An Energy-Saving Pulsed Magnetic Field Generator Based on Modular Marx Circuit

A high-intensity pulsed magnetic field generator, as a high-power pulsed current generator with inductive loads, can be used in transcranial magnetic stimulation, tumor therapy, and so on. This article presents a new type of pulse generator called the Marx-based modular energy-saving pulse generator (MEPG) that can improve the output performance of conventional pulsed magnetic field generators in the biomedical field. The MEPG includes a front-end energy-feeding circuit and a series of discharging modules at different levels. It can regulate the current of inductive coils, which in turn controls the magnetic field output from the coils. The MEPG incorporates a commutator switch and energy-feeding diode in the front-end circuit, facilitating the feedback of load energy to capacitors at all levels. The MEPG offers flexible adjustment of the output current change rate by controlling the switching sequence of the discharge modules. Moreover, the amplitude of the output current can be fine-tuned by adjusting the switching on time or capacitor voltages at different levels. The converter switch’s opening and closing at the discharge end corresponds to the two distinct output modes: exponential wave and triangular wave pulsed current. To assess the MEPG’s output performance and energy recovery efficiency, a three-stage MEPG system was constructed. The coil was subjected to pulse currents of different amplitudes and pulse widths in both simulations and measurements, revealing the platform’s excellent energy recovery efficiency. Finally, we demonstrated that the MEPG possesses a versatile output functionality by outputting a set of customized pulse current waveforms in the coil.