Experimental Evaluation of a Ferrite-Coupled Trigger Architecture for Parallel Thyristor Switching in Pulsed Power Systems

This paper investigates circuit architectures for synchronized switching of parallel thyristors in pulsed capacitor discharge systems. Two solid-state trigger approaches are examined: ferrite-inductive coupling and amplified gate thyristor (AGT) triggering. Reliable synchronization of multiple semiconductor switches is important in pulsed power circuits where several switching branches must operate simultaneously to distribute current and reduce device stress. Five circuit configurations were designed and experimentally evaluated to analyze trigger signal propagation, switching delay, and current rise characteristics for capacitor discharge voltages up to 400 V. Experimental results show that parallel circuits triggered by ferrite-core inductors exhibit nearly identical switching behavior with timing differences between branches on the order of 0.1 µs. The current rise-time decreases with increasing discharge voltage and approaches a constant value above approximately 100 V. Parallel thyristors connected to a common capacitor show unequal current sharing due to parasitic circuit elements and path asymmetries. Compared with AGT circuits, the ferrite-coupled approach provides a simple and efficient method for distributing trigger signals across multiple switches without complex gate driver networks.