Apparatus for driving LEDs using high voltage
US8847501B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2013 |
| Grant date | Sep 30, 2014 |
| Priority date | — |
| Expiry date | May 9, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/48
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus for driving LEDs using high voltage includes a plurality of LEDs divided into a plurality of LED segments connected in series and a plurality of three-terminal voltage controlled current limiting devices. Each of the current limiting devices is associated with one of the LED segments and has a first terminal connected to a negative end of the associated LED segment, a second terminal applied with a bias voltage and a third terminal connected to a common node. A current source is connected between the common node and ground. A power-loss reduction circuit having a plurality of LEDs controlled by an LED controlling circuit may further be inserted between the common node and the current source to reduce the power loss in the current source because of the high voltage at the common node.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.