High power factor switched DC power supply
US5532918A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1994 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Apr 14, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P80/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high-power-factor power supply has a full-wave rectifier for rectifying an AC line voltage, a power regulator including switch means responsive to a control signal for controlling the application of the rectifier output to a load; and a control circuit for producing a switching control signal. The control signal includes a pair of AC line detectors: a first connected in a closed-loop automatic gain control arrangement, and the other connected in an open-loop arrangement. The control circuit initially produces a CURRENT DEMAND REFERENCE signal that is directly related to the difference between the power supply DC output voltage and a self-generated constant reference, and to the waveform shape of the AC line voltage, and is inversely related to magnitude changes of the AC line voltage. The control signal then produces the switching control signal in response to both the CURRENT DEMAND REFERENCE signal and the current flowing in the power supply. The invention avoids the square law dependency of prior art high-power-factor power supplies, can operate over a broad input dynamic range, and is "self-biasing" in that the power supply itself generates any needed reference voltages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.