Redundant (e.g., Added Circuit Or Loop) Patents (Class 340/508)
  • Patent number: 6246318
    Abstract: A modular safety switching device is set up such that various signaling devices in a set of possible connectable signaling devices can be connected. In this case, a typical combination of inputs and outputs that are used is provided for each signaling device. The nature of the connection of the signaling device is unique for each signaling device within the set, by which the safety switching device can identify during startup, on the basis of the electrical connections that are made, which type of signaling device is connected and what function is required for identical signaling devices. The safety switching device automatically changes itself to the required operating mode in accordance with this association.
    Type: Grant
    Filed: August 5, 1999
    Date of Patent: June 12, 2001
    Assignee: Pilz GmbH & Co.
    Inventors: Richard Veil, Winfried Gräf
  • Patent number: 6230086
    Abstract: In a railway information transmission method and system wherein information is transmitted by a consecutive transmission mode between on-vehicle control equipment and ground control equipment, a redundant code which is updated in accordance with a predetermined procedure every transmission processing is affixed to information to-be-communicated, the information being then transmitted, and on a reception side, the redundant code which is contained in the received information is correlated with a redundant code which is created on this side and which is updated in a predetermined procedure. Thus, the trouble of a transmission path can be simply found, and further, the safety of train service based on an automatic train control or the like can be enhanced.
    Type: Grant
    Filed: March 2, 1999
    Date of Patent: May 8, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Oguma, Atsushi Kawabata, Korefumi Tashiro, Michio Fujiwara, Shinya Tanifuji
  • Patent number: 6198389
    Abstract: A intruder detection system is described comprising a programmable alarm control panel capable of issuing an alarm signal representative of an intruder in a protected zone wherein the control panel is electrically coupled to a plurality of sensors by both a commonly connected status line and individual zone signaling lines between the panel and each sensor. The control panel is capable of providing distinct status information to each sensor to which it is coupled thereby permitting each individual sensor in the loop to be separately operational based on its own status as active or bypassed. For instance, if the sensor of zone 1 is active it can be set to an appropriate stability level for intrusion detection; alternatively, if, at the same time, the sensor associated with zone 2 is bypassed, it can be set to operate as a high sensitivity occupancy detector. The intruder detection system of the present invention utilizes status signals which individually identify and set each sensor.
    Type: Grant
    Filed: June 22, 1999
    Date of Patent: March 6, 2001
    Assignee: Napco Security Systems, Inc.
    Inventor: Charles S. Buccola
  • Patent number: 6166632
    Abstract: An interactive security system includes a host controller, a security service center coupled with the host controller to receive an emergency signal from the host controller, a client society comprising a client that consists of an auxiliary controller coupled with the host controller. An auxiliary controller includes a button and a lot of lights equal to the total number of the clients in the client society, wherein every client has an identification light indicating the client's number. The identification light is green in normal situation. When a client presses the button, a light indicating the identification of the emergency client's number illuminating with red on the every auxiliary controller of the client society. The alarm system of the auxiliary controller is turned on and in accordance with beep-beep sound and then transmits an emergency signal to the host controller.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: December 26, 2000
    Inventor: Tai-Sheng Chen
  • Patent number: 6163263
    Abstract: A self-monitoring power supply can be incorporated into electrical devices which are part of a multi-device communication system. The power supply is energized by electrical energy received from a medium on an intermittent basis. The self-monitoring circuitry assures that the device has sufficient energy for carrying out its functions. Noise rejection and noise immunity can be enhanced in such devices by circuitry which upon detection of a transmission start signal or a clock pulse locks out data signals for a predetermined period of time and upon detection of a data signal locks out transmission start or clock pulses for a predetermined period of time.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: December 19, 2000
    Assignee: Pittway Corporation
    Inventors: Lee D. Tice, Robert J. Clow, Manley S. Keeler
  • Patent number: 6150935
    Abstract: An alarm system which incorporates a plurality of highly sensitive, early warning, smoke detectors incorporates functionality for distinguishing between detector signals in response to ambient smoke and detector signals in response to the presence of non-smoke, fibrous materials. Detectors are spatially arranged in predetermined regions. Information concerning the arrangement of detectors is stored in the common control unit. Additionally, a performance history for each of the detectors is also stored in the control unit. If one of the detectors exhibits a relatively large output which is large enough to indicate a possible fire, a previously stored history from the outputs of that detector is analyzed. If the previously stored history indicates a fire related profile, such as a relatively gradual increase in smoke level over a period of time, the signal from that detector is regarded as being indicative of smoke and an alarm is indicated.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: November 21, 2000
