CN201418142Y

CN201418142Y - microphone

Info

Publication number: CN201418142Y
Application number: CN2009200571816U
Authority: CN
Inventors: 杨辉隆
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-05-22
Filing date: 2009-05-22
Publication date: 2010-03-03
Anticipated expiration: 2019-05-22

Abstract

The utility model relates to the field of a microphone, in particular to a microphone circuit. The microphone circuit comprises a microphone, an audio signal processing circuit, a power circuit and asignal output circuit that are sequentially and electrically connected with each other, wherein the power circuit has the noise suppression function; the signal output circuit has the function of balancing the output and a variable resistance; and the signal output circuit is connected with the audio signal processing circuit. The variable resistance is adopted to drive a noise reduction circuit directly in the signal process and in the signal output, therefore, compared with the prior art, the high fidelity can be realized, the recorded sound effect is more vivid, and the low-noise and low-resistance output can be realized, thereby effectively increasing all parameters of the microphone, so as to match any poweramp equipment flexibly; meanwhile, by matching the power noise filter technology, various interference signals brought from outside can be effectively filtered, so as to improve the recording quality.

Description

A kind of microphone

Technical field

The utility model relates to a kind of microphone, specifically is meant a kind ofly to have wideband response and high fidelity, realization to the microphone circuit of sound near the original flavor print effect.

Background technology

There are following three point defects in the conventional microphone circuit: 1, can only pick up the sound that frequency is 50Hz-15KHz, the source of sound that can't carry out following low frequency of 50Hz and the above high frequency of 15KHz picks up, and can't go back the glamour of original sound really; 2, the removal that traditional power supply Dolby circuit can only be inadequate noise partly, the non-constant of noise reduction does not have the ability that suppresses noise, and outside interference noise often influences the microphone location effect, has had a strong impact on the authenticity of sound; 3, in the traditional microphone design circuit, all carry out impedance transformation, balance output with a FET pipe, the signal-balanced degree of output is not enough, and the noise of microphone own is increased, and has increased the distortion factor of sound, the requirement of high-fidelity recording microphone can't be reached, duplicating of sound genuineness can't be realized.

The utility model content

The utility model is intended to solve the above-mentioned defective that exists in the existing microphone circuit, and then provides a kind of and have wideband response and high fidelity, realization to the novel microphone of sound near the original flavor print effect.

For addressing the above problem, the technical scheme that the utility model is taked is: a kind of microphone, comprise successively microphone, the audio signal processing circuit that is electrically connected and have the power circuit of noise suppression function and have balance output and become the signal output apparatus of resistance function, described signal output apparatus is connected with audio signal processing circuit, and described audio signal processing circuit adopts and becomes the straight crystal drive circuit of resistance.

A kind of concrete scheme is that described signal output apparatus comprises coupling capacitance, partial pressure type amplifying circuit, the symmetrical expression amplifying circuit that connects successively; The audio signal that becomes the straight crystal drive circuit output of resistance is through capacitor C 15 couplings, triode Q9, resistance R 5, R6, R22, R23 amplify in the partial pressure type amplifying circuit again, after capacitor C 16, C19 are coupled into the symmetrical expression amplifying circuit balance output that resistance R 9, R7, R10, R18, R24 are formed.Described power circuit comprises voltage doubling rectifing circuit, voltage stabilizing circuit, active filter circuit and the RC filter network that connects successively.

Another kind of concrete scheme is that described change hinders straight crystal drive circuit and comprises field effect transistor Q5, Q7, Q8; Described field effect transistor Q5 source electrode connects microphone power supply VCC end, and drain electrode connects field effect transistor Q8 source electrode and as first signal output part, and Q5 grid and Q8 drain and be connected and as the secondary signal output; Field effect transistor Q7 source electrode connects field effect transistor Q8 drain electrode, and the Q7 drain electrode is by grounding through resistance, and grid is while ground connection also; Field effect transistor Q8 grid connects the microphone positive pole.Be connected to amplitude limiter circuit between described field effect transistor Q8 grid and the drain electrode, described amplitude limiter circuit comprises diode D5, D6 and capacitor C 5, diode D5 negative electrode, D6 anode are connected with field effect transistor Q8 grid, D5 anode, D6 negative electrode are connected with capacitor C 6 negative poles, and capacitor C 6 anodal drain electrodes with field effect transistor Q8 are connected.Described power circuit comprises voltage doubling rectifing circuit, voltage stabilizing circuit, active filter circuit and the RC filter network that connects successively.

