General Electric Company

James Domenic Mieskoski

Louis Robert Nerone

Timothy Chen

James Kevin Skully

Victor D Roberts

Sayed-Amr A El-Hamamsy

Gang Yao

Laszlo Sandor Ilyes

Didier G Rouaud

Timothy A Taubert

Gordon Alexander Grigor

Clarence J Harsa

Virgil A Chichernea

Timothy B Gurin

Scott Brandonisio

Khaled I Abdel-Tawab

Provided is a lighting ballast system and method for fluorescent lamps. The system and method utilize a lamp current control loop to control the light level of a fluorescent lamp. The ballast includes an open loop detector that recognizes an open current control loop as an indication of a fault or hazard condition, and causes the ballast to output a safe lamp voltage or no voltage. The fault or hazard condition may be, for example, a very high voltage at the lamp or very low current across the lamp. The ballast also includes a disable circuit that prevents the open loop detector from triggering at times when the loop is expected to be open such as during ignition and maintenance restarting of the lamp.

Fault protection system and method for fluorescent lamp ballasts

In a lamp lighting ballast which generates a lamp lighting signal for a lamp, provided is a striation elimination circuit to increase the lumen output frequency for elimination of visual striations which may occur within the lamp. An even harmonic signal generator is configured to generate an even harmonic waveform, and an injection point is configured to receive the even harmonic signal into the lamp lighting system. The injection point is located at a location wherein the even harmonic signal alters the lamp lighting signal from a symmetric signal configuration to a high content even harmonic signal configuration prior to being received by the lamp.

Striation control for current fed electronic ballast

A voltage control startup circuit for a lighting ballast includes first and second transistors for converting direct current from a voltage source into alternating current to operate a lamp. The circuit includes an input portion for receiving a bus voltage signal, a resonant load portion for receiving a lamp load. The ballast also includes a start-up portion that delays firing of the lamp based on the detected bus voltage.

Method and apparatus for a voltage controlled start-up circuit for an electronic ballast

In accordance with one aspect of the present application, a lamp inverter circuit includes a switching portion that converts a bus voltage signal into an alternating current signal. An input portion receives the bus voltage signal, and a resonant load portion drives a lamp. A preheating portion heats the lamp prior to ignition, and thereafter renders itself inactive following ignition of the lamp. In accordance with another aspect of the present application, a method of starting a lamp includes receiving a bus voltage signal, converting the bus voltage signal into an alternating current signal, preheating the lamp to an ignition temperature, igniting the lamp and inactivating the preheating after the lamp has been ignited. In accordance with another aspect of the application, provided is a method of igniting an auxiliary lamp, including detecting a conductive state of a main lamp in a lamp ballast circuit, the detecting being by a switch that controls preheating of the main lamp. The integrity of the main lamp is detected, and current flow is switched from the main lamp to an auxiliary lamp in the event of a main lamp failure.

Method and apparatus for a unidirectional switching, current limited cutoff circuit for an electronic ballast

In accordance with one aspect of the present application, a continuous mode voltage fed inverter includes a resistor starting network configured to start a charging of the inverter. A resonant feedback circuit is configured to generate an oscillating signal following the starting of operation of the circuit by the resistor starting network. A complementary switching network has a pair of complementary common source connected switches configured to receive the oscillation signal generated by the resonant feedback circuit, wherein the oscillation signal determines a switching rate of the complementary pair of switches. A clamping circuit is configured to maintain an inverter current in an inductive mode, wherein the inductive current lags voltage across the pair of complementary common source connected switches. A fold-back circuit is connected, in one embodiment, to the complementary switching network to provide a two-level clamping action. A first-level clamps the output voltage sufficient to permit a starting of the lamp. A second level of the two-level clamping arrangement of the fold-back circuit clamps the output voltage to protect the inverter from overheating when a lamp is removed from the circuit.

Continuous mode voltage fed inverter

A method of assembling a coil includes forming a ferrite core having a top end, a bottom end, an inner opening extending from the top end to the bottom end, a cylindrical outer surface, and a step portion formed near the bottom end, the step portion extending past the outer surface. A first high dielectric material is applied on the outer surface of the ferrite core, then a conductive wire is wound onto the high dielectric material, whereafter a second high dielectric material is applied over the conductive wire.

Method of making a coil

An electrodeless fluorescent lamp having an emission suppression arrangement utilizing a capacitive filtering element formed by a first conductive layer disposed on a portion of the interior surface of the lamp envelope, a second conductive layer on a corresponding external portion of the lamp envelope and the glass material of the lamp envelope disposed therebetween, achieves significant emission reduction yet at the same time reduces eddy current losses otherwise occurring at the second conductive coating portion of the capacitive filtering element. A plurality of slots formed in the second conductive coating are effective so as to reduce the circular flow of eddy currents around the second conductive layer, such eddy currents as would otherwise adversely affect the Q of the circuit.

External metallization configuration for an electrodeless fluorescent

An electrodeless lamp (e.g., an electrodeless fluorescent lamp) includes a dielectric housing shaped to conform to a portion of a lamp envelope, which housed portion is opposite to a portion through which light is emitted. The dielectric housing includes a continuous conductor, i.e., a shorted turn, situated between the dielectric housing and the lamp envelope which conforms to at least a portion of the dielectric housing. The configuration of the shorted turn, in terms of the location and amount of surface area occupied thereby, is optimized to minimize interaction between the excitation coil and any metallic fixture and to avoid interfering with lamp starting and light output.

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Seven Hills, OH, United States of America

James Domenic Mieskoski