Inner supply data transmission of resonant flyback converters using multiplexing mode in battery chargers application

This paper proposes data transmission method in flyback converter battery charger without additional communication circuit. A battery management system (BMS) and a charger constantly transmit and receive data for the safe operation of battery and implementation of fast charging. The most conventional system uses an additional line or wireless communication modules for this data transmission. The proposed system, in comparison, does not use additional signal transceiver but instead exchanges data by alternating operation mode of the flyback converter, thus reducing the volume of the terminal and overall system. The waveform of transformer voltage is used to count the number of resonant pulses, which is used for decoding and encoding the message. Bidirectional communication between input and output is possible using an appropriate communication protocol. The experimental results are presented to verify the performance of the proposed communication method.