Design of a High Current Transcranial Magnetic Stimulator for Flux-Concentration Type Electromagnetic Coil

Transcranial Magnetic Stimulation (TMS) is a noninvasive method to cause depolarization or hyperpolarization in the neurons of the brain. The recent research has developed a novel magnetic coil that can generate higher magnetic field than a conventional coil and have converging capability, which would require a larger exciting current. In this research, a thyristor as a switching device was used for high current switching. The thyristor is a device of current drive. The current differences of each circuit in parallel connected thyristors were measured by changing gate voltage and gate rise time. The gate drive characteristic of parallel connected thyristors was also confirmed.