Constant inrush current circuit for AC input power supply unit
US9281758B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2014 |
| Grant date | Mar 8, 2016 |
| Priority date | — |
| Expiry date | Oct 10, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/062
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A power supply circuit includes a rectifier module configured to rectify an input voltage and a capacitor including a first terminal coupled to the rectifier module. In addition, the power supply circuit includes first and second transistors. The first transistor couples to a second terminal of the capacitor, and the second transistor couples in series to the first transistor. The power supply circuit also includes a resistor, configured to set an inrush current value, in parallel with the second transistor. When coupled to a power supply, the power supply circuit is configured to turn-on the first transistor such that an inrush current flows, at the inrush current value, through the capacitor, first transistor, and resistor. After a delay time, the power supply circuit is configured to turn-on the second transistor such that the inrush current drops to around zero, thus maintaining a low impedance path during steady-state operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.