Two stage power supply start up circuit
US6069805A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 28, 1999 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | May 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/12
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A two-stage power supply start up circuit is provided for pulse width modulator controllers that operate at a low steady state voltage. The invention provides for high-energy storage in low-capacitance start up capacitors by cascading switched start up stages, thereby allowing for the utilization of smaller, less expensive components. The invention utilizes a three-phase start up process with positive feedback ensuring both reliable start-up and steady state operation. The three phases are as "first phase start-up", which provides power to the control circuit, "second phase start-up", where the control chip starts switching, and "steady state", where the power supply runs in its normal mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.