    Assignee: Pittway Corporation
    Inventor: Donald D. Anderson
  • Patent number: 6127932
    Abstract: A flame sensor for sensing flame produced by the burner of a furnace. The sensor includes a closed end tube having a photosensitive element located therein. The photosensitive element is sealed off from any external light so as to only respond to infrared wavelengths of light emitted from the end of the tube when subjected to a flame produced by the burner of the furnace.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: October 3, 2000
    Assignee: Carrier Corporation
    Inventors: Larry E. Wilson, Gary D. Wedlake
  • Patent number: 6124790
    Abstract: A method for filtering an alarm can be broadly summarized by the following steps: The state of an alarm is read or determined over time, which creates a pattern of state transitions for the alarm. The pattern of state transitions for the alarm are integrated to produce a second alarm having a second pattern of state transitions. State transitions for the second alarm are controlled by using a pair of hysteresis threshold values to filter out redundant alarm state transitions that do not convey useful or necessary fault information.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: September 26, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Maxim A. Golov, Kirill R. Schmidt
  • Patent number: 6037867
    Abstract: A device for supervising movable articles or objects has a supervising member which can be attached thereto. The device includes a connector disposed in a housing. The housing includes an aperture and a rotary blocking member positionable between the connector and the aperture of the housing. The supervising member is coupled to the connector. The blocking member prevents the supervising member from being recoupled to the connector after it has been removed from the housing. An alarm system is also provided. The alarm system includes ambient condition detectors in communication with a control unit.
    Type: Grant
    Filed: January 22, 1998
    Date of Patent: March 14, 2000
    Assignee: Pittway Corporation
    Inventors: Rony K. Joseph, Scott E. Robillard
  • Patent number: 5973603
    Abstract: A house and garage alarm system is provided including at least one detector housing with a smoke and/or carbon monoxide detector situated therein. A power source is situated within the detector housing. An alarm housing is included which is connected to the corresponding detector housing and resides distant therefrom for indicating to a user that either smoke and/or carbon monoxide has been detected by the detector.
    Type: Grant
    Filed: December 17, 1997
    Date of Patent: October 26, 1999
    Inventor: Leroy H. Judy
  • Patent number: 5933077
    Abstract: An alarm system includes a controller (20), a plurality of transponders (23-26), and a transducer (50) connected to one of the transponders (23). A voltage reference which is preferably earth ground is established for the entire alarm system. A local loop comprises a pair of electrical conductors (72, 73) connecting the transducer and transponder. The transponder includes a comparator (70, 80, 80-82) having a fixed reference input and a second input which is the voltage level on the local loop. If a ground fault or other abnormal condition occurs, this is sensed by the comparator and an indication provided a loop status portion (60a) of the transducer. The controller includes a communications module (27) by which each transponder is addressed, and the transponder includes an output response portion (60b) by which the transponder identifies itself to the controller as the transponder at which the ground fault or other abnormal condition has occurred.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: August 3, 1999
    Assignee: Wells Fargo Alarm Services, Inc.
    Inventors: William R. Vogt, Leonard Noonan
  • Patent number: 5923249
    Abstract: An optional security system for monitoring door opening is designed to be plugged into the main board of a slot machine without any change of hardware or addition of extra switches. This security system allows time stamping of any access to the machine interior and will operate while the machine is powered down. Standard and optional security is designed so that when the optional security module is added it can share the same sensors as the standard system. The normal security system does not prevent the security module functioning when the power is off. Ideally, a security module can be plugged into a machine and take over or add the new security features. The isolation between the main board and the security system is achieved by the use of schottky diodes. When operating from battery power, the security subsystem remains in a low power drain "sleep" state for the majority of the time, "waking up" periodically to check the door switches and then going to sleep again.
    Type: Grant
    Filed: July 11, 1997
    Date of Patent: July 13, 1999
    Assignee: Aristocrat Leisure Industries Pty. Ltd.
    Inventor: Robert Linley Muir
  • Patent number: 5920259
    Abstract: A motion sensor has a parasitic response to at least one of radio frequency (RF) or electromagnetic (EM) impulse signals. The motion detection circuit for security systems has a dummy RF receiver for generating an RP response signal, the receiver having a response to at least one of radio frequency (RF) or electromagnetic (EM) impulse signals similar to the parasitic response. An alarm output signal is generated in response to intruder motion in the predetermined area while preventing false alarms due to the parasitic response.
