CN201563232U

CN201563232U - Three-port microphone

Info

Publication number: CN201563232U
Application number: CN2009200624813U
Authority: CN
Inventors: 张弢; 孔令华
Original assignee: ZHONGSHAN MINAMI AUDIO EQUIPMENT CO Ltd
Current assignee: Jiangxi Tianjian Electroacoustic Co ltd
Priority date: 2009-08-11
Filing date: 2009-08-11
Publication date: 2010-08-25
Anticipated expiration: 2019-08-11

Abstract

The utility model discloses a three-port microphone which comprises an outer casing. A sound recording inlet is arranged at the closed end of the outer casing. A PCB board is arranged at the open end of the outer casing. A membrane ring, a circular insulation pad, a back polar board and a copper ring are arranged between the inside of the closed end of the outer casing and the PCB board. A membrane corresponding to the sound recording inlet is fixed at the upper end of a center hole of the membrane ring. The membrane and the back polar board are arranged at interval to form a capacitor. A field effect tube is attached to the inside of the PCB board. A gate electrode of the field effect tube is electrically connected with the back polar board through the copper ring. Three ports are arranged on the outside of the PCB board, i.e. signal output end, ground end and power supply end. The signal output end is connected with a source electrode of the field effect tube, the ground end is connected with the membrane, and the power supply end is connected with a drain electrode of the field effect tube. The utility model has the advantages of low noise of the substrate, and low output impedance.

Description

A kind of three end microphones

[technical field]

The utility model relates to a kind of three end microphones.

[background technology]

Existing common microphone has two outputs, hold for one with being, another is the mixing output of signal and power supply, in the time of practical application, there is following shortcoming in above-mentioned product: 1, background noise height, after amplifying by high power, the white noise that reproduces in client's product loudspeaker is very big, sense of hearing is very poor, and the time, long meeting influence hearing, for example hearing aids industry; 2, output impedance height, higher to the cabling requirement of client complete machine, need be very near apart from next stage, the output impedance height is also introduced external interference easily in the line.For this reason, be necessary to address the above problem.

[utility model content]

The utility model has overcome the deficiency of above-mentioned technology, and the three ends output that a kind of background noise is low, output impedance is low microphone is provided.

For achieving the above object, the utility model has adopted following technical proposal:

A kind of three end microphones, include shell, blind end at shell is provided with sound typing mouth, openend at shell is provided with pcb board, between the blind end inboard of shell and pcb board, be disposed with zona, the annular insulating mat sheet, back pole plate, copper ring, upper end at the centre bore of zona is fixed with and the relative diaphragm of sound typing mouth, this diaphragm and back pole plate are provided with at interval and form capacitor, the inboard paster of described pcb board has field effect transistor, the grid of this field effect transistor is electrically connected with back pole plate by copper ring, described pcb board arranged outside has three ports, be respectively signal output part, the ground end, power end, described signal output part is connected with the source electrode of field effect transistor, and the ground end is connected with diaphragm, and power end is connected with the drain electrode of field effect transistor.

Compared with prior art, the beneficial effects of the utility model are: 1, the level of background noise of the present utility model can reach the industry standard of hearing aids, is adopted by the hearing aids industry widely; 2, of the present utility model in output impedance the performance also fine, compare conventional microphone and reduced half, load capacity is strong.

[description of drawings]

Fig. 1 is a stereogram of the present utility model;

Fig. 2 is a profile of the present utility model;

Fig. 3 is the circuit theory diagrams that output of the present utility model is connected with load.

[embodiment]

Be described in further detail below in conjunction with accompanying drawing and execution mode of the present utility model:

Referring to Fig. 1-3, the utility model is a kind of three end microphones, include shell 1, blind end at shell 1 is provided with sound typing mouth 11, post the Air Filter 9 that prevents that dust from entering at described sound typing mouth 11 lateral surfaces, openend at shell 1 is provided with pcb board 2, be disposed with zona 3, annular insulating mat sheet 4, back pole plate 5, copper ring 6 at the blind end of shell 1 between the inboard and pcb board 2, be fixed with the diaphragm 7 relative with sound typing mouth 11 in the upper end of the centre bore of zona 3, between copper ring 6 and shell 1, be provided with cavity 8, play insulation and fixation.Described diaphragm 7 one sides are covered with metal level, and this metal level and described zona 3 are electrically connected; Diaphragm 7 is provided with and the composition capacitor at interval with back pole plate 5.Described insulation spacer is used to separate diaphragm 7 and back pole plate 5 in the form of a ring, reserves the space of vibration to give diaphragm 7.Described back pole plate is the disk shape, and back pole plate 5 one sides contact with annular insulating mat sheet 4 with electret film, and opposite side contacts with copper ring 6, is fixed on 8 li of cavitys and shell 1 insulation.Described copper ring is the ring-type electric conductor, uses as the signal transmission.

Described pcb board 2 inboard pasters have field effect transistor FET, the grid of this field effect transistor FET is electrically connected with back pole plate 5 by copper ring 6, described pcb board 2 arranged outside have three ports, be respectively signal output part S, hold G, power end D, described signal output part S is connected with the source electrode of field effect transistor FET, ground end G is connected with diaphragm 7, and power end D is connected with the drain electrode of field effect transistor FET.Diaphragm 7 vibrates with outside sound, spacing between diaphragm 7 and the back pole plate 5 is along with corresponding variation is done in vibration, the voltage at the two ends of capacitor ECM changes thereupon, this change is input among the field effect transistor FET, voice signal is converted into the signal of telecommunication through signal output part S output the most at last, inserts power supply by ground end G ground connection, power end D simultaneously.

Referring to Fig. 3, during use, the utility model is as follows with being connected of load: described signal output part S is connected respectively with the end of capacitance C and the end of load resistance RL by cartridge, the other end of capacitance C is as signal end Output, and ground end G is connected the back as the ground end by cartridge with the other end of load resistance RL; Power end D with by behind the cartridge as power end Vcc.

The utility model adopts the source electrode way of output, and field effect transistor FET is operated in the voltage follow state, and gain is essentially 1, so whole background noise rank is very low.The utility model is handled two different ports of signal output and power supply input employing, can improve signal transfer quality widely like this, reduces noise.

Claims

1. end microphone, include shell (1), blind end at shell (1) is provided with sound typing mouth (11), openend at shell (1) is provided with pcb board (2), be disposed with zona (3) at the blind end of shell (1) between the inboard and pcb board (2), annular insulating mat sheet (4), back pole plate (5), copper ring (6), upper end at the centre bore of zona (3) is fixed with the diaphragm (7) relative with sound typing mouth (11), this diaphragm (7) is provided with and the composition capacitor at interval with back pole plate (5), the inboard paster of described pcb board (2) has field effect transistor (FET), the grid of this field effect transistor (FET) is electrically connected with back pole plate (5) by copper ring (6), it is characterized in that described pcb board (2) arranged outside has three ports, be respectively signal output part (S), ground end (G), power end (D), described signal output part (S) is connected with the source electrode of field effect transistor (FET), ground end (G) is connected with diaphragm (7), and power end (D) is connected with the drain electrode of field effect transistor (FET).

2. a kind of three end microphones according to claim 1 is characterized in that described sound typing mouth (11) lateral surface posts the Air Filter (9) that prevents dust and enter.