Fluorescent lamp with improved efficiency
US5436532A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1993 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Mar 26, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/2824
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Power is provided to a fluorescent lamp by connecting a source of alternating electrical current, consisting of a series of alternately positive and negative current pulses, to the lamp and shaping the current pulses such that the absolute value of the current increases as a function of time within each pulse. The shaped current source may be provided by a switched mode drive circuit, including a power transformer having a primary winding and a secondary winding, the power transformer secondary winding being connected to the lamp; a flyback transformer having a primary winding and a secondary winding, a first terminal of the flyback transformer primary winding being connected to the center of the power transformer primary winding and a second terminal of the flyback transformer primary winding being connected to a positive terminal of a source of direct current electrical power; a first switch connected between a first terminal of the power transformer primary winding and a negative terminal of the power source; a second switch connected between a second terminal of the power transformer primary winding and the negative terminal of the power source; a diode connected between a firs…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.