Capacitor charging methods and apparatus
US7787262B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2006 |
| Grant date | Aug 31, 2010 |
| Priority date | — |
| Expiry date | Feb 29, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33507
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A capacitor charging circuit is provided with a primary side output voltage sensing circuit including an RC network having an RC time constant with a predetermined relationship to the RC time constant of the output capacitor. Once the capacitor voltage reaches a fully charged level, the charging mode is terminated. The output voltage is continuously detected by measuring the voltage across the primary side RC network that decays at a predetermined rate with respect to the output capacitor and the charging mode is commenced once the RC voltage falls to a predetermined level. According to a further aspect of the invention, a switch control circuit in a flyback converter controls the switch off time in response to detection of a change in the slope polarity of the voltage at a terminal of the switch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.