Abstract: An A.C. powered smoke detector with supervision circuit for back-up battery. The circuit periodically and automatically, checks the power capacity of the back-up battery by momentarily disabling the D.C. power supply from applying D.C. voltage on a D.C. voltage bus while simultaneously applying a test load to the battery. If the test load voltage is too low, a low battery power capacity indication is provided. In one embodiment, the D.C. power supply is disabled by electrically disconnecting it from the battery. In another embodiment, a switch applies to effectively by pass the D.C. power supply and enable the application of the test load.

Abstract: A flow sensor for detecting the absence of a minimum fluid flow in a sprinkler system. The fluid acts upon a vane positioned in the fluid path. Movement of the vane controls the position of a slider. The slider's surface has reflective and nonreflective ends which, in response to the vane's movement reflect or absorb light from a light emission and detection means. The voltages from the light emission and detection means are monitored for indications of the fluid flow. The sensor uses a two wire signal transmitting system.

Abstract: A device and system for detecting the existance of fluid flow from a fluid source to a pipeline includes a cylinder with an inlet at a first end and a lateral outlet. A piston in the cylinder is moveable from a no-flow position abutting the first end in which it is maintained by a spring, to a flow position in which the piston at least partly opens the lateral outlet, by fluid flowing from the inlet to the lateral outlet. A magnetic switch detects the no-flow position of the piston, and actuates a radio transmitter to send a no-flow condition alarm. The device is used to detect interruptions in the supply of additives to oil and gas pipelines.

Abstract: A gas monitoring system for a kitchen environment in a house and the like which is supplied with gas from a pressurized gas container or from a public gas supply to sense a possibly occurring gas leak. The system comprises a valve controlling the flow of gas from the container to a cooking range. Leaked gas is detected by a sensor which activates a visual and an audible alarm circuit and which operates a valve to terminate gas flow. The electronic alarm circuit is an integrated circuit, so that it can be located in a small hermetically sealed container, together with the power supply. The alarms stay on even after the gas leaked has been removed, until the system is reset by a manual switch. A manual override is provided to allow gas flow in the event of power failure or system failure in areas where service may be delayed.

Abstract: A telecommunication system is provided consisting of a plurality of functional units each one producing a status signal. A maintenance processor is coupled to each of the functional units and receives the status signals. This processor produces signals representative of the status of the system. A remote alarm reporting unit is coupled to the processor and generates optically isolated alarm signals corresponding to the status representative signals generated by the processor.

Abstract: A siren having one or more stacked speakers, each speaker having a substantially circular lower horn member having an upwardly facing surface including a substantially convex annular portion and a substantially concave central cavity portion. A substantially circular upper horn member having a downwardly facing surface including a substantially convex annular outer portion and a central opening, is spaced above the lower horn member, thereby defining an annular, radially outwardly diverging sound director between the upper and lower horn members. A diffuser horn is coupled to a central opening in the upper horn member and projects downwardly into the cavity portion of the lower horn member. A siren driver is mounted in the upper horn member adjacent to the central opening for projecting a sound wave through the diffuser horn into the cavity, where the sound wave is reflected upwardly out of the cavity into the sound director, through which the sound is projected horizontally in a 360.degree. pattern.

Abstract: A monitoring system for an electronic instrument includes within itself a microprocessor and a watchdog circuit each provided with its own oscillator which generates a clock pulse and operating on the basis of this clock pulse. The watchdog circuit transmits a periodic interrupt pulse to the microprocessor which transmits a response pulse to the watchdog circuit in return. The watchdog circuit monitors the operation of the microprocessor by measuring the phase difference between the interrupt and response pulses and the microprocessor monitors the operation of the watchdog circuit by measuring the period of the interrupt pulse.

Abstract: A pressure gauge has a turning button, a turning disc and a sliding block disposed thereon that, through a protruding wheel fixed on the needle shaft moves the sliding block to force a contact point of a conducting metal piece to contact with a contact point of the turning disc, can start an alarm in case the needle of the gauge comes to reach the designated pressure.

Abstract: A walk-through metal detector comprising an array module supporting transmit and receive coil arrays. Surrounding the array module, yet not touching it, is an outer shell protecting the array module from contact. A passageway tube passes through the opening in the array module, and is supported by the outer shell, further isolating the array module from mechanical vibration. The array module has a relatively high resonant frequency; thus, vibration induced signals are higher in frequency than actual target signals and are disregarded by the detection circuitry. The metal detector also includes a bypass chute, mechanically isolated from the array module, in which metallic objects may be placed and transported to the exit of the passageway without setting any alarms. The array module supports a balanced transmit and receive coil array for insensitivity to external electromagnetic interference.

