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6744219 Operating circuit for a discharge lamp with preheatable electrodes  
The invention relates to a novel operating circuit for a discharge lamp, in the case of which the lamp electrodes are preheated by driving switching transistors of an oscillator circuit such that...
6741040 Operating device for lamps with a regulated SEPIC converter  
The invention relates to a novel operating device for lamps, in particular low-pressure gas discharge lamps, in which a SEPIC converter is used for charging a storage transistor from an AC voltage...
6741043 Ballast with adaptive end-of-lamp-life protection  
A ballast ( 100 ) having an inverter ( 110,120,122 ) and a direct current blocking capacitor ( 130 ) coupled in series with a ballast output ( 108 ) includes a control circuit ( 140 ) for providing...
6741041 Power controller  
A power controller is provided which can control the emission power from a light source to follow an appropriate response property based on a target value. The power controller includes feedforward...
6734639 Sample and hold method to achieve square-wave PWM current source for light emitting diode arrays  
An apparatus for controlling overshoots in the switching of LED arrays in a system having a switching voltage converter providing the biasing voltage for the LED array. By synchronizing a switching...
6734637 Hot-restrike ignition system for a high-frequency high-intensity discharge lamp assembly  
A hot-restrike ignition system for a high-frequency high-intensity discharge lamp includes a resonant circuit that is connectable across the lamp in parallel with a ballast circuit that is used to...
6734641 Device for turning on light and illumination apparatus  
A device for turning on light allowing the brightness of an inverter-type illumination apparatus to be adjusted without having to install an additional oscillation circuit. The device comprises an...
6731078 Ballast for operating electric lamps  
The invention relates to a ballast for operating electric lamps, having an inverter (WR), a DC voltage supply circuit (GLV) for the inverter (WR), a load circuit, connected to the inverter (WR),...
6727663 Circuit arrangement for feeding a load  
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...
6727662 Dimming control system for electronic ballasts  
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...
6727661 Self-ballasted fluorescent lamp  
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...
6724154 Cold cathode lamp and lamp control circuit  
A cold cathode gas discharge lamp unit and control circuit for controlling the light emission of the cold cathode gas discharge lamp. A lamp unit includes a dc power source and a control circuit...
6720738 Method and circuit arrangement for producing an ignition voltage for fluorescent lamps  
The invention, which relates to a method for generating a starting voltage for a fluorescent lamp, in which the starting voltage is generated by means of alternating voltage that is impressed on an...
6720741 Electronic ballast having open circuit in output  
Gas discharge lamps may conduct current from the common rail to earthen ground through a fixture containing the lamps. A transistor is coupled in series in the current path to the common rail. When...
6717372 Multi-lamp driving system  
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...
6717375 Discharge lamp lighting device and system comprising it  
A discharge-lamp lighting device is provided which decreases arc jumps, suppresses the fluctuation in brightness of the lamp, and prolongs a life of the lamp, by positively accelerating growth of...
6717370 High speed stop circuit for an electronic ballast  
In an electronic ballast equipped with a high-frequency bridge circuit, a microprocessor for controlling lamp operation and a stop circuit for interrupting the operation of the ballast in case of a...
6713744 Scanner having cold-cathode-tube light source and method of controlling a drive signal for illuminating a cold-cathode-tube light source  
The scanner includes the switch 10 that is closed when a document is read, the boosted-voltage conversion circuit 12 that boosts a DC voltage of 12 volts (V) supplied from a power source (not...
6710555 Discharge lamp lighting circuit with protection circuit  
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...
6710552 Circuit arrangement for operating discharge lamps  
In the case of circuit arrangements for operating gas-discharge lamps (Lp), a charge pump (D 5 , D 6 , C 31 , C 32 ) is often used for the purposes of power-factor correction. If this is the case,...
6710556 Discharge lamp lighting apparatus  
In a discharge lamp lighting apparatus 1 , power is supplied from a DC power supply 2 through a switch control circuit 3 to a lighting circuit 4 and a discharge lamp 5 . Power is supplied...
6707262 Discharge lamp operating circuit having a circuit for detecting the proximity to capacitive operation  
The invention relates to an operating circuit for a discharge lamp, having a detection circuit for identifying the proximity to capacitive operation, which uses lamp current fluctuations for...
6707260 Circuit arrangement including DC-AC converter having a dependable start circuit  
A self-oscillating bridge circuit comprises a start circuit for rendering one of the switches conductive for the first time at the start of operation. The start circuit is configured in such a way...
6707263 High-intensity discharge lamp ballast with live relamping feature  
A dimming ballast ( 100 ) for a high-intensity discharge lamp ( 10 ) includes an ignitor ( 120 ), a control circuit ( 140 ), and a dimming interface ( 160 ) for connection to an external dimming...
6703797 Method for activating illuminator and illumination device  
A method for activating an illuminator and an illuminating device. The invention uses pins on an application specific integrated circuit (ASIC) in a scanner to output pulses of different...
6703793 Switching power unit  
The switching power unit is a switching power unit of PWM system in which, in response to a secondary-side output voltage detected by an output voltage detecting circuit, a control circuit controls...
