Abstract: An electromagnetic stimulator circuit has a precharge power supply, a capacitor, a set of switches, and a stimulator coil. The switches, which can be implemented using a variety of devices, enable flexible control over the coil current waveform without requiring the physical reconfiguration of circuit elements. The shape of the output current pulse is controlled by the modulation of the switches, and much of the energy applied to the coil is returned from the coil to the capacitor for reuse on the succeeding pulse. Less power is required and less heat energy is generated.