Passive Safety Circuits for Wireless Power Transfer

Abstract

A magnetic inductive resonance charging circuit includes a resonant network having an inductive secondary coil that converts a magnetic field received from an inductive primary coil into an alternating current (AC) signal and a synchronous rectifier that rectifies the AC signal to generate a direct current (DC) signal for application to a load. The synchronous rectifier includes a variety of configurations for shunting the AC waveform of an AC current source in the event of a fault. For example, a rectifier controller may hold a pair of normally open switches of the rectifier off and a pair of normally closed switches of the rectifier on to shunt the AC current source when an over-voltage, over-current fault condition or an over-temperature fault condition is detected. Configurations are provided for grounding the capacitive electromagnetic interference produced in the chassis of an electric vehicle when the resonant network is unbalanced.

Dependencies are inferred from the claim text.