Research On The Technologies Of High-density Electrical Transmitter

High-density resistivity method is an array exploration methods, hundreds of electrodesarrangement could be handled at one time. During the measuring process, data collection measureeach measuring point automatically and draw cross-sectional view of measuring point bycomputer software. The method is mainly used on engineering geological problems,such as oldmining deep exploration, looking for underground water sources, dams detection and so on. Highdensity resistivity methods is a leading geological exploration method, but there are somedeficiencies of current market instruments, single transmitted signal, fixed poler arrangement, theinstrument is heavy, power consumption, poor immunity, low sampling accuracy. Theseshortcomings limit its application areas.This paper is researched on transmitter-related technology.It consists of the designing oftransmitter hardware circuit, analysising and researching of the transmitted signal, designing ofthe distributed intelligent electrode conversion device,PC software designing and do theexperiment of laboratory experiments with the transmitter device. These parts are the mainresearch content of this paper.The transmitter device is made of the PC104computer, transmitter circuit, distributedintelligent interface and power. All operations are performed in the application of computer.It iscommunicated with the transmitter controller through RS-232serial. The transmitter circuits areconsist of the DC-DC power modules, voltage regulator circuit, full-bridge inverter circuit,reverse isolation circuit and over-current protection circuit. The transmitter system can sendpseudo-random coding，custom coded signal and any digital coded signal made of1,0,-1.The transmitted signal part introduced the principle of pseudo-random codedsignal,analysising its frequency distribution,energy distribution and pointed out the relationship of the frequency and depth. At the same time, describes a self-defined encoding method andanalysis its spectrum. Finally, describeing the principle of denoising and researching on theimmunity characteristics of the pseudo-random coding.The part of distributed intelligent electrode conversion device describes its function, structurecharacteristics and hardware circuits. They communicate each other through RS-485serialcommunication. The electrodes can connect each other in any way, unified numbering and theycan send meesages to each other stable and reliable in high efficiency and long-distancecommunication. Meanwhile,the paper describes the normal arrangement of electrodes and theircharacterastics.Application software design of High-density electrical is based on MFC dialog applicationand it is connected to instrument by RS232serial port and USB2.0interface. The entire systemcan operate stable and reliable. Serial communication part use MSComm control to write and datatransmission can be achieved by calling the appropriate function. At the same time, this paperdescribes the characteristics of universal serial bus USB2.0and data transfer mode. The USB2.0high-speed communication system is completed at last and tested Its transmission speed. Theresult shows that this system meets the requirements of high-speed transmission of large amountsof data.Indoor testing of high-density electrical equipment demonstrated the reliability and stabilityof the transmission signal. Meanwhile, The entire system was tested by two mode of electrodearrangement which are Wenner method and Schellenberg and got resistance graph which is sameto the actual curve.