CN104714456A - Method for improving low-frequency signal output amplitude and controlling accuracy - Google Patents
Method for improving low-frequency signal output amplitude and controlling accuracy Download PDFInfo
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- CN104714456A CN104714456A CN201510120966.3A CN201510120966A CN104714456A CN 104714456 A CN104714456 A CN 104714456A CN 201510120966 A CN201510120966 A CN 201510120966A CN 104714456 A CN104714456 A CN 104714456A
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- amplitude
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- dac
- frequency signal
- low frequency
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
- G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
- G05B19/0423—Input/output
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/20—Pc systems
- G05B2219/26—Pc applications
- G05B2219/2612—Data acquisition interface
Abstract
The invention discloses a method for improving low-frequency signal output amplitude and controlling the accuracy. The method is realized through a circuit, the circuit can improve the low-frequency signal output amplitude resolution ratio on the basis that an operational amplifying circuit improves the low-frequency signal amplitude, and the circuit comprises the operational amplifying circuit and an overlapping circuit. According to the principle, the low-frequency signal amplitude is amplified through the operational amplifying circuit, so that amplified reference signal sources are output; the output reference signal sources with a low resolution ratio are overlapped through the signal overlapping circuit, so that large signal output is realized under the condition of not losing the low-frequency signal amplitude resolution ratio. The method for improving the low-frequency signal output amplitude and controlling the accuracy overcomes the defect that in the prior art, the low-frequency signal output amplitude accuracy is limited by a digital-analog conversion (DAC) chip, that is, when the low-frequency signal output amplitude is amplified proportionally through the operational amplifying circuit and meets the requirement, the resolution ratio of the low-frequency signal output amplitude is lowered.
Description
Technical field
The present invention relates to a kind of method improving the output of low frequency signal amplitude and control accuracy in electronic signal process, signal analysis, electronic test equipment field.
Background technology
In work on hand, a lot of application requirements provides pure simulation low frequency signal, conventional method controls digital-to-analogue by microprocessor one to transform chip one DAC1, as: DAC0832, AD7520 and peripheral circuit produce and export the low frequency signal of simulating signal, when needs low frequency significantly signal time also need to amplify signal.As Fig. 1 for the low frequency signal amplitude commonly used export and control method the operational amplification circuit figure that adopts; Described operational amplification circuit 1 comprises, microprocessor 1, D/A converter module one DAC1, amplitude fading control circuit module 1, operational amplifier one A1, feedback resistance one Rf1, input resistance one Ri and balance resistance one R11; Described microprocessor 1 is connected with described D/A converter module one DAC1 input end and amplitude fading control circuit module 1 input end; Described amplitude fading control circuit module 1 output terminal is connected with D/A converter module one DAC1 output terminal, described D/A converter module one DAC1 output terminal is connected with the input end of described operational amplifier one A11 simultaneously, the input end of described operational amplifier one A11 is connected with input resistance one Ri, base terminal is connected with balance resistance one R11, and described feedback resistance one Rf1 two ends are connected with the input/output terminal of operational amplifier one A11 respectively; Described microprocessor 1 controls D/A converter module one DAC1 and signal is carried out full amplitude output, the signal that completely amplitude exports simultaneously controls the decay of its signal amplitude by described amplitude fading control circuit module 1, produce attenuation amplitude output voltage signal one VDAC1, attenuation amplitude output voltage signal one VDAC1 amplifies signal through described operational amplifier one A11 again, and enlargement factor is-Rf1/Ri.
Weak point is: conventional low frequency signal amplitude exports and control method, its low frequency signal output amplitude precision produced is limited to analog-digital chip one i.e. DAC1 stamen sheet, simultaneously when low frequency signal output amplitude through operational amplification circuit scale amplifying and amplitude meets the demands time, the resolution of low frequency signal output amplitude but greatly reduces.In FIG, export VOUT1=-Rf1/Ri*VDAC1, the signal exported as VDAC1 is the Low Frequency Sine Signals of peak value 10V, when the resolution of amplitude fading control circuit module is 10; If when the signal peak needing VOUT1 to export is the Low Frequency Sine Signals within 10V, then Rf1/Ri=1, it is 10/1022=9.36mV that amplitude controls minimum value; If need signal amplitude to be amplified the signal peak making VOUT1 export when being the Low Frequency Sine Signals within 20V, then Rf1/Ri=2, amplitude controls minimum value 20/1022=19.52mV, output signal control accuracy reduces one times, if signal enlargement range is larger, then signal control accuracy will reduce larger.
Summary of the invention
The technical matters that the present invention mainly solves is to provide a kind of method improving low frequency signal amplitude and export and control its precision, make it overcome existing method medium and low frequency signal output amplitude after amplifying circuit carries out amplitude amplification to its signal, but greatly reduce the resolution drawback of low frequency signal output amplitude.
