Teltone Corporation

Other

Fasirand Corporation

Daniel R Asmussen

George E Long

Barry C Breen

Martin J Kenney

James A Sloate

Michael D Shride

Thomas P Dillon

Ray Ma

Disclosed is a system for rapid, wireless communication of electrically-generated and detected, serial digital data signals via a plurality of infrared (or other compatible wireless medium) transceivers. Signals are communicated without electrical connection among computers, fax machines, computer peripheral equipment, or may be employed within self-contained communication, control data-acquisition, and/or display systems. The system operates at predetermined maximum data rates and sub-multiples thereof. The disclosed transceivers can be joined with additional circuits, to form an arrangement that operates as a wireless modem. In each arrangement, light is continuously modulated at either of two precise multiples of the predetermined maximum data rate, and is synchronized to transmitted-data transitions. Upon receipt of light-signals thus produced, the system's receiving transceiver synchronizes received-data electrical output signals to the received modulated light signals. Received light-modulation periods are measured and verified continuously within each data-state interval, minimizing data-delay times and transition-timing distortions in the system's electrical output signals.

Frequency-alternating synchronized infrared

A self-contained theft and vandalism deterrent system for equipment security includes sensors (12) for detecting conditions to which an alarm (24, 26, 28, 50) is responsive. The analog signals from the sensors (12) are serially delivered by a multiplexer circuit (16) when they are then directed to a network (20) for conversion to digital signals. The digital signals are delivered to a micro processor (22) where the signals are evaluated to determine if an alarm condition exists. The sensing means (12) include sound and vibration detectors for monitoring the ambient envelope. The micro processor (22) includes built in reprogramming and comparator circuits for varying the level at which a given condition will trigger an alarm response.

Signalling system with ambient condition reference monitoring

An incoming signal (tone) and the feedback signal of a biquadratic filter are converted into square waves by zero crossing comparators. The phase state of the square waves is decoded and the decoded result is phase compared to determine if a 90.degree. phase shift exists between the incoming and feedback signals. If a 90.degree. phase shift does not exist, a counter is incremented or decremented, depending upon whether the phase comparison indicates that frequency of the incoming signal is greater, or less than the feedback signal. The output of the counter is decoded and utilized through a switching circuit to control the center frequency of the biquadratic filter (determined by the impedance of its feedback path). The switching circuit changes the impedance of the feedback path so that the center frequency is moved toward the frequency of the incoming signal. When the center frequency of the biquadratic filter is at the frequency of the incoming signal, the output of the frequency decoder provides a coded indication of the frequency of the incoming signal.

Step-servoed tone detector

A circuit for making existing automatic number identification (ANI) equipment in a telephone central office compatible with multifrequency tone telephone using tone-to-pulse converters. In a typical ANI system, the telephone of one party on a two-party line includes an identification circuit, such as a connection to ground, while the other telephone does not include such a connection. When one party initiates a call, the tone-to-pulse converter interrupts the direct line pair connection between the telephone and the central office, in order to convert the multifrequency tones generated by the telephone into corresponding pulses recognizable by the central office. During this period, a voltage comparator in the preferred embodiment of the identification forwarding circuit serves to detect the voltage condition of the line pair portion connected to the one telephone, which condition varies depending on the presence or absence of the connection to ground in the telephone. A controlled gate, responsive to the voltage comparator, in turn connects a similar identification circuit as in the telephone to the line pair portion connected to the central office in the event that the voltage comparator recognizes a first voltage condition, and isolates the similar identification circuit from the line pair portion connected to the central office when the voltage comparator recognizes a second voltage condition.

Identification forwarding circuit for use with tone-to-pulse converters

A link is connected between each linefinder/first selector combination of a telephone system. The links, in turn, are selectively connected to a group of ports, several links to one port, and the ports are connected to one or more telephone signal processors. When a telephone goes OFF HOOK, the sleeve or C lead of the linefinder at which that telephone's scanning switch is then pointing (determined by the associated link being connected to an available port) is grounded. When the address of this link next occurs in a time multiplex cycle, the link is latched, and the telephone's tip and ring leads are connected to the link's port. After signal processing has ended, or some other release action occurs, the port generates a release signal that disconnects the link from the port. While any link is connected to its associated port, a make-busy ground circuit forming part of eack link applies a false busy signal to the linefinders associated with the other links common to the same port. The false busy signals prevent the linefinders associated with the other links from attempting to seize the busy port via those links. Termination of a conversation flowing through one link creates a WINK signal that causes a release of its associated linefinder, even though another link may be connected to the associated port at the time the conversation is terminated. In the case where two links associated with the same port attempt to seize that port at substantially the same time, the link having the earlier address in the time multiplex cycle actually seizes the port. The second link, upon sensing the creation of a false busy signal (causes by the seizing of the port by the first link) is dumped. Dumping the second link causes the dumped link's linefinder scanning switch to route the second call to a linefinder having a link whose associated port is available for signal processing.

Growing community of inventors

Kirkland, WA, United States of America

Daniel R Asmussen