With Impedance Level Coding Patents (Class 340/537)
  • Patent number: 10119304
    Abstract: A point of sale assembly having antitheft functionality. A sealed consumer product package has a face with at least one opening extending into the sealed consumer product package. A consumer product is positioned inside the sealed consumer product package. A lock having a sensor and a body that is positioned outside the sealed consumer product package. The lock has at least one locking arm extending into the opening of the sealed consumer product package and secured to the consumer product.
    Type: Grant
    Filed: January 28, 2016
    Date of Patent: November 6, 2018
    Assignee: The Gillette Company LLC
    Inventor: James Arthur Meech
  • Patent number: 10037682
    Abstract: A system, method, and device are provided for activating an emergency protocol when a weak point on a user device is compromised as a result of an applied stress. The system comprises the user device and its relationship with a network element. When the weak point on the user device undergoes stress and breaks, a distress signal is sent to the network element. The network element then proceeds to activate the emergency protocol which may include placing a call to an emergency response team.
    Type: Grant
    Filed: August 4, 2015
    Date of Patent: July 31, 2018
    Assignee: Google LLC
    Inventors: Rohan Shah, Thad Eugene Starner
  • Patent number: 9053655
    Abstract: According to one aspect of the present invention, there is provided a driver of a display unit including a latch circuit holding gradation information, a D/A converter outputting analog signal based on the gradation information held by the latch circuit, a test circuit provided between the latch circuit and the D/A converter, the test circuit inputting or outputting test signal regarding the latch circuit, a switch connecting voltage output of the D/A converter and a driver output terminal in normal operation, and a test switch connecting the test circuit and the driver output terminal in test operation and disconnecting the test circuit and the driver output terminal in normal operation.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: June 9, 2015
    Inventor: Yoshihiko Hori
  • Patent number: 8565717
    Abstract: A mobile telephone equipped for activation of an emergency mode comprises a housing, a detection circuit triggered, especially interrupted, from outside the housing and a strap member cooperating with the detection circuit for triggering, especially interrupting, the detection circuit upon pulling the strap member off the housing. An electronic control unit of the telephone monitors triggering of the detection circuit, to activate an emergency mode in case of such triggering and to automatically perform emergency operations in the emergency mode. The strap member comprises a strap, a first connector attached to the strap and a bridging circuit portion. The housing comprises a second connector that cooperates with the first connector for fastening the strap member to the housing. The connectors are configured as mating snap-fit connectors, with the connector or of the strap member comprising at least two bridging circuit terminals.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: October 22, 2013
    Inventor: Andrzej Jaroslaw Galuszka
  • Patent number: 8339256
    Abstract: A magnetic resonance imaging (MRI) system includes an interventional instrument and a switched, segmented transmission (Tx) line which ensures safety during an MRI protocol while the interventional instrument is located in the system. The transmission line includes at least two electrically conductive Tx line segments separated by a non-conductive gap. An electrically conductive bridge, having an open and a closed state, and a parallel connected impedance bridge, having a known impedance which suppresses RF current between the line segments, bridge the non-conductive gap. A measurement unit measures the impedance across the Tx line while the conductive bridges are open. The line segments are verified to be decoupled if the measured impedance of the line is substantially equal to that of the impedance bridge.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: December 25, 2012
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Steffen Weiss, Oliver Lips, Sascha Krueger
  • Patent number: 8319599
    Abstract: An electrical appliance (100) comprises a digital control system (SC), configured for enabling the performance of a plurality of pre-determined basic functions, and an auxiliary device (200) comprises means (PM, 230-231) for acquiring and/or processing auxiliary information. The electrical appliance (100) and the auxiliary device (200) moreover comprise respective communication means (270), for setting up between them a bi-directional communication of data. The control system (SC) of the electrical appliance (100) is provided for enabling execution of additional functions with respect to the basic functions and for sending to the auxiliary device (200), via the communication means (270), requests for auxiliary information, necessary for the performance of said additional functions.
    Type: Grant
    Filed: January 10, 2008
    Date of Patent: November 27, 2012
    Assignee: Indesit Company S.p.A.
