Abstract: A high-pressure metal halide arc discharge lamp having an arc tube with a pair of main electrodes disposed within the tube at opposite ends and a starting electrode located adjacent one of the main electrodes. A tubular sleeve of insulating material, such as quartz, is disposed about the starting electrode, which is recessed within the sleeve but exposed through the open end thereof to the interior atmosphere of the arc tube. Since the starting electrode does not project beyond the open end of the sleeve, conduction between that electrode and the adjacent main electrode is minimized or prevented during normal lamp operation, thereby minimizing or preventing electrolysis.

Abstract: A high pressure sodium vapor discharge lamp having an arc tube coaxially mounted within an outer glass envelope by means including a coiled spring engaging one end of the arc tube and coaxially disposed in the partially compressed state between that end of the arc tube and a dome portion of the outer envelope. In one embodiment the dome of the outer envelope is disk-shaped and a large diameter end of the coiled spring bearing against the dome is constrained in a coaxially centered position by the sidewalls of the outer envelope. In another embodiment, the dome of the outer envelope is provided with an inwardly projecting dimple about which the coiled spring is coaxially fitted to provide self-centering of the arc tube. The partially compressed spring compensates for arc tube length variations and thermal expansion.

Abstract: A frequency responsive power control system includes an improved isolator in series electrical connection with respect to a ballasted lamp load. The isolator has a high inductive impedance at low current for blocking ballast induced noise signals from interferring with proper operation of frequency responsive switching circuits in the system. In a particularly useful embodiment, the isolator is inductively matched to the capacitive characteristic of the ballasted lamp load so that the isolator-load circuit combination is resonant at a frequency sufficiently removed from any of the control system activation frequencies so as to block any noise signals induced by the ballasted load which might otherwise cause undesired activation of the switching circuits and flickering of the ballasted lamp loads. Under saturation current, with the switching circuit conducting, the isolator functions collectively with the load to provide an impedance which blocks control signals from reaching the load.

Abstract: In an apparatus for preheating a fuel-air mixture mounted in the flow of that mixture between a carburetor and the intake manifold of a combustion engine wherein such mixture is passed through a multi-passaged PTC resistor heater into such engine manifold, a tab is provided which is mounted between the carburetor and the PTC resistor and proximate the latter. The tab projects into the flow of the fuel-air mixture to divert or redirect such flow through the PTC resistor and into the manifold to obtain a desired distribution of such mixture therein.The redirection tab acts as a venturi which causes further mixing of such fuel-air mixture as it flows through such PTC resistor and such tab further has a baffle effect which redirects the fuel-air mixture as stated above.

Abstract: A method of operating a high intensity discharge lamp having a pair of electrodes hermetically sealed within an arc tube, the method comprising frequency modulation of a carrier waveform in the kilohertz range to provide a variable frequency AC output, and applying the AC output across the electrodes of the lamp to thereby operate the lamp in a manner which minimizes or avoids acoustic resonance effects within the arc tube. The circuit includes an inverter having a first input provided by a DC power source and a drive input coupled to a square wave carrier generator which is frequency modulated by a ramp generator. The resulting variable frequency AC output of the inverter is then coupled across the lamp electrodes.

Abstract: A photoflash unit comprising a plurality of 2n flashlamps attached to a printed circuit board and disposed in a linear array with the longitudinal axes of respective lamps aligned in parallel. The circuit board has a substantially rectangular portion with n spaced apart extensions projecting vertically from a longer side thereof, the extensions being located behind alternate lamps of the linear array. Each extension contains portions of circuit patterns bridged by a mass of switch material to provide a solid state radiation switch on each extension and adjacent to a respective lamp for receiving radiant energy emitted by that lamp. The unit further includes a plurality of reflector cavities within each of which a respective one of the flashlamps is nested. Each reflector cavity includes a recessed rear wall section for accommodating a circuit board extension, such that each of the extensions are disposed between a respective lamp envelope and the recessed rear wall of the associated reflector.

Abstract: A photoflash unit comprising a plurality of 2n flashlamps attached to a printed circuit board and disposed in a linear array with the longitudinal axes of respective lamps aligned in parallel. Circuit patterns on the circuit board include a plurality of n selective terminal means, each associated with a respective pair of the lamps and connected to one lead-in wire of each of the lamps of the associated pair, and a common terminal associated with all of the 2n lamps but directly connected to the other lead-in wire of one lamp of each pair. The circuit board has a substantially rectangular portion with n spaced apart extensions projecting vertically from a longer side thereof, the extensions being located behind alternate lamps of the linear array.

Abstract: A high-voltage type photoflash lamp having an ignition structure including an improved primer material for the reliable ignition of filamentary combustible material distributed within the oxygen-filled envelope of the lamp. The primer material comprises a particulate fuel such as zirconium powder, a binding agent such as nitrocellulose, and an additive of finely divided inert material which is insoluble and nonconductive and has a particle size of less than about five microns diameter.

Abstract: A wire support for the coiled-coil filament of a tubular double-ended incandescent lamp in which the support is formed of a single wire which extends longitudinally along a portion of the inner wall of the lamp envelope, with each end of the support wire terminating in a loop of a size to be circumferentially engageable with the inner wall of the envelope, and a midportion of the support wire extending laterally in closed loop form to firmly embrace a localized point on a turn of the filament so that the turn extends through that midportion loop and is supported therefrom.

