Communication apparatus having a non-ringing call receiving mode and an energy-saving stand-by mode

摘要

A communication apparatus has a power saving stand-by mode for reducing power consumption during stand-by and a non-ringing call receiving mode for communication without ringing an attached telephone set at the arrival of a call. In the power saving stand-by mode, an operation state of a relay for attaining the non-ringing call receiving mode is held by a stand-by power supply to render both modes compatible to each other.