High power factor electronic ballast
US5814976A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 6, 1997 |
| Grant date | Sep 29, 1998 |
| Priority date | — |
| Expiry date | Aug 6, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B41/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high power factor electronic ballast for operating a high pressure gas discharge lamp comprises a boost converter function and a buck function. The boost converter function and the buck function have common components. The combination boost-buck converter reduces parts count, as compared to the parts count required for the separate boost and buck circuits of the prior art, by making some components of the single circuit act simultaneously in both the boost and buck functions. The rigid forcing of the ac input current waveform to follow the ac input voltage waveform is relaxed, to give performance priority to the buck function for the common components. Harmonics are allowed to enter the system in moderation in return for a less expensive and more reliable system that does not compromise lamp power control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.