Bendable transformer for wearable electronics

Abstract

This paper proposes a bendable transformer for wearable electronics. This transformer is bendable to wrap around the forearm. A model using partial equivalent circuit theory (PEEC) is established to analyze the characteristic of the bendable transformer. The bendable transformer is then applied to an LLC DCDC converter. A prototype is built and tested to verify the mode. This LLC resonant converter provides a 5 V, 500 mA (USB) output. Simulation and experimental results are included to confirm the usefulness of the transformer and the validity of the model.