Abstract: One or more security receptacles, provided for safekeeping keys, include a deposit opening especially configured in a shape corresponding to the longitudinal cross-section of the key handle. A set of ramps oblique and a normally locked horizontal ramp in the receptacle prevent access to the key. The horizontal ramp may be released from its horizontal position by disabling the lock so that the key falls to a lower portion of the receptacle. Disabling of the lock is accomplished by transmitting a coded signal to a receiver incorporated in the lock. Access to the key is then possible, preferably requiring a second key to open the lower portion of the receptacle.
Abstract: This apparatus having means responsive to a dual multifrequency telephone output to provide an electrical signal to an automatic gain control so as to provide preconditioning to a signal for amplification so as to provide an amplified signal to a comparator with visual light source responsive thereto to indicate activity at the other end of the phone line and a tone decoder also receiving the amplified signal to a digital binary code corresponding to the dual tone multifrequency signal received.
Abstract: A method and apparatus for controlling a cellular mobile telecommunication system. A switch and a telecommunication control complex cooperate to set up connection between a telecommunication network, such as the common carrier public telephone network, and a plurality of mobile units. The switch sets up connections between trunks to the telephone network and communication links connected to the cell sites of the mobile telecommunication system. The telecommunication control complex, including a mobile telecommunication controller and the cell site controllers, controls the radio connections between these communication links and the mobile units.
December 19, 1983
Date of Patent:
July 8, 1986
AT&T Bell Laboratories
Ronald G. Cornell, George D. Huensch, Kenneth W. Shelhamer, Pramod Warty
Abstract: A sound reproduction system wherein two full range driver sets are employed to produce out-of-phase sound pressure lobes directed to either side of a listening area whereby the listening area is situated in the region of sound minimum pressure between drivers. The system decreases localization of speaker produced sound and enhances stereophonic and polyphonic effects.
Abstract: An amplifier for differentially driving a two wire line has two output terminals for connection to the line. The differential voltage on the line is monitored and a negative-feedback voltage derived therefrom is combined with the input signal voltage. This combination is applied to a reference impedance. The resulting current in this impedance controls the current fed to the line. In one embodiment the control is direct via controlled current sources for example precision current mirrors and in another embodiment a current mirror controls the current to one wire and the current to the other wire is controlled indirectly via circuitry arranged to maintain equal voltage excursions on the two wires of the line.
Abstract: A telephone communications interface adapted to provide a data link for receiving and transmitting serial data via FSK modulated carrier signals over telephone lines to a computer. An operational amplifier in a duplexer circuit has a variable impedance feedback circuit, which is automatically adjusted by a computer subroutine to adjust the amplifier gain, so as to compensate for variations in the telephone company line impedance. The gain is adjusted to minimize the amplitude of any transmitted carrier signal, which might appear at the input of the conventional band pass filter for the receiver carrier signal.
Abstract: A card authenticating apparatus for a card-based transaction processing system. A device is incorporated which allows a sales-person of a store equipped with the apparatus to automatically call a card controlling operator of a card issuer company for consultation as to completion of the transaction in concern, as occasion requires.
Abstract: A cordless telephone system which provides improved performance through a number of moved circuits including the use of a single oscillator in a remote unit for providing both a standard for the transmitted signal and a local oscillator signal. The remote unit is layed out to minimize interference between the transmitted and received signal and includes a vertically disposed transmitting antenna and horizontally disposed receiving antenna.
Abstract: A system is added to a terminal device for automatically responding to a ringing signal of a telephone set and receiving information. Upon reception of an incoming call, an automatic telephone answering apparatus is started to send an outgoing message to a calling party. Thereafter, in response to a remote control signal supplied from the calling party, a ringing signal generating circuit is operated to generate the same signal as the ringing signal of the telephone set. The system to be connected to the telephone circuit independently can be operated without being modified, and the terminal device is started in response to the ringing signal generating circuit, so that the terminal device is connected to the telephone circuit to receive information.
Abstract: Method and apparatus is disclosed for displaying special service information at a selected station during a silent interval between ringing. The apparatus, a data receiver (100), is connected to the tip and ring leads of any well-known station set and comprises a line interface unit (101), a converter (102), a control circuit (103), and a display unit (126). A frequency shift keyed (FSK) signal which represents the special service information is filtered from the ringing signals by the line interface unit. The converter detects the FSK signal and demodulates the special service information from the FSK signal. Upon detection of the FSK signal, the control circuit receives and stores the special service information. The stored special service information is then periodically sent to the display unit to begin exhibiting the information during the silent interval before the next ringing signal.
Abstract: A surveillance apparatus for the detection and prevention of damages due to fires, gas, robbery and other destructive conditions of a building which has a large number of rooms each furnished with a telephone set and a door provided with a lock. The telephone cables extending between respective rooms and a main terminal board of the building are utilized as wires for transmitting detection signals of detectors provided in respective rooms to indicators provided in a central surveillance room during the locking of the door.
