Method and apparatus for a LED driver with high power factor
US8432109B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2011 |
| Grant date | Apr 30, 2013 |
| Priority date | — |
| Expiry date | Oct 31, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/385
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control circuit of a LED driver according to the present invention comprises an output circuit, an input circuit and an input-voltage detection circuit. The output circuit generates a switching signal to produce an output current for driving at least one LED in response to a feedback signal. The switching signal is coupled to switch a transformer. The input circuit samples an input signal for generating the feedback signal. The input signal is correlated to the output current of the LED driver. The input-voltage detection circuit generates an input-voltage signal in response to an input voltage of the LED driver. The input circuit will not sample the input signal when the input-voltage signal is lower than a threshold. The control circuit can eliminate the need of the input capacitor for improving the reliability of the LED driver.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.