Light-emitting diode driver circuit and lighting apparatus
US8305001B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 21, 2010 |
| Grant date | Nov 6, 2012 |
| Priority date | — |
| Expiry date | Feb 1, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/3725
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A light-emitting diode driver circuit includes: a first-rectifier circuit to output a first-rectified voltage; a transformer including primary and secondary coils and an auxiliary coil inductively coupled to the primary or secondary coils, the primary coil being applied with the first-rectified voltage; a transistor connected in series to the primary coil; a second-rectifier circuit to output a second-rectified voltage obtained by rectifying a voltage generated in the auxiliary coil; a capacitor to be charged with the second-rectified voltage; and a control circuit to control on and off of the transistor based on a charging voltage of the capacitor so that the charging voltage becomes equal to a predetermined voltage, the secondary coil outputting a voltage that varies with a frequency corresponding to a frequency of the first-rectified voltage and that corresponds to a turns ratio between the primary and secondary coils, as a voltage for driving a light-emitting diode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.