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: July 6, 1999
    Assignees: Shmuel Hershkovitz, Pinhas Shpater
    Inventor: Pinhas Shpater
  • Patent number: 5909174
    Abstract: A control device is provided with a controllable element and a control unit that delivers an output signal which, when a control command signal applied to the input side is at an activating level, continuously or periodically assumes an activating level and continuously assumes a deactivating level when the control command signal is at a deactivating level or there is a functional failure of the control unit. The control device incorporates a redundancy logic unit that logically links the control command signal with the output signal of the control unit to form the control signal for the controllable element in such fashion that when the output signal of the control unit is continuously at its deactivating level, the control signal, corresponding to the control command signal, is at its activating or deactivating level, while otherwise the control signal is at its activating or deactivating signal level depending on the level of the output signal of the control unit.
    Type: Grant
    Filed: March 20, 1997
    Date of Patent: June 1, 1999
    Assignee: Mercedes-Benz AG
    Inventors: Juergen Dietz, Armin Staehle, Stefan Woerner
  • Patent number: 5805062
    Abstract: An isolation amplifier that transmits data to a receiver via a current loop, where the isolated portion of the circuit is powered by a photovoltaic array illuminated by a light source powered directly by the current loop. Optionally, the photovoltaic array is additionally illuminated by any excess power tapped from the current loop by the non-isolated portion of the circuit. Preferably, the light source is an array of light-emitting diodes. Preferably the photovoltaic array is an array of photocells sensitive to the same wavelengths emitted by the light-emitting diodes. Preferably, there are optical conductors connecting the LED's to the photocells.
    Type: Grant
    Filed: October 21, 1996
    Date of Patent: September 8, 1998
    Assignee: Mini-Systems, Inc.
    Inventor: Alan R. Pearlman
  • Patent number: 5789925
    Abstract: A sensor system includes a single sensor means, two sensed signal processing circuits for processing the output signal of the sensor means, both the signal processing circuits being substantially equal in circuit construction, and an abnormality detecting circuit for detecting an abnormality on the basis of the difference between the output signals of the two sensed signal processing circuits.
    Type: Grant
    Filed: July 2, 1996
    Date of Patent: August 4, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masahiro Yokotani, Wataru Fukui, Naoki Hiraoka, Shunichi Wada
  • Patent number: 5777550
    Abstract: A high reliability instrument system includes means for applying a test condition to the instrument and for determining whether the instrument properly responds to the test condition, and means for inhibiting the generation of an instrument output in response to such testing. This provides verification that most of the instrument system components, but not the system output, are properly functioning. The system further includes means for overriding the output-inhibiting function when it is desired to test the entire instrument system including the system output. The instrument system may include a gap-type ultrasonic instrument, with the test condition comprising a pulse applied to one crystal, the effects of which are detected at the other crystal to determine sensor integrity. The system is preferably configured as a two-wire on-off instrument system, in which application of the test condition at a transmitter is controlled by signals applied to the two-wire signal loop at a remote receiver.
    Type: Grant
    Filed: January 3, 1997
    Date of Patent: July 7, 1998
    Assignee: Drexelbrook Controls, Inc.
    Inventors: Frederick L. Maltby, Glen L. Mitchell, Mort Gorowitz
  • Patent number: 5757265
    Abstract: A field bus system may be used in which transmission ability of the system can be maintained even if communication error occurs due to noises or failure of a transmission line. The system can be easily shifted at a lower cost from a conventional system to the field bus system without degrading the high reliability thereof. The transmission line is constituted by a multiple-cable transmission line having at least three transmission cables. An external power supply supplies power to field devices through a pair of transmission cables of the multiple-cable transmission line. The field devices are connected to the transmission cables through a transmission line switching unit constituted by a plurality of rectifier elements, so that the field devices are supplied with current flowing in one predetermined direction when any of the pairs of transmission cables is selected.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: May 26, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Makoto Kogure, Koji Tomaoki, Toshimitsu Tsuchihashi
  • Patent number: 5721530
    Abstract: There is provided an alarm system for detecting and warning of the presence of alarm and trouble conditions in a plurality of zones. The system comprises a loop controller having supply lines extending to the plurality of zones and a module connected to the supply lines within each zones. The module includes means for detecting whether communication between the module and the loop controller has been disrupted. If an alarm condition occurs in a particular zone, the module initiates communication of the alarm condition to the loop controller. During normal operation, when communication with the loop controller has not been disrupted, the module has shared operations with the loop controller to determine whether an alarm condition exists. When communication with said loop controller has been disrupted, temporarily or otherwise, the module continues to operate independently of the loop controller and determines whether an alarm condition exists.
