CN107786924B

CN107786924B - Circuit for solving crosstalk problem of earphone with microphone function

Info

Publication number: CN107786924B
Application number: CN201610799296.7A
Authority: CN
Inventors: 杨志豪
Original assignee: Guangdong Desheng Electronics Co ltd
Current assignee: Guangdong Desheng Electronics Co ltd
Priority date: 2016-08-31
Filing date: 2016-08-31
Publication date: 2021-03-16
Anticipated expiration: 2036-08-31
Also published as: CN107786924A

Abstract

The invention relates to a circuit for solving the crosstalk problem of an earphone with a microphone function, which comprises an MIC + circuit, an electret (MIC), a loudspeaker R, a loudspeaker L, R positive electrode, an L positive electrode, a GND end and an inductor T, wherein the inductor T comprises an A/C end and a B/D end, and the inductor T generates a reverse electrodynamic induction type and cancels a residual signal generated by a common ground signal, so that the MIC + circuit cannot be interfered. The R and L signals output by the R anode and the L anode are respectively connected with the cathode through the horn, the horn R and the horn L. Then the positive pole signal is transmitted to an MIC + circuit through a lead to carry out signal processing after an electret picks up a sound signal, and the negative pole signal is transmitted to a B/D end of the inductor T through the lead and then flows to the GND end to form a loop. The method has the advantages of reasonable design, simple and convenient operation and capability of effectively removing the interference of the residual signal to the MIC + line.

Description

Circuit for solving crosstalk problem of earphone with microphone function

Technical Field

The invention relates to the field of anti-interference circuits, in particular to a circuit for solving the problem of crosstalk of an earphone with a microphone function.

Background

With the development of modern life towards the direction of simplicity, convenience and quickness, music listening becomes an indispensable entertainment, especially more and more people begin to listen to music by using mobile phones at present, so that the development of mobile phone earphones begins to be faster and faster, earphones with a microphone function in the market generally comprise a four-stage (1. GND 2.MIC 3. R4. L) accessory 01 with a 3.5mm plug, and due to the low impedance of the common ground and a loudspeaker, a ground wire connected to equipment generates certain impedance for alternating current signals. Especially in case of high sound pressure, some of the sound is transmitted to the MIC through the common ground wire. Wires passing through the MIC path interfere with the devices to which they are connected.

Disclosure of Invention

The invention aims to provide a circuit for solving the problem of crosstalk of an earphone with a microphone function, and adopts the following technical scheme for realizing the aim:

a circuit for solving the crosstalk problem of an earphone with a microphone function comprises an MIC + line (1), an electret (2), a loudspeaker R (3), a loudspeaker L (4), an R anode (5), an L anode (6), a GND end (7) and an inductor T (8), wherein the inductor T (8) comprises an A \ C end (9) and a B \ D end (10); the inductor T (8) is connected with the GND end (7) between an A/C end (9) and a B/D end (10) of the inductor T (8), the inductor T (8) generates reverse induced electromotive force, the reverse induced electromotive force is mutually offset with a residual signal generated by a ground signal, so that MIC + line (1) is not interfered, R and L signals output by the R positive electrode (5) and the L positive electrode (6) respectively pass through the horn R (3) and the horn L (4), the negative electrode of the horn R (3) is connected with the negative electrode of the horn L (4), then pass through the A/C end (9) of the inductor T (8) and then flow to the GND end (7) to form a loop, after the electret (2) picks up a sound signal, the positive signal is transmitted to the MIC + line (1) through a lead to be processed, and the negative signal is transmitted to the B/D end (10) of the inductor T (8) through the lead and then flows to the GND end (7) to form the loop .

On the basis of the technical scheme, the loudspeaker R (3) and the loudspeaker L (4) adopt a stereo surrounding type earphone loudspeaker.

The invention adopts a method of increasing inductance T to design a new circuit, after the circuit is improved, the inductance is utilized to generate reverse induced electromotive force, the reverse induced electromotive force and the residual signal generated by the common ground signal are mutually offset, the common ground is realized, but the sound of a loudspeaker cannot be connected to a microphone circuit to interfere the equipment on the microphone circuit, the circuit is optimized while the interference is eliminated, and the circuit is safer and more reliable in operation.

Drawings

Fig. 1 is a schematic diagram of the circuit operation of the present invention.

