High frequency supply system for gas discharge lamps and electronic ballast therefor
USRE33057E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1987 |
| Grant date | Sep 12, 1989 |
| Priority date | — |
| Expiry date | Apr 2, 2007 |
Classification
- Technology area (CPC —)General
Abstract
The invention is both a system for supplying high frequency alternating current to gas discharge lamps, such as fluuorescent lamps, and the like and a unit that can be placed in or adjacent to a lighting fixture to convert a direct current supply into high frequency AC and also provide the ballast needed for operation of the gas discharge lamps. This unit contains a symmetrical, class B, push-pull current-limited, tuned-collector, sinusoidal oscillator which is self starting, highly efficient and stable over a wide range of input voltage, with or without load. The number of parts is a minimum and the parts are relatively low cost, the power losses are very low and the system operates at high power factor with low acoustic and radio noise and low flicker. The system may derive the current from a commercially available source at any voltage and phase but preferably three phase primary of a building transformer can convert this into six phase at the output terminals which can be converted to DC of low ripple even without filtering. From the central building supply, it is possible to send AC at suitable voltage to subcenters in the building for rectification, inversion and use in light…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.