AC/DC converter having a switchable PFC, a controller therfor, and a method of operating a contoller
US8963451B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2012 |
| Grant date | Feb 24, 2015 |
| Priority date | — |
| Expiry date | Apr 20, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of controller an AC/DC to converter is disclosed, the converter having a power factor correction stage and a signal indicative of a required power and operating with a switching cycle having a switching frequency being the inverse of a switching period. The method comprises switching on the PFC stage, in response to a signal indicative of an average switching frequency rising above a first threshold. The method further comprises switching off the PFC stage, in response to the signal indicative of an average switching frequency falling below a second threshold. The method may further comprise switching on the PFC stage, in response to a positive step change in the signal indicative of a required power, and switching off the PFC stage, in response to indicative step change in the signal indicative of a required power.A controller and an AC/DC converter operable according to such a method are also disclosed as is an LED lighting system comprising such a controller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.