Wireless charger, system and method
US11682931B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 2022 |
| Grant date | Jun 20, 2023 |
| Priority date | — |
| Expiry date | Jun 21, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J50/402
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A wireless charger includes a plurality of charging units for charging wirelessly chargeable devices. Each charging unit includes one or more transmit coils for producing a wireless charging signal. Each charging unit also includes a driver circuit for driving the one or more transmit coils. The driver circuit is switchable according to a charging PWM duty cycle of that charging unit. Each charging unit is operable to perform a Q factor measurement by injecting excitation energy into the one or more transmit coils of that charging unit to produce a free resonance signal, and measuring a decay rate of the free resonance signal. Each charging unit is operable to alter its charging PWM duty cycle during a time window in which another charging unit of the wireless charger is performing a Q factor measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.