General Electric Company

Gordon Alexander Grigor

Louis Robert Nerone

George A Farrall

Laszlo Sandor Ilyes

James Kevin Skully

James Domenic Mieskoski

Timothy A Taubert

Melvin C Cosby

David O Wharmby

Clarence J Harsa

Thomas Farkas

Kurt W Haas

Benito Trevino

Khaled I Abdel-Tawab

Wayne J Cline

Fluorescent lamp ballasts and methods are disclosed in which a resonant impedance of a self-oscillating inverter is modified to control the inverter frequency to selectively preheat lamp cathodes using power from the inverter output during a preheating period after power is applied and to change the inverter frequency to a different range following ignition of the lamp.

Fluorescent lamp ballast with electronic preheat circuit

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

A multiple integrated lamp system is powered by a power source. The system includes a first integral lamp having lamp electronics and a lamp integrated as a single unit, and a second integral lamp having lamp electronics in a lamp also integrated as a single unit. A first connection wire is connected from a first pin of the first integral lamp to a second pin of the first integral lamp. A second connection wire is connected from a first pin of the second integral lamp to a second pin of the second integral lamp. A first power line is connected at a first end to the power source, at a second end to a third pin of the first integral lamp, and at a third end to a third pin of the second integral lamp. Further, a second power line is connected at a first end to the power source, at a second end to a fourth pin of the second integral lamp, and a third end to a fourth pin of the second integral lamp.

Wiring geometry for multiple integral lamps

A power supply circuit ( ) configured to control operation of a load ( ) including a converter ( ) configured to convert a DC signal to an AC signal, a drive circuit connected to the converter ( ) to control operation of the converter ( ), and a shutdown circuit ( ) connected to the drive circuit to turn off the converter ( ). The shutdown circuit ( ) includes a diode ( ) and a switch ( ).

Shutdown circuit for a half-bridge converter

A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating the gas discharge lamp and including a resonant inductance and a resonant capacitance. A d.c.-to-a.c. converter circuit induces an a.c. current in the resonant load circuit. The converter circuit comprises first and second switches serially connected between a bus conductor at a d.c. voltage and a reference conductor, and which are connected together at a common node through which the a.c. load current flows. A voltage-breakover (VBO) device is effectively connected between the common node and a second node. A network is provided for setting the voltage of the second node with respect to the common node at less than the breakover voltage of the VBO device when the lamp is operating at steady state. A polarity-determining impedance is connected between the common node and one of the bus conductor and the reference conductor, to set the initial polarity of pulse to be generated upon the firing of the VBO device.

Lamp ballast circuit with simplified starting circuit

An electrodeless gas discharge lamp includes a vitreous envelope containing a discharge medium. An excitation coil is positioned in relation to the vitreous envelope so as to excite the discharge medium therein. The excitation coil is adapted to be driven by an RF oscillator. The excitation coil has first and second ends and is effective for exciting the discharge medium to emit light with electromagnetic fields that are generated by the excitation coil. The excitation coil includes a first wire wound generally helically from the first end to the second end in a first helical direction to form first winding turns, and further includes a second wire wound generally helically from the first end to the second end in second helical direction opposite to that of the first helical direction to form second winding turns. Preferably, a generally cylindrical former is provided for holding the first and second wires between the first and second ends of the coil. Such former includes a positioning arrangement for maintaining specific positions of the first and second wires with respect to each other along the former.

Growing community of inventors

Cleveland Heights, OH, United States of America

Gordon Alexander Grigor