Method of regulating lamp current through a fluorescent lamp by pulse energizing a driving supply
US5631523A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 1995 |
| Grant date | May 20, 1997 |
| Priority date | — |
| Expiry date | Sep 19, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of regulating an operating current conducted from a source through a fluorescent lamp involves conducting a charging current from the source through an energy storage element of a resonator circuit to store a predetermined different degree of energy in the element than is stored by conduction of the operating current, and then releasing the stored energy to regulate the operating current delivered to the plasma within the lamp. The conductive time interval during which charging current flows is adjusted to regulate the lamp current to an optimal level for the best illumination efficiency from the lamp and the longest useful lifetime of the lamp. The conductive time interval is adjusted based on the voltage across the plasma. The known negative impedance characteristics of the plasma correlate the sensed voltage to the lamp current conducted by the plasma, thereby allowing regulation of the lamp current to the desired optimal level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.