Design of a contactless battery charger for cellular phone

Author

Kim, Chang-Gyun ; Seo, Dong-Hyun ; You, Jung-Sik ; Park, Jong-Hu ; Cho, Bo H.

Author_Institution

Sch. of Electr. Eng., Seoul Nat. Univ., South Korea

Volume

48

Issue

6

fYear

2001

fDate

12/1/2001 12:00:00 AM

Firstpage

1238

Lastpage

1247

Abstract

In this paper, the design of a contactless charger for the lithium-ion battery of a cellular phone is presented. In this charger, the primary core of the transformer is in the charger unit and the secondary core is in the telephone. The gap (3 mm) between them is the thickness of the two plastic cases. The transformer core design for the maximum coupling coefficient with the size constraint on the secondary side is presented. Analysis of the primary-side series resonant power converter with the loosely coupled transformer is performed, and the design optimization is presented. For the battery-charging control, a simple control circuit is presented and its performance is verified from the experimental results

Keywords

battery chargers; cellular radio; electromagnetic induction; lithium; power transformers; resonant power convertors; secondary cells; transformer cores; transformer windings; Li; Li-ion secondary battery; battery-charging control circuit; cellular phone; contactless charger design; design optimization; loosely coupled transformer; maximum coupling coefficient; primary-side series resonant converter; secondary side size constraint; transformer core design; transformer primary core; Batteries; Cellular phones; Coupling circuits; Geometry; Inductance; Plastics; Resonance; Telephony; Topology; Transformer cores;

fLanguage

English

Journal_Title

Industrial Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0278-0046

Type

jour

DOI

10.1109/41.969404

Filename

969404