Abstract: A DC circuit for efficiently operating two arc discharge flashlamps. The lamps are parallel connected across a single supply storage capacitor, and a single trigger capacitor is employed in connection and the two alternately activated trigger sources for the two lamps.

Abstract: A photoflash unit having a flashed lamp indicator comprising two layers of film having different colors, one of the layers being a heat-shrinkable material and the other layer being translucent and substantially unaffected by the heat of lamp flashing. An adjacent indicia sheet provides an aperture through which one of the indicator colors is visible. Upon flashing of an associated lamp, the heat shrinkable layer shrivels from view and the color of the other layer becomes visible through the aperture to clearly identify which lamp was flashed. In one embodiment, the two-color indicator is used to identify the last lamp flashed in a sequence, while each of the preceding lamps in the sequence has a respectively associated single-layer color indicator which shrinks away to leave a void upon flashing of the lamp.

Abstract: An intrusion alarm circuit including a single electroacoustical transducer, such as a diaphragm-supported piezoelectric element, connected to an amplifier in a positive feedback loop configuration. The transducer functions as both a sound pickup and sound generator. When the ambient sound level exceeds a preselected threshold level, the resulting vibration of the transducer generates a voltage which activates the amplifier, whereupon the transducer vibrations are sustained and amplified in the manner of an oscillator, thereby producing an audible alarm.

Abstract: In a compact multilamp photoflash arrangement for providing more lamps in a given volume, a reliable sequencing circuit of normally open and normally closed switches is provided by employing a series-parallel combination of the normally open switches which minimizes resistance buildup and circuit discontinuity problems.

Abstract: A photoflash lamp array comprising a plurality of high-voltage type flashlamps mounted on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive high-voltage firing pulses applied thereto. The circuit board has an integral connector tab with a pair of terminals on one side connected to the igniting circuitry. Electrostatic protection is provided by a conductive shield of planar configuration disposed parallel to the circuit board and spaced therefrom on the side opposite that on which the lamps are disposed. The conductive shield is shaped with a portion thereof extending toward the end of the connector tab on the side opposite from the terminals to provide a discharge path for electrostatic charges in proximity to the tab. Preferably the shield extension is narrower than the tab and fits within a slotted recess therein between the tab and a back housing member.

Abstract: A switching circuit for energizing a load, such as fluorescent lamp ballasts, in response to a control signal of preselected frequency superimposed on AC power circuits which supply the load. A triac is gated to conduct the AC power to the load by a circuit including an impedance element and a series resonant LC network tuned to the frequency of the control signal. The gate circuit is arranged to block the control signal during all but a small portion of each half cycle of the applied AC power, thereby reducing the consumption of control signal power.

Abstract: A compact photoflash unit is provided for arranging more lamps in a given volume while maintaining performance requirements. Two parallel columns of horizontally disposed lamps are mounted in a planar array with the lamps of one column staggered with respect to the other with the bases interdigitated. A multiple reflector system for the lamps comprises a pair of adjacent strip-like reflector panels each having a column of side-by-side reflector cavities aligned with an associated column of lamps, the cavities of one panel being staggered with respect to the cavities of the other. Each panel is fore-shortened with respect to its associated lamps and covers the lead-in wires and bases of the lamps associated with the adjacent panel.

Abstract: A photoflash unit comprising two parallel columns of horizontally disposed lamps mounted in a planar array with flash indicators aligned behind each lamp. The lamps of one column are staggered with respect to the other, and the two columns are located on opposite sides of the vertical centerline of the unit. The lamps are connected to switching circuitry for sequentially flashing the lamps in response to firing pulses applied to a connector at one end of the unit. The two columns of staggered lamps are positioned so that the lowest lamp is located on the side of the unit centerline opposite that on which the lens axis is located when the unit is connected to a camera, thereby farther removing the closest lamp from the lens axis to minimize the "red-eye" effect. The switching circuitry is connected to provide an order of flashing that proceeds alternately between the two columns from the lowest to the highest lamp of the array, thereby providing a more readily interpretable flash indicator pattern.

