METHOD AND DEVICE FOR FOREIGN OBJECT DETECTION IN INDUCTION ELECTRIC CHARGER

摘要

An example embodiment of the invention is a method and device for detecting foreign objects (FO) near the primary coil of an induction charger used in charging electric vehicle batteries. Individual sensors of a sensor array are configured to output a sensing signal in response to magnetically coupling the high frequency alternating magnetic field produced by the primary coil. A disable signal line is configured to disable the power source when a controller determines from scanned sensor signals, that a FO is present. An alarm can be activated by the microprocessor to alert the user to the presence of a FO on or near the primary coil. In this manner, damage can be avoided that could otherwise be caused from the presence of a FO near the primary coil. Moreover, a more efficient charging operation can be achieved by avoiding dissipating energy by heating a FO.