Abstract: A light emitting diode (LED) driving system drives a plurality of LED strings. A plurality of current sources are respectively connected to the plurality of LED strings. A multi-phase control signal generator generates a plurality of multi-phase control signals that respectively maintain turn on or turn off states of the current sources so as to selectively conduct the corresponding LED strings.

Abstract: A driver circuit or controller flexibly drives either a half-bridge or a full-bridge switching network in a backlight inverter without modification, redundant circuitry or additional components. The driver circuit includes four outputs to provide four respective driving signals that establish a periodic timing sequence using a zero-voltage switching technique for semiconductor switches in the switching network.

Abstract: An improved electron multiplier bias network that limits the response of the multiplier when the multiplier is faced with very large input signals, but then permits the multiplier to recover quickly following the large input signal.

Abstract: A backlight used for a liquid crystal display includes a plurality of light emitting units, and a phase controller for adjusting the phase of the light emitting units. The light emitting units are turned on and off based on pulse signals of a predetermined cycle having an on-period and an off-period. Under the control of the phase controller, the light emitting units are turned on or off with different phases.

Abstract: A pulse power system includes an energy storing device for storing electric energy; a high power arc switch comprising: a cylindrical housing having a central axis and defining a predetermined discharging region; a first electrode disposed within the cylindrical housing to be movable in a direction of the central axis; a second electrode disposed within the cylindrical housing and spaced away from the first electrode at a predetermined distance, an arc generating between the first and second electrodes as the first electrode approaches the second electrode; an insulating member formed at a portion between the first and second electrodes except for the discharging region; and a solenoid coil for forming a magnetic field within the discharging region in a direction of the central axis, the arc formed between the first and second electrodes being spirally moved in a direction of the central axis by a magnetic field formed in a circular direction by the arc and the magnetic field formed by the solenoid coil in th

Abstract: An electronic ballast for a low-pressure discharge lamp (LA) contains an inverter that is fed with direct voltage (UBUS) and the output of which is connected to a load circuit containing terminal contacts for the lamp (LA), a heating transformer that has a primary winding (Tp), which is connected to the output of the inverter, and a respective secondary winding (Ts1, Ts2), which is located in a heating circuit with a coil (W1, W2), for heating each of the two electrodes of the lamp (LA), and a series circuit arrangement that is connected in parallel with the load circuit and which contains the primary winding (Tp) of the heating transformer and an electronic switch arrangement (S3, S4). For the purpose of identifying the type of lamp and the state of the lamp, the currents in one of the two heating circuits and in the primary winding (Tp) of the heating transformer are measured and evaluated.

Abstract: An ornamental lighting device is provided with a flexibly-shapable light-flickering tube that can be bent into user-designed signs, such as marks, graphics, letters, and many various others, and displayed in a flickering manner. The ornamental lighting device includes an elongated transparent tube having a hollowed inside; a cable of insulated conductive wires including one common wire and a plurality of triggering wires; a plurality of bands of serially-connected lamps mounted in the hollowed inside of the elongated transparent tube, each band of lamps having one end electrically connected to the common wire and the other end connected to one of the triggering wires; and a controller connected to the cable, which is capable of applying a voltage alternately in a predetermined sequence to the triggering wires so as to light up the associated lamps in the lamp bands in the predetermined sequence.

Abstract: A lamp power supply circuit for an image forming device, which is not provided with a full-wave rectifier and any additional noise reducing circuit but is capable of effectively suppressing inrush current not to produce noise that may cause erroneous operation of the image forming device and affect any external appliance. A lamp lighting control system for use in an image forming device, which can realize soft-starting of an exposure lamp or a fixing heater-lamp by gradually increasing a conducting angle .beta..sub.i (i=0, 1 . . . ) for applying a voltage to a lamp through phase control of an AC power-supply voltage V.sub.AC for an initial period of energizing the exposure lamp or the fixing heater-lamp. Wherein, the conducting angle is gradually increased per even-number unit of cycles of AC power-supply voltage V.sub.AC on the condition that even numbers of cycles in the same unit have the same conducting angle, e.g., .beta..sub.0 =.beta..sub.1 <.beta..sub.2 =.beta..sub.3 <.beta..sub.4 =.beta..sub.

Abstract: A dimming control circuit for a plurality of lighting fixtures includes a separate semiconductor power switch, e.g., a silicon-controlled rectifier or SCR, for providing controlled amounts of pulsed, unidirectional electrical current to each lighting fixture. In one embodiment, a pair of SCRs, arranged in parallel, opposed relationship, are controllably pulsed to produce an alternating sequence of positive and negative electrical current pulses, of independently-controlled duration, and oppositely-conducting diodes then connect these SCRs to two separate lighting fixture. One such lighting fixture thus receives the positive current pulses, and the other such lighting fixture thus receives the negative current pulses. In an alternative embodiment, each lighting fixture receives pulsed, unidirectional current directly from a separate, independently-controlled SCR.

