Abstract: An optical coupling apparatus is disclosed, including: a monochromatic light source configured to emit monochromatic light; a monochromatic light photodetector configured to receive the monochromatic light; and a monochromatic light transmission medium, wherein at least a portion of the monochromatic light transmission medium is disposed between the monochromatic light source and the monochromatic light photodetector, and the monochromatic light is transmitted to the monochromatic light photodetector via the monochromatic light transmission medium, wherein a wavelength of the monochromatic light is shorter than a wavelength of infrared light. Embodiments of the present disclosure provide an optical coupling apparatus with a higher upper limit of operating frequency, which may better meet user requirements.

Abstract: A power supply unit for a fire detector, especially a smoke alarm, includes a power unit and battery terminals for connecting a predeterminable battery. The power unit has first connection means for connection to a power supply network and second connection means for connecting the fire detector. In order to increase the functionality of a fire alarm, the battery terminals are operatively connected by at least one first electric connection with the second connection means. The first electric connection includes hereby at least one diode.

Abstract: A system for testing an electronic device comprises a first output, a second output, and a third output connected to a positive input, an identification input, and a negative input of the electronic device, respectively. The system further comprises a switch comprising at least two dynamic contacts, each of which is connected to a resistor for the use of identification.

Abstract: The invention relates to a signal display device for displaying signals on signal paths of a wiring harness, for example, which may be connected to the signal outputs of an electronic apparatus generating/receiving signals, or looped into the signal paths between a signal-generating electronic apparatus and a signal-receiving electronic apparatus. A signal to be displayed each time is measurable from a plurality, preferably all, of the signal paths, and each measured signal is fed to an evaluation unit that, for each measured signal, activates a multicolor display element based on a value of the signal, such that one of several colors may be displayed using the multicolor display element.

Abstract: A method of and a system for detecting a person occupying a vehicle seat or a corresponding underlay whereby the underlay is provided with a single dynamic sensor and whereby the measurement signal is compared with a reference signal in comparing means, wherein the system comprises first measuring means for measuring a first measurement signal in a first frequency band representing a signal for human presence, and second measuring means for measuring the reference signal as a second measurement signal in a second frequency band representing a signal for background noise, comparing means for indicating an occupancy, wherein the signal strength in the first measurement signal in the first frequency band of human presence signal domination is compared to the signal strength in the reference signal in the second frequency band where essentially only background noise exists.

Abstract: A self-powered current loop transmitter transmits a process variable over a wireless link, deriving operating power from the current which drives the loop. A storage capacitor is connected across the system input terminals through a switch to provide the operating power for the system components.

Abstract: A self-contained backup power source such as a battery is provided for components within an electrically powered device such as a storage controller, photocopier or the like, to maintain diagnostic status data and to power a service indicator aid, or diagnostic indicator, such as an LED. A switch selects the backup power source when a primary power source of the electrically powered device is no longer available to the component, such as when the component is removed from the electrically powered device, the primary power source is disconnected as a safety precaution when servicing or replacing the component, or a higher-level assembly, in which the component is provided, is removed from the electrically powered device. The diagnostic indicator may be powered separately from the data storage device.

Abstract: A self-contained backup power source such as a battery is provided for components within an electrically powered device such as a storage controller, photocopier or the like, to maintain diagnostic status data and to power a service indicator aid, or diagnostic indicator, such as an LED. A switch selects the backup power source when a primary power source of the electrically powered device is no longer available to the component, such as when the component is removed from the electrically powered device, the primary power source is disconnected as a safety precaution when servicing or replacing the component, or a higher-level assembly, in which the component is provided, is removed from the electrically powered device. The diagnostic indicator may be powered separately from the data storage device.

Abstract: The present invention is an apparatus for indicating valid data in a removable memory media. In an embodiment of the invention, an alert may be employed with the removable media, such as NVRAM, to indicate that the battery backup is functional and that the memory content may be valid. One type of alert may be a blinking light source, such as a blinking light emitting diode (LED). In a another aspect of the present invention, contents of an appliance, such as a computer or storage controller, may be arranged so that an alert employed on the removable memory media in accordance with the present invention may be visible to an administrator without opening the chassis of the appliance.

