Telephone answering machine - has static logic circuit selecting required control functions by movable or static switches

摘要

Each of the switches makes only one single contact; each contact is made between a specified circuit point and a common terminal, e.g. frame. Each switch controls an input of a static flip-flop with two inputs. The device may have five switches realising following functions: operation as a plain answering machine; as a recording answering machine; prerecording on an endless tape; test playback of the prerecorded message; playback of messages from other subscribers. A further circuit for static change-over switching may be provided. A loudspeaker may be provided for playback of a message during recording, and a switch for uninterrupted recording of a message.