Advanced frequency reduction of quasi-resonant converters
US10298137B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2017 |
| Grant date | May 21, 2019 |
| Priority date | — |
| Expiry date | Sep 27, 2037 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for frequency reduction of a quasi-resonant (QR) converter includes detecting a valley point of a resonant waveform of the QR converter, by detecting a voltage level of the resonant waveform falling below a first threshold voltage. A blanking time is formed from the beginning of a QR conversion cycle to the valley point. The blanking time is extended in response to a first reduction of an output loading of the QR converter, while maintaining a primary current of the QR converter at a first current level. The primary current is reduced to a second current level being less than the first current level, while maintaining the blanking time at a maximum blanking time, in response to a second reduction of the output loading.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.