Abstract: A focused beam of light from a light source is directed into a closed smoke chamber, having inlets for admitting smoke particles, toward a reflector which reflects and refocuses the beam back into the light source, the direct beam and the reflected beam passing through a test zone within the chamber. In the event that smoke particles enter the test zone, the direct and reflected beams strike and bounce off of those particles to produce scattered radiation that will be picked up and detected by a light responsive sensor to generate an alarm signal. By closely controlling, rather than baffling the light, optimum operation is obtained, efficiency is enhanced and false alarms are minimized.

Abstract: Instrumentation and monitoring systems utilize, as differential temperature sensors, heated, split-well thermowells of duplex design, mounted to the sidewall of a pressure vessel and communicating through a penetration in the sidewall with the fluid state within the vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the presence of steam versus water. The systems monitor the differential temperature outputs of plural such sensors to produce alarm indications and perform verification and error checking of the sensor output indications.

Abstract: In an electric desired-value transmitter for automotive vehicles, particularly as electric gas pedal, having an actuating element and a potentiometer the wiper of which is coupled to the actuating element, a switch which is also coupled with the actuating element is connected to a comparison device to which the output voltage of the desired-value transmitter and at leasst one comparison voltage are fed. When the actuating element is in that position in which the switch is actuated, the comparison device is preferably fed two comparison voltages, one of which lines somewhat below the value of the output voltage which is given off by the desired-value transmitter upon proper operation and the other of which lies somewhat above said value.

Abstract: An alert device is provided which initiates an alarm if a person wearing the device ceases normal movement. The device includes a movement sensor having at least one mercury switch which generates a signal when the mercury shifts in response to movement. The device also includes a microcomputer to receive the mercury switch input signals--the microcomputer being programmed to distinguish between inputs indicative of normal wearer movement and inputs which may represent a wearer in duress. Preferably, the motion sensor provides three mercury switches oriented to sense movement in three normal planes.

Abstract: A lighting device for illuminating operation switches installed on a steering wheel inlcudes a light-emitting diode and an instrument light. The light-emitting diode is turned on by means of a constant-voltage generator which is connected to a power source via a light switch to apply voltage that is less than a predetermined value to said light-emitting diode via a slip ring in response to turning ON of the light switch. The instrument light is connected to the power source via the light switch and is turned on in response to turning ON of the light switch.

Abstract: A scattered-light smoke detector having an improved shield structure. A detector circuit is provided on a printed circuit board which is disposed at an upper portion of a smoke detecting section. The smoke detecting section includes a planar base and a surrounding wall extending downwardly from a lower surface of the base and having an opening or openings which allows or allow smoke to enter therethrough. The surrounding wall defines a smoke detecting space therein. A light emitting element and a photodetector element which are disposed at positions where they are not opposite each other and optical axes thereof intersect each other at a predetermined angle and said photodetector element can receive light from the light emitting element scattered by smoke entering the smoke detecting space. The printed circuit board is attached on an upper surface of the base. A shield layer is interposed between said printed circuit board and said base.

Abstract: A tin oxide carbon monoxide sensor is operated in a manner to exclude effects of ambient temperature and humidity. Resistance of the sensor is measured at a lower temperature and again at a higher temperature. The target gas concentration is determined as a function of the first and second resistances, thereby cancelling the effects of humidity and ambient temperature.

Abstract: A single assembly of a water heating system for heating the water and air in a room, and an electrochemical reactor which activates a gas alarm for human safety upon detection of a predetermined dosage of gas, such as, for example, a fatal dose of a gas such as carbon monoxide, and which detoxifies the gas.

Abstract: The detection system for obstruction to vehicle according to the invention comprises a plurality of light emitting elements disposed in the rear of a car, a modulation for emitting modulation lights from the light emitting elements, light receiving elements for receiving the reflected light that the modulation light comes in contact with an external obstruction to reflection, a detection circuit for detecting output signals of the light receiving elements, thus detecting the obstruction from an output of the detection circuit, and a rearward obstruction can be detected securely particularly when the car moves backward, a new light source for obstruction detecting is not particularly required, and thus no area must be prepared for installation.

Abstract: The capacitive proximity sensor for motor vehicles comprises a capacitance-measuring device for measuring the capacitance between at least one capacitor plate (1) which is fixed to the motor vehicle, on the one hand, and the environment, on the other hand, and an indicator for receiving the output signal of the measuring device.To provide a proximity sensor in which the disturbing and parasitary capacitances occurring in practice are particularly taken into account, the output signal S.sub.c of the capacitance-measuring device (5) is delivered to an amplifier (6), which is provided with a degenerative feedback loop (9) comprising a storage device (11) and a switch (10) so that the output signal (s.sub.A) of the amplifier (6) is held constant during normal travel, and the switch (10) is opened to interrupt the degenerative feedback loop (9) for a measurement. The switch is closed when the measurement has been completed.

Abstract: A method of and apparatus for detecting free-ranging pests, for example mice, without providing an attractant material. The presence of a pest is sensed by at least one of a plurality of sensors, a signal is emitted indicating the sensing of a pest by that sensor, and the fact that a signal has been emitted is indicated by an indicating means that is operatively coupled to the sensors.