For solving the problems of the technologies described above, the technical matters that the present invention mainly solves is to provide a kind of method improving low frequency signal amplitude and export and control its precision, it is realized by a circuit, described circuit comprises operational amplification circuit, low frequency signal amplitude is amplified by described operational amplification circuit, the reference signal source after making it export amplification; Described operational amplification circuit comprises, microprocessor, D/A converter module DAC, amplitude fading control circuit module, operational amplifier A 1, feedback resistance Rf, input resistance Ri and balance resistance R1; Described microprocessor is connected with described D/A converter module DAC input end and amplitude fading control circuit module input; Described amplitude fading control circuit module output terminal is connected with D/A converter module DAC output terminal, described D/A converter module DAC output terminal is connected with the input end of described operational amplifier A 1 simultaneously, the input end of described operational amplifier A 1 is connected with input resistance Ri1, base terminal is connected with balance resistance R1, and described feedback resistance Rf two ends are connected with the input/output terminal of operational amplifier A 1 respectively; Signal is carried out full amplitude output by described Microprocessor S3C44B0X D/A converter module DAC, the signal that completely amplitude exports simultaneously controls the decay of its signal amplitude by described amplitude fading control circuit module, the low frequency signal that described D/A converter module DAC produces amplifies through described operational amplifier A 1 pair of signal again, and enlargement factor is-Rf/Ri; Described raising low frequency signal amplitude exports and controls the method for its precision, also comprise supercircuit, described supercircuit is by superimposed for the not high output reference signal source of precision after amplifying thus realize exporting not losing the large-signal in low frequency signal amplitude resolution situation;
Preferably, described supercircuit includes relay, multiple input resistance, with multiple balance resistance, described relay wiring end is connected with microprocessor and D/A converter module DAC, multiple described input resistance Ri1, input resistance Ri2, with relay contact switch K2 after input resistance Ri3 is in parallel, relay contact switch K3 is connected, the other end is connected with the input end of operational amplifier A 1, multiple balance resistance R1, balance resistance R2, one end and relay contact switch K4 after balance resistance R3 parallel connection, relay contact switch K5 is connected, the other end is connected with the base terminal of operational amplifier A 1, described Microprocessor S3C44B0X D/A converter module DAC, break-make relay contact switch K2, relay contact switch K3, relay contact switch K4, loop, relay contact switch K5 place is needed according to amplitude, control by amplitude fading control circuit module after the full amplitude of D/A converter module DAC exports, complete attenuation amplitude output voltage signal VDAC, there is provided full magnitude output signal VDAO, for amplifying circuit simultaneously.
Preferably, multiple described input resistance Ri1, input resistance Ri2, input resistance Ri3 resistance are equal to each other and equal with feedback resistance Rf resistance, improve precision.
The invention has the beneficial effects as follows that overcoming prior art medium and low frequency signal output amplitude precision is limited to analog-digital chip and DAC stamen sheet, namely low frequency signal output amplitude is through operational amplification circuit scale amplifying, when amplitude meets the demands, but reduce the drawback of low frequency signal output amplitude resolution.
Accompanying drawing explanation
Fig. 1 is the conventional circuit diagram that low frequency signal amplitude exports and control method adopts;
Fig. 2 of the present inventionly a kind ofly improves a kind of circuit diagram that low frequency signal amplitude exports and the method that controls its precision adopts;
Wherein, 1, operational amplification circuit one; 2, amplitude fading control circuit module one; 3, microprocessor one; 4, operational amplification circuit; 5, amplitude fading control circuit module; 6, supercircuit; 7, microprocessor; 8, relay; A11, operational amplifier one A11; A1, operational amplifier A 1; Ri, input resistance one Ri; Ri1, input resistance Ri1; Ri2, input resistance Ri2; Ri3, input resistance Ri3; R11, balance resistance one; R1, balance resistance R1; R2, balance resistance R2; R3, balance resistance R3; Rf1, feedback resistance one Rf1; Rf, feedback resistance Rf; DAC1, D/A converter module one; DAC, D/A converter module; VDAC1, attenuation amplitude output voltage signal one; VDAC, attenuation amplitude output voltage signal; VDAO, digital-to-analog conversion voltage output signal; K2, relay contact switch K2; K3, relay contact switch K3; K4, relay contact switch K4; K5, relay contact switch K5; The final voltage signal exported in the operational amplification circuit one that VOUT1, existing method adopt; The final voltage signal exported in the operational amplification circuit that VOUT, the inventive method adopt.
