Study And Accomplishment Of Virtual Analog Electronics Experiments

Instrument are progressing towards Virtual Instrument (VI) , but instruments for teaching and scientific researching in university laboratories of our country have been almost traditional instruments, and it is rare in all universities now to design VIs based on personal computer and utilize them to experimental teaching. In order to speed up the procedure of VIs coming to laboratories, and advance experimental teaching reform, author of the paper exploited analog electronics experimental VIs.The paper analyses background, significances and applying demands of the subject, studies several popular architectures and environments of VIs, discusses performances of data acquisition card, waveform acquisition, waveform output and their main technology.Introduces details of low frequency amplifier, high frequency amplifier, amplitude modulation and detection, frequency modulation and demodulation, phase modulation and demodulation 5 VIs exploited by LabVIEW environment. Presents new methods of direct demodulating frequency, direct demodulating phase and indirect modulating phase, application of these new methods to phase modulation and demodulation VI proved they are correct and easy to realize. Contrasts data and waveform by these VIs with that by traditional instruments, accumulated available experiences for teaching and scientific research. Illustrates VIs' characteristics that they have rich practical measuring functions, and some of them posses simulation to demonstrate understandably angle modulation and demodulation if used triangle and zigzag as modulating signal.Connecting exploited achievements, summarizes general method of designing VI, technological essentials of engineering exploiting, problems met and solutions, means and conclusions of practical testing, comparison and analysis. All of them are significant and valuable to exploit VIs and apply them to experimental teaching.Lastly, investigates VI precision, talks over VI peculiar parameters and their affection to instrumentations, looks into VI performance and factors determined it, indicates deficiencies of these exploited VIs, and sets forth technologies to promote their performance and increase their function, prospects their development and application in the future.