Q-factor determination for foreign object detection circuit in wireless charging system
US10833540B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2019 |
| Grant date | Nov 10, 2020 |
| Priority date | — |
| Expiry date | Apr 28, 2039 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a wireless charging system, a power-transmitting node (TX) has a power transmitter for transmitting power wirelessly to a power-receiving node (RX), a sampling and sensing circuit, a processor, and a signal receiver for receiving signals from the RX. The processor detects the presence of a foreign object (FO) during a power-transfer session using Quality Factor (QF) values. Estimated QF parameters are determined via exponential curve fitting using peak values of a damped sinusoidal waveform generated by a resonant circuit. Then the estimated parameters in the exponential curve are used to calculate the QF, which provides a robust measurement result even in a noisy environment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.