Abstract: Methods and devices are provided for the detection of bacterial agents such agents as Bacillus anthracis and Clostridium botulinum with high sensitivity and selectivity. More specifically, methods and devices are based on a phosphorescence-emission detection system using chelate-stabilized lanthanides (e.g, Eu(III), Tb(III), and Sm(III)) to detect various spore-specific small organic molecules (e.g., dipicolinic acid, diaminopimelic acid, n-acetlymuramic acid, and the like). By careful selection of the chelating agent or ligand coordinated to the lanthanide, both high specificity and selectivity can be obtained. Examples of suitable and preferred sensor systems include N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) and N-(2-hydroxyethyl)iminodiacetic acid (HEIDA) combined with europium (III) and/or terbium (III). The chelate-stabilized lanthanides react with the spore-specific “target” molecules to form a characteristically phosphorescent product which can then be detected.

Abstract: A detector for smoke, heat or the like, which has test function circuitry capable of initiating verification of the detector operation, including testing of a communication path between the detector and a central control unit. The test is actuated on receipt of a signal initiated at the detector, which indicates success by illuminating the detector's LED. An operator is able to initiate the test by means of a laser pointer.

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.

Abstract: A method and apparatus for testing a balanced diode mixer and local oscillator combination in a microwave receiver. The diodes comprising a balanced mixer are unbalanced in a selective, controlled manner to generate an offset signal. The unbalancing of the mixer is accomplished by heating one of a pair of mixer diodes. By measuring an offset voltage output of the balanced diode mixer after one of the diodes has been heated, it is possible to measure an artificially created diode mismatch offset voltage and thereby verify that the balanced mixer/oscillator combination is working properly. The heating step is performed by either forward biasing the mixer diode or by placing a resistive heating element adjacent to the diode.

Abstract: A doorbell circuit detects when one of a plurality of doorbell switches is depressed and provides an audible indication of the particular doorbell switch depressed. The doorbell circuit includes a detector circuit which will function properly with the diode, normally connected in parallel across one of the doorbell switches, connected with either polarity. A power supply is developed for the detector circuit from the doorbell transformer by way of the diode connected in parallel across one of the doorbell switches. The detector circuit includes one or more full-wave rectifiers, which provide a positive DC output signal irrespective of the polarity of the diode connected in parallel across the doorbell switch. Each of the doorbell switches is connected to an amplifier, which, in turn, is connected to a comparator.

Abstract: Intensity of optical emission from a combustion flame within a gas turbine combustor is monitored through an optical window in the combustor wall by a primary detector. Because the window is susceptible to becoming coated with deposits during combustor operation, compensation for presence of a coating is achieved by directing illumination from an optical signal source, such as a silicon carbide light-emitting diode, into the window for internal reflection at an optical interface defined by the combustion side surface. A compensation detector, such as a silicon carbide photodiode, detects intensity of the internally reflected illumination as an indicator of the window coating thickness. The compensation detector is located at a non-combustion side of the window, along with a reference detector that responds to intensity of optical signal source illumination reflected from the non-combustion side surface of the window.

Abstract: A communication system includes a control element, a bidirectional communications link, and one or more devices coupled to the link. The control element, via driver circuits, reversibly applies a predetermined potential to the link for the purpose of energizing the one or more devices as well as communicating therewith. The devices can respond at appropriate time intervals. During the responding time intervals, the control element can continue to supply power to the devices.

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.

Abstract: An alarm indicating system utilizing a plurality of remote sensors connected to a wired-OR address bus, the sensors having means for forming a binary address which is placed on the address bus as a series of high and low signal levels when the remote sensor is activated. The system includes a plurality of comparators, each having a binary address corresponding to a remote sensor. The comparators detect the activation of its corresponding remote sensor by monitoring the address bus for presence of the designated address and activating a central alarm indicating system. The system also includes a testing means which can present test addresses onto the address bus, thereby activating the sensors and testing the operation of the comparators. The system includes a means for disabling the testing means when a remote sensor is activated by an external alarm, and therefore the testing means does not interfere with the operation of the system.

