Patent ID: 9712925
Date: 2017-07-18
CPC Classifications: H01Q,H02J,H04R

Claim:
1. A charging device for wirelessly charging at least one hearing aid, the charging device comprising: a cylindrical container defining a cylinder axis; an antenna for generating an alternating magnetic field in said cylindrical container in an event of electrical excitation; a charging circuit for electrically exciting said antenna; said antenna being a birdcage antenna having end rings and rods disposed parallel to said cylinder axis around a cylinder jacket, said rods having ends at edges of said cylinder jacket and each of said rods connected to one of said end rings, said birdcage antenna being integrated in said cylindrical container switching elements, one of said switching elements disposed in each of said rods of said antenna; said charging circuit used to alternately generate, in said antenna, a circular magnetic field, in which case said switching elements are operated in a closed mode, and a linear magnetic field, in which case said switching elements are operated in an open mode; and a charging capacitor operatively connected to said charging circuit for defining a switching time for continuously switching between the circular magnetic field and the linear magnetic field during a charging process.