Abstract: A small self-contained voltage monitoring device, which can be connected to a power line, has a display driver in circuit with a plurality of lamps to light one lamp at a time, depending on the power line voltage. A first oscillator in circuit with the display driver is actuated to operate a sound generator and alarm if the power line voltage falls outside a preset range. A second oscillator is in circuit with the first oscillator if the power line voltage is interrupted even momentarily, both oscillators are actuated by an auxiliary power source to generate a different sounding alarm. The alarm will continue to sound even if the power line voltage is restored until the auxiliary power source is manually deactivated.

Abstract: A flow sensor to detect changes in the mass flow per unit time of pneumatically conveyed particles within a system. The flow sensor or detector includes a conduit segment formed of a hard material so that a wall of the segment will vibrate due to the impacting of the particles thereagainst as they flow through the conduit segment. There is associated with the segment a vibration excitable piezoelectric transducer which has a resonant frequency and which at the resonant frequency generates an electrical signal or high voltage as compared to that generated by the transducer at all other frequencies, above and below the resonant frequency. Any deviation in the high generated voltage is utilized to detect a change in the kinetic energy of the particles flowing through the conduit segment.

Abstract: A wiper control system controls an automotive wiper in accordance with rain conditions. Rain conditions are detected by means of a rain sensor which has a vibrator adapted to vibrate at an amplitude corresponding to rain conditions. The vibrator is adapted to produce a sensor signal having an amplitude corresponding to its vibration. The vibrator vibrates at a resonant frequency outside of the audible frequency range and has adequate sensitivity for detecting rain conditions.

Abstract: This tank leakage detection system senses at an early stage the failure of a liner membrane made of a non-corroding material such as lead which allows the escape of a corrosive liquid contained within the tank to the space between the liner membrane and the outer steel walls of the tank. The detection system is made up of a small reservoir located on the bottom of the main tank which is in fluid communication with the space in the main tank between the outer steel walls and the liner membrane. The small reservoir extends laterally beyond one side of the tank and has a tubular projection extending upwardly along the side of the main tank which contains a float which is in turn connected via a linkage to a switch which controls an alarm system.

Abstract: The atmospheric pressure actuated alarm of the present invention comprises a pressure transducer which senses the atmospheric pressure and produces an electrical transducer signal in response thereto. A difference amplifier is connected to the pressure transducer for measuring the transducer signal and for producing an output signal whenever the transducer signal is of a magnitude outside a predetermined range. An operational amplifier is connected to the difference amplifier for amplifying the transducer signal. A latch is connected to the operational amplifier for receiving the amplified signal. A signal alarm and a power source are connected in series with the latch. The latch is changeable from an open condition to a closed condition in response to the amplified signal being greater than a predetermined magnitude. When the latch moves to the closed condition, it connects the power source to the alarm signal and causes actuation of the alarm signal.

Abstract: A gate-turn-off thyristor failure detecting circuit includes a detector which detects an off-gate signal for a gate-turn-off thyristor and a current level detector which compares the signal with a predetermined value and produces an output signal indicative of the failure of the gate-turn-off thyristor.

Abstract: A personal liquid chemical agent detector incorporating a sensor which changes resistance in response to contact with liquid, first and second switches which function as pins for attaching the detector to the wearer and as electrical switches, a battery, a resistor, and a detector and alarm circuit. A conductor incorporating a resin, conductive flakes and dye crystals selected which are solvent in selected chemical agents. A conductive paint incorporating a resin, conductive flakes a dye solution including one or more volatile solvents and a plasticizer. The invention overcomes the problem of requiring additional switches for manual testing of the detector and battery prior to use and for disconnecting the battery after use at times the detector is removed by the wearer. The invention further overcomes the problem of independent verification of detection by providing a conductor with concurrent electrical and visual appearance responses to selected chemical agents absorbed by the conductor.

