Method for dynamic reduction of LED current in LED driver, and associated drivers, driver circuits and lighting circuits
US9706616B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 2016 |
| Grant date | Jul 11, 2017 |
| Priority date | — |
| Expiry date | Jan 14, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/48
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
There is disclosed a driver for driving a series arrangement being a variable number of strings of LEDs wherein each string has a capacitance connected in parallel with the respective string; the driver comprising: a controllable current source adapted to be connected in series between the series arrangement and a rectified AC supply to and source a controllable current (Istr) through the series arrangement; and a current source controller adapted to control the controllable current source; wherein the current source controller is operable to source a relatively lower current (ILED′) when a difference (Vstr3A) between the voltage across the series arrangement and the voltage of the rectified AC supply is relatively higher and a relatively higher current (ILED) when the difference is relatively lower. Associated driver circuits and lighting circuits, and methods are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.