US 4,731,821 AGranted

Single wire telephone intercommunication system

OwnerThomas H. Jackson, IIIinventor

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Abstract

A residential digital logic circuit telephone system is provided for internal voice communications and digital interfaces control which enables two or more conventional twelve button touch-tone telephone devices to be used as a voice intercommunication system utilizing a single bidirectional conductor and for selectively actuating and controlling the operation of other electrical and electronic devices connected to the system from multiple remote locations. In a preferred embodiment of the system, two to five touch-tone telephones inside a residence may be actuated selectively by means of a ringing signal from any one of said telephones to another or all the other telephones by means of a single conductor bidirectional voice communication circuit arrangement which has been established between a calling telephone and a responding telephone. The intercom ringing system is distinct from the normal ringing signal from an incoming outside call. In another embodiment, a two-way communication resident front door speaker device is connected to the intercommunication system so that visitors may be screened before being admitted to the residence by means of an electronic control signal for unlocking the residence door.

Claims11

Dependent claims

An improved telephone intercommunication system having a plurality of CMOS digital logic circuits providing two-way voice communication through the use of a single bidirectional conductor within said system, the improvement comprising:

a. at least two telephone interface circuit devices connected in parallel to a tip and ring conductor pair from a local telephone company for sending and receiving voice messages;
b. an inline hold circuit device connected in series with said telephone interface circuit devices;
c. at least two telephone intercommunication circuit devices each connected to said interface circuit devices to receive and send both voice and non-voice signals therebetween;
d. at least two interface intercommunication control circuit devices for receiving at least three types of input signals and generating at least three control output signals;
e. a plurality ring signal circuits for shaping and transmiting a plurality of ring signals to said telephone, intercommunications circuit devices and said control circuit devices;
f. a digital logic circuit for decoding digital input signals from said telephone intercommunication circuits and outputting coded digital signals;
g. a latch decoder device for receiving a plurality of digital input signals from said digital logic circuit and generating a corresponding plurality of output signals responsive to said digital input;
and
h. a power supply source having an input and a plurality of voltage outputs for operation of said devices and circuits.

6 more elements

Dependencies are inferred from the claim text.