Relationship Between Output Rise Time and Efficiency of Pulse Generation Circuit Using Saturable Pulsed Transformer

This research presents an improvement of output voltage rise time by sacrificing energy efficiency in a Marx generator using a saturable pulse transformer (SPT). The aim is to reduce the output rise time, which is defined by the time between 10% and 90% of the peak voltage, and to show the relationship between rise time and efficiency. In this research, a four-stage Marx generator has been used for circuit demonstration. It uses a single primary capacitor to charge four secondary stages in parallel through the SPT. The saturation of the transformer acts as a magnetic switch on each stage so that the capacitors on the secondary side discharge in series to the load. The experimental results have shown that the rise time of the load voltage depends on the timing of the core saturation, and the shortest rise time was obtained under a circuit condition where the transformer saturates before the energy transfer from the primary to the secondary is completed, where the energy efficiency is not optimum. In other words, there exists a tradeoff between the output rise time and the energy efficiency of the pulsed power circuit. This article suggests that the relationship between the rise time and the efficiency is caused by the diodes, which play the role of an opening switch.