Abstract: An electronic fluorescent lamp ballast having at least an energy storing component, a controlling component which has two states, and two socket elements which enables the filaments of the fluorescent lamp to be connected in series with the energy storing component. A constant current flows through a portion of the energy storing component when the controlling component is in one state producing an "energy latching" effect which will enable the ballast to achieve a very high efficiency of energy transfer. The ballast also has a self adjustable frequency of operation as a function of lamp impedance variation due to age and enables constant ionization within the fluorescent lamp.

Abstract: A power supply circuit comprises a single discharge capacitor having a charging sufficient to trigger discharge in a discharge lamp. The discharge capacitor is associated with means for accumulating energy, with which it is charged. The energy accumulating means receives commercially available alternating current and applies the accumulated energy to the discharge capacitor to charge the latter. The power supply circuit may include an auxiliary capacitor which has a smaller capacitance and higher potential rating than the discharge capacitor. The auxiliary capacitor may have a potential rating sufficient to activate the discharge lamp alone. The discharge capacitor cooperates with the auxiliary capacitor to define discharge period. Preferably, the power supply circuit may include means for blocking or shutting off power supply at a given timing to precisely control the discharge period.

Abstract: A multicolor display device having seven illuminated optically stable states includes three triads of associated electro-optical components. In each triad, a light sensor is electrically coupled with a display light emitting diode and auxiliary light emitting diode. An optical feedback is established in each triad between the auxiliary light emitting diode and the light sensor tending to maintain its associated display light emitting diode either in the illuminated or extinguished condition. Light signals of respectively different colors emitted by three display light emitting diodes are blended to obtain a composite light signal of a color in accordance with the conditions of respective display light emitting diodes.

Abstract: An electronic ballast system for operating fluorescent lamps at full and partial brightness is disclosed having a series reactance selectively switched into or out of the system by a reactance switch. The electronic ballast has an input filtering section, a voltage-clamped current source, and an oscillator whose frequency is determined in part by load reactance. Series filament capacitors provide lamp filament power control during starting and running at full and partial brightness.

Abstract: An emergency lighting circuit includes a lamp which can be energized by a battery-inverter circuit upon power failure. The battery is connected to the inverter circuit and the lamp by operation of a relay which is connected to the rectifier supplying charging current to the battery. The rectifier is connected across the line in series with a ballast reactor. The circuit can be used as emergency lighting only or the lamp can be employed for normal lighting purposes and switched to the inverter power when line voltage is interrupted.

Abstract: A solid state bridge inverter is disclosed wherein the power for driving the transistors is generated by the current flowing to the load. Windings are so connected on the drive transformers that one transistor cannot possibly turn on until the other one is fully off including storage and turn off time. This is accomplished in such a manner that the load may be highly inductive without any detrimental effect upon the power transistors. Also disclosed is a unique method for deriving the power for the logic circuitry as well as a concept where a single magnetic element can provide both a balun type filter action on the input as well as power factor correction and smoothing action to supply filtered DC voltage and current to the inverter while maintaining a 0.9+ power factor to the AC line. Further disclosed is a combination of the above described components along with further unique circuit configurations to provide a highly efficient solid state fluorescent ballast.

Abstract: A lighting apparatus which provides high voltage pulses for starting a high pressure sodium lamp. The apparatus includes two capacitors, two blocking diodes, a voltage sensitive symmetrical switch, and multiple resistances across which pulses are distributed. The aforementioned elements are electrically connected together and with a tapped ballast reactor so that one of the capacitors charges through an impedance in the negative half-cycle, and thereafter, when line voltage goes positive, the other capacitor charges through an impedance equal to the sum of the multiple resistances. When the voltage of the capacitors reaches a predetermined voltage exceeding the breakdown voltage of the voltage sensitive symmetrical switch, the capacitors discharge. This discharge, because of an autotransformer relationship within the reactor, produces a high voltage pulse of predetermined height and width once per each cycle of the source voltage.

Abstract: An output section which takes output by a coaxial line from the output cavity of a microwave tube such as a klystron, and has a structure such that the coaxial line is divided into a coaxial line section continuous with the output cavity, and a coaxial line section including a dielectric air-tight ring which is fastened so as to be vacuum-tight between the internal and external conductors, and with the internal and external conductors of these divided coaxial line sections each joined so as to be air-tight by thin weld rings. The output section obtained is easy to manufacture, has high reliability, and is applicable to high power usage.

Abstract: There is provided a dimmer passing device for a headlamp of a vehicle having a light switch which drives a light relay when it is on, a momentary control switch which activates the light relay when it is on, a latch circuit which alternately turns on and off an internal switching element in response to the on state of the momentary control switch, and a dimmer relay which causes the light relay to energize a low beam of the headlamp when the internal switching element is turned off and which causes the light relay to energize a high beam of the headlamp when the internal switching element is turned on.

Abstract: A travelling wave tube comprising a tube and a helix mounted in the tube, the helix being made of diamond and being coated at least partially with an electrically conductive material.

