Switching power supply having a high efficiency starting circuit
US6125046A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 1999 |
| Grant date | Sep 26, 2000 |
| Priority date | — |
| Expiry date | Nov 5, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/36
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A switching power supply having a high efficiency starting circuit uses a field effect transistor to provide initial starting current to a pulse width modulated signal generator within a switching control circuit. The field effect transistor (FET) has a drain connected to a source of supply voltage, a source connected to the PWM signal generator, and a gate connected to a feedback voltage that is derived from an output voltage of the switching power supply. During start up of the switching power supply, the FET provides current to the PWM signal generator. When the feedback voltage reaches a predetermined level, the FET supplies substantially near zero current to the PWM signal generator, thereby eliminating the electrical inefficiencies typically associated with a conventional switching power supply starting circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.