US Patent 11309716 High efficiency power converting apparatus

A system includes a transmitter circuit coupled to an input power source, a transmitter coil coupled to the transmitter circuit, a receiver coil magnetically coupled to the transmitter coil, a rectifier coupled to the receiver coil and configured to convert an alternating current voltage into a direct current voltage, and a high efficiency power converter comprising a first stage and a second stage connected in cascade between the rectifier and a battery, wherein the first stage is configured to charge the battery, and the second stage is configured to provide isolation between the first stage and the battery.