Sensor and method for foreign object detection in induction electric charger
US9829599B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 2015 |
| Grant date | Nov 28, 2017 |
| Priority date | — |
| Expiry date | Jan 2, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J2310/48
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention detects foreign objects FO near a primary coil 100 of an induction charger. A sensors 111 of a sensor array 110 output sensing signals in response to magnetically coupling the alternating magnetic field 103 produced by the primary coil. A controller 165 connected to each sensor 111 scans the sensing signals and determines whether there is a foreign object perturbing the magnetic field 103 near a sensor. The magnetic field has a spatial distribution that varies by location across the primary coil area. Each sensor has a magnetic field sensing sensitivity that is inversely proportional to the magnetic intensity of the magnetic field produced by the primary coil at a location of the sensor, to reduce the collective dynamic range of the signals, thereby contributing to maintaining a high accuracy in signal sampling. A reference sensor coil 155 compensates for magnetic field drift of the primary coil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.