    Inventors: Valerio Aisa, Paolo Santonicola, Valerio Cascio
  • Patent number: 7499815
    Abstract: A system and method for readily generating radial clearance data for a radial clearance between locations on at least two parts in a rotating machine includes rendering an image of a cross section view of at least a portion of the machine on a display. The locations on the two parts are identified on the rendered cross section, and a radial stack path between the identified locations is automatically determined. The radial clearance between the identified locations when the machine is not operating is determined, based at least in part on the determined radial stack path. Data generated by a deflection analysis model of the machine are used to determine radial deflections of the identified locations during machine operation at one or more machine operating conditions. Data representative of the radial clearance between the identified locations during the machine operation at the one or more machine operating conditions are generated.
    Type: Grant
    Filed: November 2, 2006
    Date of Patent: March 3, 2009
    Assignee: Honeywell International Inc.
    Inventors: Dave G. Dischinger, Charles P. Silcox, Amitabh Tandon, Muralidharan Kendai, Karthikeswaran Kalusivalingam
  • Patent number: 7315234
    Abstract: A load control apparatus is connected to a master station through a power line supplied with direct-current power. The load control apparatus is driven by the direct-current power supplied from the power line to communicate with the master station through the power line. The load control apparatus includes a PLC part, first and second branch lines, connected to the power line, an impedance element connected to only the second branch line, a motor connected to only the first branch line, a condenser connected in parallel with the motor, the condenser having a capacitance resonating with an inductance component of the motor and frequency of the communication signal, a control part configured to perform a variety of processes, based on the communication signal received by the communication part communicating with the master station, and a circuit power part connected to the second branch line through the impedance element and configured to supply the PLC part and the control part with the desired power.
    Type: Grant
    Filed: March 28, 2006
    Date of Patent: January 1, 2008
    Assignee: Yazaki Corporation
    Inventors: Yo Yanagida, Terumitsu Sugimoto
  • Patent number: 7259687
    Abstract: A multi-module DC-DC converter provides synchronization between modules based on identification of a module within a chain. A resistor network can be used for the chain so that each module obtains a particular voltage based on its position within the chain. A master module provides a source current to drive the chain so that each module can determine its relative position in the chain based on voltage readings. With this configuration, a master module can determine how many modules are in the chain, and each slave module can determine its relative position in the chain. The module information contributes to synchronization between the modules for use in current ripple cancellation, for example, in the multi-module DC-DC converter.
    Type: Grant
    Filed: October 21, 2005
    Date of Patent: August 21, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Stefan W. Wiktor, Xuening Li
  • Patent number: 7218223
    Abstract: The present technology involves a method and apparatus for detecting and reporting magnetic fields in the proximity of a utility meter as an approach to determining tampering of such meter. The sensitivity level of the magnetic field sensors may be adjustable allowing either remote or local sensitivity adjustments to a magnetic field sensor to compensate for variations in the electromagnetic environments of different meter installation sites. Alternatively, the output of each magnetic field sensor may be connected to the input of an adjustable threshold circuit. When the output voltage of the magnetic field exceeds a predetermined threshold voltage, a magnetic event signal is generated. Threshold adjustments to the adjustable threshold circuit may be performed locally at the meter site or remotely from a station. The output of each magnetic field sensor may be monitored by a locally or remotely programmable magnetic sensor output monitor.
    Type: Grant
    Filed: January 18, 2005
    Date of Patent: May 15, 2007
    Assignee: Itron, Inc.
    Inventors: Brian Keith Seal, Brent Martin
  • Patent number: 7091872
    Abstract: A transmitter for a line locator system that controls the electrical current, voltage or power applied to the target line is disclosed. Control of the electrical output of the transmitter can be achieved passively or by means of a feedback control system. A transmitter connected directly to a line can include an operator control and monitoring of current being supplied to a line to be located. Some transmitters include a current regulating circuit that controls current supplied to a line. In some transmitters, feedback controllers and feedback loops are used to regulate output current, voltage or power. Some control loops are based on monitoring currents in circuits; some control loops monitor power output from an inductive mode transmitter antenna. An inductively coupled transmitter with power output control is also disclosed.
