Purespectrum, Inc.

Transworld Lighting, Inc.

Earl F Crandall

Robert C Smallwood, Sr

Ray J King

Robert G Crandall

A high frequency sinusoidal wave is generated and applied directly to a gas discharge lamp in a power efficient electronic ballast. Uniting a high frequency current fed oscillator with a transformer, where direct current may be applied to the center tap of the transformer primary winding to enable the impression of a sinusoidal alternating current at the secondary winding. This sinusoidal alternating current is applied directly to a gas discharge lamp. Feedback from the transformer controls the switching of the oscillator at resonant frequency.

High frequency electronic ballast with sine wave oscillator

A gas discharge lamp is driven with a constant current square wave from a current transformer where the number of volt-microseconds are designed such that at the start of each square wave, the voltage rises to the required ionization potential for the lamp, while the plasma has not yet started to conduct. As soon as the lamp ionizes the gas within the lamp and current flows, the voltage drops and current flows at the desired level. The current level is set to prevent the input of excessive power pulses into the lamp, to reduce the creation of infrared photons. In addition, the plasma is driven at this current level almost continuously (with reversing polarity), which does not allow the plasma time to cool down. Consequently, the lamp becomes a more efficient light emitter, thereby requiring less energy to achieve the same light output.

Method and system for driving a plasma-based light source

A high frequency sinusoidal wave is generated and applied directly to a gas discharge lamp in multiple phases in a power efficient electronic ballast. Uniting a high frequency current fed oscillator with a transformer, where direct current may be applied to the center tap of the transformer primary winding through an appropriately sized inductor to enable the impression of a sinusoidal alternating current at the secondary winding. This sinusoidal alternating current is applied directly to a gas discharge lamp. Feedback from the transformer controls the switching of the oscillator at resonant frequency.

A gas discharge lamp includes a plurality of gas discharge bulbs arranged on a base along a perimeter defining a middle region and at least one reflective mirror positioned in the middle region and operative to reflect light outward from the middle region. Alternatively, at least one light pipe can be positioned in the middle region and configured to gather light and redirect the light outward from the middle region.

Fluorescent lamp system using reflectors

An electronic ballast for a gas discharge lamp includes an adjustable constant current source circuit adapted to convert a direct current input to provide an initial start current and a variably controlled constant current. A coupling transformer circuit is connected to the adjustable constant current source and adapted to couple the initial start current to the gas discharge lamp to provide a corresponding start voltage approximately equal to a strike voltage of the gas discharge lamp and to convert the variably controlled constant current to a square wave current to power the gas discharge lamp thereafter. A current sense circuit is adapted to sense an operating current at the coupling transformer and to provide corresponding current sense information to the adjustable constant current source, wherein said current sense information is used to vary the variably controlled constant current.

High efficiency ballast for gas discharge lamps

A multi-phase gas discharge lamp includes an interior space defined by at least one wall. A plasma-forming gas is disposed in the interior space. At least three electrodes are positioned to access the interior space, each electrode adapted to receive one phase of a multi-phase AC power source and energize the plasma-forming gas in response. The multi-phase energization of a plasma-forming gas maintains the energy level in the plasma, which maximizes efficiency of a gas discharge lamp.

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Raleigh, NC, United States of America

Earl F Crandall