Abstract: There is disclosed a multi-flashlamp article capable of providing both highly intense audible and visual signals. The article is ideally suited for use as an intrusion alarm and includes a combustible member within the assembly's light-transmittable housing. A prestressed spring actuates the combustible by deforming a tubular primer having a quantity of fulminating material therein. This deflagrating material ignites a second quantity of fulminating material within the combustible's container to effect a suitable audible signal.

Abstract: High purity, fine Si.sub.3 N.sub.4 powder produced by the vapor phase reaction of SiCl.sub.4 with NH.sub.3 is amorphous. The crystallization rate of the amorphous powder is enhanced by heating the powder while in intimate contact with a titanium containing material, for example, TiN codeposited with the Si.sub.3 N.sub.4 by the simultaneous reaction of TiCl.sub.4 with NH.sub.3.

Abstract: A composite metallic article for effecting a seal with glass, said article comprising a nickel-iron alloy core portion, a low carbon steel alloy sheath portion bonded to the core, and a uniformly thick shell portion of a glass-wetting material bonded about the sheath. A method for making the article is also disclosed.

Abstract: A high-speed, solid-state, electronic circuit for alternately coupling two separate video signal paths to a third video signal path in response to high frequency square wave excitation, the circuit utilizing two dual-gate metal oxide semiconductor field effect transistors having oppositely phased signals applied to respective switching gates for cancellation of switching transient signals.

Abstract: Low thermal expansion ceramics of essentially 100 percent cordierite solid solution are prepared by the devitrification of a glass frit compact having the nominal composition in weight percent 16 percent MgO, 30 percent Al.sub.2 O.sub.3, 54 percent SiO.sub.2. These ceramics exhibit adequate density and strength and are useful for example in the fabrication of gas turbine engine components such as rotor vanes and heat exchangers.

Abstract: A circuit for efficiently operating two arc discharge flashlamps. The lamps are series connected and directly coupled through series circuitry across an alternating current (AC) source. A storage capacitor is connected between the junction of the lamps and one terminal of the source. Trigger pulses are alternately applied to the lamps so that the storage capacitor is charged when one lamp flashes and discharged when the other lamp flashes. RC timing circuits energized by the AC source control the time of pulsed ignition of respective lamps with respect to the phase of the AC waveform of the source.

Abstract: A metal halide arc discharge lamp has an elongated outer envelope within which is disposed an arched arc tube, the position of the arc tube being transverse to the axis of the envelope.

Abstract: A tungsten-halogen lamp for use in motor vehicle headlights comprises a tubular sealed glass capsule containing two coiled tungsten filaments, parallel to each other and disposed substantially orthogonally to the axis of the capsule. The two filaments are offset laterally from each other and one of the filaments is a coiled coil, in order to reduce the lateral traverse of both filaments.

Abstract: A multiflash system including an arc discharge flashlamp having an elongated tubular envelope and containing three electrodes. A direct current voltage source comprising a large storage bank with positive and negative terminals is connected across two of the electrodes, and a storage capacitor is connected between the third electrode and the negative terminal of the source. The capacitor-connected electrode defines a first arc path with the electrode connected to the positive terminal of the source and a second arc path with the electrode connected to the negative terminal of the source. Trigger pulses are applied to the lamp so as to alternately energize the first and second arc paths, the storage capacitor being charged when the first arc path is energized to flash and discharged when the second arc path is energized to flash.

Abstract: Hermetically sealed electrochemical cells are checked for electrolyte leakage by immersing the completed cell in a liquid medium such as chemically pure deionized water and monitoring the medium for electrical and/or chemical changes that would be caused therein if the electrolyte were leaking from the cell. Such changes could be determined by measuring the electrical conductivity of the liquid medium, the ion concentration, or the pH.

Abstract: An electrically-activated photoflash lamp unit including a linear array of lamps positioned within a housing which pivots about the unit's coupling means. The coupling means includes an elongated body member having a connector tab at one end thereof for plugging within a camera's socket. Sequential activation of the lamps is provided by flash-activating pulses from the camera's power source which pass up through the elongated body member and pivot location of the housing to each lamp.

Abstract: Circuitry implementing at least two amplitude level detectors and a method for monitoring their ability to track rapid changes in signal level is shown. The monitoring circuit uses a delay network to provide an indication that the detectors have not been driven into conduction during a specific interval of time. If this operation persists, a resetting circuit discharges the detector output filter network, thereby allowing the detectors to re-establish an output indicative of the present input signal level. A commutating circuit is shown which allows a single delay network to be used in conjunction with at least two level detectors.

Abstract: A color cathode ray tube screen structure, having means for enhancing the absorption of ambient light and providing improvement in the contrast of the image display, is comprised of three superimposed substantially continuous window-defining layers of optical filter materials. The primary, secondary and tertiary filter layers have discretely disposed window areas formed therein to expose a pattern of filter areas representing the respective filter materials. The filter windows are of a shaping similar to that of the apertures in a spatially related pattern mask member. Each window exhibits a uniform periphery free of indentations, being so defined by a uniform opaque interstitial encompassment homogeneously made up of the three distinct layers of filter materials. Disposed over the filter windows is a patterned screen of cathodoluminescent phosphor elements, which upon electron excitation produces color-emissions that are colormetrically related to the respective filter windows therebeneath.

Abstract: A master timing generator capable of tracking an externally generated clock signal and of maintaining desired operation during periods of disruption or perturbation of the clock signal by noise or other high-energy disturbances. The master timing generator includes a voltage controlled oscillator controlled by an input dc control voltage to produce an output signal which is maintained in a particular phase relationship with the clock signal by phase lock loop circuitry coupled to the oscillator. A dc standby voltage signal representative of the value of the control voltage applied to the oscillator is retained during operation of the master timing generator in a standby unit which, in the absence of noise affecting the clock signal, is electrically uncoupled from the oscillator.

Abstract: A flash lamp assembly for use with a camera and the power source associated therewith. The assembly includes several leadless, capacitively-ignited flash lamps retained within a longitudinal, light-transmitting housing and activated by the passage of electrical energy through the housing either in the form of a capacitive discharge or by direct connection to a pair of resilient contacts. Spaced conductive means located about each flash lamp receive the energy and capacitively ignite the lamp. Means for electrically connecting each lamp to the above power source are also described and include a mechanism for sequentially advancing the assembly's housing therein.

Abstract: The method of reducing arcing in a high power gas transport laser consists of introducing molecular oxygen into the carbon dioxide mixture in which the glow discharge takes place. The oxygen may be in pure form or may be mixed with nitrogen as in air and is admitted to the recirculating gas mixture in predetermined quantities during operation of the laser. The effect of this addition of oxygen to the circulating gas mixture is to prevent the formation of oxide coatings on the copper electrode surfaces, and specifically on the cathode, thereby eliminating this cause of arcing in the laser.

Abstract: A sensing system for measuring the angle of aim of an adjustable remote lighting fixture comprising a pendulum adapted to be mounted on the remote fixture, a potentiometer coupled to the pendulum, and a battery-powered measuring circuit connectable by means of a cable to the potentiometer to thereby form a resistance bridge circuit. During operation, a microammeter connected in the bridge circuit provides a read out proportional to the angle formed between the suspended pendulum and a predetermined reference surface of the remote fixture.

Abstract: An electric choke assembly includes a heater to heat a coiled bimetallic spring which opens a choke valve. The heater comprises a double ring electroded thermistor for the purpose of generating two different heating rates which are controlled by a bimetallic thermostat blade located in the same chamber of the assembly as the thermistor.