6700335 Method and circuit for regulating power in a high pressure discharge lamp  
A ballast ( 100 ) and method for regulating power in a high pressure discharge lamp ( 130 ) is disclosed. In a preferred embodiment, ballast ( 100 ) comprises a microcontroller ( 102 ), a buck...
6700328 Discharge lamp driver circuit designed to minimize radiation or noise  
A discharge lamp driver circuit is provided which features a field canceller. The driver circuit includes a power supply circuit which turns on and off a switching element to step up a dc voltage...
6700331 Control circuit for dimming fluorescent lamps  
The present invention constitutes a control circuit which permits the dimming of the illumination emitted from a fluorescent lamp. A controllable source of alternating current power is converted to...
6696798 Ballast circuit for operating a discharge lamp  
A ballast circuit for a discharge lamp capable of protecting the circuit when the lamp reaches its end of life with a cost effective circuit arrangement. The circuit includes a DC voltage sensing...
6696791 Method for starting a discharge lamp  
A method for starting a discharge lamp having two filaments includes the following steps: ( 1 ) preheating only one of the two filaments; ( 2 ) igniting the lamp; ( 3 ) operating the lamp with a...
6696803 Self-oscillating electronic discharge lamp ballast with dimming control  
A simplified electronic ballast for a discharge lamp which provides dimming by control of inverter frequency through modulation of magnetizing current in a transformer such that the switching...
6696800 High frequency electronic ballast  
A method and ballast for driving a high intensity discharge (HID) lamp include generating a very high frequency driving signal for the HID lamp, generating a low frequency modulating signal,...
6696797 Electronic ballast having valley frequency modulation for a gas discharge lamp  
An electronic ballasts for a gas discharge lamp. The ballast includes a variable frequency power generator, a tuned driver network, and a valley correction modulation system. The driver network has...
6693393 Ballast for a discharge lamp  
A ballast for a discharge lamp includes a DC-DC converter which provides a regulated DC output so as to start and keep operating the lamp. A controller is included to give a closed-loop control for...
6686703 High frequency electronic ballast  
An improved high frequency ballast is disclosed. The high frequency ballast establishes a lamp current for a gas discharge lamp during a starting operation of the gas discharge lamp wherein an...
6683419 Electrical control for an LED light source, including dimming control  
A control for a light with an LED light source. The LED light source mimics an operation of an incandescent light source with respect to a dimming control. The LED light source includes at least...
6683418 Inverter type illumination lighting apparatus  
An illumination lighting apparatus has a resonance load circuit including a discharge tube, a power supply circuit for generating DC voltage from commercial AC voltage, and an inverter for...
6680584 Device for driving discharge lamp  
A referential rectangular wave is generated in a referential rectangular wave generating circuit 21, a level of the referential rectangular wave is integrated in an integrating circuit 22 to...
6680585 Method and apparatus for modulating HID ballast operating frequency using DC bus ripple voltage  
An apparatus and method to implement an electronic ballast for a high intensity discharge lamp having AC lamp current centered at approximately 300 kHz minimizes the ballast cost and utilizes...
6680583 Sign lamp lighting transformer with protective functions  
An abnormality detection circuit detects abnormality relating to ground fault in secondary winding circuitry of transformer, non-grounding fault of transformer assembly casing or false connection...
6680582 System and method for employing pulse width modulation for reducing vertical segregation in a gas discharge lamp  
A system for driving a gas discharge lamp includes a bridge circuit providing a pulse voltage signal, a controller which generates a pulse width modulated signal corresponding to a desired...
6680588 Low noise backlight system for use in display device and method for driving the same  
Disclosed is a backlight system and a method for driving backlight capable of reducing noises and voltage fluctuations in power voltage due to a turn-on/turn-off of the lamp. The backlight system...
6677716 Operating device for gas discharge lamp  
Free-running half-bridge inverter (HP) for operating gas discharge lamps having a current transformer as a feedback device. The half-bridge transistors (T 1 , T 2 ) are essentially voltage...
6677718 HID electronic ballast with glow to arc and warm-up control  
An HID ballast is powered by a power source to control a load. The HID ballast includes a switching section connected to a first bus and a second bus, and further configured to output a...
6674252 Non-blinking direct current fluorescent lamp circuit  
A non-blinking direct current fluorescent lamp circuit includes a switch, a bridge rectifier, a voltage regulation circuit, a filter capacitor, an ignition circuit, a contact points converter, a...
6674246 Ballast circuit having enhanced output isolation transformer circuit  
A ballast circuit includes an output isolation transformer having a primary winding and first and second secondary terminals coupled to opposing ballast lamp terminals for additively applying...
6670778 AC power generating apparatus having electrolytic capacitor and ceramic capacitor  
An AC power generating apparatus for lighting a discharge lamp has a smoothing circuit with an electrolytic capacitor therein for smoothing ripples included in a DC voltage supplied from a power...
6670780 Method for operating high-pressure discharge lamp, lighting apparatus, and high-pressure discharge lamp apparatus  
Disclosed is a method for operating a high-pressure discharge lamp, a lighting apparatus, and a high-pressure discharge lamp apparatus each capable of operating the lamp at a power lower than the...
6667587 Flickering mode control system for a high intensity discharge lamp  
A flickering mode control system, for operating a high intensity discharge lamp at a flickering mode, comprises an output power controllable transformer and a flickering control unit. The...