In the figure: 1-MIC + line; 2-an electret; 3-horn R; 4-horn L; 5-R positive electrode; 6-L positive electrode; 7-GND terminal; 8-inductance T; 9-A/C terminal; 10-B/D terminal.

Detailed Description

The invention is explained in further detail below with reference to fig. 1 and the specific examples.

The application provides a solve earphone crosstalk problem circuit with microphone function, including MIC + circuit 1, electret 2, loudspeaker 3, loudspeaker L4, R anodal 5, L anodal 6, GND end 7 and inductance T8, inductance T8 includes A/C end 9 and B/D end 10, inductance T8 with GND end 7 is in be connected between inductance T8's A/C end 9 and B/D end 10, inductance T8 produces the back-induction electromotive force, and the back-induction electromotive force offsets each other with the residual signal of ground signal production, realizes common ground to can not disturb crosstalk MIC + circuit 1. After the R and L signals output by the R anode 5 and the L anode 6 respectively pass through the horn R3 and the horn L4, the cathode of the horn R3 is connected with the cathode of the horn L4. Then the sound signal passes through the A/C end 9 of the inductor T8 and then flows to the GND end 7 to form a loop, after the electret 2 picks up the sound signal, the positive electrode signal is transmitted to the MIC + line 1 through a lead for signal processing, and the negative electrode signal is transmitted to the B/D end 10 of the inductor T8 through a lead and then flows to the GND end 7 to form a loop.

Assuming that the impedances of the horn R3 and the horn L4 are 32 ohms, the point a is the ground GND terminal of the horn R3 and the horn L4. When the signal generated at the position of the A point is in a plus shape, the phase of the signal generated at the position of the D point at the second dotted terminal is 180 degrees from that of the signal generated at the position of the A point due to the mutual inductance of the inductor T8. This causes the two signals to meet within the inductor T8, which have the same magnitude and opposite phases, and cancel each other out. Thus, the signals from horn R3 and horn L4 at the B point location are zero, so residual signals reaching horn R3 and horn L4 do not interfere with crosstalk to the MIC + line 1 equipment.

The basic flow of playback signals is that L and R signals output by the L anode 6 and the R anode 5 respectively pass through a loudspeaker R3 and a loudspeaker L4 and pass through two earphone loudspeakers. Then the current flows to the GND terminal 7 through the A/C terminal 9 of the inductor T8 to form a loop together with the negative pole.

After an electret 2 picks up a sound signal, a positive electrode signal is transmitted to an MIC + line 1 through a lead for signal processing, a negative electrode signal is transmitted to a B/D end 10 of an inductor T8 through the lead, and then the negative electrode signal flows to a GND end 7 to form a loop.

The foregoing is a preferred embodiment of the present invention, and it will be apparent to those skilled in the art that variations, modifications, substitutions and alterations can be made in the embodiment without departing from the principles and spirit of the invention.

Claims

1. A circuit for solving the crosstalk problem of an earphone with a microphone function is characterized by comprising an MIC + line (1), an electret (2), a loudspeaker R (3), a loudspeaker L (4), an R anode (5), an L anode (6), a GND end (7) and an inductor T (8), wherein the inductor T (8) comprises an A/C end (9) and a B/D end (10); the inductor T (8) is connected with the GND end (7) between an A/C end (9) and a B/D end (10) of the inductor T (8), the inductor T (8) generates reverse induced electromotive force, the reverse induced electromotive force is mutually offset with a residual signal generated by a ground signal, so that MIC + line (1) is not interfered, R and L signals output by the R positive electrode (5) and the L positive electrode (6) respectively pass through the horn R (3) and the horn L (4), the negative electrode of the horn R (3) is connected with the negative electrode of the horn L (4), then pass through the A/C end (9) of the inductor T (8) and then flow to the GND end (7) to form a loop, after the electret (2) picks up a sound signal, the positive signal is transmitted to the MIC + line (1) through a lead to be processed, and the negative signal is transmitted to the B/D end (10) of the inductor T (8) through the lead and then flows to the GND end (7) to form GND And (4) a loop.

2. The circuit for solving the crosstalk problem of the earphone with the microphone function as claimed in claim 1, wherein the speaker R (3) and the speaker L (4) are stereo surround type earphone speakers.