CN2407516Y - Audio signal precprocessing device for radio acoustic transmitter - Google Patents
Audio signal precprocessing device for radio acoustic transmitter Download PDFInfo
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- CN2407516Y CN2407516Y CN 99247941 CN99247941U CN2407516Y CN 2407516 Y CN2407516 Y CN 2407516Y CN 99247941 CN99247941 CN 99247941 CN 99247941 U CN99247941 U CN 99247941U CN 2407516 Y CN2407516 Y CN 2407516Y
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Abstract
The utility model relates to an audio signal processing device for a radio soniferous transmitting device, which comprises a pre-emphasis circuit, an audio amplifying circuit, an equalizer, a phase shift circuit and a high and low sound track filter, wherein, the audio amplifying circuit is control to amplify by a CPU unit; coded signals of the feedback quantity of the CPU unit are controlled by the output the CPU unit to the audio amplifying circuit according to the test result of amplifying output signals of the CPU unit to adjust the amplitude of audio signals; output signals of the equalizer have phase shifting through the equalizer to make the output signals have quadrature lagging. The utility model can make the amplitude of strong and weak audio signals output symmetrically; the utility model can also eliminate whistles caused by the superimposition of the signals; therefore, the distance (ranges) of using a microphone of users can be enlarged.
Description
The utility model relates to the audio signal pretreatment unit of audio signal pretreatment unit, particularly a kind of radio sound transmitting equipment.
Existing wireless microphone equipment is made up of speech processing section, modulating part, oscillating part, radio frequency part usually, and voice signal is handled by amplitude modulation or frequency modulation, transmits with wireless mode.Therefore wireless microphone is suitable for various environment, is particularly suitable for using in environment such as teaching, report, interview, performance, Karaoke.Yet existing wireless microphone equipment is relatively poor to the ability of the self-adaptive processing of the voice signal that picks up, if the user near microphone talk be easy to generate the whistle, if away from microphone talk, then noise increases and maybe can not transmit voice signal.
The purpose of this utility model provides a kind of audio signal pretreatment unit that can eliminate the radio sound transmitting equipment of whistle cry.
The purpose of this utility model is achieved in that the audio signal pretreatment unit of radio sound transmitting equipment comprises: preemphasis circuit; Equalizer; Height vocal cores bandpass filter, it is characterized in that also comprising: the audio amplifier circuit of controlling its gain by CPU element, CPU element is according to the code signal of the testing result of it being amplified output signal to this its feedback quantity of audio amplifier circuit output control, to adjust the amplitude of audio signal; And phase-shift circuit, to the equalizer output signal phase shift, make its quadrature lagging.
The audio frequency amplifier output signal is given CPU element through A/D converter, and CPU element outupt coded signal after adjudicating is delivered on the negative feedback branch road of audio frequency amplifier, with the feedback quantity of control audio amplifier through D/A converter again.
Audio amplifier circuit is made up of dual-stage amplifier, first order amplifier is a negative feedback amplifier, thermistor RT, diode D6 and resistance R 100 are serially connected between first order amplifier out and the ground successively, the code signal of CPU output converts aanalogvoltage to through D/A converter and is added between diode D6 and the thermistor RT, resistance value between the first order amplifier out that changes operational amplifier according to this aanalogvoltage and the first order amplifier feedback end, and then the amount of negative feedback of change first order amplifier; The output signal of first order amplifier is amplified output through second level amplifier again.
Audio amplifier circuit is made up of negative feedback amplifier, thermistor RT, diode D6 and resistance R 100 are serially connected between negative feedback amplifier output and the ground successively, the code signal of CPU output converts aanalogvoltage to through D/A converter and is added between diode D6 and the thermistor RT, change resistance value between negative feedback amplifier output and the feedback end according to this aanalogvoltage, and then change the amount of negative feedback of negative feedback amplifier.
The utility model also is provided with an equalizer, is used for the output signal of audio frequency amplifier is made equilibrium treatment.
The utility model also is provided with a height vocal cores bandpass filter, and the 30KHZ high frequency whistle that is used for filtering phase-shift circuit output signal is composition and the following low-frequency ac composition of 50HZ.
The utility model has the advantages that: because CPU element is carried out automatic gain control to audio amplifier circuit, phase-shift circuit postpones to handle to the audio signal of amplifying, thereby the audio frequency signal amplitude that flows to modulation circuit is reached unanimity, with can erasure signal the stack whistle of causing, this means the user can be in (distance) in a big way the use microphone.
Below in conjunction with accompanying drawing the utility model is described in detail.
Fig. 1 is the integrally-built circuit block diagram of explanation the utility model;
Fig. 2 is the circuit diagram of an embodiment of the utility model.
