CN202103852U

CN202103852U - Audio signal generator prepared by single transistor

Info

Publication number: CN202103852U
Application number: CN2011201324531U
Authority: CN
Inventors: 刘家发
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-04-28
Filing date: 2011-04-28
Publication date: 2012-01-04
Anticipated expiration: 2021-04-28

Abstract

The utility model relates to an audio signal generator prepared by single transistor. The audio signal generator comprises a direct-current power supply DC, a power supply filter circuit, a common-emitter amplification circuit, a three-level RC phase shift circuit and an AC negative feedback circuit; and is characterized in that the common-emitter amplification circuit is connected with the three-level RC phase shift circuit, and the emitter electrode of a PNP transistor VT1 is connected with the AC negative feedback circuit. In order to make up and overcome the problem that although the professional audio signal generator on market has a plurality of functions and good property, the price thereof is high, and general professional persons are difficult of accepting, the audio signal generator prepared by an RC oscillator is used for measuring related technology indexes and data of a sound equipment circuit, and can be an audio signal generator with simple circuit structure, stable working property, convenient use and low price.

Description

The audio signal generator of single transistor fabrication

Technical field

The utility model belongs to the application of electronic technology field, is the audio signal generator about a kind of single transistor fabrication.

Background technology

With the technical indicator of apparatus measures stereo set, the resolution of its measurement is much higher more than people's ear, and for design, debugging or the maintenance of acoustics circuit, audio signal generator is having important role aspect the technical indicator measurement of stereo set.In fact the ordinary audio signal generator is exactly an oscillating circuit, and the oscillating circuit kind mainly contains two kinds, and a kind of is the LC oscillator, and another kind is the RC oscillator.What the utility model embodiment used is the audio signal generator made from the RC oscillator, is used for measuring acoustics circuit relevant technical indicator and related data.

Many audio signal generator softwares that use are on computers arranged on market at present, and software can be installed operation on computers.But these computer software signal generators belong to amateur purposes more, and the audio signal quality of transmission and sound card have very big related, and it can't replace the effect of audio signal generator fully.Aspects such as the described audio signal generator of the utility model requires in signal waveform, the peak-to-peak value (P-P) of signal output amplitude, signal output distortion degree, harmonic wave all can satisfy the measurement requirement of general stereo set technical indicator.

Though the audio signal generator function admirable of professional use on the market exists high, the general sound equipment professional of price to be difficult to defectives such as acceptance.In order to remedy and to overcome these problems, be necessary to develop that a kind of circuit structure is succinct, stable work in work, cheap, handy audio signal generator.

The audio signal generator that below specifies described single the transistor fabrication of the utility model related relevant technologies content in manufacturing process.

The utility model content

Goal of the invention and beneficial effect: though many, the function admirable of audio signal generator function of professional use on the market exists high, the general sound equipment professional of price to be difficult to defectives such as acceptance.In order to remedy and to overcome these problems; The utility model embodiment is the audio signal generator made from the RC oscillator; Be used for measuring acoustics circuit relevant technical indicator and relevant data, be a kind of circuit structure succinctly, stable work in work, handy and cheap audio signal generator.

Technical scheme: the audio signal generator of single transistor fabrication; Comprise DC power supply DC, electric source filter circuit, common emitter amplifying circuit, three grades of RC phase-shift circuits and exchange negative-feedback circuit; It is characterized in that: be connected to three grades of RC phase-shift circuits in the common emitter amplifying circuit, the emitter of PNP transistor VT1 is connected to the interchange negative-feedback circuit.

The composition of each several part circuit and the connection features between the components and parts

The connection features of common emitter amplifying circuit is: the base stage of PNP transistor VT1 connects three grades of RC phase-shift circuits; The collector electrode of PNP transistor VT1 links to each other with the negative pole of an end of resistance R 5, electrochemical capacitor C5; The other end connection circuit negative pole VSS of resistance R 5; The positive pole of electrochemical capacitor C5 connects audio signal output end, and the emitter of PNP transistor VT1 connects the interchange negative-feedback circuit.

Three grades of RC phase-shift circuits: form by resistance R 1, resistance R 2, resistance R 3, resistance R 4, capacitor C 1, capacitor C 2 and capacitor C 3; It is characterized in that: the end of the base stage connecting resistance R3 of PNP transistor VT1, an end of resistance R 4 and an end of capacitor C 3; The other end connection circuit negative pole VSS of resistance R 4, the termination circuit ground of resistance R 3, the other end of capacitor C 3 links to each other with an end of capacitor C 2, an end of resistance R 2; The other end connection circuit ground of resistance R 2; The other end of capacitor C 2 links to each other with an end of capacitor C 1, an end of resistance R 1, the other end connection circuit ground of resistance R 1, the collector electrode of another termination PNP transistor VT1 of capacitor C 1.

Exchange negative-feedback circuit: be made up of resistance R 6, electrochemical capacitor C4, it is characterized in that: the end of the emitter connecting resistance R6 of PNP transistor VT1 and the negative pole of electrochemical capacitor C4, the positive pole of the other end of connecting resistance R6 and electrochemical capacitor C4 is with connection circuit ground.

Electric source filter circuit: form by electrochemical capacitor C6, capacitor C 7 and capacitor C 8; One end of the negative pole of electrochemical capacitor C6 and capacitor C 7 and an end of capacitor C 8 are with connection circuit negative pole VSS, and the other end of the positive pole of electrochemical capacitor C6 and capacitor C 7 and the other end of capacitor C 8 are with connection circuit ground.

