Switching power supply
US6191965A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 2, 2000 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Jun 2, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A switching power supply is provided which is capable of preventing abnormal operation of a synchronous rectifier circuit thereof, which is caused by a discontinuous current mode, and capable of enhancing an input power factor thereof. A transformer has a primary winding and a secondary winding. A first switching element is connected in series with the primary winding of the transformer, for switching an input voltage. A diode rectifies an induced voltage induced in the secondary winding of the transformer to generate a rectified current. A control signal is generated which has a current value or a voltage value approximately proportional to a current value of the rectified current. A second switching element is connected in parallel with the diode in an equivalent fashion and has a control terminal to which the control signal is input. The second switching element operates in response to the control signal for rectifying the induced voltage. A current is prevented from flowing into the primary winding during an OFF period of the first switching element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.