Fluorescent lamp with wide range of luminous intensities
US5420481A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 27, 1993 |
| Grant date | May 30, 1995 |
| Priority date | — |
| Expiry date | Sep 27, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus is provided for controlling the luminous output of a fluorescent lamp over a wide dimming range. The luminous output is controlled by controlling the lamp current, while the lamp is immersed in a lateral electrostatic field. The lamp and external electrostatic ionization electrodes are driven by a true analog voltage-to-current converter that has a dynamic range inherently wider than conventional PWM circuits. A modified, transformer coupled, push-pull converter with an analog-current-driven primary circuit is used in one embodiment of the apparatus. The lamp driver must be capable of providing a high compliance voltage consistent with the I-V profile of the lamp. A subordinate primary winding on the transformer may be used to reduce magnetization current and to supply sufficient energy for supporting the lateral electrostatic field that is generated by the ionization electrodes which may be printed on a PWB mounted behind the lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.