Abstract: A circuit for detecting and indicating an interruption in the electrical connection between a signal device and a signal processing device, which has been provided with an amplifier at its input. The signal device has a relatively low impedance and the signal processing device has a relatively high impedance. The circuit includes an alarm device which generates an alarm when the predetermined upper limit of the amplifier input voltage has been exceeded. Also included are a supply circuit to feed an auxiliary dc current into the connection between the signal device and the signal processing device. The supplied auxiliary current is controlled by the amplifier input voltage to rise during an increased amplifier input voltage. As a result, a lower current supply can be provided under normal circumstances, which reduces misinterpretations. Preferably, the circuit is used in connection with ECG measuring devices.

Abstract: The present invention relates to a water detection subassembly and method for forming same, for use in association with water detection system operating within a digital computing center. The subassembly includes a perforated protective semi-circular shield fitted about a fabric mesh supporting copper conductors connected to a low voltage source. The perforations of the shield are formed into two distinct patterns: The first series comprises sets of openings adjacent to the apex of the shield and periodically spaced therealong. Each opening has a common arcuate length L, a width W, and an internal spacing S and, more importantly, is of sufficient dimension to allow easy entry of aerosol mixtures of air and water droplets originating from above the shield.

Abstract: A device for detecting the presence of water in a fuel tank comprising a fitting mounted at the lower most portion of said tank having a water sensing alloy on said fitting. The fitting positions the water sensing alloy in the tank in the position where water will tend to collect. The fitting also includes an integrally mounted indicating device such as a go/no-go device or a meter to determine the presence of water in the tank. The length by which the fitting extends into the tank can be used to determine the depth of water in the tank and when the amount of water collected at the bottom or sump of the tank exeeds a predetermined depth it will be detected by the indicator connected externally to the water sensing alloy. A useful water sensing alloy is comprised of a composition of lead, tin, and zinc each being present in an amount of between about 20-45% by weight, with the composition also containing small amounts of up to about 0.

Abstract: A self test circuit for a combustion products detector automatically periodically tests whether the sensitivity of the sensor is in a predetermined range between minimum and maximum sensitivities. Transistor switches selectively connect different test impedances across the sensor for respectively simulating two amounts of combustion products, one of which is slightly less than the amount corresponding to the maximum sensitivity level and the other of which is slightly greater than the amount corresponding to the minimum sensitivity level. If the sensor either produces a smoke output signal in response to the first test or fails to produce an output signal in response to the second test, then the smoke alarm is actuated after the tests are completed to produce a unique fault signal, the alarm annunciator being inhibited during the test.

Abstract: The device for determining and/or monitoring a predetermined filling level in a container has two oscillatory rods secured with spacing adjacent one another on a diaphragm the edge of which is connected to a screw-in part. By means of the screw-in part the device is so secured in a screw-threaded aperture of the container wall at the height of the filling level to be detected that the oscillatory rods project into the container. At the side of the diaphragm remote from the oscillatory rods a bridging member is held spaced from the diaphragm by flexurally elastic rod-shaped supports. Each of the rod shaped supports is rigidly connected at one end to an oscillatory rod. Between the bridging member and the diaphragm there is held, with preloading of the diaphragm, a transducer column comprising in a stack a piezoelectric excitation transducer and a piezoelectric reception transducer.

Abstract: Safety device used in the detection of a conductive liquid in an enclosure to be monitored, in which the variation of the resistance as a result of the presence of the liquid between electrodes triggers an electrical alarm circuit, wherein it comprises in combination: a liquid detecting member constituted by two spaced electrodes and forming four contacts; a first field effect transistor, whose gate, source and drain terminals are connected to a power supply and to the four aforementioned contacts in such a way that the first field effect transistor is non-conducting when the conductive liquid is absent and where there is no deterioration to any one of the connections connecting the terminals of the first transistor to one or other of the said contacts; and a second field effect transistor, whose source and drain terminals are connected to a second power supply and whose gate terminals are connected to the drain terminal of the first field effect transistor in such a way that the second transistor is conducti

Abstract: A transient power alarm is often the result of a traffic overload placed on a communication system circuit carrier circuit. The disclosed power control arrangement recognizes such transient power alarms and outputs a special message to alert the system user to the possibility that traffic grading across carrier is unbalanced. The control arrangement also monitors the time that the system is powered solely by reserve battery and sheds its traffic load if the time that the system is operating solely on reserve battery exceeds a first threshold. Also, the system is programmed to automatically disable itself if the reserve battery time exceeds a second threshold.