Abstract: A starter circuit for a high power discharge lamp connected to an AC source via a series inductor. The starter circuit comprises a capacitor connected in series with a triac across the lamp, and a branch including a first resistor connected in series with a zener diode and a second resistor between the junction of the capacitor and triac and one side of the AC source. A driving circuit for the triac includes a diac connected to the junction of the second resistor and zener diode.

Abstract: A low wattage high intensity discharge lamp having a quartz arc tube and a glow starter disposed within a bulbous glass envelope containing an inert gas, such as argon, at subatmospheric pressure. The starter within the envelope comprises a first bimetal connected to one of the arc tube lead-in wires, a second bimetal connected to one end of a conductive support wire sealed through the bulbous envelope, and a fixed first contact attached to another conductive support wire sealed through the bulbous envelope and also connected to the other lead-in wire of the arc tube. The bimetals are electrically connected together at one end which makes a normally closed contact with the fixed contact in the quiescent state of the starter.

Abstract: A lightning arrester including a metallic enclosure with an opening, a first electrode of electrically conducting metal traversing the enclosure opening and having a first discharge surface within the enclosure, a plug of electrically insulating material placed about the first electrode to hermetically seal the enclosure opening, and an inert gas mixture filling the enclosure. The first electrode has a thin long cylindrical portion and a flat end portion, like a nailhead, which provides the first discharge surface. Portions of the enclosure provide a second electrode having a second discharge surface within the enclosure which faces the first discharge surface, with a predetermined gap therebetween. The long thin portion of the first electrode within the enclosure is surrounded by a sleeve composed of a fusible, electrically and thermally conducting material.

Abstract: A circuit for starting and operating a low wattage high intensity discharge lamp from a source of AC line voltage. The circuit includes a glow starter device having a first terminal connected to a first bimetal, a second terminal connected to a second bimetal, and third terminal connected to a rigid conductive member, the bimetals being electrically connected together at one end which makes a normally closed contact with the rigid member in the quiescent state of the device. A choke coil and a capacitor are series connected in that order between one of the AC input terminals and the second terminal of the starter device, and a second AC input terminal is connected to the third terminal of the starter. The first and third terminals of the starter device are connected across the discharge lamp terminals.

Abstract: A lamp operating circuit comprising a DC power source, an inverter including step-up transformer inductance windings and a controlled transistor switch connected across the output of the DC source, and a high frequency oscillator coupled to the transistor switch for operating the same at predetermined intervals. A low wattage HID lamp is connected across the inverter through a ballast capacitor series connected to one terminal of the lamp and a ballast inductance coupled in series with the other lamp terminal. The ballast inductance and ballast capacitor are selected to resonate sinusoidally at a frequency having a half period coinciding with the on-time of the transistor.

Abstract: A reflector lamp comprises an arc discharge tube disposed at about the focus of a parabolic reflector. The arc tube is supported by two lead-in support wires which extend through the back of the reflector. The external ends of the lead-in support wires are secured in a stabilizer support which is adhesively bonded to the back of the reflector.

Abstract: A photoflash unit having a plurality of flashlamps mounted on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive firing pulses applied thereto. The circuitry includes a plurality of solid-state switches capable of being activated by radiant energy generated during flashing of lamps located adjacent to respective switches. Initially, each of the switches has a resistance sufficiently high to provide an open circuit to the applied firing pulses, and after being activated by radiation, the switch undergoes chemical conversion to a conductive state over a finite time interval. The switches are prepared from compositions comprising admixtures of silver carbonate and/or silver oxide, silver-coated glass beads and a binder; the admixtures may also include electrically non-conductive particulate solids, such as titanium dioxide, and/or silver-coated metal beads.

Abstract: A photoflash lamp array having a plurality of 2n flashlamps, a common terminal connected to one lead-in wire of each of the lamps, and a plurality of n selective terminal means, each associated with a respective pair of the lamps and directly connected to the non-common lead-in wire of one lamp of each pair. A respective normally open switch is coupled between the non-common lead-in wires of each of the pairs of lamps associated with a selective terminal. Each of the switches is responsive to the flashing of the directly connected lamp of an associated pair so as to electrically connect the other lamp of the pair to the associated selective terminal. In one specific example, ten lamps are selectively paired to be operated sequentially by firing pulses successively applied to five selective terminals together with a common terminal.

Abstract: A photoflash unit having a plurality of flashlamps mounted in a planar array on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive firing pulses applied thereto. The circuitry includes a plurality of solid state switches capable of being activated by radiant energy generated during flashing of lamps located adjacent to respective switches. Initially, each of the switches has a resistance sufficiently high to provide an open circuit to the applied firing pulses, and after being activated by radiation, the switch undergoes chemical conversion to a conductive state. The switches are prepared from compositions which include a selected proportion of silver-coated glass beads to consistently assure a predetermined low resistance after conversion and maintenance of good adherence and electrical contact with the printed circuit board circuitry.

Abstract: A glow bottle starter having three lead-in wires and containing two bimetals connected together at one end and a rigid tungsten rod. The bimetals make normally closed contact with the tungsten rod in the quiescent state of the starter, and upon electrical current flow through one or both of the bimetals to cause elevation to a predetermined temperature, the bimetals are operative to separate from the tungsten rod. In a circuit including the glow-bottle starter for starting a discharge lamp, one of the bimetals and the rigid tungsten rod are connected across the output of a ballast circuit, and the tungsten rod and other bimetal are connected across the lamp.