Development of Bipolar Triangular Wave Transient Electromagnetic Transmission System

This paper is developed to present a theory research and engineering application of a high-accuracy bipolar triangular wave current pulse inverter for transient electromagnetic method (TEM) transmitting system, in which produced pulse current can be used for shallow geology survey including exploration of minerals and unexploded ordnance, hydrological survey and geological mapping. The peak current in the bipolar triangular wave current pulse generated by the system is up to 10A and PRF ranges between 1Hz through 10 kHz. Proposed transmitting system consists of micro control unit, digital-to-analog conversion circuit, power amplification circuit and power change circuit. Actually measured result of the current waveform of the transmission system is provided at the end of the paper and it is shown that the system is able to generate high-quality triangular wave current pulse with linear rising edge and falling edge.