Engineers Unveil a System That Delivers Electricity Wirelessly – To a Moving Target

Science Alert  May 8, 2020 Wireless power transfer set-ups typically suffer from an inherent sensitivity to the relative movement of the device with respect to the power source. Researchers at Stanford University show that robust and efficient wireless power transfer can be achieved by using a power-efficient switch-mode amplifier with current-sensing feedback in a parity–time symmetric circuit. In this circuit, the parity–time symmetry guarantees that the effective load impedance on the switch-mode amplifier remains constant, and hence the amplifier maintains high efficiency despite variation of the transfer distance. They experimentally demonstrated that such a circuit could wirelessly transfer around 10 W […]