TWI401977B - Audio-adapter having volume adjusting function - Google Patents

Description

Audio switching device with volume adjustment function

The present invention relates to an audio switching device.

At present, earphones are widely used in various audio devices, such as mobile phones, MP3s, etc., and there are more and more types of audio interfaces for headphones, such as the traditional 2.5mm/3.5mm audio interface and miniUSB audio interface. In order to facilitate the user's use of headphones to adapt to a variety of audio interfaces, audio switching devices are usually designed to achieve switching between various audio interfaces, but the conventional audio switching device is only for the transfer of audio signals, the function is very Single, can not meet the other needs of users, for example, some users often use two earphones to listen to music when using headphones, but the volume can not be adjusted according to each person's wishes, only two earplugs can be adjusted at the same time. The volume is difficult to meet the needs of two people at the same time. In addition, the volume of some headphones is too small, often unable to meet the needs of users.

In view of the above, it is necessary to provide an audio switching device with a volume adjustment function, which can separately adjust the volume of two earplugs on the earphone connected thereto.

An audio switching device with a volume adjustment function includes a first audio interface, a second audio interface, a first amplifier, a second amplifier, a first variable resistor and a second variable resistor. The first audio interface and the second audio interface respectively comprise a left ear canal audio pin, a right ear canal audio pin and a ground pin, and the second audio interface further comprises a power pin, the first audio interface The ground pin is connected to the ground pin of the second audio interface, the power pin of the second audio interface is connected to the non-inverting input of the first and second amplifiers, and the left ear canal audio of the second audio interface The pin is sequentially connected to the inverting input end of the first amplifier through a first capacitor and a first current limiting resistor, and the first variable resistor is connected in series between the inverting input end and the output end of the first amplifier The output end of the first amplifier is connected to the left ear canal audio pin of the first audio interface through a second capacitor, and is also connected to the ground pin of the first audio interface through a first limiting resistor. Two audio interface The ear canal audio pin is sequentially connected to the inverting input end of the second amplifier through a third capacitor and a second current limiting resistor, and the second variable resistor is connected in series to the inverting input end of the second amplifier The output end of the second amplifier is connected to the right ear canal audio pin of the first audio interface through a fourth capacitor, and also through a second limit resistor and a ground pin of the first audio interface Connected.

Compared with the prior art, the first and second amplifiers can amplify the audio signal, and adjust the resistance values of the first variable resistor and the second variable resistor to adjust the left and right sides of the earphone connected thereto. The volume of the earplugs is very convenient and meets the needs of users.

Referring to FIG. 1 to FIG. 3, a preferred embodiment of the audio switching device with volume adjustment function includes a first audio interface 10, a body portion 20, a second audio interface 30, and a first button. 21, a second button 22, a first current limiting resistor 23, a second current limiting resistor 24, a first variable resistor 25, a second variable resistor 26, a first amplifier A1, a first The second amplifier A2, a first limit resistor 27, a second limit resistor 28, five capacitors C1~C5 and an inductor L. The resistance values of the first current limiting resistor 23, the second current limiting resistor 24, the first variable resistor 25, and the second variable resistor 26 are set to R1, R2, R3, and R4, respectively.

The first audio interface 10 includes a left ear canal audio pin 14 , a right ear canal audio pin 16 , and a ground pin 18 . The second audio interface 30 includes a power pin 32 and a left ear canal audio lead. A foot 34, a right ear canal audio pin 36 and a ground pin 38. In this embodiment, the first audio interface 10 and the second audio interface 30 are respectively illustrated by a 3.5 mm audio interface and a miniUSB audio interface. The first audio interface 10 and the second audio interface 30 may also be other types. The audio interface can be designed according to actual needs. The first button 21 and the second button 22 are rotary buttons, and other types of buttons having the same function can also be selected.

The first audio interface 10 and the second audio interface 30 are respectively disposed at opposite ends of the main body portion 20, and the first button 21 and the second button 22 are respectively disposed on opposite sides of the main body portion 20, and other electronic components are respectively It is disposed inside the body portion 20. The first button 21 is connected to the adjustment end of the first variable resistor 25 for adjusting the resistance value of the first variable resistor 25. The second button 22 is connected to the adjustment end of the second variable resistor 26 for adjusting the resistance value of the second variable resistor 26.

The ground pin 18 of the first audio interface 10 is connected to the ground pin 38 of the second audio interface 30. The power pin 32 of the second audio interface 30 is connected to the non-inverting input terminals of the first and second amplifiers A1 and A2 through the inductor L, and is also connected to the ground pin 38 through the capacitor C5. The left ear canal audio pin 34 of the second audio interface 30 is sequentially connected to the inverting input end of the first amplifier A1 through the capacitor C1 and the first current limiting resistor 23, and the first variable resistor 25 is connected in series The inverting input terminal and the output terminal of the first amplifier A1. An output end of the first amplifier A1 is connected to the left ear canal audio pin 14 of the first audio interface 10 through the capacitor C2, and the grounding pin 18 of the first audio interface 10 is also transmitted through the first limiting resistor 27 Connected. The right ear canal audio pin 36 of the second audio interface 30 is sequentially connected to the inverting input terminal of the second amplifier A2 through the capacitor C3 and the second current limiting resistor 24, and the second variable resistor 26 is connected in series The inverting input terminal and the output terminal of the second amplifier A2. The output of the second amplifier A2 is connected to the right ear canal audio pin 16 of the first audio interface 10 through the capacitor C4, and the grounding pin 18 of the first audio interface 10 is also transmitted through the second limiting resistor 28. Connected.

