| CPC H02J 50/60 (2016.02) [H02J 50/12 (2016.02); B60L 53/124 (2019.02); H02J 2310/48 (2020.01)] | 20 Claims |
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1. An apparatus for detecting a metal foreign matter in a wireless charging system, wherein the wireless charging system comprises a wireless charger and a to-be-charged device, and the apparatus comprises a phase-lock control module, an excitation module, a resonance module, a signal collection module, and a determining module, wherein an output end of the phase-lock control module is connected to all of a first input end of the phase-lock control module, an input end of the excitation module, and an input end of the determining module, a second input end of the phase-lock control module is connected to an output end of the signal collection module, an input end of the signal collection module is connected to an output end of the resonance module, and an input end of the resonance module is connected to an output end of the excitation module;
the phase-lock control module is configured to output a first signal to the excitation module, wherein the first signal is used to control a frequency of a second signal generated by the excitation module;
the excitation module is configured to: generate the second signal based on the first signal, and output the second signal to the resonance module, wherein the frequency of the second signal is determined based on a frequency of the first signal, and the second signal is used to excite the resonance module;
the resonance module comprises at least one foreign-matter detection coil and at least one resonant capacitor, and is configured to generate a third signal under excitation of the second signal by using a resonant circuit comprising a target coil and a target capacitor, wherein the at least one foreign-matter detection coil is connected to the at least one resonant capacitor, the target coil is one or more of the at least one foreign-matter detection coil, the target capacitor is one or more of the at least one resonant capacitor, the at least one foreign-matter detection coil is distributed above a transmit coil of the wireless charger or a receive coil of the to-be-charged device, and an area of the at least one foreign-matter detection coil cover an area of the transmit coil or an area of the receive coil;
the signal collection module is configured to: collect the third signal, and output the third signal to the phase-lock control module;
the phase-lock control module is further configured to adjust the frequency of the output first signal based on a difference between a phase of the first signal and a phase of the third signal, wherein a difference between a phase of the frequency-adjusted first signal and the phase of the third signal is less than a first specified value, and a frequency of the second signal that is generated by the excitation module based on the frequency-adjusted first signal is the same as a resonance frequency of the resonant circuit; and
the determining module is configured to: determine, based on the frequency-adjusted first signal and a pre-stored fourth signal, whether there is a metal foreign matter in an area of the target coil, or determine, based on a fourth signal and the difference between the phase of the first signal and the phase of the third signal, whether there is a metal foreign matter in an area of the target coil, wherein the fourth signal is a signal that is output by the resonant circuit in a resonant state when there is no metal foreign matter in the area of the target coil.
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