Electronic ballast with high power factor
US8212492B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2009 |
| Grant date | Jul 3, 2012 |
| Priority date | — |
| Expiry date | Mar 6, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention provides an electronic ballast for a fluorescent lamp, including a rectifier for converting an alternating current input voltage into a direct current output voltage, and a circuit including a combined power factor correction (PFC) stage and an inverter, wherein the PFC stage and the inverter share a switch. Also provided is a controller for an electronic ballast, including a duty ratio controller that controls a duty ratio of a switch of the ballast, and means for adjusting the duty ratio according to a nonlinear function, so that an arc is sustained across the lamp. The controller and the ballast allow dimming of the fluorescent lamp while maintaining a high power factor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.