Low-noise switching power supply having variable reluctance transformer
US4876638A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1988 |
| Grant date | Oct 24, 1989 |
| Priority date | — |
| Expiry date | Feb 10, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F2038/026
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
There is provided a low-noise switching power supply for producing a regulated output voltage from an unregulated supply. The power supply includes a main transformer having first, second and third legs. A primary winding associated with a first leg produces an alternating magnetic flux in the core. A load winding associated with a second leg produces the output voltage from the power supply. A control winding is associated with the third leg. The regulated output voltage is compared to a reference voltage and used to operate a control circuit which alternately short circuits the control winding so as to vary the reluctance pass in the transformer and maintain the output voltage at a substantially constant predetermined value. A feedback circuit including a coupling transformer connects the primary coil to the switching circuit to improve regulation and provide a "soft start" capability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.