METAL DETECTION METHOD, METAL DETECTION DEVICE, METAL DETECTION METHOD FOR WIRELESS POWER SUPPLY DEVICE, AND WIRELESS POWER SUPPLY DEVICE

摘要

Provided are a metal detection method, a metal detection device, a metal detection method for a wireless power supply device, and a wireless power supply device which are capable of accurately detecting whether an object is a metal or a nonmetal. An oscillation circuit (10) oscillates and produces a sine wave having a single fundamental frequency, and excites a metal detection coil (Ls) by the oscillation current (It) of the sine wave. An electromagnetic wave of the sine wave having the single fundamental frequency is radiated from the metal detection coil (Ls). A high-pass filter circuit (11a) receives the oscillation current (It), removes the fundamental frequency component from the oscillation current (It), and extracts a high-harmonic component of the fundamental frequency. A comparison circuit (12) determines the presence or absence of a metal.

主权项

1. A method for exciting a metal detection coil arranged in a metal detection area to use an electromagnetic wave radiated from the metal detection coil and detect whether or not metal exists in the metal detection area, the method comprising:
exciting the metal detection coil with a sinusoidal oscillating current having a single fundamental frequency to radiate an electromagnetic wave from the metal detection coil; and detecting whether or not metal exists in the metal detection area from a change in the fundamental frequency in the oscillating current flowing to the metal detection coil.