Compared with prior art, microphone described in the utility model adopts above-mentioned change resistance directly to drive Dolby circuit in signal processing and signal output, not only make microphone have high fidelity, make the sound effect of recording more true to nature, more realize the output of microphone low noise low-resistance, effectively improved the parameters of microphone, it can be complementary with any back level equipment flexibly; Cooperate the power supply filter technology of making an uproar simultaneously, effectively the various interference signals brought of the filtering external world have further improved recording quality.

Description of drawings

Fig. 1 is signal output apparatus described in the utility model and signal processing circuit principle schematic;

Fig. 2 is a power circuit principle schematic diagram described in the utility model.

Embodiment

The utility model is described in further detail below in conjunction with drawings and Examples.

Microphone described in the utility model comprises microphone, audio signal processing circuit, signal output apparatus and power circuit.

Microphone obtains audio signal reprocessing output by microphone, and processing procedure generally comprises that filter is made an uproar, amplification, impedance transformation etc.Two groups of signals of output after traditional microphone circuit impedance transformation, it is tested the back find that two signals have energy imbalance, the circuit noise test is bigger, distortion phenomenon is serious, can not reach the specific (special) requirements of high-fidelity, at this defective, the utility model adopts at audio signal processing circuit and becomes the straight crystal drive circuit of resistance, the output of matching with signal output circuit balance.

With reference to Fig. 1, described change hinders straight crystal drive circuit and comprises field effect transistor Q5, Q7, Q8; Field effect transistor Q5 source electrode connects microphone power supply VCC end, and drain electrode connects field effect transistor Q8 source electrode and as first signal output part, and Q5 grid and Q8 drain and be connected and as the secondary signal output; Field effect transistor Q7 source electrode connects field effect transistor Q8 drain electrode, and the Q7 drain electrode is by grounding through resistance, and grid is while ground connection also; Field effect transistor Q8 grid connects the microphone positive pole.Also be connected to amplitude limiter circuit between field effect transistor Q8 grid and the drain electrode, diode D5 negative electrode, D6 anode are connected with field effect transistor Q8 grid in the amplitude limiter circuit, and D5 anode, D6 negative electrode are connected with capacitor C 6 negative poles, and capacitor C 6 anodal drain electrodes with field effect transistor Q8 are connected.

The foregoing circuit connected mode is called the straight crystal drive circuit of change resistance, adopts three FET pipes in the circuit, and middle FET manages Q8 and is used for impedance transformation, output low-resistance signal; Two FET pipes Q5, Q7 are used for balance output control up and down, guarantee the output of balance low noise high-fidelity; D5, D6, C5 carry out amplitude limit control to audio frequency, and control input signals is undistorted, further guarantee output high-fidelity signal.

With reference to Fig. 1, the audio signal that the straight crystal drive circuit of change resistance sends is coupled through C15, amplify through partial pressure type amplifying circuit Q9, R5, R6, R22, R23 again, amplifying the signal that comes out is coupled through C16, C19 again, by R9, R7, R10, R18, the output of R24 symmetrical expression amplifying circuit balance, this partial circuit is a signal output apparatus.

As described in the background art, when the noise of microphone power circuit was big, this noise also can directly have influence on the recording quality of microphone, and therefore adopting good filtering mode in the microphone power circuit also is necessary for improving microphone property.

With reference to Fig. 2, the utility model microphone power circuit comprises voltage doubling rectifing circuit, voltage stabilizing circuit, active filter circuit and the RC filter network that connects successively.

Wherein voltage doubling rectifing circuit is connected with extraneous AC power, and faint AC signal is carried out rectification, promotes direct voltage again, and this circuit can effectively be removed the interference of alternating current, and alternating current circuit and DC circuit are isolated fully.This circuit comprises diode D2, D3, the D4 that is connected in turn with positive source, is parallel with capacitor C 3 in diode D2, D3 two ends, is parallel with capacitor C 1 in diode D3, D4 two ends, and diode D4 negative pole is as rectification output end.

Voltage stabilizing circuit comprises voltage stabilizing didoe D5 and capacitor C 4 in parallel, this voltage stabilizing circuit one end ground connection, and an end is connected with the active filter circuit of back level.

