Hybrid bulk capacitance circuit for AC input AC/DC switching mode power supplies
US11431261B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 2021 |
| Grant date | Aug 30, 2022 |
| Priority date | — |
| Expiry date | Apr 14, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J2207/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A bulk capacitor circuit for an AC input AC/DC Switching Mode Power Supply, such as an AC/DC adapter/charger without active power factor correction, is provided, comprising a plurality of bulk capacitors having different voltage ratings, and driver and control circuitry comprising AC input voltage sensing and comparator circuitry, which enables selective connection of one or more of the plurality of bulk capacitors, responsive to a sensed AC input voltage range. A startup circuit provides power to the driver circuit initially, so that the AC input voltage can be determined before power-up and enabling of the DC/DC converter. This solution provides for a reduction in capacitor volume, with associated improvement in the power density of an isolated AC/DC power supply, while the startup circuit ensures that an appropriate bulk capacitance is connected at startup for low line AC input, to maintain the ripple voltage in an appropriate range for reliable operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.