Circuits and methods for increasing power factor of switch mode power supply
US8964415B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 2012 |
| Grant date | Feb 24, 2015 |
| Priority date | — |
| Expiry date | May 3, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A switching mode power supply (SMPS) includes a rectifying device configured for converting a periodically varying input AC (alternating current) voltage into a DC (direct current) voltage, and a transformer including a primary winding, a secondary winding, and an auxiliary winding. The primary winding is coupled to the rectifying device. An input capacitor is coupled to the rectifying device and the primary winding of the transformer. A first power switch is coupled to the input capacitor. A control circuit is coupled to the first power switch and is configured to control the first power switch based on a phase or amplitude of the input AC voltage. By controlling the charging and discharging of the input capacitor, power is provided to the primary winding during a longer portion of the AC input voltage cycle, allowing the rectifier device to have a larger conduction angle to increase a power factor (PF).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.