Circuit and method for driving LED lamp with a dimmer
US8878448B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 2011 |
| Grant date | Nov 4, 2014 |
| Priority date | — |
| Expiry date | Mar 15, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A system for driving an LED (light-emitting diode) lamp includes a dimmer circuit coupled to a line input voltage for varying a magnitude of an input voltage and a transformer having a primary winding, a secondary winding, and one or more auxiliary windings, the primary winding coupled to the dimmer circuit. The system also includes an output rectifying circuit coupled to the secondary winding for providing an output current to the LED lamp and a power switch coupled to the primary winding for controlling a current flow in the primary winding. The system further includes a controller having a comparator and a capacitor for providing a control signal to control the power switch for regulating the output current. The controller coupled to the dimmer circuit for receiving an average input voltage signal from the dimmer circuit, wherein the control signal is characterized by a duty cycle that is determined by a ratio of a charging current to a discharging current of the capacitor, and the ratio is related to the average input voltage signal from the dimmer circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.