Auxiliary active clamp circuit, a method of clamping a voltage of a rectifier switch and a power converter employing the circuit or method
US6882548B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 2003 |
| Grant date | Apr 19, 2005 |
| Priority date | — |
| Expiry date | Mar 29, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention is directed to an auxiliary active clamp circuit and a method of clamping a voltage of a rectifier switch associated with a power converter. The power converter includes a main active clamp circuit associated with a main power switch coupled to a primary winding of a transformer and a rectifier switch coupled to a secondary winding of the transformer. The main power switch conducts during a main conduction period of the power converter and the rectifier switch conducts during an auxiliary conduction period of the power converter. In one embodiment, the auxiliary active clamp circuit includes an auxiliary clamp capacitor, coupled across the rectifier switch, that stores a clamping voltage substantially equal to an off-state voltage of the rectifier switch. The auxiliary active clamp circuit also includes an auxiliary clamp switch, coupled in series with the auxiliary clamp capacitor, that receives a drive signal from a secondary winding and conducts during the main conduction period thereby clamping a voltage across the rectifier switch at about the clamping voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.