Abstract: An autodyne microwave motion-detection system includes a supervisory circuit for monitoring the operating status of the microwave energy-producing component of the system. According to a preferred embodiment, the supervisory circuit of the invention comprises a relatively low-cost, "general purpose UHF" diode, i.e. a multipurpose diode commonly used in circuits designed to accommodate UHF frequencies of up to only about 3 Gigahertz. The supervisory diode is positioned within, or in close proximity to, the resonant cavity of the microwave energy-producing element, the latter being designed to produce microwave energy at a substantially higher frequency (e.g., 10.5 Gigahertz). Due to its close proximity to the microwave energy-producing element (e.g. a Gunn diode) and its presence within the energy field produced thereby, the supervisory diode develops a small, but readily detectable, voltage whenever such element is radiating microwave energy.

Abstract: A multi-input electrical monitor has a plurality of input terminals for connection to a plurality of condition responsive transducers whereby the input terminals receive electrically both high and low signals when the transducers respond to respective preselected conditions; a signal generator responds to the existance of such conditions when particular combinations of such electrically high and/or low signals are received by the input terminals.

Abstract: A multi-input electrical monitor has a plurality of input terminals for connection to a plurality of condition responsive transducers whereby some of the input terminals receive electrically high signals while other of the input terminals receive electrically low signals when the transducers respond to abnormal conditons; a signal generator responds to the existance of such abnormal conditions even though the input signals indicative thereof can be either electrically high or low.

Abstract: An alarm system suitable for use in a telecommunications network in which a central switching system is capable of selectively providing a signal of a predetermined polarity to a plurality of remotely located stations without being dependent upon or impeding the ability of the central switching system to process relatively high volume communications traffic. Each of the remote stations is connected to the telecommunications network by an electrical conduction path. The stations are substantially unresponsive to the predetermined polarity signal. In response to an alarm indication signal, the system effects a reversal in the polarity of the signal provided to a selected subset of the remote stations. Each station in the selected subset responds to the polarity reversal by indicating an alarm condition.

Abstract: A personnel monitoring system includes a transmitting or transponding unit that is worn or carried by the individual being monitored. This transmitting or transponder unit periodically, or upon request, transmits a uniquely encoded signal that identifies the person being monitored, as well as information about the condition or activities of the person being monitored. Such condition or activites are sensed by sensors, coupled to the transmitting unit, that monitor selected body functions or parameters, such as heart rate, amount of skin perspiration, muscle movement, and the like. The monitoring system also includes a field monitoring device, or FMD, that is positioned near the person being monitored (or at a location where the person being monitored should be found). The FMD receives, processes, and stores the periodic or requested signals transmitted from the transmitting unit as directed by a program stored in a factory-removable and replaceable memory pack.

Abstract: A communication line monitor for use in a security or fire detection system of the type including a central alarm station and a communication line. A remote transmitter is coupled to the communication line at the remote end thereof and is assigned one unalterable preassigned address out of 6,561 different addresses. The remote transmitter continuously transmits an eight bit trinary code over the communication line corresponding to its preassigned address. A monitor located at the central alarm station is coupled to the communication line and indicates an alarm condition when the signals received from the remote transmitter fail to correspond to the remote transmitter's preassigned address. The monitor includes a plurality of switches to condition the monitor for identifying the remote transmitter's address. The switches are resettable to any other one of the different addresses.

Abstract: A self-diagnostic circuit for use in alarm systems and the like, of the kind having a plurality of alarm detection switches connected in a loop, indicators associated with each of the switches for indicating locally the detection of an alarm condition and a central controller for reversing voltage polarity in the loop whenever an alarm condition is detected by one of the switches. The self-diagnostic circuit comprises: a first switch for detecing an alarm condition connected in an alarm loop; a second switch automatically activatable in response to operation of the first switch; an alarm indicator automatically operable in response to activation of the second switch; and, an automatically operable circuit for preventing deactivation of the second switch until after diagnosis of alarm system operation, even when the first switch no longer detects the alarm condition. Any such first switch exhibiting erratic switching behavior can be easily identified by continued operation of the associated alarm indicator.

