Based on the audio frequency processing system that low-pass filtering is amplified
Technical field
The utility model relates to a kind of electronic system, specifically refers to a kind of audio frequency processing system amplified based on low-pass filtering.
Background technology
Along with people pursue more and more higher to quality of life, present home theater enters into every household substantially, brings very large enjoyment to people's life.But, often there will be the unclear situation of sound when people watch film, thus have influence on film play quality.
Utility model content
The purpose of this utility model is to overcome the defect that current audio treatment system is easily directed at the audio distortion after process, provides a kind of audio frequency processing system amplified based on low-pass filtering can stablizing processing audio.
The following technical scheme of the purpose of this utility model realizes: the audio frequency processing system amplified based on low-pass filtering, primarily of audio collection module, the frequency selection circuit be connected with audio collection module, the micro-processor interface circuit be all connected with frequency selection circuit and current source circuit form, and are also provided with two-stage low-pass filtering amplifying circuit at the output of micro-processor interface circuit and current source circuit.It is by amplifier P1, amplifier P2, triode VT5, triode VT6, positive pole is connected with micro-processor interface circuit, the electric capacity C6 of minus earth, one end is connected with the normal phase input end of amplifier P1, the resistance R7 that the other end is connected with current source circuit, positive pole is connected with amplifier P1 inverting input after resistance R8, the electric capacity C7 that negative pole is connected with the negative pole of electric capacity C6, be serially connected in the electric capacity C8 between the output of amplifier P1 and inverting input, negative pole is connected with the output of amplifier P1, the electric capacity C9 that positive pole is connected with the base stage of triode VT5, one end is connected with the collector electrode of triode VT5, the resistance R9 that the other end is connected with the emitter of triode VT6, positive pole is connected with the base stage of triode VT6 after resistance R10, the electric capacity C10 of ground connection while negative pole is connected with the negative pole of electric capacity C8, one end is connected with the positive pole of electric capacity C10, the resistance R11 that the other end is connected with the inverting input of amplifier P2, the resistance R12 be in parallel with resistance R11, be serially connected in the electric capacity C11 between the output of amplifier P2 and inverting input, and the resistance R13 be serially connected between the normal phase input end of amplifier P2 and output forms, the emitter of described triode VT5 is connected with electric capacity C8 negative pole, and the collector electrode of triode VT6 is connected with the normal phase input end of amplifier P2.
Described frequency selection circuit is by triode VT1, triode VT2, positive pole is connected with the base stage of triode VT1 after resistance R1, negative pole then through the electric capacity C1 that electric capacity C2 is connected with the base stage of triode VT1 after electric capacity C3, and the resistance R2 that one end is connected with the base stage of triode VT2, the other end is then connected with the collector electrode of triode VT1 forms; The collector electrode of described triode VT2 is connected with the positive pole of electric capacity C1, its emitter is then connected with current source circuit, and the emitter of triode VT1 is then connected with the tie point of electric capacity C2 and electric capacity C3 and micro-processor interface circuit simultaneously.
Described micro-processor interface circuit comprises electric capacity C4, electric capacity C5, resistance R6, and field effect transistor Q1; The positive pole of electric capacity C4 is connected with the emitter of triode VT1, its negative pole is connected with the grid of field effect transistor Q1, one end of resistance R6 is connected with the grid of field effect transistor Q1, other end ground connection, the negative pole of electric capacity C5 is connected with the drain electrode of field effect transistor Q1, positive pole is then connected with the positive pole of current source circuit and electric capacity C6 simultaneously, and the source electrode of described field effect transistor Q1 is connected with current source circuit.
Described current source circuit is by triode VT3, triode VT4, the voltage stabilizing didoe D1 that N pole is connected with the base stage of triode VT3, P pole is connected with the emitter of triode VT3 after resistance R4, one end is connected with the base stage of triode VT3, the resistance R3 of other end ground connection, and the resistance R5 that one end is connected with triode VT4 emitter, the other end is connected with the positive pole of electric capacity C5 forms; The described collector electrode of triode VT3 is connected with the source electrode of field effect transistor Q1, emitter is connected with the base stage of triode VT4, the grounded collector of triode VT4, and the P pole of voltage stabilizing didoe D1 is connected with external power source.
