Abstract: A control device and signaling are provided to operate selected numbers of the ballasts in a multi-ballast, multi-lamp luminaire. The luminaire has a control input for receiving a control signal from a wall switch, for example. The number of ballasts operated by the luminaire increases or decreases sequentially in response to one of consecutive pulses, signal level transitions or interrupts in the control signal. The control device can be programmable or hard-wired to the relays (e.g., a counter and decoder) to allow for a more economical implementation. Different subsets of the ballasts can be selected via the programmable integrated circuit to distribute the burn times of the lamps.

Abstract: A reliable and efficient circuit for lighting a discharge lamp is described. An inverter accepts a direct current supply voltage and outputs an alternating current lamp voltage to drive the discharge lamp at a relatively high frequency. In one embodiment, the inverter includes semiconductor switches in a full-bridge configuration, a transformer feedback circuit to control the semiconductor switches, and a series L-C resonant circuit. In one embodiment, the inverter includes semiconductor switches in a half-bridge configuration, a transformer feedback circuit to control the semiconductor switches, and a series L-C resonant circuit. The inverter can drive multiple discharge lamps in a parallel configuration. A bypass circuit can also be coupled across a cathode of the discharge lamp to extend the life of the discharge lamp. The bypass circuit activates when a lamp cathode wears out.

Abstract: The invention provides a self-ballasted fluorescent lamp provided with a function for operating normally when the self-ballasted fluorescent lamp is inadvertently connected to a lighting fixture provided with a light bulb dimmer if the dimmer is at the maximum level, and with a function for reliably stopping operation of the ballast circuit if the dimmer is in a dimmed state and thereby latch the lamp in an unlit state and protect the ballast circuit. Even if the self-ballasted fluorescent lamp is connected to a power source via a light bulb dimmer, when a current detected by a current detection circuit exceeds a predetermined current value, a stop circuit stops operation of an inverter circuit and latches it in that stopped state in order to maintain the self-ballasted fluorescent lamp in an unlit state.

Abstract: An electronic ballast for supplying a lamp comprises a control loop for controlling the rms value of an operational parameter so as to be constant. In the control loop, the actual rms value of the parameter is generated as a linear combination of its average value and its peak value.

Abstract: An apparatus for driving a plasma display panel that includes first and second signal lines for supplying first and second voltages, respectively, and first and second inductors coupled to one terminal of a panel capacitor. A first current path is formed from the panel capacitor to the second signal line via the second inductor to drop the voltage of the panel capacitor from the first voltage to the second voltage. A second current path is formed to recover the current flowing to the second inductor towards the first signal line, while the voltage of the panel capacitor is sustained at the second voltage. A third current path is formed from the first signal line to the panel capacitor via the first inductor while the current flowing to the second inductor is recovered, to raise the voltage of the panel capacitor from the second voltage to the first voltage.

Abstract: A dimming control system includes a first circuit (100) and a second circuit (400). First circuit (100) is coupled in series with the AC line source (10) and receives brighten and dim commands from a user. The brighten and dim commands are communicated to second circuit (400) by momentarily altering the AC voltage waveforms observed by second circuit (400). Second circuit (400) provides an adjustable output signal that is coupled to inverter circuitry within an electronic dimming ballast. The output signal is adjusted by the second circuit (400) in dependence on the observed AC voltage waveforms.

Abstract: A lighting control system provides variable arc current to one or more fluorescent gas discharge lamps and provides a heating voltage to the lamp electrodes. The system includes a start-up circuit which includes circuitry for providing a starting voltage to an output power conditioning circuit. The latter drives a switching unit to control the application of DC power to the fluorescent gas discharge lamps and to provide an operating voltage to an input power factor correction circuit. The input power factor correction circuit boosts the converted DC power and the operating voltage. The start-up circuit includes a plurality of voltage doubling rectifier circuits and a plurality of zener diodes which receive the operating voltage and are electrically connected to the input power factor correction circuit and the output power conditioning unit so as to provide a regulated bias voltage supply to the output power conditioning unit and to the input power factor correction circuit.

Abstract: A splashplate antenna system configured using hybrid mode-matching techniques has improved secondary beam characteristics, including improved sidelobe performance, improved electric and magnetic plane correlation, reduced cross-polarization, improved electric and magnetic plane phase center correlation, and improved overall matching between the waveguide and the splashplate (sub-reflector). Internally, the waveguide contains a wall constructed from a series of varying dimensioned cross-sections that cause signals introduced to radiate in a multiple mode, Gaussian-like field pattern. The Splashplate is configured so that the waves received from the waveguide maintain the circular pattern symmetry, as well as other characteristics.

Abstract: A method for driving a surface-discharge AC (alternating current)-type PDP (Plasma Display Panel) is provided which is capable of shortening a scanning period by securing a wide range in which a voltage to induce sustaining discharge can be set without causing flicker to occur and without causing black luminance to be increased. A sub-field is made up of a resetting period, a scanning period, a wall charge forming period, and a sustaining period. During the scanning period, time interval between scanning pulses is shortened. During the wall charge forming period, each of common electrodes and data electrodes is made to be at a ground potential and a wall charge forming pulse having a same potential as that of a scanning pulse is applied to all scanning electrodes. The time interval between wall charge forming pulses is for example 3 &mgr;sec to 50 &mgr;sec. This causes space charges being left in a display cell to be attracted on each of electrodes, whereby wall charges build up.

Abstract: A laser pointer and an image sensor are employed as one measuring system, and two measuring systems are arranged such that a laser beam is irradiated in the opposite direction. One laser pointer and one image sensor are arranged on the measuring reference portion, and also One laser pointer and one image sensor are arranged on the measured portion. The parallel displacement &Dgr;X and the inclination &thgr; of the measured portion are calculated separately based on measured results obtained by these two measuring systems.

