Abstract: A three way lamp having two gas discharge light tubes mounted on the same housing in a light-transmitting bulb.

Abstract: A ballast adaptor circuit which makes it possible to convert a conventional two lamp rapid start T12 ballast for operation of two T8 fluorescent lamps and by means of a simple modification that does not require cutting wires or extensive rewiring of the T12 ballast device. The adaptor circuit comprises an auxiliary circuit including a tuned series-parallel LC network connected in parallel with either one or both of the lamps. The LC network is tuned to supply an odd harmonic current to the lamps, preferably the seventh harmonic. Improved starting is achieved by adding a series RC circuit and a SIDAC trigger device to the network to produce voltage pulses at the peaks of the AC supply voltage.

Abstract: A high intensity discharge lamp with a safety switch which automatically shuts off the lamp upon rupture of the outer envelope. The switch is formed by a carbon rod disposed in the interior space between the arc tube and the outer envelope and connected in series with one of the electrodes so that the current flow through the rod maintains it at an elevated temperature during operation of the lamp. Upon rupture of the outer envelope, the carbon rod oxidizes and falls, thereby interrupting the electrical path to the electrodes.

Abstract: Composite cermets having a central core of a first cermet composition and one or more surrounding layers of different cermet compositions are formed by a multi-step pressing operation, followed by sintering. A tungsten/alumina or molybdenum/alumina composite cermet is useful as an end closure for alumina arc tubes of metal halide discharge lamps.

Abstract: Starting and operating method and apparatus for discharge lamps comprises a current-limiting and rectifying means which provides at its output a low-ripple current-limited direct current. To effect lamp starting, a series-connected inductor and capacitor form a high "Q" resonant circuit with the capacitor connected across the lamp to be operated. This starting circuit connects through a blocking capacitor and charging resistor across the low-ripple source of DC. A pair of transistors which comprise an oscillator are connected emitter-to-collector across the source of DC, with the common-connected emitter and collector connected to the blocking capacitor. A drive air-core transformer has separate feedback windings in the starting and operating circuits and drive windings are associated with the transistors. A trigger diode is used to initially pulse one of the transistors which initially oscillate to generate square waves having a frequency corresponding to the resonant frequency of the starting circuit.

Abstract: A precision rotating rod guide for damping the vibrations of an axially moving, rotating rod as it passes through a work station which comprises a pair of duplicate guide members on each side of a work station. Each of the guide members include three coacting ball casters equidistantly angularly disposed about the axis of a rod passing through the guide members thereby damping the vibrations imparted to the rotating axially moving rod at the work station.

Abstract: Ballast apparatus operates a HID lamp at high frequency and high power factor. Series-connected current-limiting input inductor and input capacitor connect across apparatus input and are tuned off resonance to pass predetermined lagging current. An additional input capacitor is connected across input terminals to that input power factor approaches unity. Full-wave diode bridge has input connected across series-connected input capacitor and filter capacitor connects across bridge rectifier output. During normal operation, the filter capacitor develops a DC potential which is current limited by series-connected inductor and capacitor. Inverter has input connected across filter capacitor and inverter an output that drives the HID lamp through a high-voltage generating and variable impedance resonant circuit.

Abstract: Convection air-cooling of a compact electric discharge lamp unit that is adapted for use as a screw-in energy-conserving substitute for an incandescent-type lamp bulb is enhanced by partitioning the lamp housing into two separate compartments and providing vents and connecting air passageways that direct ambient air through the respective housing compartments along two different paths--thereby cooling the compartments independently of one another. A light source (such as a convoluted low-pressure discharge lamp) is located within one of the compartments and an electrical circuit for energizing the lamp is located in the other compartment. The "segregated air-flow" mode of cooling prevents heat that is generated by the lamp from being introduced into the compartment that contains the electrical circuit and thus prevents the circuit components from becoming overheated and possibly damaged.

Abstract: Reliable starting of a fluorescent lamp that is designed to emit light of a selected color (red, for example) is achieved by using a thin transparent coating of conductive material (such as tin oxide) on the inner surface of the glass envelope in combination with a first overlying layer of a suitable light-filtering pigment material and a second overlying layer of a suitable phosphor. The resulting multi-layered arrangement of such materials and the phosphor eliminates the need for including additives (such as admixed silica and barium sulfate) in the phosphor coating as starting aids and solves the problems of poor light output and unreliable starting which are created by the use of such additives. Multiple layers of pigment material having the proper coating density can also be used.

Abstract: A high intensity discharge lamp, for example a high pressure sodium or sodium halide lamp, which utilizes a refractory metal spiral with positive electric potential applied to it positioned around the arc tube to aid in starting and inhibit sodium migration through the arc tube during operation.

Abstract: High-pressure-sodium HID lamps characteristically display an increasing operating voltage throughout life. The industry has established operating standards as a trapezoidal figure on a graph wherein lamp wattage is plotted on the axis of ordinates and lamp voltage is plotted on the axis of abscissas. The parallel trapezoid sides represent minimum permissible and maximum permissible operating lamp wattages and the remaining sides of the trapezoidal figure are two lines of sharply rising positive slope which represent minimum permissible and maximum permissible lamp voltages.The lamp-life operating characteristics are describable by a curve which enters into the trapezoid through the line representing minimum lamp voltages and which exits from the trapezoid through the line representing maximum lamp voltages.

Abstract: A compact halogen-cycle type incandescent lamp is provided with an envelope that is composed of a selected hard glass (a borosilicate or an aluminosilicate type glass for example) and then dosed with an amount of bromine which is correlated with the glass composition in such a manner that it counteracts the deleterious release of water-vapor forming constituents by the glass envelope when the lamp is energized and the glass is hot. The halogen-cycle lamp is especially adapted for use as the concentrated light source in a general service type lamp or a sealed-beam headlamp and, when so employed, has a fill gas pressure that is so correlated with the gas pressure of the non-oxidizing atmosphere in the outer envelope that the total gas pressure does not exceed 1,000 Torr and the envelope of the halogen-cycle lamp operates at a temperature which is sufficient to reliably sustain the halogen cycle but is below the softening temperature of the particular hard glass from which the halogen lamp envelope is made.

Abstract: A lightweight, transistorized, inverter circuit is particularly adapted for starting and operating a screw-in compact fluorescent lamp intended for incandescent lamp replacement. Household-type AC is converted to DC with one terminal connected to the center tap of a transformer primary through a choke which constitutes a high impedance at the operating frequency. A tuned circuit capacitor is connected across the transformer primary and a current-limiting capacitor and the lamp to be operated are connected in series across the transformer primary. A pair of transistors are connected in push-pull arrangement between the end portions of the transformer primary and the other terminal of the DC source, with the base electrodes of the transistors connected to the transformer secondary winding so that the push-pull connected transistors oscillate at the tuned circuit resonant frequency which is determined by the inductance of the transformer primary winding and the total capacitance of the connected capacitor means.