Abstract: Apparatus for warning of a leak in a hydraulic system. The warning apparatus includes a liquid level sensor, mounted above the hydraulic fluid reservoir, and a signal assembly. The sensor includes an expansion chamber with a float chamber pipe inside. The float chamber pipe opens into the expansion chamber a substantial distance above the expansion chamber bottom. Hydraulic fluid, which expands when the equipment is started, flows through the open pipe end and into the expansion chamber. If the liquid level in the float chamber pipe drops below a set level, a float in the pipe also drops to activate the signal assembly. If the hydraulic system springs a leak, the alarm activates to minimize damage. Before re-starting the equipment the excess fluid held in the expansion chamber is allowed to drain back into the reservoir. Drainback is done either passively, through a constricting passageway at the expansion chamber bottom, or actively, typically by the operator after use.

Abstract: A supervisory device of a varying quantity measuring apparatus including a main scale and an index scale which are moved relative to each other in accordance with a physical varying quantity, a main power supply circuit which outputs a predetermined DC stabilized voltage by operating a power switch, and an encoder which is driven by the voltage output from the main power supply circuit and converts the relative movement of said both scales into electric signals to be displayed.

Abstract: A monitor and control system for water purification apparatus includes first and second conductivity cells located in the input water path and the purified product water path of the apparatus, respectively. The conductivity cells produce output signals exhibiting amplitudes representative of the impurity concentrations in the respective water paths. These signals are detected and modified by circuitry which imposes logarithmic characteristics upon the two signals. The two logarithmically variable signals are differentially combined to produce a signal for display which is representative of the percent of impurity rejection of the water purification apparatus. The detected signal are also individually combined with signals representative of the temperature of the water being processed. The temperature-corrected signals are then displayed to provide an indication of the impurity concentrations of the input and purified water paths in parts per million.

Abstract: An apparatus for sensing the difference between a polar fluid and a non-polar fluid includes a control assembly, a probe assembly and a conduit electrically coupling the probe assembly to the control assembly at a remote location thereto. The probe assembly includes a float, at least one fluid sensor mounted beneath the float, a fluid sensor circuit for providing a signal indicative of the polar characteristics of the fluid, and a logic circuit having a first state when the signal indicates a polar fluid and a second state when the signal indicates a non-polar fluid. The control assembly includes circuitry responsive to the state of the logic circuit for controlling alarms, visual indicators, and machine operations. The probe assembly may also include a detector for detecting the state of the fluid. If the fluid has a non-liquid state then the logic circuit has a third state which indicates the non-liquid state of the fluid.

Abstract: An oil level sensor assembly adapted for installation in an automobile engine crankcase at the level corresponding to "low oil". The sensor assembly utilizes the principle that air is expandable whereas oil is not. Accordingly, when it is desired to sense the oil level, a predetermined amount of fluid is trapped within a chamber sealed by a diaphragm. If the oil level is adequate, then the sensor will be below the oil level and the trapped fluid will be oil. However, if the oil level is low, the trapped fluid will be air. After the fluid is trapped, a spring operating on the diaphragm attempts to expand the chamber. If the admitted fluid is air, the chamber can be expanded and a switch contact will be made, to provide an indication of low oil level. On the other hand, if the chamber is filled with oil, the chamber will not expand and the switch contact will not be made.

Abstract: An optical smoke detector having a conical masking body located directly between a light source and a light receiver. The masking body is provided with a reflecting surface so that rays from the light source are diverted into a reaction zone to supplement direct rays from the light source to the zone. In one embodiment the reflecting surface is cuspidate while in another embodiment a second masking body is added which shadows the light receiver from viewing the base of the first masking body.