Abstract: The present invention represents an integrated antenna assembly comprising a cellular communications antenna and a satellite communications antenna. Such an antenna assembly can, therefore, be used for communications over either frequency range. A wireless telephone using this assembly can, therefore, operate with either a terrestrial cellular communications system or a satellite communications system. In a preferred embodiment of the invention, the satellite communications antenna is a quadrifilar helix antenna and the cellular communications antenna is a sleeve dipole. The whip portion of the sleeve dipole is positioned axially in the center of the quadrifilar helix antenna. This orientation permits operation in both the satellite and cellular frequency ranges without significant electromagnetic coupling.

Abstract: A light emitting diode (LED) illumination structure has a button-sized battery, a circuit board, an LED chip and a contact switch. A positive electrode of the LED chip electrically connects to a positive electrode of the button-sized battery, and a negative electrode of the LED chip electrically connects to the circuit board via a conductive wire. A transparent molding material encapsulates the LED chip and the conductive wire. One terminal of the contact switch electrically connects to the circuit board while the other terminal connects to a negative electrode of the button-sized battery. Direct attachment of the positive electrode of the LED chip to the positive electrode of the button-sized battery provides electrical connection and heat dissipation from the LED chip through the button-sized battery to stabilize the high brightness characteristic. The LED illumination structure is thereby constructed with a reduced size.

Abstract: An emergency lighting arrangement and an emergency lighting apparatus, the arrangement being configured to be coupled to a supply network and the arrangement comprising an electronic ballast for igniting and burning a fluorescent lamp, the emergency lighting apparatus comprising a battery (Batt), recharge device (3) for recharging the battery from the supply network, a supply device (4) for supplying the battery voltage further, and a control unit (B), which is configured to control the devices of the emergency lighting apparatus. The electronic ballast of the emergency lighting system is a controllably dimmable ballast, and the emergency lighting apparatus further comprises a dimming control unit (C) for controlling the dimming of the electronic ballast.

Abstract: The invention relates to a ballast for operating at least one low-pressure discharge lamp, preferably a three- or four-lamp ballast. In order for all parallel- or series-connected low-pressure discharge lamps (L40-L43) to shine equally bright even in the case of strong dimming, the ballast according to the invention has a transformer (Tr40) for balancing the currents in the lamp branch circuits and a transformer (Tr41) for compensating the losses owing to parasitic capacitances.

Abstract: The present invention provides a driver circuit with load discharge detection particularly suitable for use with electro-luminescence (EL) lamps. The driver circuit determines the moment at which the load has been discharged by a defined discharge current. This information is used to start the new charging cycle of the load. The discharge time adapts itself to different load sizes or load voltages. Also, a minimum amount of time is used to discharge the load, so that a maximum amount of time is available for charging the load at a predetermined frequency. As a result, a higher performance can be achieved.

Abstract: A multi-lamp system for driving a lamp set having a first lamp and a second lamp comprises a driving circuit for converting a DC signal to an AC signal, a transformer having a primary side coupled to the driving circuit and a secondary side for outputting the AC power, and a current balance circuit coupled to the low voltage terminal of the lamp set for balancing the current values flowing through the first lamp and the second lamp. The current balance circuit comprises a magnetic core, a first winding coupled to the first lamp and a second winding coupled to the second lamp. The first winding and the second winding are wound on the magnetic core and have the same coil number.

Abstract: Here is disclosed a plasma generator using microwave wherein a plasma generating chamber is provided with a plurality of wave guide tubes extending in parallel one to another at regular intervals, each of the wave guide tubes being formed with a plurality of coupling ports arranged intermittently in an axial direction of the wave guide tube and dimensioned so that coupling coefficient thereof become gradually higher toward a distal end of the wave guide tube, and a plurality of dielectric windows provided through the plasma generating chamber in association with the respective coupling ports so that microwave electric power radiated through the coupling ports into the plasma generating chamber may be uniformized and thereby plasma of a large area may be generated with high and uniform density.

Abstract: A lamp string with an open-circuit-proof structure, which comprises a socket, a bulb receptacle, a bulb and a fuse assembly; the center hole of the socket is furnished with a rectangular cavity for receiving a fuse assembly, and an outer rectangular cavity for mounting bulb receptacle plugged with a bulb; the center of the socket is furnished with a fuse assembly; in case of the tungsten filament of a bulb being burned out, or a bulb receptacle of a socket being lost, the power-supply circuit can still be maintained in a closed circuit condition through the fuse assembly, i.e., the whole lamp string can be always in lighting-up condition.

Abstract: A control circuit for operating a lamp or other electrically operated device using a conventional wall socket outlet that is selectively energized under the control of a conventional wall mounted switch. To permit the lamp to be independently controlled using either the wall switch or the lamp switch, a wall adapter unit is employed that plugs into the wall outlet and into which the lamp's power cord is plugged. Sensing means are employed to detect the operation of either the wall switch or the lamp switch to control an electrically operated switch which turns the lamp ON and OFF whenever either the wall switch or the lamp switch are operated. Different embodiments are provided for use with conventional electrical wiring and with either a conventional lamp or lamp incorporating additional circuitry to adapt it for use with the wall socket adapter.

Abstract: A discharge lamp lighting circuit includes an open-circuit protection means to protect a driving means when a discharge lamp is not lighted. The open-circuit protection means is adapted to send out to a control means a signal for limiting a current flowing in the driving means to or below a predetermined value when the tube current is equal to or lower than a first value predetermined, and a signal for sequentially increasing a current flowing in the driving means up to a rated current when the tube current is higher than the first value and also is equal to or lower than a second value predetermined, and to stop a driving signal sent from the control means when a tube current flowing in the discharge lamp has a value equal to or lower than the first value after a predetermined time.