Referring to Fig. 1, the speech pretreatment unit comprises: preemphasis circuit; Audio amplifier circuit; Equalizer; Phase-shift circuit and height vocal cores bandpass filter.After the voice signal that flow-guiding mouth, microphone pick up carries out the preemphasis processing, amplify by audio amplifier circuit, audio amplifier circuit is controlled its feedback quantity according to the code signal of CPU element, with the output amplitude of automatic adjustment audio signal, promptly, when the audio frequency amplifier output signal is excessive, give CPU element through the A/D conversion, CPU element outupt coded signal after adjudicating is delivered on the negative feedback branch road of audio frequency amplifier through the D/A conversion, feedback quantity is increased, and gain reduces; When the audio frequency amplifier output signal is too small, give CPU element, CPU element outupt coded signal after adjudicating through the A/D conversion, deliver to by D/A converter on the negative feedback branch road of audio frequency amplifier, feedback quantity is reduced, and gain is risen, thereby has adjusted the output amplitude of audio signal automatically.Audio signal after the amplification is made equilibrium treatment by equalizer, then by the phase-shift circuit phase shift, makes its quadrature lagging.
Fig. 2 shows the utility model embodiment circuit diagram.Audio frequency enters through mechanical air deflector (by its size of streamline gate control, change its direction by guide ring, adjust its weight by mozzle, apply for a patent separately), delivers to microphone after preliminary treatment.The signal of telecommunication after the conversion (audio frequency), deliver to operational amplifier IC2 and amplify through input adjustment potentiometer W1, capacitor C 1, preemphasis circuit R1, C2, in order to cooperate the even of signal power, the signal after the amplification is done an amplitude limit adjustment by the potentiometer W2 as equalizer again.Audio amplifier circuit is that operational amplifier IC2 (comprising dual-stage amplifier) and the peripheral circuit of DIP8 formed by model, and wherein first order amplifier is a negative feedback amplifier; Thermistor RT, diode D6 and resistance R 100 are serially connected between first order amplifier out (the 17th pin) and the ground successively, and they finish the adjustment of CPU element to the negative feedback amplifier amount of negative feedback at last.The 5th pin of IC2 is the audio signal input end of having handled (first order amplifier input terminal), the 7th pin is the output of first order amplifier, the 6th pin is the negative feedback end of first order amplifier, and the 2nd pin is a second level amplifier input terminal, and the 1st pin is the output of second level amplifier.When the complete machine feedback quantity is excessive or too small, the output signal of audio frequency amplifier is given the 16th pin (test side) of CPU element IC4 through modulus converter A/D, since keyboard prefabricated certain encoding state, after handling, IC4 gives digital to analog converter D/A from code signal of IC4 the 17th pin (output) output, convert aanalogvoltage to and be added between diode D6 and the thermistor RT.Change the output of operational amplifier IC2 first order amplifier and the resistance value of feedback end (the 6th pin and the 7th pin) according to this aanalogvoltage, change the size of its amount of negative feedback, thereby reach the purpose of adjusting modulation sensitivity.Proper signal after automatic gain control is given second level amplifier from the 2nd pin again, amplifies the back and exports from the 1st pin.Fig. 2 shows the circuit of phase-shift circuit and height vocal cores bandpass filter.Resistance R 1, capacitor C 3 constitute phase-shift circuit, make through amplifying signal to lag behind 90 °, and height vocal cores bandpass filter is made up of two electric capacity and resistance R 3-R5, and the 30KHZ high frequency whistle that is used for filtering phase-shift circuit output signal is composition and the following low frequency composition of 50HZ.
Audio frequency amplifier of the present utility model is not limited to the foregoing description, for example, audio amplifier circuit can be made up of negative feedback amplifier (one or more levels amplifier), thermistor RT, diode D6 and resistance R 100 are serially connected between negative feedback amplifier output and the ground successively, the code signal of CPU output converts aanalogvoltage to through D/A converter and is added between diode D6 and the thermistor RT, change resistance value between negative feedback amplifier output and the feedback end according to this aanalogvoltage, and then change the amount of negative feedback of negative feedback amplifier.With realize to by force/the off beat equilibrium output of signal frequently.
CPU element is made of CPU IC4 and memory IC 1.CPU IC4 can be that the model that Motorola produces is the chip of AT89C2051 or AT89C51.IC4 is the CPU single-chip microcomputer, in be programmed into the function program software of 2K.R5, the C16 that 1 pin of IC4 is connect is the element of usefulness of automatically reseting, and 2,3,6 pin are the keyboard instruction input, are connected to three buttons over the ground.4,5 pin connect the 4MHZ crystal oscillator, provide service conditions to single-chip microcomputer, and C17, C18 are load capacitances, can adjust frequency difference.7,8,9,10 pin connected storage IC1 are used for the access of program.The output signal of audio frequency amplifier is sent into IC4 the 16th pin through A/D converter, after CPU obtains this information, exports the code signal of control audio amplifier gain from IC4 the 17th pin after adjudicating.