    Type: Grant
    Filed: July 1, 2002
    Date of Patent: August 15, 2006
    Assignee: Metrotech Corporation
    Inventors: Russell N. Bigelow, Stevan Polak, James Long, Joseph Shtargot
  • Patent number: 6727815
    Abstract: A fire alarm system may comprise a control center, a wired communication pathway connected to the control center, and a relay station having a receiver and a signal evaluation circuit connected to the communication pathway. First decentralized alarm boxes may be wired to the communication pathway, and second decentralized alarm boxes may communicate with the receiver of the relay station via a wireless channel, wherein the first and second alarm boxes, in case of fire, produce an alarm signal which is transmitted to the control center via the communication pathway. A set of separate coupling modules may be disposed in the relay station and may be disconnectably connected to the signal evaluation circuit and the communication pathway via appropriate connecting elements, the coupling modules being designed for different communication modes.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: April 27, 2004
    Assignee: Job Lizenz GmbH Co., KG
    Inventor: Gerhard Röpke
  • Patent number: 6714832
    Abstract: A method of operating a vacuum processing system including a plurality of processing units for processing wafers, a transferring unit for carrying the wafers and a control unit for controlling the processing units and the transferring unit. At least two of the plurality of processing units are connected to the transferring unit and wafers are processed using the processing units. The method includes the steps of judging whether each of the processing units is operable or inoperable, isolating inoperable ones of the processing units judged in the judging step from wafer processing, carrying wafers to operable ones of the processing units using the transferring unit and processing the wafers using only the operable processing units.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: March 30, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Kouji Nishihata, Kazuhiro Joo, Shoji Ikuhara, Tetsuya Tahara, Shoji Okiguchi
  • Patent number: 6518879
    Abstract: A fire alarm apparatus, for checking line disconnection or occurrence of a fire, regardless of the installation place of a terminal endpoint resistor installed for checking disconnection of a line of fire detectors. When a signal representing a present voltage state of the detectors is input through the line, a control section compares the voltage level of the signal with a reference voltage level, and generates either a line disconnection control signal or a fire control signal. A first alarm section provides indication of disconnection of the line in response to the line disconnection control signal and a second alarm section provides indication of the occurrence of fire in response to the fire control signal. The apparatus can thus monitor a state of the detecting line, the common line and the fire detectors, regardless of the installation place of the terminal endpoint resistor.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: February 11, 2003
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Min-Sik Koo, Kang-Ok Kim
  • Patent number: 6384723
    Abstract: A communication protocol facilitates transmission at maximum rates for various types of cables. Signal to noise characteristics are improved by using voltage waveforms. The protocol can be used to transmit information between a common control unit and a plurality of spaced apart devices coupled thereto. Alternately, the protocol can be used for transmission of information between devices. The common control unit transmits clock pulses, while in a low impedance state. The devices respond to the clock pulses and transmit data on the communications link, in a low impedance state, when the common control unit has assumed a high impedance state. Clock signals and data signals are separated to improve signal to noise characteristics by transmitting same with opposite polarities. A clock detection circuit responds to the polarity of the clock pulses. A data detection circuit responds to the polarity of the data pulses.
    Type: Grant
    Filed: November 2, 1998
    Date of Patent: May 7, 2002
    Assignee: Pittway Corporation
    Inventors: Manley S. Keeler, Lee D. Tice, Robert J. Clow
  • Patent number: 6307469
    Abstract: The present invention provides a remote detection device including a conventional measurement device, such as a thermostat, having an internal contact which is wired in series with a resistor and two wires of a standard telephone line. When the measurement device reaches or surpasses a predetermined set value, such as a predetermined temperature, the measurement device will close the internal contact such that the resistor will short the telephone line. Accordingly, when the ambient condition has reached or surpassed the predetermined set value, the owner or manager of a building will receive a busy signal when dialing a telephone line connected to the remote detection device. In another embodiment the remote detection device may comprise a computer program component which periodically monitors the status of a communication line connected to the measurement device at the remote location.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: October 23, 2001
    Inventor: Karl F. Mandry
  • Patent number: 6281789
    Abstract: An alarm system which includes multiple notification appliances for signaling an alarm condition. The system controller intelligently controls the notification appliances including notification devices such as an audible or visual alarm through multi-bit digital messages sent over common communication lines. The alarm system has both a supervisory or standby mode and an active mode of operation. In the standby mode, the notification appliances are powered at a first polarity DC voltage. In an active mode of operation, the first polarity voltage is reversed (or forward biased) to energize all the notification appliances on the communication lines. The system controller controls operation of the visual alarms by issuing synchronization signals, wherein the line voltage drops to zero, which trigger the visual alarms. An audible alarm command signal is embedded within the synchronization signal to control operation of the audible alarm.