Abstract: An individual source identification of several signal providers or pick-ups with closable contacts disposed in a twin-wire signal line, in particular for fire detectors in fire alarm systems. The signal pick-up system allows to distinguish actuation of individual sensors separately and apart from a short circuit formation. The fire alarm system also allows connection to automatic sprinkler devices. The fire sensor system is easy to install in that the individual settings of the individual detectors at a construction site are minimized.

Abstract: A fail-safe alarm system includes a device which allows current to flow in only one direction to insure that the supervisory current in an alarm circuit is flowing in the intended direction rather than in a wrong direction caused by a miswiring.

Abstract: A detector system having multiple sensors, each sensor detecting a different danger condition, has an address comparator for determining whether an access address coincident with a selected address is present in an access signal received from a central monitoring unit. The detector exchanges an information signal with the central monitoring unit using the coincidence detection signal of the address comparator. Success coincidence detection signals, corresponding to successively selected addresses being present in the access signal, are counted by a counter. If the detector has two sensors, the counter may be a D flip-flop circuit, and if the detector has more than two sensors, the counter may be a ring counter. The counter generates a signal for operating respective analog switches connected to the outputs of each sensor so as to successively through-connect the output of one sensor to the output of the detector system for transmittal to the central monitoring unit.

Abstract: A device for generating an alarm signal in the event of an abnormality in the environment of a detector includes a pair of signal/power supply lines, a number of detectors for detecting an abnormality, e.g., fire, gas leakage, or burglary, and an alarm receiver including a signal processing circuit for receiving a signal from a detector indicating the presence of an abnormality. The signal process circuit includes a signal storage circuit, and a converting circuit for changing one or a combination of at least two of a polarity, voltage, current, or impedance of a power source if the abnormality persists for a predetermined time. The change in the power source parameter is supplied via the supply lines to a signal holding circuit in the vicinity of the detector. The signal holding circuit is responsive to the changed parameter and changes state, thus providing an indication at the detector that the abnormality has persisted for the predetermined time.

Abstract: A remote parameter monitoring system utilizes a series of half-wave rectifier diodes in combination with a unique overlapping wiring arrangement to provide for location-specific detection of a parameter condition existing at a plurality of spaced locations. In one embodiment of the invention, the system is used for monitoring cracks in helicopter rotor blades and indicating to the crew in the cockpit both the fact of a cracked blade and the specific blade which is cracked. In such embodiment, the system includes a three-phase alternating current transformer whose primary windings are supplied by the helicopter's three-phase alternating current generators and whose secondary windings make up part of the wiring loops between the cockpit and the rotor blades. By controlling currents flowing in opposite directions in the wiring loops, the system allows for blade-specific crack detection of up to six rotor blades by means of only three wires between the rotor blade assembly and the cockpit area.

Abstract: Each hydrophone receiver element is attached in electrical parallel with the series combination of a switching diode and a zener diode so that the physical orientation of the element is the same for each element network. The response element networks then are assembled into a cable section, the element networks constituting a group array. A test circuit applies a relatively high dc voltage input to the cable section. The switching diodes are not rendered conductive for the elements properly connected. Hence, the output is substantially the same as the input. However, if one or more of the elements are reverse connected, the switching diode for that response element is rendered conductive and the output drops to the level of the zener breakdown voltage. Hence, the whole array-connected group can be tested with a single test.

Abstract: A fault tolerant control system employing input sensing network and in association therewith a signal processing system which eliminates the effect of radiofrequency interference, electromagnetic interference, transients, and random false alarm signals. The sensing network comprises a linear circuit or a resistor disposed in parallel with one or more semiconductors which are preferably diodes or the like. The network senses current flow so as to provide a signal having a maximum voltage established by the semiconductors with the linear circuit or network providing a linear change in voltage with current until the voltage of the semiconductor is reached when the voltage then becomes non-linear.