The utility model compared with prior art, has the following advantages and beneficial effect:
(1) the utility model is provided with two-stage low-pass filtering amplifying circuit, and it distortionlessly can amplify audio signal, makes sound effect better improve film play quality.
(2) the utility model structure is simple, and energy efficient.
Accompanying drawing explanation
Fig. 1 is overall structure schematic diagram of the present utility model.
Embodiment
Below in conjunction with specific embodiment, the utility model is described in further detail, but execution mode of the present utility model is not limited thereto.
Embodiment
As shown in Figure 1, the audio frequency processing system amplified based on low-pass filtering of the present utility model, primarily of audio collection module, the frequency selection circuit be connected with audio collection module, the micro-processor interface circuit be all connected with frequency selection circuit and current source circuit form, and are also provided with two-stage low-pass filtering amplifying circuit at the output of micro-processor interface circuit and current source circuit.
Wherein, two-stage low-pass filtering amplifying circuit distortionlessly can amplify audio signal, makes sound effect better improve film play quality.It is by amplifier P1, amplifier P2, triode VT5, triode VT6, positive pole is connected with micro-processor interface circuit, the electric capacity C6 of minus earth, one end is connected with the normal phase input end of amplifier P1, the resistance R7 that the other end is connected with current source circuit, positive pole is connected with amplifier P1 inverting input after resistance R8, the electric capacity C7 that negative pole is connected with the negative pole of electric capacity C6, be serially connected in the electric capacity C8 between the output of amplifier P1 and inverting input, negative pole is connected with the output of amplifier P1, the electric capacity C9 that positive pole is connected with the base stage of triode VT5, one end is connected with the collector electrode of triode VT5, the resistance R9 that the other end is connected with the emitter of triode VT6, positive pole is connected with the base stage of triode VT6 after resistance R10, the electric capacity C10 of ground connection while negative pole is connected with the negative pole of electric capacity C8, one end is connected with the positive pole of electric capacity C10, the resistance R11 that the other end is connected with the inverting input of amplifier P2, the resistance R12 be in parallel with resistance R11, be serially connected in the electric capacity C11 between the output of amplifier P2 and inverting input, and the resistance R13 be serially connected between the normal phase input end of amplifier P2 and output forms, the emitter of described triode VT5 is connected with electric capacity C8 negative pole, and the collector electrode of triode VT6 is connected with the normal phase input end of amplifier P2.
Frequency selection circuit can screen signal, picks out useful signal.It is by triode VT1, triode VT2, positive pole is connected with the base stage of triode VT1 after resistance R1, negative pole then through the electric capacity C1 that electric capacity C2 is connected with the base stage of triode VT1 after electric capacity C3, and the resistance R2 that one end is connected with the base stage of triode VT2, the other end is then connected with the collector electrode of triode VT1 forms; The collector electrode of described triode VT2 is connected with the positive pole of electric capacity C1, its emitter is then connected with current source circuit, and the emitter of triode VT1 is then connected with the tie point of electric capacity C2 and electric capacity C3 and micro-processor interface circuit simultaneously.
Micro-processor interface circuit comprises electric capacity C4, electric capacity C5, resistance R6, and field effect transistor Q1; The positive pole of electric capacity C4 is connected with the emitter of triode VT1, its negative pole is connected with the grid of field effect transistor Q1, one end of resistance R6 is connected with the grid of field effect transistor Q1, other end ground connection, the negative pole of electric capacity C5 is connected with the drain electrode of field effect transistor Q1, positive pole is then connected with the positive pole of current source circuit and electric capacity C6 simultaneously, and the source electrode of described field effect transistor Q1 is connected with current source circuit.
Described current source circuit is by triode VT3, triode VT4, the voltage stabilizing didoe D1 that N pole is connected with the base stage of triode VT3, P pole is connected with the emitter of triode VT3 after resistance R4, one end is connected with the base stage of triode VT3, the resistance R3 of other end ground connection, and the resistance R5 that one end is connected with triode VT4 emitter, the other end is connected with the positive pole of electric capacity C5 forms; The described collector electrode of triode VT3 is connected with the source electrode of field effect transistor Q1, emitter is connected with the base stage of triode VT4, the grounded collector of triode VT4, and the P pole of voltage stabilizing didoe D1 is connected with external power source.
As mentioned above, just well the utility model can be realized.