    Type: Grant
    Filed: May 14, 1999
    Date of Patent: August 28, 2001
    Assignee: Simplex Time Recorder Company
    Inventors: Michael A. Furtado, Mark P. Barrieau, Anthony J. Capowski
  • Patent number: 5670937
    Abstract: A line monitor uses two wire data transmission in a fire alarm and detection system. A line voltage monitoring mechanism is within each wiring/contact monitoring circuit such that the exact value at any time of varying source voltage is known. The monitoring current resultant from the monitoring arrangement is strictly a function of impedance and not a function of source voltage because a line-monitoring scaling factor is incorporated into the final calculation. The monitoring scheme also results in the alarm and trouble voltage thresholds being suitably altered to take account of changed line voltage conditions.
    Type: Grant
    Filed: May 16, 1995
    Date of Patent: September 23, 1997
    Assignee: General Signal Corporation
    Inventors: Robert W. Right, Hilario S. Costa
  • Patent number: 5489888
    Abstract: A sensor system is disclosed for the contactless measuring of the distance between a sensor body and an object. The sensor body contains an identification resistor, the resistance value of which can be interrogated by a control unit which is connected to the sensor body and which is located outside the sensor body. The interrogation makes it possible to determine whether the electrical connection between the control unit and the sensor body exists or is interrupted. If it is interrupted, this can be detected by the control unit in an unambiguous manner due to the missing connection to the identification resistor, and the control unit can generate an alarm signal in order to avoid faulty positioning of the sensor body relative to the object.
    Type: Grant
    Filed: August 10, 1994
    Date of Patent: February 6, 1996
    Assignee: precitec GmbH
    Inventors: Manfred Jagiella, Kilian Barth
  • Patent number: 5382909
    Abstract: Detection of liquid leaks and other changes in variables is disclosed. The event causes two elongate conductors to become electrically connected at a location which is determined by the event, thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. The system comprises a balancing component so that its sensitivity is not dependent on the location of the event along an elongate path. A fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration. Alternatively the locating member comprises a plurality of discrete resistors.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: January 17, 1995
    Assignee: Raychem Corporation
    Inventors: Michael Masia, James P. Reed, Robert S. Wasley, Larry R. Reeder, Peter L. Brooks, Thomas W. Tolles, Louis M. Frank, Mauro Bonomi, Ray F. Stewart, John Lahlough, Laurence Welsh
  • Patent number: 5015958
    Abstract: Detection of events, e.g. liquid leaks and other changes in varibles. The event causes two conductors to become electrically connected, and thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. Preferably a fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, preferably coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration, or part of a cable in which the conductors are separated by a member shaped to prevent capillary action of a liquid from connecting the conductors. Alternatively the locating member comprises a plurality of discrete resistors.
    Type: Grant
    Filed: June 27, 1989
    Date of Patent: May 14, 1991
    Assignee: Raychem Corporation
    Inventors: Michael Masia, James P. Reed, Robert S. Wasley, Paul D. Hauptly, Larry R. Reeder, Peter L. Brooks, Thomas W. Tolles, Louis M. Frank, Mauro Bonomi, Denis Wales, Ray F. Stewart, John Lahlouh, Laurence Welsh
  • Patent number: 4999607
    Abstract: An expansive and expandable monitoring system which in one of its broadest embodiments includes a multi-sector, multi-condition monitoring system including radio linked alert monitors, smoke monitors and an expandable range of activity monitors such as door-opening monitors and toilet-flushing monitors and including method and apparatus for identifying a particular monitor within a sector; wherein each sector stands itself as a unique sub-system built about a two-wire bus on which both power identifying signals are simultaneously conveyed along the same two wires; and within each sector, the plurality of monitoring devices receive operating power from a common power source and convey identifying signals to a common discriminator (identifier) arrangement all along the common two-wire bus, each monitoring device being constructed with a unique arrangement of current modulating and signal/voltage isolation elements to facilitate the common bus--common power source--common discriminator scheme of the present inve
    Type: Grant
    Filed: March 13, 1989
    Date of Patent: March 12, 1991
    Assignee: Biotronics Enterprises, Inc.