The circuit working principle: the circuit of the described audio signal generator of the utility model is with a RC phase shift oscillator; Signal phase difference in the circuit between the base stage of PNP transistor VT1 and the big utmost point of collection is 180 °; Constitute three grades of RC phase-shift circuits via resistance R 1～R3 and capacitor C 1～C3 again; Phase shift is 1800 ° altogether, and the total phase difference of circuit is 360 °.Therefore, circuit is fed back to same-phase after through three grades of phase shifts, is positive feedback, has satisfied the phase condition of oscillating circuit and the requirement of oscillation amplitude.In order to increase the stability of RC phase shift oscillator circuit positive feedback work, in the common emitter amplifying circuit, be connected to the interchange negative-feedback circuit, the capacitor C 6～C8 in the circuit is an electric source filter circuit, with the interference free performance of intensifier circuit.

Description of drawings

Accompanying drawing is the embodiment circuit working schematic diagram of the utility model audio signal generator that a single transistor fabrication is provided, connects the positive pole of DC power supply DC the circuit in the accompanying drawing, and VSS is the negative pole of circuit.

Embodiment

Implement according to the circuit working schematic diagram of the audio signal generator of single transistor fabrication shown in the accompanying drawing and the components and parts specification requirement of description of drawings and the following stated, can realize the utility model.

The selection of components and parts and technical parameter thereof

VT1 is the positive-negative-positive silicon transistor, and model is: 2SC9015, and β value >=80 also can be selected the positive-negative-positive high frequency transistor of germanium materials such as penetrating current is little, the homemade model 3AG1C of working stability, 3AG1D for use;

Resistance is selected 1/8 metalfilmresistor for use, and the resistance of resistance R 1, R2 is 2K Ω, and the resistance of resistance R 3 is 8.2K Ω, and the resistance of resistance R 4 is 24K Ω, and the resistance of resistance R 5 is 1.1K Ω, and the resistance of resistance R 6 is 470 Ω;

C1～C3 is an oscillating capacitance, and selecting capacity for use is the terylene capacity of 0.047 μ F; C4 is for exchanging negative feedback electric capacity, and capacity is 30 μ F/16V; C5 is the audio frequency output coupling capacitor, and capacity is 50 μ F/16V; C6 is the low frequency filtering electric capacity of DC power supply DC, and capacity is 470 μ F/16V; C7, C8 are the high-frequency filter capacitor of DC power supply DC, and its capacity is respectively 0.01 μ F, 5100PF;

DC is a DC power supply, and supply voltage is 6V, uses the common alkaline battery of 4 joints.

Circuit production and debugging

The circuit of audio signal generator is so long as the electronic devices and components performance of selecting for use is intact; The annexation of components and parts is welded in the accompanying drawing to specifications; After physical connection line and welding quality process scrutiny were errorless, circuit need not debugged basically and get final product operate as normal.

The direct current retaining of serial connection universal instrument records the normal electrical flow valuve and should be about 17mA in the collector loop of PNP transistor VT1.If it is bigger to record the operating current deviation, but the resistance of the biasing resistor R4 of appropriate change PNP transistor VT1 makes operating current reach normal value.

On audio signal output end, connect the insert earphone of an impedance >=2000 Ω, connect the switch SW of the DC power supply DC of audio signal generator, circuit can produce self-oscillation, can obtain the audio signal of 1kHz at audio signal output end.Under the condition of load impedance >=2000 Ω high resistants, the output voltage of audio signal is greater than 1000mV.

Claims

1. the audio signal generator of a single transistor fabrication comprises DC power supply DC, electric source filter circuit, common emitter amplifying circuit, three grades of RC phase-shift circuits and exchanges negative-feedback circuit, it is characterized in that:

The base stage of PNP transistor VT1 in the common emitter amplifying circuit connects three grades of RC phase-shift circuits; The collector electrode of PNP transistor VT1 links to each other with the negative pole of an end of resistance R 5, electrochemical capacitor C5; The other end connection circuit negative pole VSS of resistance R 5; The positive pole of electrochemical capacitor C5 connects audio signal output end, and the emitter of PNP transistor VT1 connects the interchange negative-feedback circuit;

An end, an end of resistance R 4 and the end of capacitor C 3 of the base stage connecting resistance R3 of PNP transistor VT1 in three grades of RC phase-shift circuits; The other end connection circuit negative pole VSS of resistance R 4; The one termination circuit ground of resistance R 3; The other end of capacitor C 3 links to each other with an end of capacitor C 2, an end of resistance R 2, the other end connection circuit ground of resistance R 2, and the other end of capacitor C 2 links to each other with an end of capacitor C 1, an end of resistance R 1; The other end connection circuit ground of resistance R 1, the collector electrode of another termination PNP transistor VT1 of capacitor C 1;

The end of the emitter connecting resistance R6 of PNP transistor VT1 in the interchange negative-feedback circuit and the negative pole of electrochemical capacitor C4, the positive pole of the other end of connecting resistance R6 and electrochemical capacitor C4 is with connection circuit ground.

2. the audio signal generator of single transistor fabrication according to claim 1; It is characterized in that: electric source filter circuit is made up of electrochemical capacitor C6, capacitor C 7 and capacitor C 8; One end of the negative pole of electrochemical capacitor C6 and capacitor C 7 and an end of capacitor C 8 are with connection circuit negative pole VSS, and the other end of the positive pole of electrochemical capacitor C6 and capacitor C 7 and the other end of capacitor C 8 are with connection circuit ground.