    Type: Grant
    Filed: April 1, 1997
    Date of Patent: February 24, 1998
    Assignee: General Signal Corporation
    Inventors: Robert W. Right, Hilario S. Costa, John P. Hewlin
  • Patent number: 5701115
    Abstract: There is provided an alarm system for detecting and warning of the presence of alarm and trouble conditions in a plurality of zones. The system comprises a loop controller having supply lines extending to the plurality of zones and a module connected to the supply lines within each zones. If an alarm condition occurs in a particular zone, the module initiates communication of the alarm condition to the loop controller. The system also includes means for variably controlling a specific personality of the module, such as a microcontroller, so that the module functions selectively in a variety of specific ways. The means for variably controlling includes means for selectively storing configuration data, such as an EEPROM, in the module to define the specific personality.
    Type: Grant
    Filed: May 16, 1995
    Date of Patent: December 23, 1997
    Assignee: General Signal Corporation
    Inventors: Robert W. Right, Hilario S. Costa, John P. Hewlin
  • Patent number: 5694114
    Abstract: A high speed secure fiber optic communication system that includes a coherent alarm system utilizes a pair of single mode fiber optic cables in combination with one or more light sources, phase modulators, detectors and polarization scrambling elements to form a Sagnac interferometer. The phase modulator is driven so that counter propagating light beams in the Sagnac loop experience a different optical path as they pass through the loop. When the two beams are recombined on the central beamsplitter of the Sagnac loop, the two beams interfere with each other and the data impressed as phase modulation on the light beams by the phase modulator is recovered as amplitude modulation on the output detector of the Sagnac interferometer. The coherent alarm system applies a relatively low frequency background signal to the Sagnac interferometer and watches for changes occurring to the background signal that indicate the presence of an intruder.
    Type: Grant
    Filed: May 6, 1994
    Date of Patent: December 2, 1997
    Assignee: McDonnell Douglas Corporation
    Inventor: Eric Udd
  • Patent number: 5679987
    Abstract: The invention discloses a method and its device for acquiring swiftly and firmly the connectivity information of electric conductor cords for connecting a plurality of apparatus groups or switching boards in information wiring facilities. The unused extra cores of an electric plural core conductor cord for connecting every apparatuses of apparatus groups A and B with each other through switching boards are connected to a voltage applicator and a voltage (or current) detector through information collecting connectors and the electric connectivity restrictions between every apparatuses of the apparatus groups of the electric conductor cord described above are acquired depending on its electric conduction. According to the invention, the connectivity information of the electric conductor cords in information wiring facilities can be obtained accurately and firmly. Furthermore, the use of the extra cores enable to reduce the cost of the device and to easily apply the invention to the facilities already built.
    Type: Grant
    Filed: November 1, 1995
    Date of Patent: October 21, 1997
    Inventor: Hideharu Ogawa
  • Patent number: 5652566
    Abstract: A redundant alarm system including a central controller that interfaces with a first alarm, a second alarm, a visual indicator and an acoustic sensor. When an alarm condition exists, the controller activates the primary alarm causing the primary alarm to generate an audible first alarm signal. The audible first alarm signal is transmitted from the primary alarm to the acoustical sensor. The acoustical sensor detects the audible first alarm signal and transduces the audible first alarm signal into a first feedback signal that is relayed to the controller. If the controller does not receive the first feedback signal from the acoustical sensor within a predetermined time after activating the primary alarm, the controller activates the secondary alarm and the visual indicator.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: July 29, 1997
    Assignee: Aequitron Medical, Inc.
    Inventor: Scott Anthony Lambert
  • Patent number: 5646596
    Abstract: An interactive window display enables a person to activate one or more electrical devices located inside an enclosure from outside of the enclosure. Each electrical device is electrically connected to an infrared sensor located inside the enclosure. Each infrared sensor emits a light beam through a window of the enclosure. A person on the outside of the enclosure can manually place a small reflective card against the window in the path of the light beam of a selected infrared sensor. The light beam is reflected back to the infrared sensor. Upon sensing the reflected light beam, the infrared sensor produces a signal that energizes an electrical circuit and activates the associated electrical device.
