Effects of different triggering mechanisms on pulse shaping of a TMS pulse generator based on supercapacitor energy storage

High-voltage pulse generators are useful in many applications such as transient surge simulators, electric fence energizers, and transcranial magnetic stimulation (TMS) systems. Traditionally they are based on a high-voltage DC power supply with or without voltage multipliers for raising the voltage to several thousand volts. In contrast to these complex and costly approaches, we use a pre-charged supercapacitor followed by a step-up transformer and associated output circuitry to develop an inexpensive and flexible high-voltage pulse generator for applications in transcranial magnetic stimulation. Our new approach is to use the high-power delivery capability of commercial supercapacitors. In this work, we explore the advantages of different waveforms applied to the MOSFET associated with the secondary stage of the circuit topology and how they affect the final pulse shape.