    Inventor: Wayne W. Evans
  • Patent number: 4881060
    Abstract: An improved alarm system and method for use in a fire detection system of the type including at least one sensor for sensing the level of a parameter of a fire condition such as heat or smoke density and which transmits electrical signals indicative of the sensed levels over a communication link. The alarm system and method provides for indicating a first alarm condition by receiving electrical signals from the sensor, keeping time from the time that the parameter reaches a first level, and indicating the first alarm condition when the parameter reaches a second level within a first predetermined time period. The second level has a magnitude greater than the first level. The alarm system and method also indicates a first alarm condition corresponding to a third level of the parameter prior to the third parameter level being reached.
    Type: Grant
    Filed: November 16, 1988
    Date of Patent: November 14, 1989
    Assignee: Honeywell Inc.
    Inventors: Joseph M. Keen, David S. Schiller
  • Patent number: 4777378
    Abstract: A manually operable electrical toggle switch (60) is connected in a low current signalling link (40) via a non-intelligent slave unit (20) in a time slot assignment multiplex system for automotive vehicles to an intelligent master unit (10) which in response to a binary input from the switch (60) provides an output signal on such a signalling link (40) to control high current to a load (70) connected to a slave unit (20). The switch (60) has conductive plastics contacts (63) to avoid oxide corrosion problems and may be all plastics. The binary input from the switch (60) is provided by one of two resistances (R2or R3) which are distinguishable in the master unit (10) from each other and from both a short circuit and an open circuit in the signal line (42) of the link (40).
    Type: Grant
    Filed: May 27, 1987
    Date of Patent: October 11, 1988
    Assignee: Salplex Limited
    Inventor: Kevin T. Talbot
  • Patent number: 4777473
    Abstract: An alarm system incorporating a dynamic range testing feature whereby the system polls and tests, on a regular basis, the resistance of the circuits of alarm condition resistor elements in the alarm system, primarily to detect when the circuit of a resistor element has degraded to a pre-trouble resistance range, such that the circuit of the resistor element can be serviced and repaired prior to its degrading to a point which will trigger the alarm system. The alarm system includes a central control system, and a plurality of modules at potential alarm locations coupled by a pair of connecting lines to the central control system. Each module includes two alarm condition resistor elements associated therewith for detecting an alarm condition, which is indicated by an increase in the electrical resistance thereof, as by the opening of a switch or the breakage of a resistor element, and each module further includes a reference resistor which is provided for a reference measurement.
    Type: Grant
    Filed: August 22, 1986
    Date of Patent: October 11, 1988
    Assignee: Fire Burglary Instruments, Inc.
    Inventors: Lance Weston, Harry D. Schweiger
  • Patent number: 4751498
    Abstract: A single-wire loop alarm system in which an identification module is placed across each alarm switch. Any module which is across an open switch is powered by the loop current and, in response to a pulse count in the loop representing its address, changes the loop impedance in order to report on its status. The loop current may alternate in direction so that oppositely poled modules may be used, thus allowing a larger number of powered modules to accommodated at the same time.
    Type: Grant
    Filed: March 11, 1986
    Date of Patent: June 14, 1988
    Assignee: Tracer Electronics, Inc.
    Inventors: Ram Shalvi, Rudor M. Teich, Keith Guillaume
  • Patent number: 4711368
    Abstract: A tamper proof package for determining whether or not a package has been opened or tampered with before opening the package is provided. The package has an electrical conductor of known resistance which is so positioned that any attempt to open the package or to tamper with the contents destroys all or part of the conductor. The resistance of the conductor can be measured at the time of sale or during the shelf life of the package to determine whether or not the package has been opened or tampered with.
    Type: Grant
    Filed: July 9, 1986
    Date of Patent: December 8, 1987
    Inventor: Leon Simons
  • Patent number: 4586028
    Abstract: Alarm system providing a signal by turning on alarms, lights, sirens, automobile horns or wake-up signal based on interruption of a monitor loop. Monitor loop includes a resistor which connects to the inputs of a low-power low-offset voltage dual comparator for providing an ON signal for turning on a buzzer alarm and also for driving a relay through a switching transistor. The relay can include normally closed and normally open contacts for operating an existing closed loop or open loop device or circuits. The alarm system also includes a line-adjust circuit for adjusting the particular resistance and the monitor loop, a latch circuit for latching the buzzer and relay in an ON position based on circuit interruption, and includes internal power source as well as provision for external power.
