CN211352432U

CN211352432U - Double-tube-core capacitor microphone

Info

Publication number: CN211352432U
Application number: CN202020194571.4U
Authority: CN
Inventors: 侯帆
Original assignee: Shenzhen Commlite Technology Co ltd
Current assignee: Shenzhen Commlite Technology Co ltd
Priority date: 2020-02-22
Filing date: 2020-02-22
Publication date: 2020-08-25
Anticipated expiration: 2030-02-22

Abstract

The utility model discloses a two pipe core electric capacity miaow heads, including field effect transistor JFET1 and field effect transistor JFET2, on the G utmost point of field effect transistor JFET1 and field effect transistor JFET2 all received the corresponding microelectrode of miaow head diaphragm, the S utmost point and the equal ground connection of miaow head metal casing of field effect transistor JFET1 and field effect transistor JFET2, two signal output poles are regarded as respectively to field effect transistor JFET1 and field effect transistor JFET 2' S D utmost point, the utility model discloses can work in camera microphone interface and cell-phone microphone interface simultaneously, do not need change over switch or outside patch cord.

Description

Double-tube-core capacitor microphone

Technical Field

The utility model relates to a microphone technical field specifically is a double tube core electric capacity miaow head.

Background

At present, a mobile phone or a camera is generally used for recording audio and video, and in the aspect of recording, microphone interfaces of the mobile phone and the camera are defined differently, so that the microphone can be used in the mobile phone or the camera only by using an external patch cord or using a change-over switch on a product. Causing deficiencies in product compatibility, cost, etc.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a double tube core electric capacity miaow head to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

a dual-die capacitor microphone comprises a field effect transistor JFET1 and a field effect transistor JFET2, G electrodes of the field effect transistor JFET1 and the field effect transistor JFET2 are connected to fixed electrodes corresponding to microphone diaphragms, S electrodes of the field effect transistor JFET1 and the field effect transistor JFET2 and a microphone metal shell are grounded, and D electrodes of the field effect transistor JFET1 and the field effect transistor JFET2 are respectively used as two signal output electrodes.

As a further technical solution of the present invention: the D poles of the field effect transistor JFET1 are connected to the 1 pole and the 2 pole of the TRRS joint, the D pole of the field effect transistor JFET2 is connected to the 4 pole of the TRRS joint, and GND is connected to the 3 pole of the TRRS joint.

As a further technical solution of the present invention: the TRRS joint is 3.5mmTRRS joint.

As a further technical solution of the present invention: the D poles of the field effect transistor JFET2 are connected to the 1 pole and the 2 pole of the TRRS joint, the D pole of the field effect transistor JFET1 is connected to the 4 pole of the TRRS joint, and GND is connected to the 3 pole of the TRRS joint.

As a further technical solution of the present invention: the D electrode of the field effect transistor JFET1 is connected with a resistor R1 and a capacitor C1, and the D electrode of the field effect transistor JFET2 is connected with a resistor R2 and a capacitor C2.

As a further technical solution of the present invention: the capacitor C is a signal coupling capacitor.

As a further technical solution of the present invention: the resistor R is a bias resistor.

Compared with the prior art, the beneficial effects of the utility model are that: the invention can work in the microphone interface of the camera and the microphone interface of the mobile phone at the same time, and does not need a change-over switch or an external patch cord.

Drawings

FIG. 1 is a circuit diagram of embodiment 1;

fig. 2 is a circuit diagram of embodiment 2.

FIG. 3 is a circuit diagram of an external load according to embodiment 1.

FIG. 4 is a circuit diagram of the external bias voltage of embodiment 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1: referring to fig. 1, a dual-die capacitive microphone includes a fet JFET1 and a fet JFET2, wherein G electrodes of the fet JFET1 and the fet JFET2 are connected to a fixed electrode corresponding to a microphone diaphragm, S electrodes of the fet JFET1 and the fet JFET2 and a microphone metal case are grounded, and D electrodes of the fet JFET1 and the fet JFET2 are respectively used as two signal output electrodes.