Active filter circuit comprises compound transistor D6, and the D6 base stage connects voltage stabilizing circuit voltage stabilizing end, connects diode D4 negative pole by resistance R 3 simultaneously; The D6 collector electrode also connects diode D4 negative pole, and the D6 emitter is connected with the end of parallel resistor R6, capacitor C 5, C6, the other end ground connection of resistance R 6, capacitor C 5, C6, and the D6 emitter also is connected with the RC filter network simultaneously.This filter circuit can be exported pure 48V DC power supply to the complete filtering of faint AC signal.The 48V direct current by IN2 and IN1, IN3 and the power supply of IN1 formation balanced type, provides power supply to microphone behind R4, R5, R7, R8; And the audio signal of microphone output is after C9, C10 coupling, and balance is exported to back utmost point equipment, for example power amplifier, sound console etc.

Increase the RC filter network in addition at power supply output loop end, comprise resistance R 11, R12 and capacitor C 11, C12, simulaed interference signal that this effective filtering external world of circuit energy is brought and digital interference signal etc. are further enhanced recording quality.

Above-mentioned is more preferably execution mode of the utility model, need to prove, do not breaking away under the utility model design prerequisite, to the present embodiment institute as little variation and be equal to replacement and all belong to the utility model protection range.

Claims

1, a kind of microphone, comprise the microphone, the audio signal processing circuit that are electrically connected successively, it is characterized in that: also comprise power circuit with noise suppression function and signal output apparatus with balance output function, described signal output apparatus is connected with audio signal processing circuit, and described audio signal processing circuit adopts and becomes the straight crystal drive circuit of resistance.

2, microphone according to claim 1 is characterized in that: described change hinders straight crystal drive circuit and comprises field effect transistor Q5, Q7, Q8; Described field effect transistor Q5 source electrode connects microphone power supply VCC end, and drain electrode connects field effect transistor Q8 source electrode and as first signal output part, and Q5 grid and Q8 drain and be connected and as the secondary signal output; Field effect transistor Q7 source electrode connects field effect transistor Q8 drain electrode, and the Q7 drain electrode is by grounding through resistance, and grid is while ground connection also; Field effect transistor Q8 grid connects the microphone positive pole.

3, microphone according to claim 2, it is characterized in that: be connected to amplitude limiter circuit between described field effect transistor Q8 grid and the drain electrode, described amplitude limiter circuit comprises diode D5, D6 and capacitor C 5, diode D5 negative electrode, D6 anode are connected with field effect transistor Q8 grid, D5 anode, D6 negative electrode are connected with capacitor C 6 negative poles, and capacitor C 6 anodal drain electrodes with field effect transistor Q8 are connected.

4, microphone according to claim 1 is characterized in that: described signal output apparatus comprises coupling capacitance, partial pressure type amplifying circuit, the symmetrical expression amplifying circuit that connects successively; The audio signal that becomes the straight crystal drive circuit output of resistance is through capacitor C 15 couplings, triode Q9, resistance R 5, R6, R22, R23 amplify in the partial pressure type amplifying circuit again, after capacitor C 16, C19 are coupled into the symmetrical expression amplifying circuit balance output that resistance R 9, R7, R10, R18, R24 are formed.

5, according to claim 1 or 2 or 4 described microphones, it is characterized in that: described power circuit comprises voltage doubling rectifing circuit, voltage stabilizing circuit, active filter circuit and the RC filter network that connects successively.

6, microphone according to claim 5, it is characterized in that: described voltage doubling rectifing circuit comprises diode D2, D3, the D4 that is connected in turn with positive source, capacitor C 3 is parallel to diode D2, D3 two ends, capacitor C 1 is parallel to diode D3, D4 two ends, and diode D4 negative pole is as rectification output end.

7, microphone according to claim 6 is characterized in that: described voltage stabilizing circuit comprises voltage stabilizing didoe D5 and capacitor C 4 in parallel, this voltage stabilizing circuit one end ground connection, and an end is connected with power filter.

8, microphone according to claim 7 is characterized in that: described active filter circuit comprises compound transistor D6; The D6 base stage connects voltage stabilizing circuit voltage stabilizing end, connects diode D4 negative pole by resistance R 3 simultaneously; The D6 collector electrode also connects diode D4 negative pole, and the D6 emitter is connected with the end of parallel resistor R6, capacitor C 5, C6, the other end ground connection of resistance R 6, capacitor C 5, C6, and the D6 emitter also is connected with the RC filter network simultaneously.