    Type: Grant
    Filed: July 11, 1983
    Date of Patent: April 29, 1986
    Inventor: George T. McKinzie
  • Patent number: 4514720
    Abstract: A method and apparatus for increasing the response sensitivity and the interference resistance in an alarm system such as a fire alarm system which cyclically samples a plurality of alarm units in the system for obtaining a series of measured values from each alarm unit, the measured values being utilized to form a quiescent value which is stored in a quiescent value memory. With each sampling cycle a current comparison value is formed from the alarm measured value, the stored quiescent value, and a comparison value from a previous sampling cycle stored in a comparison value memory. The current comparison value is then written in the comparison value memory as the new comparison value. The current comparison value is compared with a rated limiting value, and if the comparison value is greater than or equal to the rated limiting value, a display unit is activated indicating an alarm.
    Type: Grant
    Filed: May 5, 1982
    Date of Patent: April 30, 1985
    Assignee: Siemens Aktiengesellschaft
    Inventors: Karla Oberstein, Peer Thilo
  • Patent number: 4491828
    Abstract: A multi-zone alarm system operative with a two-wire alarm loop and having a simple network at each alarm sensor for providing a coded signal indicative of sensor identity and relatively simple circuitry at a central location for interrogation of the remote sensors and determination of those sensors providing an alarm signal.
    Type: Grant
    Filed: September 2, 1982
    Date of Patent: January 1, 1985
    Assignee: American District Telegraph Company
    Inventors: Aaron A. Galvin, Roy L. Harvey
  • Patent number: 4467273
    Abstract: Disclosed is a system for identifying which one of a plurality of interchangeable transducer heads is connected with an ultrasonic scanner. The system includes a unique impedance mounted on each transducer head and an impedance determining circuit in the scanner for determining the impedance of the interconnected transducer head. The impedance determination circuit is connected to a character generator for producing an alpha-numeric representation of the transducer head designation along the margin of a cathode ray tube on which an ultrasonic image is displayed. Also disclosed is an improved resolver mounting in which a cylindrical axle is used as a pivot pin between two scan arms of the ultrasonic scanner. A potentiometer for resolving the angle between pivotally connected arms is mounted on one arm with its shaft resiliently connected with the axle for rotation with the axle and other scan arm.
    Type: Grant
    Filed: September 29, 1980
    Date of Patent: August 21, 1984
    Assignee: Technicare Corporation
    Inventors: Dale C. Rudolph, Michael D. Ray
  • Patent number: 4441100
    Abstract: A security installation has four, for example, normally-closed sensor switches which open in the presence of an intruder. Each switch is in series with a respective resistor and these series combinations are connected in parallel across a pair of bus lines which connect to a central monitoring point. There, normally open test switches are connected across the bus lines in series with respective resistors which have values corresponding to the resistors of the sensor switches. Constant current is applied to the bus lines, and a voltage monitor senses the rise in voltage when one of the sensors opens, and this initiates a scanning unit which closes the test switches in sequence. When the test switch corresponding to the opened sensor is closed, the line voltage reverts to the predetermined value, and the closed test switch identifies the operated sensor.
    Type: Grant
    Filed: January 6, 1982
    Date of Patent: April 3, 1984
    Assignee: Racal Security Limited
    Inventor: John L. Galloway
  • Patent number: 4435700
    Abstract: The detection of events such as illegal entry detection, or the occurrence of predetermined hazards are detectable by a system including a circuit loop 2 which incorporates event actuatable switches 1, 35, 37, 38. Each switch has associated therewith means (9, 36, 37a, 39) for both maintaining electrical continuity in the loop, following operation of the associated switch and for producing an electrical condition in the loop which is indicative of switch operation. A control circuit 7 is arranged to respond according to the condition produced and produce an alarm characteristic of the condition.
    Type: Grant
    Filed: September 7, 1982
    Date of Patent: March 6, 1984
    Inventor: Patrick H. Alley
  • Patent number: 4423410
    Abstract: A multi-zone alarm system operative with a two-wire alarm loop and having a simple network at each alarm sensor for providing a coded signal indicative of sensor identity and relatively simple circuitry at a central location for interrogation of the remote sensors and determination of those sensors providing an alarm signal.