Claims (6)
1. the audio signal pretreatment unit of a radio sound transmitting equipment comprises: preemphasis circuit is characterized in that also comprising:
Control the audio amplifier circuit of its gain by CPU element, CPU element is according to the code signal of the testing result of it being amplified output signal to this its feedback quantity of audio amplifier circuit output control, to adjust the amplitude of audio signal; With
Phase-shift circuit to the equalizer output signal phase shift, makes its quadrature lagging.
2. audio signal pretreatment unit according to claim 1, it is characterized in that: the audio frequency amplifier output signal is given CPU element through A/D converter, CPU element outupt coded signal after adjudicating, deliver on the negative feedback branch road of audio frequency amplifier, through D/A converter again with the feedback quantity of control audio amplifier.
3. audio signal pretreatment unit according to claim 1, it is characterized in that: audio amplifier circuit is made up of dual-stage amplifier, first order amplifier is a negative feedback amplifier, thermistor RT, diode D6 and resistance R 100 are serially connected between first order amplifier out and the ground successively, the code signal of CPU output converts aanalogvoltage to through D/A converter and is added between diode D6 and the thermistor RT, resistance value between the first order amplifier out that changes operational amplifier according to this aanalogvoltage and the first order amplifier feedback end, and then the amount of negative feedback of change first order amplifier; The output signal of first order amplifier is amplified output through second level amplifier again.
4. audio signal pretreatment unit according to claim 1, it is characterized in that: audio amplifier circuit is made up of negative feedback amplifier, thermistor RT, diode D6 and resistance R 100 are serially connected between negative feedback amplifier output and the ground successively, the code signal of CPU output converts aanalogvoltage to through D/A converter and is added between diode D6 and the thermistor RT, change resistance value between negative feedback amplifier output and the feedback end according to this aanalogvoltage, and then change the amount of negative feedback of negative feedback amplifier.
5. audio signal pretreatment unit according to claim 1 is characterized in that: also be provided with an equalizer, be used for the output signal of audio frequency amplifier is made equilibrium treatment.
6. audio signal pretreatment unit according to claim 1 is characterized in that: also be provided with a height vocal cores bandpass filter, the 30KHZ high frequency whistle that is used for filtering phase-shift circuit output signal is composition and the following low-frequency ac composition of 50HZ.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 99247941 CN2407516Y (en) | 1999-11-24 | 1999-11-24 | Audio signal precprocessing device for radio acoustic transmitter |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN 99247941 CN2407516Y (en) | 1999-11-24 | 1999-11-24 | Audio signal precprocessing device for radio acoustic transmitter |
Publications (1)
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CN2407516Y true CN2407516Y (en) | 2000-11-22 |
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CN 99247941 Expired - Fee Related CN2407516Y (en) | 1999-11-24 | 1999-11-24 | Audio signal precprocessing device for radio acoustic transmitter |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104269165A (en) * | 2014-09-10 | 2015-01-07 | 韩熠 | Guitar digital delay effector |
CN105101006A (en) * | 2014-05-13 | 2015-11-25 | 深圳Tcl新技术有限公司 | Wireless microphone and wireless karaoke control system |
WO2016078227A1 (en) * | 2014-11-21 | 2016-05-26 | 中兴通讯股份有限公司 | Gain processing method and device |
CN106231502A (en) * | 2016-08-29 | 2016-12-14 | 广州声姆音响设备有限公司 | The frequency response method of reduction treatment of a kind of phase-shift circuit and circuit |
-
1999
- 1999-11-24 CN CN 99247941 patent/CN2407516Y/en not_active Expired - Fee Related
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105101006A (en) * | 2014-05-13 | 2015-11-25 | 深圳Tcl新技术有限公司 | Wireless microphone and wireless karaoke control system |
CN104269165A (en) * | 2014-09-10 | 2015-01-07 | 韩熠 | Guitar digital delay effector |
WO2016078227A1 (en) * | 2014-11-21 | 2016-05-26 | 中兴通讯股份有限公司 | Gain processing method and device |
CN106231502A (en) * | 2016-08-29 | 2016-12-14 | 广州声姆音响设备有限公司 | The frequency response method of reduction treatment of a kind of phase-shift circuit and circuit |
CN106231502B (en) * | 2016-08-29 | 2019-04-26 | 广州声姆音响设备有限公司 | A kind of the frequency response method of reduction treatment and circuit of phase-shift circuit |
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Legal Events
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C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
C19 | Lapse of patent right due to non-payment of the annual fee | ||
CF01 | Termination of patent right due to non-payment of annual fee |