DATA COMMUNICATION APPARATUS

摘要

A data communication apparatus has a master unit and a slave unit. The master has a first inductive coupling arrangement (24) and an RF oscillator (22) for generating a signal. The slave unit has a data store (40) storing data, a second inductive coupling arrangement (44) for coupling with the first inductive coupling arrangement (24) for enabling the slave unit to derive a power supply from the signal generated by the generating means. The slave unit is arranged to provide an analogue signal representing the stored data when the slave unit derives a power supply from the signal. The master unit has an output device (7) responsive to an analogue signal provided by the slave unit for generating an output representing the analogue signal provided by the slave unit. Generally the analogue signal is an audio frequency signal and the output device is a loudspeaker.