High power factor electronic ballast with lossless switching
US6670779B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 5, 2001 |
| Grant date | Dec 30, 2003 |
| Priority date | — |
| Expiry date | Dec 5, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic converter receiving low frequency input power, converting this power to DC power at a voltage greater than the input voltage peak, and providing output power from a commutator stage. Lossless switching of the power semiconductor devices in the input stage is achieved by turning each device on at an instant when voltage across the device's current terminals is zero. Current through a main inductor of the input circuit is triangular and substantially unidirectional for at least a few high frequency cycles. To ensure lossless switching, current through the main inductor of the input circuit may be reversed briefly before switching. For use as an electronic arc lamp ballast, the commutator stage also uses lossless switching, and substantially unidirectional triangular current through an output inductor is reversed periodically.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.