Abstract: A wye-type air-core gauge system provides magnitude indications of measurands in response to PWM signals generated by a control unit that receives electrical signals from a sensor that represents magnitude variations of the measurand. The size of the stator coils of the gauge makes possible a very low profile gauge suitable for mounting in an instrument cluster.

Abstract: The invention relates to a method and apparatus for testing the response of a stress wave sensor to confirm that the transducer and amplifier are functioning satisfactorily.A pulser is connected to the stress wave sensor at a point between the transducer and the amplifier. The pulser supplies a first and a second electrical pulse in series to the stress wave sensor. The first electrical pulse has a large amplitude such that it causes an operative transducer to oscillate and produce an additional electrical pulse. The first electrical pulse and the additional electrical pulse are supplied to the amplifier. An operative amplifier amplifies the first electrical pulse and any additional pulse to give an output signal, the output signal indicates if either the transducer or amplifier are not operating satisfactorily, the lack of an output signal indicates the amplifier is inoperative.

Abstract: A telltale for sensing and responding to ambient light levels. A photosensor monitors light levels and causes a bulb or other controlled element to be energized if ambient levels reach a threshold. In one embodiment a time delay is instituted between sensing the threshold light level and bulb energization. This prevents false triggering on transitory conditions. An additional embodiment has a threshold level that uses hysteresis to avoid unstable sensing near the threshold level. A preferred use for the telltale is in apprising a motor vehicle operator when to turn on the vehicle headlamps.

Abstract: An electronic measurement circuit for high speed comparison of the relative amplitudes of a predetermined number of electrical input signals independent of variations in the magnitude of the sum of the signals. The circuit includes a high speed electronic switch that is operably connected to receive on its respective input terminals one of said electrical input signals and to have its common terminal serve as an input for a variable-gain amplifier-detector circuit that is operably connected to feed its output to a common terminal of a second high speed electronic switch.

Abstract: The device comprises: a high frequency alternating voltage generator the output of which is connected to a sensor probe 5 which is to be applied to a substrate to be measured, an amplifier the input of which is connected to the sensor probe, and a detector arranged to furnish a D.C. voltage signal based on the output from amplifier. The generator, the amplifier and the detector are located inside a metal envelope enclosure. An electromagnetic radiation shield is disposed inside the envelope to separate the amplifier and the detector from the high frequency generator. In operation, voltage output from the detector is indicative of the electrical impedance of the substrate as sensed at the probe. In the preferred application, the substrate is skin and the measured electrical impedance is indicative of the water content of the skin.

Abstract: A self-contained handheld peak ignition breakdown voltage probe locates faulty sparkplugs in an internal combustion engine. The probe has a novel dual-polarity detection system suitable for all ignition systems, distributorless or distributor types. Each nanosecond peak breakdown ignition event is signalled by a high-intensity LED lamp lit for a fixed period of time. An adjustable calibrated threshold level provides precise control of acceptance level. Other problems such as cabling, plug gap, and relative compression may also be inferred. The simple arrangement of integrated circuits provides a novel and useful tool for locating ignition problems.

Abstract: A circuit is described for applying a potential to an electrode of a biosensing test cell, which electrode, when properly inserted in a female connector, is contacted by a pair spaced apart contacts. The circuit includes a source of excitation potential and an operational amplifier having one input connected to the source of excitation potential. A switching circuit is coupled between the operational amplifier and a first one of the spaced apart contacts, with the switch means exhibiting an impedance. A feedback circuit is connected between the second of the spaced-apart contacts and another input to the operational amplifier, to feed back a potential appearing at the second contact. The feedback is for the purpose of maintaining the output of the operational amplifier at a level which compensates for impedance losses in the swtiching circuit.

Abstract: In order to detect interlamination shorts (8 ) in the case of laminated core stacks, the core stack (1) is magnetized with an auxiliary winding. The iron surface (15) is scanned with a measuring coil arrangement (5) comprising two electrically separated, mechanically interlinked coils (6, 7). The output signals from the coils are compared with each other in a downstream measuring instrument (9); in the case of an interlamination short, the fault current through the short-circuited laminations will induce in the coils different, phase-shifted voltages which make it possible to infer the position and size of the interlamination shorts.

Abstract: Disclosed is a gas insulated switch device comprising at least two hollow cylindrical containers each accommodating top end portions of a system of line cables, and a disconnector having contacts coupled to the line cables via detachable conductors, wherein electrical tests on the cables, etc. in a first container can be conducted from a test window formed in a side wall of an adjacent second container, by means of a test tank attached thereto. The side walls of the first and second containers comprise a pair of opposing windows that are coupled to each other, via an electrically insulating spacer; branch conductors, which are disposed within the first container and have inner end portions that can be selectively coupled to the line cables or the contacts of the disconnector within the first container, comprise outer end portions projecting into the second container through the electrically insulating spacer disposed between two windows coupled to each other.

Abstract: The present invention provides a passive superconducting sensor for quench detection in a superconducting coil. The sensor consists of a first circuit electrically connected to two voltage taps of a superconducting coil. The first circuit uses nonsuperconducting components and preferably contains a resistive element. The first circuit is magnetically coupled to a second circuit by a hybrid transformer. The second circuit is superconducting and contains a readout coil and preferably a second hybrid transformer. The second hybrid transformer is magnetically coupled to a sense coil which detects flux changes in the superconducting coil. The readout coil is coupled to a readout device which measures changes in the current through the readout coil. The current in the readout coil can be made a function only of the resistance of the superconducting coil between the voltage turns and thus can be used to detect a quench.