The principle of the capacitance microphone is that an extremely thin diaphragm is used as one electrode of a capacitor, the diaphragm is separated from the capacitor by a few tenths of millimeters, another fixed electrode is arranged, a capacitor with a few p farads is formed, the thin film electrode changes the capacitance of the capacitor along with the vibration of sound waves to form an electric signal, and the internal resistance of the capacitor is extremely high and reaches the level of G ohms because the capacitor is only a few p farads. Therefore, a circuit, also called a "pre-amplifier circuit", is usually integrated inside the condenser microphone, and an external bias voltage circuit is needed to supply power to the circuit. The circuit is generally composed of JFETs as the main component.

As shown in fig. 3, the D-poles of fet JFET1 are connected to the 1 and 2 poles of the TRRS connection, fet JFET2 is connected to the 4 pole of the TRRS connection, and GND is connected to the 3 pole of the TRRS connection. The TRRS joint is 3.5mmTRRS joint. The D-poles of fet JFET2 are connected to the 1 and 2 poles of the TRRS connection, the D-pole of fet JFET1 is connected to the 4 pole of the TRRS connection, and GND is connected to the 3 pole of the TRRS connection. The microphone interface of the mobile phone uses 3 and 4 poles, when the 3.5mm interface of the mobile phone is accessed, the mobile phone applies bias voltage to the 3 and 4 poles, and the microphone works to output sound signals. The microphone interface of the camera uses 1, 2 and 3 poles, when the 3.5mm interface of the camera is accessed, the camera applies bias voltage to the 1, 2 and 3 poles, the microphone works and outputs sound signals. Therefore, the multi-compatibility of the product can be realized by only using one microphone without using a change-over switch or an external patch cord, the manufacturing process and additional devices can be simplified in the whole design, and the total cost of the product is reduced.

As shown in fig. 4, the D-pole of the fet JFET1 is connected to the resistor R1 and the capacitor C1, and the D-pole of the fet JFET2 is connected to the resistor R2 and the capacitor C2. The capacitor C is a signal coupling capacitor. The resistor R is a bias resistor. After bias voltage is applied to the D pole, the D pole can work respectively to output sound signals, VBIAS is the bias voltage, R is a bias resistor, and C is a signal coupling capacitor.

Example 2: the difference from embodiment 1 is that, as in the design of fig. 2, all poles are led out, and the design of fig. 1 can also be realized through external connection, and can also be flexibly designed according to actual product requirements.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A dual-die capacitive microphone comprises a field effect transistor JFET1 and a field effect transistor JFET2 and is characterized in that G poles of the field effect transistor JFET1 and the field effect transistor JFET2 are connected to fixed electrodes corresponding to microphone diaphragms, S poles of the field effect transistor JFET1 and the field effect transistor JFET2 are grounded with a microphone metal shell, and D poles of the field effect transistor JFET1 and the field effect transistor JFET2 are used as two signal output poles respectively.

2. The dual die capacitive microphone of claim 1, wherein the D-poles of the fet JFET1 are connected to the 1 and 2 poles of the TRRS connector, the D-pole of the fet JFET2 is connected to the 4 pole of the TRRS connector, and GND is connected to the 3 pole of the TRRS connector.

3. The dual die capacitive microphone of claim 2, wherein the TRRS connector is a 3.5mm TRRS connector.

4. A dual die capacitive microphone according to claim 3 wherein the D-poles of fet JFET2 are connected to the 1 and 2 poles of the TRRS connection, the D-pole of fet JFET1 is connected to the 4 pole of the TRRS connection and GND is connected to the 3 pole of the TRRS connection.

5. The dual-die capacitive microphone according to claim 1, wherein the D-pole of the fet JFET1 is connected to the resistor R1 and the capacitor C1, and the D-pole of the fet JFET2 is connected to the resistor R2 and the capacitor C2.