Power supply apparatus and power line communication apparatus

摘要

A power supply apparatus has a coupled transformer that inputs and outputs a communication signal and a capacitor that has high impedance to a commercial power supply frequency and low impedance to a communication signal frequency. The capacitor is connected between a primary winding of the coupled transformer and a power reception terminal. To both ends of the capacitor, a switching regulator is connected via a noise reduction circuit. To a secondary winding of the coupled transformer, a modem of a power line communication apparatus is connected. In the configuration, the coupled transformer and the switching regulator are thus connected in series.