Abstract: The linear position of an elongated element (1) is measured using a transmission medium (2). The transmission medium comprises an emitter (3) of microwaves and a receiver (4) of microwaves and has at its one end the elongated element (1) and at its other end an electrical short-circuit (23). An asymmetrical sawtooth standing wave with substantially linear flanks is generated by reflection of the microwaves on the short-circuit (23) and on the elongated element (1). The position of the elongated element is determined by measuring the amplitude of the longer flank of the standing wave with the receiver. The method may be used in difficult circumstances and is suitable to measure mechanical vibrations of high-frequency.

Abstract: According to the present invention, a method and device for detecting failure of heating elements in various jets of a thermal jet printing device is provided. The printing device which includes a plurality of thermally actuated printing jets, each of which jets includes a resistance heating element, is actuated when a current is supplied to generate a bubble. The bubble expands eject a drop of ink. Electrical circuit means are provided including power supply means to supply current to the electrical resistance elements. Control means are also provided to selectively connect the elecrical resistance elements to this power supply in preselected arrays for forming bubbles in selected configuration to perform the ink jet printing. The operation includes a test circuit coupled to the resistive heater elements and operable by the control circuit to generate a failure signal representative of a resistance above a preselected value in any resistance heating elements.

Abstract: A fuel or fluid level measurement arrangement for a spacecraft includes one or more electromagnetic transmission lines extending into the reservoir. The presence of fuel adjacent the transmission line changes the dielectric constant or loss characteristics of the transmission line(s) in a measurable manner. In one embodiment, strip transmission lines extend parallel to the fluid surface at various degrees of ullage, and the fuel level can be established to within the spacing between the transmission lines.

Abstract: For the measurement of gas, vapor, or aerosol fractions of a measured gas, the fraction to be determined is absorbed in a reaction solution, and a change of resistance from a reaction between the fraction and the reaction solution is determined as the measured variable by an ohmmeter, using electrodes in the reaction solution. The measured gas entering a test container through a sealing unit tight to the reaction solution and passing the medium to be determined, is improved with regard to all-purpose use and convenient measurement. This is done pursuant to the invention by placing the reaction solution in a disposable test container that can be inserted or connected interchangeably to the measuring device which has electrodes. The test container is sealed, at least at one end, with a sealing unit that is permeable to the medium to be determined and impermeable to the reaction solution.

Abstract: A continuity tester comprising a transmitter operatively connected to the ends of a plurality of wires which are extended through an electrical conduit. The other ends of the wires are connected to a receiver unit. The transmitter sequentially supplies power to the individual wires connected thereto with diodes being sequentially illuminated at the receiver to establish the identification and continuity of the individual wires.

Abstract: A method and apparatus for determining the impedance of the discharge in a plasma reactor system comprising a tuning box having variable capacitors is described. The impedance of the discharge is determined in dependence on a pre-established relationship between the operational positions of the variable capacitors on the one hand and the impedance of the discharge on the other. The ionic current relative to the discharge in the reactor also may be determined by taking into account the high frequency voltage of the reactor.

Abstract: A detector and alarm is provided for monitoring air pressure variations in a monitored space, which variations correspond to an intrusion. An infra-sonic detector includes a microphone or the like and a low pass filter to retain only low frequency infra-sonic signals or a bandpass filter to retain a particular range of frequencies between approximately 5 Hz and 12 Hz. The instantaneous infra-sonic signals are compared against a variable reference signal, which is a voltage lagging or delayed variant of the instantaneous signals. In this manner the detector is self adjusting for slow variations in the instantaneous signals but responds immediately to rapid variations to trigger an alarm. In one embodiment the detector only senses negative going air pressure changes to trigger an alarm in order to minimize the incidence of false alarms.

Abstract: A cross coil type instrument includes a plurality of coils cross-arranged around a movable permanent magnet, a needle fastened to the movable permanent magnet through a shaft projecting from the movable permanent magnet and penetrating the coils, a reset-to-zero permanent magnet arranged in the vicinity of the movable permanent magnet, and a stopper so as to make contact with the needle at a reference indication position when the movable permanent magnet is driven only by the reset-to-zero permanent magnet.

Abstract: For calibrating a network analyzer, calibration measurements are successively performed in any desired order on three different calibration standards connected between the two test ports; the first calibration standard is a two-port circuit all of whose complex scatter parameters are known and which is, for example, implemented by a direct connection of the two test ports; the second calibration standard is an attenuator of random transmission but known reflection; the third calibration standard preferably is a two-port circuit exhibiting random reflection which, however, is equal on both sides and different from the reflection of the second calibration standard.

Abstract: Disclosed is a container holding a partially conductive ionic fluid with a flexible tactile surface covering the fluid and sealing the container. Along the bottom of the container a series of parallel conductors are located with the farthest spaced apart conductors being connected to a voltage source. Measurements of changes in voltages between individual pairs of conductors will provide an indication of any localized deformation of the flexible tactile surface. Such a tactile sensor can be utilized in any device where an electrical output is desired which is indicative of the surface or surface characteristics of the object to be contacted.