    Type: Grant
    Filed: September 15, 1995
    Date of Patent: July 8, 1997
    Assignee: IDC, Inc.
    Inventor: Darryl M. Gumm
  • Patent number: 5640140
    Abstract: The alarm processing apparatus has fault detection means which detect faults with regard to specific individual items, and which are provided in constituent elements, which have redundancy; fixed fault detection means which determine the individual frequencies of occurrence of the faults detected by the fault detection means and which detect fixed faults related to the individual items, based on the relative magnitude of the frequencies with respect to the allowable maximum fault occurrence frequencies for those items; and selection means which by means of a system configuration command and at a timing which is delayed to longer than the response time of the fixed fault detection means, outputs an alarm for either the faults detected by the fault detection means in response to the system configuration command or the fixed faults detected by the fixed fault detection means.
    Type: Grant
    Filed: August 30, 1994
    Date of Patent: June 17, 1997
    Assignee: Fujitsu Limited
    Inventors: Akihiko Oka, Kanta Yamamoto
  • Patent number: 5631630
    Abstract: A simplified, home-improvement-type, low voltage security system to prevent infants from entering the swimming pool area by monitoring the exit doors of a home leading to the swimming pool and the swimming pool by combined passive and active motion detectors and an alarm. Photoflood lamps can be added to the security system.
    Type: Grant
    Filed: September 18, 1995
    Date of Patent: May 20, 1997
    Inventor: Terrance J. McSweeney
  • Patent number: 5621383
    Abstract: In a ring network system formed by a plurality of nodes connected to one another through a ring-shaped path, each of the nodes collects all of node information signals representative of states of the nodes and memorizes the node information signals in a node information signal memory included in each node. The node information signal is periodically transmitted to each node from an adjacent one or ones of the nodes through the ring-shaped path and is renewed from time to time. Such collection of all of the node information signal in each node makes it easy to check an alarm by a superintendent.
    Type: Grant
    Filed: April 5, 1996
    Date of Patent: April 15, 1997
    Assignee: NEC Corporation
    Inventor: Shunji Yoshiyama
  • Patent number: 5619131
    Abstract: An electronic monitoring system provides an actual value sensor which detects an actual value of a component to be monitored, e.g., the rotational speed of a drive motor, and emits actual value signals, a signal path along which actual value signals are transmitted, and an evaluating unit connected to the signal path. The signal path is divided into two separate but parallel signal paths along which the actual value signals emitted by the actual value sensor are processed differently. For example, the actual value signals emitted by the actual value sensor may undergo digital signal processing along one path and analog signal processing along the other path. The actual value signals transmitted along the two paths are received by the evaluating unit which compares the signals and initiates appropriate steps if there are deviations between the two sets of actual value signals.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: April 8, 1997
    Assignee: Landis & Gyr Business Support AG
    Inventors: Josef Lelle, Gerhard H. Ulrich
  • Patent number: 5552764
    Abstract: In a receiving circuit which serves as a system in use, a gate circuit is enabled in response to a specifying signal. In a receiving circuit which serves as a backup system, a gate circuit is enabled in response to a specifying signal. When no signal is applied to an input terminal, alarm detection signals are outputted. However, a system-in-use/backup-system specifying circuit is first supplied with the alarm detection signal of the backup system. Thus, the system-in-use/backup-system specifying circuit determines or detects that the receiving circuit serving as the system in use is normal.
    Type: Grant
    Filed: January 25, 1993
    Date of Patent: September 3, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Hideyuki Tsujimoto
  • Patent number: 5524099
    Abstract: An intrusion detector operating mode selection circuit sets an intrusion detector operating mode responsive to an encoded acoustic signal. An acoustic signal decoder receives an encoded acoustic signal and generates a mode selection signal in response thereto. The encoded acoustic signal is a plurality of spaced-apart acoustic pulses encoded by the relative inter-pulse timing of the spaced-apart pulses. A mode of the intrusion detector is set responsive to the mode selection signal.
    Type: Grant
    Filed: May 25, 1994
    Date of Patent: June 4, 1996
    Assignee: C & K Systems, Inc.
