Patent ID: 11888337
Assignee: PHILIPS I.P. VENTURES B.V.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 0:
1. A method of controlling an inductive power transfer circuit the method comprising:
measuring an input characteristic of input power in a primary circuit,
wherein the primary circuit comprises a tank circuit and a switching circuit,
wherein the primary circuit generates an electromagnetic field;

measuring a tank characteristic of power in the tank circuit;
receiving, in the primary circuit, secondary device information from a at least one secondary device, wherein the secondary device is arranged to couple to the primary circuit via the electromagnetic field;
estimating power consumption in the inductive power transfer system as a function of at least the tank characteristic;
comparing the input characteristic, the secondary device information, and the estimated power consumption to determine when there is an unacceptable amount of parasitic metal present in proximity to the primary circuit; and
restricting or stopping the inductive power transfer from the primary circuit in response to a determination that the unacceptable amount of parasitic metal is present in proximity to the primary circuit.