Abstract: A diagnostic status indicating apparatus is used with an alarm system having a plurality of normally-closed switch contacts which are opened upon occurrence of an alarm condition. Light-emitting diodes are connected across the normally-closed switch contacts at an opposite polarity to that of the current normally passing through the contacts in the operating mode. In order to diagnose the alarm-generating condition of the electrical contacts, a switch removes the operating voltage and connects a test voltage at a reverse polarity, whereupon the LED for any open circuited electrical contact is activated. The device is preferably based upon a double-pole-double-throw switch and includes indicators for a test condition and for a ground fault.

Abstract: A remote sensing and indicating system for monitoring and displaying at a central operating location the state or position of a remotely located multiple state element. The multiple state element may be a subsea valve which may be either in an open state or a closed state. The system electronically scans valve position switches, stores data indicating the position and drives lamps to display valve position. Switches at the remotely located valve are selectively closed in response to the state of the valve. The switches are connected to the central location by only two leads.

Abstract: A monitoring system for a protection loop that has a plurality of switches in series utilizes modules with inexpensive diodes and resistors, and is conveniently and easily added to existing burglar alarm circuits and loops. A monitoring module that includes a diode and a paralleled resistor is connected across each switch. First and second interrogating signals are alternately applied to the protection loop. First comparator circuit means provides an output in response to each first interrogating signal when one of the monitored switches in the protection loop is open as indicated by the response of the module resistors; and second comparator circuit means provides an output in response to each second interrogating signal when more than one of the monitored switches in the protection loop is open as indicated by the response of the module diodes.

Abstract: An alarm detection, indication and supervision circuit with reduced power drain during failure of commerical power supply whereby standby batteries may maintain detection capability for an extended period. Separate detection and alarm indication loops are provided each with an end-of-line resistor which is removed from the circuit in response to a commercial power failure. A nearly unlimited number of detectors may be used on the detection circuit and each may have an auxiliary relay for control of local apparatus to permit local control, under changing ambient conditions. In response to an alarm signal, the potential on both loops is switched from a limited current supply to a hard supply and the polarity is reversed.

Abstract: A single zone system which may use a single cable pair for both detectors of nonstandard conditions and audio/visual alarms. The audio/visual alarms are polarity responsive and in response to an alarm detection, comprising an increase in line current, the polarity is reversed and the line current supervision circuit disconnected. Some detectors or signaling devices may be polarity sensitive so that they present a high impedance under normal and reverse polarity conditions, and a lower impedance on abnormal conditions and prior to polarity reversal. Other detectors may be polarity insensitive and include a relay which may be activated from line potential subsequent to detection of an abnormal condition. The relay may be used to operate door closers or to initiate other appropriate action.

Abstract: A selectively testable fire detector comprises a fire detecting circuit supplied with a first voltage and which detects smoke and/or temperature, a self-holding circuit which is actuated by the output signal of the fire detecting circuit, a counter which counts pulses superimposed on the first voltage and outputs a signal when the counted number reaches a predetermined number assigned thereto, a latch circuit which latches the output signal of the counter and transmits to the fire detecting circuit a signal which actuates the fire detecting circuit, and a reset signal generating circuit which resets the counter and latch circuits by a second voltage which is higher than the first voltage.

Abstract: A fail safe type of monitoring circuit for contacts is provided using an opto-isolator. The opto-isolator is energized in response to the operation of the contacts to clearly indicate whether the contacts are open or closed, and whether the circuit components are functioning in a valid manner.

Abstract: An annunciator system includes circuitry which, upon depressing of a momentary switch isolating the annunciator system from closed loop inputs of an electronic burglar alarm sensing unit, identifies the status of each access switch in a closed loop circuit containing the plurality of access switches. The annunciator system also indicates the integrity of electrical connections to the respective access switches and to an audible alarm unit.