Switch mode power supply circuit with increased power factor for mains
US5673184A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1995 |
| Grant date | Sep 30, 1997 |
| Priority date | — |
| Expiry date | May 31, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Switch mode power supplies produce a brief pulse-like load on the mains and have a high harmonic content. Such a high harmonic load on the mains is undesirable. There are increasingly strict regulations for the level of harmonic loads connected to the mains. The present switch mode power supply includes a series circuit formed by an inductor and a diode connected between a charge capacitor, which is dimensioned to be relatively small, and a pickoff of a primary winding of a transformer of the switch mode power supply. A relatively large energy storage capacitor connected to the primary winding is decoupled from the charge capacitor by a second diode. The series circuit produces an additional charging current, which extends the current which is drawn from the mains during one half cycle of the mains voltage, and reduces the amplitude of the current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.