    Inventors: Stephen A. Rickman, Richard A. Johnson, Richard J. Hess
  • Patent number: 5479161
    Abstract: A system for calibrating the sensors of a redundant sensor system by calculating a first set of error signals based on differences between a combination of the outputs and known values and calculating a second set of error signals based on differences between the parity among preselected sensors and a predetermined value and calculating, from the first and second set of error signals, a plurality of calibration signals to be added to the output of the individual sensors which are in error so as to correct their outputs.
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: December 26, 1995
    Assignee: Honeywell Inc.
    Inventors: Charles L. Keyes, Douglas M. Weed
  • Patent number: 5475365
    Abstract: A multisensor intrusion detection system having greatly improved immunity to false alarms is disclosed. This system employs a first sensor for sensing an intrusion in a volume of space by a first physical phenomenon and a second sensor for detecting an intrusion in the volume of space by a second physical phenomenon different from the first physical phenomenon. The first sensor generates a first signal in response to the detection of an intrusion into the volume of space, and the second sensor generates a second signal in response to a detection of an intrusion. A microcontroller generates an alarm signal upon the occurrence of one first signal and one second signal within a first interval, the occurrence of another first signal within a subsequent second interval and the occurrence of another second signal within a third subsequent interval.
    Type: Grant
    Filed: December 2, 1994
    Date of Patent: December 12, 1995
    Assignee: C & K Systems, Inc.
    Inventors: Paul M. Hoseit, Gordon S. Whiting
  • Patent number: 5473309
    Abstract: An apparatus for testing the operation of an irrigation system is disclosed. The apparatus pinpoints defects in the irrigation system controller by simulating control signals and processing the control signals through controller output chips. Visual indicators offer an indication of defects in output chips. The apparatus may be coupled to the controller and receives potential from the controller. The potential is converted to produce a signal for operating the tester. An oscillator/clocking section produces serial data input, strobe pulse, and clock pulse signals to simulate signals produced by the controller microprocessor. These signals operate the visual indicators and are simultaneously processed through the controller output chips. Defects low in the output chips prevent the operation of visual indicators. The absence of an operating visual indicator represents a defect in the output chips.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: December 5, 1995
    Inventor: Dale H. Marcum
  • Patent number: 5448224
    Abstract: A heat detector includes an external temperature detector for detecting an external temperature outside the heat detector and an internal temperature detector for detecting an internal temperature inside the heat detector. A microcomputer calculates a temperature difference between the external temperature detected by the external temperature detector and the internal temperature detected by the internal temperature detector. The microcomputer monitors the above-described temperature difference to detect an event in which the temperature difference has remained greater than a predetermined value for a predetermined duration or longer. If the microcomputer detects that the temperature difference has remained greater than the predetermined value for the predetermined duration or longer, the microcomputer outputs an abnormal signal representing that the external temperature detector is abnormal.
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: September 5, 1995
    Assignee: Nohmi Bosai Ltd.
    Inventor: Mikio Mochizuki
  • Patent number: 5424708
    Abstract: An alarm system monitoring method for remote monitoring. A local alarm monitoring station receives alarm indications from alarms being monitored, and transfers the alarm indication to a first hub station. A load processor at the hub station, determines whether the first hub station should handle the call by comparing its current load of calls to a predetermined limit. If the limit is not crossed by local handling of the call, the first hub station will handle the call, and the load number is modified accordingly. If the first hub station cannot handle the new call, the call is transferred to a second hub station for processing.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: June 13, 1995
    Assignee: Honeywell Inc.
    Inventors: Carol D. Ballesty, Paul R. Knirk, Barry R. Mumm
  • Patent number: 5416725
    Abstract: A notification system for reporting events occurring within a defined area being monitored thereby. The notification system includes a plurality of sensors installed at selected locations within the defined area and a sensor interface coupled to each of the sensors. The sensor interface periodically polls the sensors and stores status information received therefrom. Coupled to the sensor interface is a computer system for receiving and analyzing the stored status data. Upon determining from the status data that an event requiring issuance of a notification has occurred, the computer system issues a series of notifications for which each recipient of a notification receives a selected message regarding the event.
    Type: Grant
    Filed: October 15, 1993
    Date of Patent: May 16, 1995
    Assignees: P.C. Sentry, Inc., Harris Partners, Ltd.
    Inventors: Steven M. Pacheco, Dennis B. Harris
  • Patent number: 5402101
    Abstract: A danger alarm system includes a plurality of detectors, each of which having a microprocessor, a current drain controllable by the microprocessor for data exchange with a central station, an address register, and a nonvolatile memory for containing an individual binary serial number.