Abstract: The present invention encompasses a high voltage switch utilizing first and second terminal electrodes and an intermediate electrode disposed therebetween. A high voltage pulse, applied to the intermediate electrode, initiates sequential overvoltaging of the region between one of the terminal electrodes and the intermediate electrode and, then between the intermediate electrode and the other electrode; thereby permitting electrical current to flow between the terminal electrodes. The geometry of the electrodes is chosen so as to yield a field enhancement factor between each region which is sufficiently low to permit highly reliable, predictable, and controllable sequential electrical breakdown.

Abstract: A dimming system for fluorescent lamps is disclosed which includes a first switching means connected to said source terminals and to said load terminals for controlling the supply of power to said load terminals, a switch control connected to switching means for modulating said load terminals to modulate the sinusoidal power on a time ratio variable basis in order to supply a variable amount of power to said load terminals; and an inverting reducing transformer connected to said source terminals between said source terminals and a second switch means.

Abstract: A lamp control control circuit has triacs for controlling a current from an AC power supply and supplying a controlled current to lamps; a phase angle control unit for generating phase angle control pulses for a soft start; switching controllers for triggering the triacs in response to phase angle control pulses, respectively; and switches for selecting the lamp which is to be energized. The control circuit has additional switches for detecting the lamp selecting operation of the switches. The phase angle control unit is started in response to a signal from those switches.

Abstract: A ballast circuit for developing a predetermined desired D.C. voltage to enhance the operation of a gas discharge tube in a lighting unit of the type which also comprises an incandescent filament is disclosed. The ballast circuit operates from an applied 220 volt, 50 Hz alternating current (A.C.) source. The ballast circuit has an input stage comprised of a resistive capacitive network. The resistive capacitive network has values selected so as to reduce the applied 220 volt, 50 Hz excitation to a desired range for further development by the ballast circuit in providing a desired D.C. operational voltage for the gas discharge tube. Further, the ballast circuit provides means to prevent circuit malfunctions due to sudden changes in the applied A.C. source voltage. Still further, the ballast circuit provides a desired power factor operation of the gas discharge tube.

Abstract: A circuit for suppressing interference pulses occurring in transformers with high leakage inductance. The circuit includes current controlled switches connected to the transformers having secondary windings. The switches are controlled by a trigger circuit and a control device. The interference pulses are suppressed by a pulse suppression circuit connected between the secondary windings of the transformers and the trigger circuit. Furthermore the transformers' secondary windings are interconnected in phase to the pulse suppression circuit. The correct interconnection is controlled and/or indicated.

Abstract: A circuit for starting and ballasting a compact high intensity arc discharge lamp, and for preventing failure of the arc discharge. A filament connected in series with the arc lamp provides illumination during arc start-up and functions as a ballast during normal arc operation. An oscillatory starting circuit supplies starting voltage to the arc lamp until an operating arc is established. The circuit includes a "keep-alive" feature which prevents the arc from extinguishing during power fluctuations.

Abstract: Two lamps are controlled in that one is off and the other one on or vice versa with fractural transition from one state to the other being controlled by a differential amplifier with integrated, pulse or trigger switch operated Miller integrator. The differential amplifier control circuit elements (transistors, triacs) in separate circuit paths for the lamps. The control is either a direct one (d.c.) or an indirect one through phase shifting of firing pulses in a.c. operated triacs.

Abstract: A controlled dimmer lighting system suitable for television studios, remote television pickups and stage lighting employs small, solid state dimmer circuits of the SCR-type on a dimmer per lamp basis. Each dimmer and its associated series-connected lamp is directly connected to a respective power outlet, and a preselected group of the dimmers is controlled in unison by a common time-variable pulse generator for firing the SCRs. The common pulse generator is mounted in a lighting control console, and pulse signals for controlling the dimmers are coupled by miniature coaxial signal cables to the dimmers of the preselected group. The system eliminates the power patch panels and dimmer room required in current studio lighting systems and achieves a simplification in grid outlet wiring, resulting in a significant reduction in size and cost as compared to available studio lighting systems.

Abstract: A lighting control apparatus to provide variable intensity light from high pressure discharge lamps using two high pressure discharge lamp loads connected in series to provide more widely variable intensity of light. The outputs of two ballasts may be connected in series to feed the series connected discharge lamp load. Preferably a feedback signal proportional to load current is used to stabilize operation. In addition, circuitry is preferably provided to maintain a predetermined minimum current to prevent extinguishing of the lamps from low current and "hot restrike" circuitry is provided to limit the maximum load voltage when the lamps are extinguished.