Automatic answering device for use in live speech communication and circuit components thereof

摘要

This device enables apartment dwellers to communicate with and thereby identify persons desiring ingress to an apartment building through a controlled access vestibule. The convenience and security of a conventional intercom is provided by this device, but without substations and their associated dedicated wiring. Communication is initiated via residential telephones which effect a ringing signal (to be sent) from the central telephone office to the device. This device automatically answers the incoming call on the line, transmits an audible signal in the preferred embodiment, enables voice communication, and disconnects.