    Type: Grant
    Filed: July 6, 1992
    Date of Patent: March 28, 1995
    Assignee: Esser Sicherheitstechnik GmbH
    Inventors: Horst Berger, Heiner Politze, Peter Ungemach
  • Patent number: 5387899
    Abstract: An alarm system is described wherein both an open connection between an alarm monitor and an alarmed unit or a short circuit across the connection between the monitor and the unit can be detected. A controllable, normally open test device is placed in parallel with a normally open alarm contact. If current flows when the test device is open, either a short circuit or an alarm condition exists. If current does not flow when the test device is closed, an open connection between the monitor and the unit exists. Advantageously, the integrity of connections between alarm monitors and alarmed units is enhanced.
    Type: Grant
    Filed: July 29, 1993
    Date of Patent: February 7, 1995
    Assignee: AT&T Corp.
    Inventors: Amato A. DiLauro, Richard J. Kriete, George S. Micallef, Vladimir Zaltsman
  • Patent number: 5200734
    Abstract: A detecting and alarming system includes a main alarm circuit provided in a headquarter control center, at least a terminal alarm circuit provided at a local station, and at least a connecting loop conecting the main alarm circuit and each terminal alarm circuit, whereby upon a cutting or a shortcircuiting of the connecting loop between the headquarter control center and the local station, an alarm will be actuated for warning the breaking or shortcircuiting situation.
    Type: Grant
    Filed: January 6, 1992
    Date of Patent: April 6, 1993
    Inventor: Tieng-Fu Lin
  • Patent number: 5155480
    Abstract: An apparatus for non-blocking event reporting from event reporting units to a monitoring circuit includes a first and second common wire coupling the units to the monitoring circuit. A constant level signal is generated on the first wire and a pulse signal is generated on the second wire. The monitoring circuit detects the level and pulse signals and reports multiple overlapping events occuring at the event reporting units.
    Type: Grant
    Filed: December 27, 1990
    Date of Patent: October 13, 1992
    Assignee: ADC Telecommunications, Inc.
    Inventor: Greg C. Pfeiffer
  • Patent number: 5140305
    Abstract: An apparatus for detecting speed sensor failure in an overspeed protection device is disclosed. The apparatus comprises a plurality of tachometers having outputs for indicating the speed of rotation of a machine relative to plural setpoints. If the comparison indicates that certain conditions exist, then a sensor failue is indicated. The apparatus may also be employed to detect a failure of, or loss of power to or within, one of the tachometers.
    Type: Grant
    Filed: January 17, 1991
    Date of Patent: August 18, 1992
    Assignee: Westinghouse Electric Corp.
    Inventor: Joseph D. Hurley
  • Patent number: 5140622
    Abstract: A data transmission system with double lines comprises a plurality of sensor terminals connected to the current line in cascade, and a controller connected to a current input side of the first sensor terminal. A switch device in each sensor terminal connects the current line to a sensor circuit for a specified time after a current begins to flow to the current input side of the sensor terminal, and connects the current line to the current output side of the sensor terminal after an elapse of the specified time. After that switching, the current begins to flow to the next sensor terminal. If the sensor turns on while the current is flowing to the sensor circuit, the value of the current of the current line may be greater. The controller detects value of the current and decides state of the sensor circuit in the sensor terminal according to the value of the current.
    Type: Grant
    Filed: April 1, 1991
    Date of Patent: August 18, 1992
    Assignee: Idec Izumi Corporation
    Inventors: Shigehiro Shino, Kazuhiko Uemura, Kiyoshi Kurashita
  • Patent number: 5132628
    Abstract: A device for detecting errors of a plurality of electric parts which are built in electronic equipment has error detecting circuits in the form of relays. The relays are interconnected one-to-one to various electric parts which are the subject of error detection, while display circuits are interconnected one-to-one to the relays. Output signals of the relays are fed to a reporting circuit without the intermediary of the display circuits. When an electric part is free from an error and only a display circuit associated therewith has failed, no error signal is fed to the reporting circuit. Only when any of the electric parts has really failed, an error signal is delivered to the reporting circuit to cause the latter to take an adequate measure such as the interruption of power supply.
