Design Of EMC For Non-cable Self-positioning Seismic Instrument

With the gradual increase of energy demand, more and more methods areapplied to resource exploration, seismic exploration is a commonly used geophysicalexploration method and has a very wide range of application in the field of resourceexploration. Of course, seismic exploration instruments become particularly importantaspect of seismic exploration, due to the complexity environment, laying and earlymeasurement of seismic instruments has become a great problem. By receivinginformation of GPS, self-positioning non-cable seismic instrument could positioneditself, instead of the original survey work, get rid of bulky cable with independentstorage structure, and equip with wireless communication module to achieve real-timestate of the seismic instrument. At the same time, in order to achieve instrumentminiaturization, portability, and improve integration, have to integrate the aboveaspects together, because of the different nature of the signals, it will causeelectromagnetic interference between each other, so it is very necessary to do thecorresponding electromagnetic compatibility design of self-positioning non-cableseismic instrument.At the beginning of this article, introduce the basic meaning of electromagneticcompatibility and the domestic and foreign research progress, and present the mainresearch content of this paper, discuss the three elements of electromagneticinterference, according to the analysis and calculation of transmission routesconsisting of conductive coupling and radiated coupling by creating models,understand the process of electromagnetic interference, and ahead of thecorresponding suppression measures. EMC design of PCB is an important part of theEMC design of the entire seismic instrument, the analog signal acquisition part isextremely vulnerable to the PCB itself and the impact external, through a lot ofliterature and experiments, find PCB EMC design rules and specification. The completion of above work lays a theoretical foundation for the subsequent design ofelectromagnetic compatibility.Base on the analysis and calculation, start to do EMC design of seismicinstrument, the main aspects of the design include power modules, acquisition boardand wireless communication module. The design of power module is primarily byselecting small interference DC/DC chips, adding filtering capacitor and decreasingcurrent and voltage rate, the design of PCB is mainly reflected in stack setting, layout,wiring, as well as the ground plane and power plane splitting, and make shielding boxto stop analog signal acquisition part from interfering of WIFI module.Test after designing, take measures to solve problematic section to make thefinal results meet the requirement, finally, test the static noise, common-moderejection ratio and road crosstalk which could reflect the effect of EMC design,through analysis of test, prove EMC design successful, EMC design ofself-positioning non-cable seismic instrument has a strong practicality andsignificance of integration of seismic instruments.