Abstract: A light source including a spiral line pulse generator having an output coupled to one electrode of a high pressure discharge lamp and having an input for coupling to a source of lamp operating power for providing high voltage lamp starting pulses. The pulse generator includes, in addition to a spiral line circuit, a solid state electronic switch for discharging the spiral line pulse generator and a ballast capacitor connected in series with the solid state switch. The spiral line pulse generator preferably has a magnetic core associated therewith for increasing the spiral line inductance.

Abstract: An electrical load controller includes a combination of switches for selecting a desired load output level, an electronic custom gate array for converting the switch signals to a parallel binary number, a parallel to serial data encoder for converting the multi-bit parallel data signal into a multi-bit serial data signal, a frequency shift key connected to a resonant circuit generating a controllable high frequency signal and for shifting the high frequency either up or down from the center frequency coupled to a power line to transmit the binary serial data onto the power line. The system also includes a fail-safe construction so that, should the control system fail, the load will be operable. The system provides continuous communication from the controller to the power line, so that should noise interfere with one data transmission, subsequent data transmission will provide correct data to the load, thereby making load control nearly immune to extraneous noise on the power line.

Abstract: Starting and operating apparatus for high intensity discharge lamps includes first and second pairs of terminals formed for connection to an AC source and a discharge lamp respectively, a series connect ballast means and inductor connected to one of said first pair and one of said second pair of terminals a bilateral switch shunted by a capacitor and in series with an AC impedance coupled to the inductor and to the other one of said first and second pair of terminals whereby relatively wide high voltage, high frequency pulse potentials for starting the discharge lamps are provided.

Abstract: A switched AC ballast is operated synchronously with the AC line during normal running of a gas discharge lamp to limit EMI and is locked in a single phase during start-up (i.e. ignition, glow mode and warm-up) to protect the bridge switches from high voltage starting signals. Devices having a high impedance control input, such as FETs, are employed in the switching bridge thus allowing control of the upper devices in the bridge without a floating power supply. A control circuit insures proper operation of the bridge switches during all operating modes of the discharge lamp.

Abstract: An electronic flash includes a main capacitor having a discharge loop in which a circuit arrangement including a flash discharge tube, a switching element and an emission controlling capacitor is connected. During the time the flash discharge tube is maintained excited, the emission controlling capacitor is either charged or discharged to cause an emission of flashlight from the flash discharge tube.

Abstract: A light string system is provided having a plurality of mono-color or bi-color light-emitting diodes electrically connected thereto. Each light-emitting diode has a generally elongated, hollow envelope mounted thereover, and the envelope is substantially filled with light-conducting optical spheres or even fragments. The envelope may be additionally filled with light-conducting epoxy, light-conducting liquid or light-conducting gas and sealed for improved light transmission and dispersion characteristics. The light-emitting diodes may include an improved base with light-emitting diode leads disposed approximately perpendicular to the axis of the envelope for bulb stability and for enabling the bulb to stand upright on the branches. Both the envelope and the optical spheres include light-conducting glass or plastic material. The spheres may be either hollow or spherical and may be of a uniform or a mixed size.

Abstract: A microprocessor based controller for electric liturgical lights similar to an array of votive candles including controllable duration of "burn" as well as selective actuation by the user in a variety of modes. The duration of burn for all lights is controlled by a singular timer which is located within the stand supporting the array. Data indicative of the operational state of a light array may also be transferred to a remote light array for continuation of operation at the remote site.

Abstract: In an electronic flash apparatus which is provided with a first discharge tube for bounce illumination and a second flash discharge tube for direct illumination, emission of flash light by the first flash discharge tube and emission of flash light by the second are arranged to separately begin and to simultaneously end to simplify complex circuit arrangement otherwise required for having the amount of light reflected by the object of flash light emission by the first discharge tube and that of flash light emission by the second discharge tube in a fixed ratio. The second discharge tube is arranged to flash without fail despite of the simplified circuit arrangement.

Abstract: A starter circuit for a fluorescent tube lamp is connected between the cathode heaters of the tube to provide an initial heating current and then changes to a high impedance to ignite the tube. The circuit is fed by raw rectified a.c. and has a main thyristor requiring a high holding current to maintain the initial conduction. The current through the main thyristor sets up a voltage across a series diode which triggers a second thyristor to reduce the gate voltage of the main thyristor. The main thyristor ceases conduction when the current falls below the holding value and the inductive ballast impedance then produces a high energy striking pulse for the tube. The pulse voltage is limited to increase its duration. One embodiment generates a single pulse only each time the circuit is switched on and another embodiment produces pulses for a period of time before becoming quiescent. The main thyristor and the voltage limiting means are embodied in a monolithic semiconductor structure.

Abstract: Disclosed is a lighting control system which switches a light fixture on or off, depending upon the amount of ambient light. The control system particularly allows natural light from the sun to be used to the greatest extent possible to supplement electric lighting and vice versa. The system incorporates a photocell light sensor, control circuit, power source, and switching unit. The photocell light sensor is mounted in optical communication with a source of ambient light. In response to the detection by the sensor of a predetermined light level, the control circuit activates the switching unit which is interposed in a circuit furnishing electrical power to a light fixture. The power source supplies power to the control circuit at a voltage of no greater than 20 volts at a current of no greater than 8 amps.