used for performing gain or attenuation on the audio signal adjusted by the manual volume adjustment potentiometer according to the comparison signal. The utility model discloses can establish speaker broadcast volume upper limit value into 80dB, avoid in unconscious too big and long-time listening to the volume to user's hearing has been protected.

Description

Headphone Volume Adjustment Control

technical field

The utility model relates to the technical field of audio processing, in particular to a volume adjustment control device applied to earphones.

Background technique

Along with popularizing of audio and video players such as portable MP3, MP4, IPOD, listen to music with earphone and become a kind of fashion, especially popular among teenagers. However, listening to music at high volume for a long time can cause irreversible damage to people's hearing. Scientific research shows that when the volume heard by the human ear reaches 100 decibels, it can cause irreversible hearing damage for a long time; when the volume reaches 110 decibels, it is enough to cause the hair cells of the human inner ear to die, and even cause hearing loss in severe cases disease. The highest volume of MP3 and MP4 can be 120 decibels, and the volume of "loud" MP3 can reach 110 decibels. It can be seen that listening to MP3 and MP4 for a long time is enough to cause damage to people's hearing.

Utility model content

The utility model aims at the above-mentioned defects of the prior art, and provides an earphone volume adjustment control device to control the maximum volume output by the earphone.

In order to solve the above technical problems, the utility model is achieved through the following technical solutions:

An earphone volume adjustment control device, which is connected between the audio signal input terminal and the earphone speaker, includes a manual volume adjustment potentiometer, a sampling detection circuit, a level comparison circuit, and a controllable gain amplifier, wherein: the manual volume adjustment potentiometer is used It is used to adjust the size of the audio signal at the audio signal input terminal;

The sampling and detection circuit samples the audio signal adjusted by the manual volume adjustment potentiometer, and then rectifies and filters the sampled signal to convert the AC signal into a DC level;

The level comparison circuit has a built-in reference level, receives the DC level of the sampling detection circuit and compares it with the reference level, and outputs the comparison signal to the controllable gain amplifier;

The controllable gain amplifier is used to gain or attenuate the audio signal adjusted by the manual volume adjustment potentiometer according to the comparison signal.

Preferably, if the DC level of the detection circuit is lower than the reference level, the controllable gain amplifier performs gain adjustment on the audio signal adjusted by the manual volume adjustment potentiometer, otherwise, the attenuation adjustment is performed.

Preferably, the voltage of the audio signal amplified by the controllable gain amplifier has an upper limit, and the volume of the audio signal with the upper limit of the voltage is 80dB after being played through the earphone speaker.

Preferably, the amplification ratio of the controllable gain amplifier is 1/40-2.

As can be seen from the above technical scheme, the controllable gain amplifier of the utility model has a gain upper limit, and the volume of the gain upper limit after being played by the speaker is 80dB. When the audio signal input by the earphone is large to a certain extent, even if the manual volume of the earphone When the potentiometer is turned up, the sound will not be adjusted too loudly, which avoids unknowingly turning up the volume too much and listening for a long time, thereby protecting the hearing of the user.

Description of drawings

Accompanying drawing is a functional block diagram of the utility model.

Detailed ways

The utility model will be described in further detail below in conjunction with specific embodiments.

As we all know, the volume of the earphone is related to the sensitivity of the speaker in the earphone and the size of the audio signal input to the speaker. The sensitivity of the speaker is certain for a manufactured earphone, so the volume of the earphone can be determined by the audio signal of the input speaker. to decide. In this way, if the audio signal input to the loudspeaker is limited to a safe maximum value, the volume of the earphone can also be limited to a safe maximum value. Any sound above 85 decibels can cause hearing damage, because the damage depends not only on the size of the speaker, but also on the length of time it is exposed to it. Therefore, the utility model limits the maximum volume within 80db.

Below in conjunction with accompanying drawing, the utility model is further described to the principle that the audio signal of the input earphone loudspeaker is controlled: the utility model is connected between the audio signal input end and the earphone loudspeaker, and it comprises manual volume adjustment potentiometer 1, sampling wave detection circuit 2 , level comparator circuit 3, controllable gain amplifier 4, input audio signal of the present utility model is divided into two ways after being adjusted by manual volume adjustment potentiometer 1, all the way enters controllable gain amplifier 4 and audio signal is amplified or reduced, controllable The amplification factor of the gain amplifier is 1/40~2, and the other channel enters the sampling detection circuit 2 for detection, and generates a DC control level reflecting the amplitude of the audio signal, and the sampling detection circuit 2 sends the DC control level to the level Comparing circuit 3. The level comparing circuit 3 compares the DC level with its built-in reference level to obtain a comparison signal, and controls the amplification factor of the controllable gain amplifier 4 according to the comparison signal. If the amplitude of the audio signal reflected by the DC control level exceeds the upper limit of the sound volume after the maximum amplification of the controllable gain amplifier is 2 times, then the amplification factor of the controllable gain amplifier 4 is lowered to limit the output audio signal amplitude. within the specified range. The upper limit of this tolerance can be adjusted according to the sensitivity of the speaker. For example, if the upper limit of the sound from the earphone is set to 80db, then input 0-4V, and the audio signal output by the general sound source within 1V can make the sound from the earphone Control within 80db. When using the utility model, it will be found that when the audio signal input by the earphone is large to a certain extent, the volume will not be adjusted after the manual volume adjustment potentiometer of the earphone is adjusted to a certain extent, which avoids unknowingly reducing the volume. The tone is too loud, thus protecting the hearing.

The above-mentioned embodiments only express several implementations of the utility model, and the description thereof is relatively specific and detailed, but it should not be construed as limiting the patent scope of the utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the utility model patent should be based on the appended claims.

Claims (3)

1. An earphone volume adjustment control device, which is connected between the audio signal input terminal and the earphone speaker, is characterized in that it includes a manual volume adjustment potentiometer, a sampling detection circuit, a level comparison circuit, and a controllable gain amplifier, wherein: Manual volume adjustment potentiometer, used to adjust the audio signal at the audio signal input terminal; The sampling and detection circuit samples the audio signal adjusted by the manual volume adjustment potentiometer, and then rectifies and filters the sampled signal to convert the AC signal into a DC level; The level comparison circuit has a built-in reference level, receives the DC level of the sampling detection circuit and compares it with the reference level, and outputs the comparison signal to the controllable gain amplifier; The controllable gain amplifier is used to gain or attenuate the audio signal adjusted by the manual volume adjustment potentiometer according to the comparison signal. 2. The headphone volume adjustment control device according to claim 1, characterized in that: the voltage of the audio signal gained by the controllable gain amplifier has an upper limit, and the audio signal with the upper limit of the voltage is played through the earphone speaker The volume is 80dB. 3. The headphone volume adjustment control device according to claim 2, characterized in that: the amplification factor of the controllable gain amplifier is 1/40-2.

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