A study on high-power multi-function transmitting system
SHI Fu-sheng~(1,2)(1. China University of Geosciences , Beijing 100083 ,China; 2. Institute of Geophysical and Geochemical Exploration ,Chinese Academy of Geological Sciences , Lang fang 065000,China)
DEM-T70 is a high-power multi-function intelligent transmitter developed by our team independently. It is used to supply active field signal for EM prospecting by sending high-power current into ground. The transmitter adopts the following new techniques, such as GPS synchronization, DDS(Directive Digital frequency Synthesis), CPLD(Complex Programmable Logic Device) , digital PWM(Pulse-Width Modulation) constant current and generator excitation constant current etc. We have also developed the following key techniques:multi-frequency synchronization sending, high-density frequency-point sending, full-auto sweeping sending and rapid high-power inverter. DEM-T70 has the features of high-power (70 kW) , multi-function (CSAMT-Controlled Source Audio MT, SIP-Spectrum IP, TDIP-Time domain IP), its maximum frequency is 8000 Hz, maximum voltage is 1200V and maximum current is 100A. Field experiments indicate that DEM-T70' s functions are reasonable, its specifications are advanced, its performance is stable and reliable. The DEM-T70 transmitter has filled a gap of this field in our county.