Techno-economic performance comparison of compact fluorescent lamps (CFL) with light
emitting diodes (LED), electrode less fluorescent lamps (EEFL), fluorescent tubes …

A light emitting diode (LED) lighting system includes a controller to control current in one or
more LEDs in response to a dimming level input. The LED lighting system implements a …

(57) ABSTRACT A light emitting diode (LED) lighting system includes a PFC and output
Voltage controller and a LED lighting power sys tem. The controller advantageously …

A light emitting diode (LED) lighting system and method are disclosed. The LED lighting
system and method include an LED controller to accurately control a current in an LED …

A lighting system includes time division light output sensing and adjustment for ambient
light. In at least one embodiment, time division light output sensing involves modulating …

In at least one embodiment, a controller allows triac-based dimmer to properly function and
dim a load whose voltage is regulated by a switching power converter. In at least one …

4,334,250 4.409, 476 4.414, 493 4476, 706 4,523,128 4,677,366 4,683,529 4,700,188
4,737,658 4,797,633 4,937,728 4,940,929 4,973,919 4,979,087 4,980,898 4,992.919 …

5,565,761 5,747,977 5,783,909 5,963,086 5,994,885 6,016,038 6,043,633 6,072,969
6,083,276 6,084,450 6,150,774 6,211,626 6,211,627 6,229,271 6,246,183 6,259,614 …

In at least one embodiment, brightness multiple LEDs is adjusted by modifying power to
subgroups of the multiple LEDs during different times and detecting the brightness of the …

438 436 voltage indicates a particular dimming level. The drive cur rent varies for different
dimming levels. However, the light source ballast controls drive current so that the drive …