Harris Corporation

Other

James W Lester

Randall M Wagner

Randy A Callaway

Michael F Kennedy

Thomas J Johnson

Dennis P Damewood

Dennis Carl Chimienti

Terri Runyan Shafer

A paging system controller is accessible from a plurality of input devices, such as an attendant's position, a telephone interface, telephone night bell, programmable switch devices and digital data communications devices, and is user-programmable to respond to signalling activity sourced from such accessing devices to establish a paging connection to and perform prescribed audio/visual output paging signal functions with respect to one or a plurality of paging zones served by the system. The output paging signal functions include the transmission of audio tone and voice paging signals via an audio signal path from a paging source to one or more controllably energized paging loudspeaker amplifiers, the generation of one or more alert tones to a paging zone, talkback audio signalling from the paging zone to a telephone interface, the playback of prerecorded (audio/visual) messages from either or both of audio output (e.g. loudspeaker) and visual output (e.g. silent radio) devices. Respective access inputs to which the paging system controller responds are given user-programmable priorities of access permission, with a higher priority access input always being given preference over a lower priority access input. A programmable access priority table, which may be customized by the user to assign respectively different access priority levels to respectively different classes or types of input access is stored in memory employed by the control system's processor.

User-programmable paging system controller having priority-based,

A circuit for interfacing a host telephone system having a trunk line pair with a central office line pair and an additional circuit line pair includes a loop current monitor circuit for monitoring the host telephone system trunk line pair which is normally connected to the central office line pair. The loop current monitor provides a status signal output indicating the presence or absence of loop current. A relay controller receives the status signal and provides a relay control signal and a hold signal. A relay selectively connects the host telephone system trunk line pair to the additional circuit line pair in response to the relay control signal when loop current is detected after the host telephone goes off-hook. A hold termination circuit receives the hold signal and traps any loop current signals which may be detectable over the central office line pair. The relay controller circuit is active to generate the relay control signal only for an initial time period after the host telephone system goes off-hook.

Telephone interface circuit

A door phone controller has a door ajar feature for alerting a user that a door was left open. The door phone controller accommodates the door ajar feature in several different ways depending upon how it is configured to interface with the central office line. If the door phone controller is configured to interface with the central office line as an individual station, then when a door is left open, the controller alerts the user via auxiliary alert contacts specifically provided for activating a customer chime. When the door phone controller is configured as a ring-down station, the door phone controller alerts the user that the door was left ajar by dialing a pre-programmed telephone number and sending a door ajar tone. If the door phone controller is configured as an interface with a trunk port, then when the door is left open, the controller alerts the user by ringing the trunk line and also energizing the auxiliary alert contacts. The user can both enable and disable the door ajar features via the telephone interface.

Door ajar signalling device

An amplified speaker has an amplifier section including an audio amplifier powered from a power input section and a variable audio input section for supplying an input audio signal via an audio transformer to the audio amplifier. The power input section includes a rectifier bridge and a capacitor filter circuit, so that power may be obtained from an inexpensive unregulated AC source rather than an expensive regulated DC power supply. The variable audio input section permits audio signals at various levels from 30 mVrms to 70.7 Vrms to be inputted.

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Ventura, CA, United States of America

James W Lester