access icon free Metal-rim-connected inductive coupler for smartwatch applications

A metal-rim-connected inductive coupler with series-none compensation topology is proposed for smartwatch applications. By cross-connecting the receiving coil to the metal rim with a 1 mm slot, the direction of the induced current on the metal rim is transformed to be the same as the current flowing on the receiving coil, leading to a strong magnetic coupling between the transmitting coil and receiving coil. Considering the space limitation in the smartwatch, non-compensation components are needed inside the smartwatch and only a series capacitance is integrated on the transmitter side. A prototype of the proposed inductive coupler has been built and the wireless power transfer through metal rim has been validated via experiment. The experimental results show that the prototype achieves 5 W output power with 87.4% coil-to-coil efficiency.

Inspec keywords: wearable computers; electric connectors; coils

Other keywords: smartwatch applications; metal rim; series-none compensation topology; coil-to-coil efficiency; metal-rim-connected inductive coupler; receiving coil; transmitting coil; size 1.0 mm; power 5.0 W

Subjects: Microcomputers; Connectors

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