Patent ID: 6028413
Filing Date: 2000-02-22
Classification: H02J

Abstract:
A device for charging batteries in a mobile electrical device (MD) containing a charging unit (CU) which inductively transmits electrical power by means of a alternating magnetic field from at least two primary windings (W1, W2) to at least two secondary windings (W3, W4) in the mobile device (MD), characterized in that the alternating magnetic field is generated by a self-oscillating push-pull oscillator with two branches, wherein the push-pull oscillator contains switches (Q1, Q2) that are reciprocally connected with positive feedback and in each push-pull branch, contains a resonance circuit with the effective inductance of at least one primary winding (W1, W2) and with a circuit capacitance (C1, C3 or C2, C4), wherein the at least two primary windings (W1 and W2) in the charging unit (CU) are disposed spatially separate from each other so that each generates an alternating magnetic field in a different spatial region and the secondary windings (W3, W4) are disposed in the mobile device so that each spatial region is equally loaded.