Abstract: This invention describes a remote controlled device which uses the telephone network as a transmission medium and makes it possible to transmit signals in both directions between two stations. This remote control device comprises a master station giving the instructions, which is connected to a first telephone station, and a subordinate station, connected to a second telephone station, receiving and executing the instructions and signaling the execution of the instructions. The communication between these two stations uses alternately only a single telegraph channel for outgoing and incoming transmissions, and the telephone connecting the two stations is a conventional telephone line serving for conversation between two persons.
August 29, 1983
Date of Patent:
April 1, 1986
Association Intercommunale d'Electricite du Sud du Hainaut
Abstract: A telephone mouthpiece modular coupler for directly connecting a modular telephone line cord to a conventional non-modular telephone unit having electrical contacts and a telephone handset. A substantially cylindrical, flexible coupler cup containing center and annular electrical coupler contacts and a modular line jack is provided. The coupler cup is removably attachable to a mouthpiece portion of a telephone handset. When attached, the center and annular coupler contacts create electrical connections to electrical contacts of the telephone mouthpiece. The modular line cord can be connected at one end to the clip receptacle of a direct connect modem, and at an opposite end to the modular line jack of the modular coupler, directly connecting the modem to the telephone system without using a bulky and relatively inefficient acoustical coupler device.
Abstract: A utility meter reading system for sending utility usage information over a plurality of telephone lines is disclosed including a plurality of interface devices, at least one interface coupled to each of the telephone lines and each interface coupled to at least one utility usage monitor for receiving usage information therefrom and for sending alternating current representations of the usage information over its discrete telephone line responsive to receiving at least one distinct alternating current interrogation signal from its discrete telephone line, a multiplexer for sending at least one distinct alternating current interrogation signal over each of the plurality of telephone lines, the interface receiving the plurality of alternating current representations of the usage information, a receiver for converting the alternating current representations into a plurality of digital representations, each representing usage information from a single utility usage monitor, and a processor for communicating the p
Abstract: An interrogation unit for connecting into an installation via sensing elements connected to sense required information in the installation, said interrogation unit having signal supplying means for supplying signals indicative of the condition of each of various sensors in the installation, and trigger circuit means activatable upon receipt of a request signal to transmit said signals for each of the sensors in turn.
Abstract: A time independent data transmission system which allows a computer to access a remote data set at any time via a non-dedicated telephone line is disclosed. The system is coupled to a telephone instrument, a data set and the telephone transmission line and normally connects the data set to the telephone transmission line. The telephone instrument is normally disconnected. In a preferred embodiment, a counting circuit senses the number of ring bursts in a ringing signal from a caller and a central computer is programmed to transmit a ringing signal having only one ring burst. When only one ring burst is sensed, the data set remains connected to the telephone transmission line and the data set begins to communicate with the central computer when the ringing signal terminates. If more than one ring burst occurs, a non-computer call is being sensed and the data set is disconnected and the telephone connected to the telephone transmission line so that normal telephone usage is allowed.
Abstract: A method of dispensing particular information automatically from a changing data source to any particular user. The user accesses the information by dialing the dissemination service through his telephone equipment. The caller's call and subsequent dialed digital sequences, corresponding by prearrangement to specific information requests, are automatically processed. The information from a data base is transmitted to the caller by audible synthesized speech signal through the caller's telephone. Upon request by the caller, the call is automatically transferred to a particular telephone corresponding to prearranged data relevant to the particular caller. Data in the data base may be monitored and a call to a user automatically initiated in the event a particular item reaches a predetermined parameter.
Abstract: A plurality of paging terminals each serving a locality are connected by a multi-drop communication link to establish an inter-regional paging network. The terminals observe a token passing protocol to provide for an orderly sequential use of the communication link. Down terminals are skipped in the sequence. The lack of activity on the communication link will cause a start-up timer in the terminal to reset. Retransmissions are requested by a terminal from another terminal which is on-line when the terminal fails to receive a message in a particular round through the network.
May 18, 1983
Date of Patent:
March 18, 1986
BBL Industries, Inc.
Robert E. Webb, Eugene H. Kreeft, Jack T. Arnold
Abstract: A mobile radio communications system for wide area mobile radio communications allows any two remote mobile stations to hold communications by way of a public switching network. A fixed station governing an area in which a calling mobile station is located sends to an exchange its own identification (ID) data and ID data associated with a mobile station which is connected to the fixed station by radio. Based on the two kinds of ID data, a called mobile station sees a telephone number assigned to the calling mobile station and a telephone number assigned to the fixed station which is associated with the calling mobile station.
Abstract: A stereophonic receiver includes internal separation control in which the sound separation is directly in accordance with noise reduction need and the amplitude and frequency of the sound signals monitored. Each sound channel is similar and includes an input buffer and an output buffer to directly transmit the corresponding channel signal. A variable highpass filter unit interconnects the output buffer of each channel to the opposite channel, and includes a voltage sensitive input to control the transmitted signal level. A control channel includes a high frequency filter to pass the high frequency signal of the stereophonic sound, which signal is rectified and filtered by suitable attack and decay filters. A log-conversion unit senses and converts the filtered signal to a C. logarithmic D.C. signal, which is directly proportional to the amplitude and frequency of the corresponding channel stereophonic signal. The D.C.