Dc-to-dc converter
US6515876B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 2001 |
| Grant date | Feb 4, 2003 |
| Priority date | — |
| Expiry date | Nov 29, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A transformer has a primary winding connected between a pair of d.c. input terminals via an on-off switch, and a secondary winding connected between a pair of d.c. output terminals via a rectifying and smoothing circuit. The output voltage applied from the rectifying and smoothing circuit to the load is held constant by switching the input voltage through feedback control. The switch is driven in either of two different prescribed modes depending upon whether the converter is under normal or light load. In order to ascertain the load magnitude a flyback period determination circuit is connected to a tertiary winding of the transformer for providing a signal indicative of a flyback period during which a flyback voltage exists across the transformer tertiary after the switch is turned off each time. Each flyback period is compared with two different reference periods of time for hysteretic determination of whether the converter is under normal or light load. Several other embodiments are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.