The Design And Research On Key Technologies Of Module In Scopecorder

Some of the physical quantities of the world can be perceived by humans,and some cannot.The oscilloscope is like the third eye of human beings,opening the door to the world of electrical signals.However,there are more new worlds waiting to be explored.The research of this subject has laid a solid foundation for China in the field of multi-physical measurement.Its main contents are:1.Analysis and design of multi-physical sensing technology.The principle of each physical quantity sensing technology is analyzed.Thermocouples(K,E,J,T,N,R,S,B)are selected as the design targets in the research of temperature sensor.The voltage accuracy index is ±(0.08% of 10div+2?V),the cold junction temperature compensation,temperature-electromotive force query scheme was studied.The study used a Kelvin sensor system to increase strain acquisition accuracy.2.The analog channel front-end acquisition technology is generalized.The research and design generalized voltage acquisition module scheme is used as a universal back end of the multi-physical acquisition module.The multi-physical acquisition module modifies the front-end signal conditioning circuit to adapt to different sensors based on the universal voltage acquisition module.3.Design and research of high precision operational amplifier circuit.Research and design standard operation amplification feedback circuit as a universal amplification circuit,for the load bridge circuit load characteristics and signal accuracy requirements(±7.5?V)using chip integrated three op amp instrumentation amplifier circuit,for high-precision temperature signal acquisition scheme,this paper The self-built three-operator instrumentation amplifier circuit is used to improve the accuracy of the chip-integrated instrumentation amplifier.Compared to the chip-integrated ±10?V input offset voltage,it is reduced to ±2.8?V by using an autonomous built-in three op amp instrumentation amplifier circuit.It was finally verified by measurement.4.Using a voltage-controlled voltage source type second-order low-pass filter as a general-purpose filtering scheme,the bandwidth index is up to 300 kHz.Research on the acceleration module uses automatic anti-aliasing filtering(AAF)to dynamically change the cutoff frequency by controlling its clock signal.5.Research on the use of transformers to achieve power isolation between the channels,completely separate the analog ground from the digital ground,so that the independent built-in three op amp instrumentation amplifier can be realized.After testing,the modules designed in this paper meet the design requirements.