Embodiment
Below in conjunction with accompanying drawing, preferred embodiment of the present invention is described in detail, can be easier to make advantages and features of the invention be readily appreciated by one skilled in the art, thus more explicit defining is made to protection scope of the present invention.
As shown in Figure 2 of the present invention a kind of improves a kind of circuit diagram that low frequency signal amplitude exports and the method that controls its precision adopts, comprise operational amplification circuit 4, low frequency signal amplitude is amplified by described operational amplification circuit 4, the reference signal source after making it export amplification, described operational amplification circuit comprises, microprocessor 7, D/A converter module DAC, amplitude fading control circuit module 5, operational amplifier A 1, feedback resistance Rf, input resistance Ri and balance resistance R1, described microprocessor 7 is connected with described D/A converter module DAC input end and amplitude fading control circuit module 5 input end, described amplitude fading control circuit module 5 output terminal is connected with D/A converter module DAC output terminal, described D/A converter module DAC output terminal is connected with the input end of described operational amplifier A 1 simultaneously, the input end of described operational amplifier A 1 is connected with input resistance Ri1, base terminal is connected with balance resistance R1, and described feedback resistance Rf two ends are connected with the input/output terminal of operational amplifier A 1 respectively, described microprocessor 7 controls D/A converter module DAC and signal is carried out full amplitude output, the signal that completely amplitude exports simultaneously controls the decay of its signal amplitude by described amplitude fading control circuit module 5, the low frequency signal that described D/A converter module DAC produces amplifies through described operational amplifier A 1 pair of signal again, and enlargement factor is-Rf/Ri, described raising low frequency signal amplitude exports and controls the method for its precision, also comprise supercircuit 6, described supercircuit 6 is by superimposed for the not high output reference signal source of precision after amplifying thus realize exporting not losing the large-signal in low frequency signal amplitude resolution situation, described supercircuit 6 includes relay 8, multiple input resistance Ri2, input resistance Ri3 and multiple balance resistance R2, balance resistance R3, described relay 8 terminals are connected with microprocessor 7 and D/A converter module DAC, multiple described input resistance Ri1, input resistance Ri2, with relay contact switch K2 after input resistance Ri3 is in parallel, relay contact switch K3 is connected, the other end is connected with the input end of operational amplifier A 1, multiple balance resistance R1, balance resistance R2, one end and relay contact switch K4 after balance resistance R3 parallel connection, relay contact switch K5 is connected, the other end is connected with the base terminal of operational amplifier A 1, described microprocessor 7 controls D/A converter module DAC, break-make relay contact switch K2, relay contact switch K3, relay contact switch K4, loop, relay contact switch K5 place is needed according to amplitude, control by amplitude fading control circuit module 4 after the full amplitude of D/A converter module DAC exports, complete attenuation amplitude output voltage signal VDAC, there is provided full magnitude output signal VDAO, for amplifying circuit simultaneously, multiple described input resistance Ri1, input resistance Ri2, input resistance Ri3 resistance are equal to each other and equal with feedback resistance Rf resistance, improve precision.
The course of work of the method that raising low frequency signal amplitude of the present invention exports and controls its precision is as follows:
In fig. 2, VOUT=-Rf/Ri1*VDAC-Rf/Ri2*VDA0-Rf/Ri3*VDA0. is exported
The signal peak that amplitude as full in VDAC exports is the Low Frequency Sine Signals of 10V; when the resolution that amplitude controls is 10; embodiment one: when needing to output signal the output peak value of VOUT the Low Frequency Sine Signals within being 10V; relay contact switch K2, K4, K3; K5 disconnects; computing forms adding circuit, exports VOUT=-Rf/Ri1*VDAC=-VDAC, and amplitude controls minimum value 10/1024=9.76mV;
Embodiment two: when needing the Low Frequency Sine Signals of the output peak value 10 < V< 20 outputing signal VOUT, relay contact switch K2, K4 closes, K3, K5 disconnects, computing forms adding circuit, and export VOUT=-Rf/Ri1*VDAC-Rf/Ri2*VDA0=-VDAC-VDA0, it is still 10/1024=9.76mV that amplitude controls minimum value.
Embodiment three: when needing the Low Frequency Sine Signals of the output peak value 20 < V< 30 outputing signal VOUT, relay contact switch K2, K4, K3, K5 closes, computing forms adding circuit, and export VOUT=-Rf/Ri1*VDAC-Rf/Ri2*VDA0-Rf/Ri3*VDA0=-VDAC-2VDA0, it is still 10/1024=9.76mV that amplitude controls minimum value.It can thus be appreciated that amplitude exports in increase, and control accuracy does not but decline.