The capacitors C1, C2, C3, and C4 are used to filter the DC portion of the audio signal to reduce DC noise interference. The first and second limit resistors 27 and 28 are used to define an output voltage of the left and right ear canal audio pins on the first audio interface 10 to meet an audio voltage output requirement. The capacitor C5 and the inductor L form a filter circuit for filtering the voltage outputted by the power pin 32 of the second audio interface 30, and can also be deleted as needed to reduce the cost, that is, directly the power pin 32 and the The first and second amplifiers A1 and A2 are connected to the non-inverting input terminals. The first amplifier A1 is configured to amplify the left ear canal audio pin 34 to the audio signal of the left ear canal audio pin 14 for amplification, and the amplification factor is N1=R3/R1, and the first variable resistor can be adjusted The magnitude of the resistance value R3 of the device 25 is derived from the adjustment magnification. Similarly, the second amplifier A2 is used for amplifying the audio signal of the right ear canal audio pin 36 input to the right ear canal audio pin 16, and the amplification factor is N2=R4/R2, and the second can be adjusted. The magnitude of the resistance value R4 of the variable resistor 26 is derived from adjusting the magnification to meet the needs of different users.

When the audio adjustment device with the volume adjustment function is applied, a headphone audio connector (such as a 3.5 mm audio connector) is connected to the first audio interface 10, and the second audio interface 30 and an audio device are connected. After the audio connector (such as the miniUSB audio connector of the mobile phone) is connected, the internal power of the audio device supplies power to the power pin 32 of the second audio interface 30 through its audio connector, so that the first and second amplifiers A1 And A2 work, so that the earphones listen to the audio signal sent by the audio device. When the two earplugs of the earphone are respectively used by two users, the user who uses the left earplug can adjust the resistance value of the first variable resistor 25 through the first button 21, thereby adjusting the volume of the left earplug. The user using the right ear button can adjust the resistance value of the second variable resistor 26 through the second button 22, thereby adjusting the volume of the right earplug, so that the two users can adjust the volume without interfering with each other. At the same time, it also overcomes the shortcomings of some headphones whose volume is too small, which brings convenience to the user.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

The first audio interface. . . 10

Left ear canal audio pin. . . 14,34

Right ear canal audio pin. . . 16,36

Ground pin. . . 18, 38

Second audio interface. . . 30

Power supply pin. . . 32

The first current limiting resistor. . . twenty three

Second current limiting resistor. . . twenty four

The first variable resistor. . . 25

Second variable resistor. . . 26

The first limit resistor. . . 27

Second limit resistor. . . 28

First amplifier. . . A1

Second amplifier. . . A2

inductance. . . L

capacitance. . . C1, C2, C3, C4, C5

1 is a perspective view of a preferred embodiment of an audio switching device with a volume adjustment function according to the present invention.

Figure 2 is a plan view of Figure 1.

3 is an internal circuit diagram of the audio switching device of FIG. 1.

The first audio interface. . . 10

Left ear canal audio pin. . . 14,34

Right ear canal audio pin. . . 16,36

Ground pin. . . 18, 38

Second audio interface. . . 30

Power supply pin. . . 32

The first current limiting resistor. . . twenty three

Second current limiting resistor. . . twenty four

The first variable resistor. . . 25

Second variable resistor. . . 26

The first limit resistor. . . 27

Second limit resistor. . . 28

First amplifier. . . A1

Second amplifier. . . A2

inductance. . . L

capacitance. . . C1, C2, C3, C4, C5

Claims (6)

An audio switching device with a volume adjustment function includes a first audio interface and a second audio interface, the first audio interface and the second audio interface respectively comprise a left ear canal audio pin and a right ear canal audio lead The second audio interface further includes a power supply pin, and the improvement is that the audio conversion device further includes a first amplifier, a second amplifier, a first variable resistor, and a first a second variable resistor, the ground pin of the first audio interface is connected to the ground pin of the second audio interface, and the power pin of the second audio interface is connected to the non-inverting input of the first and second amplifiers, The left ear canal audio pin of the second audio interface is sequentially connected to the inverting input end of the first amplifier through a first capacitor and a first current limiting resistor, and the first variable resistor is connected in series to the first Between the inverting input end and the output end of the amplifier, the output end of the first amplifier is connected to the left ear canal audio pin of the first audio interface through a second capacitor, and is further coupled to the first limit resistor and the first An audio interface The grounding pin is connected, and the right ear canal audio pin of the second audio interface is sequentially connected to the inverting input end of the second amplifier through a third capacitor and a second current limiting resistor, the second variable resistor Connected between the inverting input terminal and the output terminal of the second amplifier, the output end of the second amplifier is connected to the right ear canal audio pin of the first audio interface through a fourth capacitor, and is further passed through a second limit. The bit resistance is coupled to the ground pin of the first audio interface. An audio switching device with a volume adjustment function according to claim 1, wherein an inductance is connected in series between the power pin of the second audio interface and the non-inverting input of the first and second amplifiers, and The power pin of the second audio interface is also connected to the ground pin of the second audio interface through a capacitor. The audio switching device with the volume adjustment function of claim 1, wherein the first variable resistor and the second variable resistor are disposed in a body portion, and the first button is disposed on the body portion And a second button, the first button is connected to the adjusting end of the first variable resistor for adjusting a resistance value of the first variable resistor, the second button and the second variable resistor The adjusting end is connected to adjust the resistance value of the second variable resistor. An audio switching device with a volume adjustment function according to the third aspect of the invention, wherein the first audio interface and the second audio interface are respectively disposed at opposite ends of the body portion, the first button and the second button They are respectively disposed on opposite sides of the body portion. The audio switching device with volume adjustment function according to claim 3, wherein the first button and the second button are rotary buttons. The audio switching device with the volume adjustment function described in claim 1, wherein the first audio interface and the second audio interface are respectively a 3.5 mm audio interface and a miniUSB audio interface.