    Type: Grant
    Filed: March 9, 1990
    Date of Patent: July 21, 1992
    Assignee: NEC Corporation
    Inventor: Yoichi Matsuo
  • Patent number: 5103206
    Abstract: A security system including a plurality of alarm equipped security units usable at discrete locations and operated by individual power sources at those discrete locations. The units are interconnected and alarm linked with one another with the system being set up such that disruption of the interconnection between units at any location in the system causes alarm operation at all of the alarm linked security units.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: April 7, 1992
    Inventor: Thiann R. Yu
  • Patent number: 5030939
    Abstract: A circuit senses the conditions of control instrumentation such as valves and graphically displays these conditions on a display panel or screen of a console. The circuit also provides signal checking or validation capability monitoring the quality of the instrument condition signals and displaying the quality of the monitored signals on the same console screen.
    Type: Grant
    Filed: September 14, 1989
    Date of Patent: July 9, 1991
    Assignee: Elsag International B.V.
    Inventor: David E. Lovick
  • Patent number: 4973943
    Abstract: A signal control system for transmission circuits which includes two ring counter type transmission circuits respectively formed of a plurality of transmitter-receivers located opposite to each other, a control circuit, and a couple of signal lines respectively formed of two alternate signal lines, a control signal line and a transmission line. The first pair formed of the first transmitter-receivers of the respective two transmission circuits are simultaneously operated, and subsequent pairs of the transmitter-receivers of the transmission circuits are synchronously operated in turn by a shift pulse. The system can transmit signals and control the transmission circuits without complicated circuits such as an address circuit and a verification circuit so that the construction is simplified and its power consumption is largely reduced.
    Type: Grant
    Filed: June 26, 1989
    Date of Patent: November 27, 1990
    Inventor: Takeo Arima
  • Patent number: 4954809
    Abstract: A fire alarm system in which a large number of terminal units, comprising detectors and interface circuits, at a variety of locations are coupled or connected in separate, independent loops of the system, each of the scattered terminal units being addressable from a central control panel. The arrangement is such that serial synchronous power transmission and data communication is effectuated over the individual loops of the system. The improvement resides in providing continuity-isolation testing for a Class A wiring scheme involved in the loops. By Class A operation is meant that there are two separate channels involved in each loop. A continuity test is sequentially performed on both channels of the loop such that discontinuities can be precisely located.
    Type: Grant
    Filed: May 1, 1989
    Date of Patent: September 4, 1990
    Assignee: General Signal Corporation
    Inventors: Robert W. Right, Simon T. Carter
  • Patent number: 4926364
    Abstract: A method and apparatus for determining a weighted average of three input values under the control of a processor includes a step of determining which of the three input values is the median value, with the remaining input values being first and second values. Then, first and second weighting factors are calculated based on a predetermined median weighting factor and the three input values. Finally, a weighted average is calculated based on the first and second weighting factors, the predetermined median weighting factor, the first and second input values and the median input value. The three input values may be sensed values provided by a temperature sensor in a nuclear power plant.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: May 15, 1990
    Assignee: Westinghouse Electric Corp.
    Inventor: Walter W. Brotherton
  • Patent number: 4899131
    Abstract: A control system has a central unit for applying DC operating current and control signals to a two line bus. The central unit applies a DC operating current to the bus, as well as signals that have first and second parts. A terminal connected to the bus detects first signal parts on the bus that are unique to that terminal, and, in response thereto, applies the second signal parts to its output terminals. A manual control unit is connected to receive operating current and signals from the output terminals. The manual control unit has a plurality of keys connected to load the bus, and is responsive to determined second signal parts for inhibiting such loading of the bus, thereby enabling the central unit to determine and address of the manual control unit.
    Type: Grant
    Filed: November 23, 1987
    Date of Patent: February 6, 1990
    Assignee: Aktiebologet Electrolux
    Inventors: Sven T. Wilk, John G. Olsson
  • Patent number: RE33807
    Abstract: A self-powered sensor for a closed-loop security system includes a self-powered sensor network which provides a switch-actuating signal upon the detection of a physical condition. An electronic switch, which is in a normally closed position, is connected between the positive and negative poles of a closed-loop security system and opens the loop upon receipt of the switch-actuating signal thereby triggering an alarm. The self-powered sensor network may include a voltage doubler for converting the AC output of a transducer to a DC voltage of an amplitude sufficient to open the switch. When the switch is opened, voltage from the closed-loop security system becomes available to power a visible or audible alarm identifying the sensor that opened the loop.
    Type: Grant
    Filed: May 16, 1990
    Date of Patent: January 28, 1992
    Assignee: Sentrol, Inc.
    Inventors: William E. Abel, Douglas H. Marman