Abstract: A photoflash lamp-reflector module for use in a photoflash unit having a plurality of such lamp-reflector modules arranged in a compact array. Each reflector has a substantially parabolic surface with a centrally disposed elongated cylindrical recess having a longitudinally extending central slot. The associated tubular lamp is nested within the recessed portion of the reflector, whereby an oversized lamp is accommodated by the reflector with little or no loss of light output.

Abstract: A compact photoflash unit comprising a plurality of flashlamps having lead-in wires connected to a circuit board containing thereon radiation-sensitive switching circuitry for sequentially flashing the lamps. Electrically conductive reflector panels are positioned between the lamps and the circuit board, and a sheet of electrically insulating material is interposed between the reflectors and the circuit board to prevent shorting of the circuitry on the circuit board by the conductive reflector. The insulating sheet, which may be of transparent plastic, is provided with T-shaped tabs which interlock with slots in the circuit board to secure the aligned position of the insulating sheet thereon. In assembling the photoflash unit, the insulating sheet is placed on the circuit board prior to mounting the lamps, and the T-shaped tabs of the sheet are inserted in the circuit board slots to secure the aligned location of holes in the insulating sheet with lamp-mounting eyelets in the circuit board.

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 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: 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: A photoflash lamp array comprising a plurality of high voltage type flashlamps mounted on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive high voltage firing pulses applied thereto. A plurality of reflectors respectively associated with the flashlamps are disposed between the lamps and circuit board, with each reflector having an aperture in alignment with a corresponding aperture in the circuit board. Connected in series with each but the last lamp of the array is a radiant-energy-activated disconnect switch comprising a strip of electrically conductive heat shrinkable, polymeric material which is attached at both ends to the circuit board so as to bridge a respective one of the apertures therein.

Abstract: A circuit for operating an arc discharge flash lamp that is directly coupled across an alternating current (AC) source. The lamp is ignited by a high voltage pulse generated by a trigger circuit energized by the AC source. A voltage multiplier, such as a doubler circuit, is connected across the flash lamp for increasing the voltage across the lamp above that provided by the AC source, thereby facilitating starting of the lamp by the trigger circuit.

Abstract: A rotary seal device for pressurized gas and vacuum pumping systems comprising an annular member coaxially mounted on the end of a hollow rotary shaft and having a spring-loaded carbon face pressing against a ceramic disc secured in coaxial alignment with the end of a stationary pipe fitting within a housing member having a threaded end cap for adjusting the pressure between the carbon face and ceramic disc.

Abstract: A photoflash unit comprising a plurality of high-voltage type flashlamps mounted on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive high-voltage firing pulses applied thereto. One lead-in wire of each of the flashlamps is connected to a common circuit conductor. Electrostatic protection is provided by a conductive array of reflectors positioned between the lamps and one side of the circuit board and a planar shield of conductive material disposed parallel to and spaced from the opposite side of the circuit board, both the reflector array and shield being electrically connected to the common circuit conductor and thereby effecting a static "grounding" system. The assembly is enclosed in a plastic housing having a light-transmitting side wall adjacent to the flashlamps.

Abstract: A high-voltage type photoflash lamp filled with a filamentary combustible material and oxygen and having an ignition structure comprising a pair of spaced apart lead-in wires bridged at their inner ends by a mass of primer material. An insulating sleeve encloses one of the wires, with the end of that wire extending beyond the open end of the sleeve. Formed at an angle from the other lead-in wire is a terminating portion which overlies and is spaced from the open end of the sleeve to provide a predetermined gap between the terminating portion and the end of the sleeved wire. The primer material is disposed to cover the open end of the sleeve and bridge the gap.

Abstract: A modular chamber construction for providing ultraviolet light irradiation within a confined space. The chamber comprises a plurality of side panel assemblies mounted on a base member and arranged to form a vertically upstanding enclosure of polygonal configuration. Two of the panels are hinged to provide doors, with the remaining panels being bolted to the base and to each other. Each of the panel assemblies contains a plurality of long, tubular fluorescent lamps and associated ballast circuits, with the lamp vertically oriented and juxtaposed to face the interior of the enclosure. A top member containing filtered ventilating fans and downwardly facing mirror configuration is bolted to the top edges of the stationary side panels by means of a peripheral flange which permits mounting by sliding the top member horizontally onto the enclosure through the door opening.