| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a non-contact power supply system, along with a metal foreign substance detector of the non-contact power supply system, capable of detecting metal foreign substance with high sensitivity and precision, using an inexpensive and simple configuration. <P>SOLUTION: An oscillation circuit 7a is connected to a metal detection antenna coil AT2 of spiral shape formed on a placement surface of a power supply device. A design value of a component of the oscillation circuit 7a is set to be such value from just after the time point of oscillation to before the time point of stable continuous oscillation condition, instead of such design value as the oscillation circuit 7a can maintain a continuous oscillation of stable amplitude. Consequently, a large change in oscillation amplitude can be generated by a small change in electromagnetic parameter that is related to oscillation. Therefore, placement of a small or thin metal piece near the metal detection antenna coil AT2 can make a change in small electromagnetic characteristics of an antenna coil part to be converted to presence/absence of oscillation of the oscillation circuit 7a, as well as a large change in oscillation amplitude of an oscillation signal Vo. As a result, a metal foreign substance detector 7 can detect a small metal piece. <P>COPYRIGHT: (C)2012,JPO&INPIT |
