Study of LC oscillation based on excitation source of two-stage full-bridge structure

Abstract

Nuclear magnetic resonance logging transmitting circuits must face the harsh operating environment of high voltage and high frequency. To reduce the voltage and current tolerated by the switching devices in the circuit and minimize the circuit loss, a high-frequency, high-voltage pulse transmitting circuit based on a two-stage full-bridge structure is designed in this paper. A new strategy for pulse excitation oscillation is proposed. The proposed strategy is based on the decision to end the excitation at the moment of peak voltage and the condition for limiting peak charging current (3.2). Finally, the circuit topology and excitation strategy proposed to achieve the overall optimal performance of sustained voltage oscillation with a peak voltage of 1180 V, precisely matching the transmitting frequency of 481 kHz and suppressing the charging current below 10 A.