Low-noise switching power supply
US6574122B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 2002 |
| Grant date | Jun 3, 2003 |
| Priority date | — |
| Expiry date | Feb 14, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/44
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A low-noise, high-power-factor power supply includes a transformer having a primary winding connected to a pair of a.c. input terminals via a rectifier circuit, and a secondary winding connected to a pair of d.c. output terminals via a rectifying and smoothing circuit. Connected between the pair of outputs of the rectifier circuit via at least part of the transformer primary, a switch is turned on and off to keep the d.c. output voltage constant. A smoothing capacitor is connected between the pair of outputs of the rectifier circuit via at least part of the transformer primary and a serial connection of a reverse blocking diode and an inductor. For noise reduction a bypass capacitor is connected between the pair of outputs of the rectifier circuit and in parallel with the serial circuit of the inductor and the reverse blocking diode and at least part of the transformer primary and the smoothing capacitor. The bypass capacitor is less in capacitance than the smoothing capacitor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.