Raising low frequency signal amplitude of the present invention exports and the method that controls its precision is improving on the basis of low frequency signal amplitude based on operational amplification circuit, then by superimposed signal circuit by superimposed for output reference signal source not high for resolution thus realize exporting not losing the large-signal in low frequency signal amplitude resolution situation.
The foregoing is only embodiments of the invention; not thereby the scope of the claims of the present invention is limited; every utilize instructions of the present invention and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present invention.
Claims (3)
1. the method improving low frequency signal amplitude and export and control its precision, be completed by a circuit, described circuit, comprises operational amplification circuit (4), low frequency signal amplitude is amplified by described operational amplification circuit (4), the reference signal source after making it export amplification; Described operational amplification circuit comprises, microprocessor (7), D/A converter module DAC(DAC), amplitude fading control circuit module (5), operational amplifier A 1(A1), feedback resistance Rf(Rf), input resistance Ri1(Ri1) and balance resistance R1(R1); Described microprocessor (7) and described D/A converter module DAC(DAC) input end and amplitude fading control circuit module (5) input end be connected; Described amplitude fading control circuit module (5) output terminal and D/A converter module DAC(DAC) output terminal is connected, described D/A converter module DAC(DAC) output terminal simultaneously with described operational amplifier A 1(A1) input end be connected, described operational amplifier A 1(A1) input end be connected with input resistance Ri1(Ri1), base terminal is connected with balance resistance R1(R1), described feedback resistance Rf (Rf) two ends respectively with operational amplifier A 1(A1) input/output terminal be connected; Described microprocessor (7) controls D/A converter module DAC(DAC) signal is carried out full amplitude output, the signal that completely amplitude exports simultaneously controls the decay of its signal amplitude by described amplitude fading control circuit module (5), described D/A converter module DAC(DAC) low frequency signal that produces is again through described operational amplifier A 1(A1) signal is amplified, enlargement factor is-Rf/Ri; Described raising low frequency signal amplitude exports and controls the method for its precision, characterized by further comprising supercircuit (6), described supercircuit (6) is by superimposed for the not high output reference signal source of precision after amplifying thus realize exporting not losing the large-signal in low frequency signal amplitude resolution situation.
2. a kind of method improving low frequency signal amplitude and export and control its precision according to claim 1, it is characterized in that, described supercircuit (6) includes relay (8), multiple input resistance Ri2(Ri2), input resistance Ri3(Ri3), with multiple balance resistance R2(R2), balance resistance R3(R3), described relay (8) terminals and microprocessor (7) and D/A converter module DAC(DAC) be connected, multiple described input resistance Ri1(Ri1), input resistance Ri2(Ri2), input resistance Ri3(Ri3) be in parallel after with relay contact switch K2(K2), relay contact switch K3(K3) be connected, the other end and operational amplifier A 1(A1) input end be connected, multiple balance resistance R1(R1), balance resistance R2(R2), balance resistance R3(R3) one end and relay contact switch K4(K4 afterwards in parallel), relay contact switch K5(K5) be connected, the other end and operational amplifier A 1(A1) base terminal be connected, described microprocessor (7) controls D/A converter module DAC(DAC), need break-make relay contact switch K2(K2 according to amplitude), relay contact switch K3(K3), relay contact switch K4(K4), relay contact switch K5(K5) loop, place, D/A converter module DAC(DAC) completely amplitude output is rear by amplitude fading control circuit module (4) control, complete attenuation amplitude output voltage signal VDAC(VDAC), full magnitude output signal VDAO(VDAO is provided simultaneously), for amplifying circuit.
3. a kind of method improving low frequency signal amplitude and export and control its precision according to claim 1, it is characterized in that, multiple described input resistance Ri1(Ri1), input resistance Ri2(Ri2), input resistance Ri3(Ri3) resistance be equal to each other and with feedback resistance Rf(Rf) resistance is equal, improves precision.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201510120966.3A CN104714456B (en) | 2015-03-19 | 2015-03-19 | A kind of method for improving the output of low frequency signal amplitude and controlling its precision |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201510120966.3A CN104714456B (en) | 2015-03-19 | 2015-03-19 | A kind of method for improving the output of low frequency signal amplitude and controlling its precision |
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Cited By (2)
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| CN107425845A (en) * | 2017-05-08 | 2017-12-01 | 华为技术有限公司 | A kind of superposition circuit and floating voltage D/A converting circuit |
| CN111366784A (en) * | 2020-03-19 | 2020-07-03 | 宁波新策电子科技有限公司 | Frequency scanning device with adjustable amplitude |
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Cited By (4)
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| CN107425845A (en) * | 2017-05-08 | 2017-12-01 | 华为技术有限公司 | A kind of superposition circuit and floating voltage D/A converting circuit |
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| CN104714456B (en) | 2018-06-01 |
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