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SamsungGranted patentBatteries & energyInterest 6/10

Samsung patents wireless charging safety check for foreign objects

This patent describes a method for electronic devices to detect if a metal object is stuck to a wireless charging surface. The device uses a low-power signal to check for a receiver, then monitors voltage fluctuations during charging to spot anomalies caused by foreign objects.

Why it mattersIt improves safety by helping prevent overheating or damage when small metal items, like coins or keys, are accidentally placed on a wireless charger.

In the filing’s own words

The disclosure relates to an electronic device and a method for detecting a foreign body, wherein a control circuit of the electronic device may be configured to: supply transmission power to a power transmission circuit; identify, on the basis of a low power wireless communication signal, whether an external device is present in a partial area of the externally exposed surface of the electronic device, which corresponds to a resonant circuit; on the basis of the presence of the external device, apply a high frequency current to the resonant circuit and transmit transmission power generated in the resonant circuit to the external device; obtain analog digital converter samples in a half-wave rectified direct current interval of a direct current link voltage corresponding to a transmission current detected in the power transmission circuit; and detect a foreign body on the basis of the analog digital converter samples.

What exactly they claim (claim 1)

1. An electronic device comprising: a communication module comprising communication circuitry configured to communicate with an external device using a low-power wireless communication method; a power transmission circuit including a resonance circuit configured for electromagnetic induction heating; a control circuit electrically connected to the power transmission circuit and the communication module, and configured to convert transmission power into a direct current (DC) link voltage; and an inverter configured to convert the DC link voltage into alternating current (AC) voltage and output a high-frequency current to the resonance circuit, wherein the control circuit is configured to control the electronic device to: identify whether the external device is present in a partial area of an externally exposed surface of the electronic device corresponding to the resonance circuit, based on a low-power wireless communication signal; transmit the transmission power generated in the resonance circuit to the external device by applying the high-frequency current to the resonance circuit, based on the external device being present in the partial area of the exposed surface; obtain analog-to-digital converter samples in a half-wave rectified DC section of the DC link voltage; and identify that a foreign object is detected based on an average value of the analog-to-digital converter samples in the half-wave rectified DC section of the DC link voltage exceeding a specified threshold value.

Facts

Company
Samsung (SAMSUNG ELECTRONICS CO., LTD.)
Official title
Electronic device and method for detecting foreign body
Patent number
US12749925B2
Application number
18610705
Filed
Mar 20, 2024
Granted
Sep 29, 2026
Inventors
5
Claims
15

Classified under

H02J 50/60 Electricity & electronicsH02J 50/12 Electricity & electronicsH02J 50/80 Electricity & electronics
Read the full filing (official PDF) ↗ Open in the Patent Tracker

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Summaries are simplified from the filing’s own abstract and first claim. A patent filing is not a product announcement.
Patent data and drawings: U.S. Patent and Trademark Office (USPTO). Nebula is not affiliated with or endorsed by the USPTO.