A robust multi-output self-regulated rectifier without any switching circuitry is proposed for wirelessly-powered biomedical devices, especially for neural stimulators. The proposed system utilizes the series and parallel resonant configuration for low and high side outputs, respectively, by using only one resonant capacitor. The proposed system provides dual high voltages of ±14 V for neuro stimulator and low voltage of 2.1 V for operating systems such as read-out and digital circuits.

This paper proposes a wireless power transfer (WPT) system by placing repeater coils to transfer power to multiple loads for the internet of things (IoT) devices and sensors in smart grid applications. The proposed system intermediate resonators (repeaters) not only function as power relays to enhance the transfer distance but also supplies power to its load attached to them. Equal power distribution and load-independent characteristics were obtained without efficiency degradation when any one of the loads was changed during system operation. Identical high-quality factor coils were designed using Litz-wire to reduce the skin effect. The coil size was 15.5 cm × 15.5 cm and the four relays achieved total efficiency of 51.7%, delivering 2 W power and output voltage of 5 V to each load with a total power transfer distance of 62 cm.