    Type: Grant
    Filed: September 2, 1982
    Date of Patent: December 27, 1983
    Assignee: American District Telegraph Company
    Inventors: Aaron A. Galvin, Roy L. Harvey
  • Patent number: 4385287
    Abstract: A security system has a locality station sensing security risks such as fires, electrical faults and break-ins, being powered by a single line from a central station. The loading on the power supply is determined by logic circuits to give direct remote indications of the security state at the locality station. The power supply is a square wave which is altered in waveform to give alternative commands to the locality station, e.g. to sound a warning or to operate a fire sprinkler, while continuing to supply power. To enable maximum use of the single line and single square wave, the latter is treated as two separate signals in that loading by the locality station is selective as regards the polarities. Similarly the alternative commands available are doubled by using separate control of the durations of the positive and negative square wave portions, while continuing to supply power.
    Type: Grant
    Filed: December 2, 1980
    Date of Patent: May 24, 1983
    Assignee: Securicor Granley Systems Limited
    Inventor: Edgar G. Eatwell
  • Patent number: 4361833
    Abstract: A multi-sensor alarm system and method of protecting a premises include at least one sensor circuit and an alarm circuit which together establish a two-wire closed loop electrical circuit path in which a wide variety of alarm sensors are accommodated. The sensors include two-contact configurations which are normally-closed or normally-open, as well as multiple-contact configurations which are characterized by both normally-closed and normally-open contacts. Each sensor differently changes the electrical parameters of the circuit path; and the alarm circuit includes a transistor which senses each parameter change, and a timer which generates an alarm signal whenever any of the sensors is actuated. Opening or closing the circuit path at any point therein will cause the alarm signal to be generated. A status indicator constantly monitors and supervises the status of the sensors in the circuit path.
    Type: Grant
    Filed: March 25, 1980
    Date of Patent: November 30, 1982
    Assignee: Monitran International, Inc.
    Inventor: Richard P. Allgood
  • Patent number: 4359721
    Abstract: A multi-zone alarm system operative with a two-wire alarm loop and having a simple network at each alarm sensor for providing a coded signal indicative of sensor identity and relatively simple circuitry at a central location for interrogation of the remote sensors and determination of those sensors providing an alarm signal.
    Type: Grant
    Filed: October 16, 1978
    Date of Patent: November 16, 1982
    Assignee: American District Telegraph Company
    Inventors: Aaron A. Galvin, Roy L. Harvey
  • Patent number: 4339746
    Abstract: An alarm control center having means for interchangeably assigning alarm parameters for each sensor loop in an array of sensor loops and for interchangeably assigning alarm outputs for each of the sensor loops. When the alarm control center senses an alarm condition on one of the sensor loops, the alarm control center increases the scanning rate for that particular sensor loop to verify the alarm condition.
    Type: Grant
    Filed: November 14, 1980
    Date of Patent: July 13, 1982
    Assignee: U.S. Philips Corporation
    Inventors: Edward M. Ulicki, Gabor Schlisser
  • Patent number: 4310835
    Abstract: Security equipment comprises a plurality of normally-open or normally-closed switch contacts connected in a loop circuit to a central control circuit. Each pair of switch contacts has a respective resistor connected in parallel therewith and the control circuit is operable to detect changes in resistance due, for example, to an intruder operating one of the switches.
    Type: Grant
    Filed: February 11, 1980
    Date of Patent: January 12, 1982
    Assignee: Donald Arthur Arnold
    Inventor: Philip C. Sefton
  • Patent number: 4274086
    Abstract: In an alarm system, differently colored leads of the connection cable between the individual distributors are respectively assigned to different current paths according to a random sequence. By providing this association, targeted manipulations at the connection lines of the signal lines are prevented.
    Type: Grant
    Filed: July 2, 1979
    Date of Patent: June 16, 1981
    Assignee: Siemens Aktiengesellschaft
    Inventors: Wolfgang Benckendorff, Hans Kubler
  • Patent number: 4118700
    Abstract: Each of a plurality of switches is connected in parallel with an impedance and the switches are coupled to form a series circuit. A reference voltage is coupled to one end of the series circuit and a termination impedance is coupled to the other end to form a voltage divider. The voltage divider ratio is determined by the switches that are operated and the divided voltage is coupled to an analog-to-digital converter producing a binary output signal that indicates which combination of switches is operated. Another embodiment of the invention uses a constant current generator instead of a termination impedance to provide linear ratios in the voltage divider.
    Type: Grant
    Filed: May 31, 1977
    Date of Patent: October 3, 1978
    Assignee: RCA Corporation
    Inventor: Thomas Francis Lenihan