Serial-type light-emitting diode (LED) device
US8766553B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 2013 |
| Grant date | Jul 1, 2014 |
| Priority date | — |
| Expiry date | Jun 10, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/46
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A serial-type LED device includes p light source units and a dimming circuit. Each light source unit includes first and second terminals, m light strings and m current balance units. Each light string includes LEDs coupled in series to have a first terminal coupled to the first terminal of a corresponding light source unit and a second terminal coupled to the second terminal of the corresponding light source unit through a corresponding current balance unit. The first terminal of the first light source unit is coupled to a second DC voltage, and the second terminal of the i-th light source unit is coupled to the first terminal of the (i+1)-th light source unit, where m and p are integers greater than or equal to 2 and i is any integer from 1 to (p−1). The dimming circuit coupled to the second terminal of the p-th light source unit controls the second DC voltage according to a current outputted from the p-th light source unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.