Lighting circuit
US6847169B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 2003 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Oct 7, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/385
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lighting circuit for lighting a vehicular lamp including a light-emitting diode, includes: a switching regulator for applying an output voltage based on a power-supply voltage received from a DC power supply provided in the outside thereof to the light-emitting diode so as to supply a supply current to the light-emitting diode; an abnormal state detector for detecting an abnormal state of the lighting circuit based on at least one of the output voltage of the switching regulator, the supply current and the power-supply voltage; and an output controlling unit for controlling the output voltage of the switching regulator based on the supply current or the output voltage of the switching regulator and lowering the output voltage of the switching regulator in a case where the abnormal state detector detected the abnormal state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.