Power supply input voltage detection circuit
US8710870B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 2011 |
| Grant date | Apr 29, 2014 |
| Priority date | — |
| Expiry date | Jun 1, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/153
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The present invention discloses a power supply input voltage detection circuit. The power supply converts an input voltage to an output voltage by a transformer which includes a primary winding and a secondary winding. The primary winding is coupled to a power switch, which receives a switching signal to adjust the output voltage. The power switch is coupled to a sensing circuit; when the power switch turns ON, the sensing circuit generates a current sense signal according to current through the primary winding. The input voltage detection circuit includes: a rising time detection circuit, which detects a period, of time during which the current sense signal rises from a low reference level to a high reference level to generate a timing signal; and a determination circuit, which generates a determination signal according to the timing signal for determining whether the input signal is a high voltage or a low voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.